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Skulls and Bones

A Guide to the Skeletal Structures and Behavior of North AmericanMammals

Glenn Searfoss

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Page ivCopyright © 1995 by Stackpole BooksPublished by STACKPOLE BOOKS 5067 Ritter Road Mechanicsburg, PA 17055All rights reserved, including the right to reproduce this book or portions thereof inany form or by any means, electronic or mechanical, including photocopying,recording, or by any information storage and retrieval system, without permission inwriting from the publisher. All inquiries should be addressed to Stackpole Books,5067 Ritter Road, Mechanicsburg, PA 17055.

Printed in the United States of America

10 9 8 7 6 5 4

First edition

Cover design by Kathleen Peters

Illustrations by Glenn Searfoss

Library of Congress Cataloging-in-Publication Data

Searfoss, Glenn.Skulls and bones : a guide to the skeletal structures and behavior ofNorth American mammals / Glenn Searfoss ; [illustrations by Glenn Searfoss].1st ed.p. cm.Includes bibliographical references (p. ) and index.ISBN 0-8117-2571-51. MammalsNorth AmericaIdentification. 2. BonesNorth AmericaIdentification. 3. SkeletonNorth AmericaIdentification. 4.BonesNorth AmericaCollection and preservation. I. Title.QL715.S43 1995599'.04471'097dc20 94-26504 CIP

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Page v

This book is dedicated to people of all ages who are interestedin the study and collection of bones. May this book aid inyour understanding of relationships between an animal'sskeletal structures and its lifestyle. For beginning andexperienced collectors, may it offer useful hints on physicalsafety, collecting techniques, and specimen preparation.

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Page vii

Contents

Acknowledgments ix

Introduction 1

Chapter 1. Classification Systems 3

Chapter 2. The Skull 16

Chapter 3. Skulls Illustrated 50

Chapter 4. The Limbs 98

Chapter 5. The Vertebral Column and Ribs 157

Chapter 6. The Significance of SkeletalStructures 180

Chapter 7. Bone-Collecting Basics 202

Chapter 8. Bone Preparation and Cleaning 215

Glossary of Terms 227

Appendix A. Things to Do 237

Appendix B. Scientific Terms and CommonNames 247

Appendix C. Scientific Classification 251

Appendix D. Suppliers 255

Appendix E. Societies and Associations 261

Recommended Reading 267

Index 273

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Page ix

Acknowledgments

There are many people who deserve recognition for their influencein the fashioning of this book. To this end, I would like to thank thefollowing people and organizations.

The editors and production staff at Stackpole Books who made thisbook possible.

The Denver Museum of Natural History and the Jefferson CountyNature Center, whose specimens from their osteology collectionsprovided the models for illustrations presented in this book.

Dr. Cheri Jones, Ph.D., Curator of Mammalogy at the DenverMuseum of Natural History, whose expertise and insightful viewsaided the development of this work.

The 1993 sixth-grade science classes and their teachers at ColeMiddle School in Denver, whose response to my specialpresentations helped determine the direction and content of thiswork.

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Page 1

Introduction

The gleaming white skull stares empty-eyed through a veil of grassand leaves. The components of an entire skeleton lie scattered acrossa shallow depression within the field. Here and there, smallsegments of sun-bleached bone poke through matted grass. Circlingon hands and knees, we ferret half-buried, bronze-stained remnantsfrom the loamy soil and clinging vegetation. One by one, we gatherbones of varied shapes and separate them into piles: ribs in this one,leg bones in that one, vertebrae over there.

This amassed collection, these small hills of bone, mark oneanimal's final remains. But what type of animal was it? How did itlive? What kind of food did it eat? How did it move? How did itbehave? From children to adults, hikers to couch potatoes, peopleare fascinated by bones. Their shape and form spark myriadquestions like these.

Once you learn how to "read" an animal's skeletal structures, youwill be able to gain insight into its environmental lifestyle, that is,what it eats. This book shows you how to identify both individualand combined skeletal structures and use inferential classification todetermine an animal's likely eating habits and behavior. Once youunderstand the basics of inferential classification, you'll be able togroup



Page 2animal remains into three environmental lifestyle categories:carnivore, herbivore, and omnivore.

Carnivores are strict meat eaters that usually live by predationand/or scavenging.

Herbivores are strict plant eaters that live by foraging, browsing,and grazing.

Omnivores eat both plant material and animal flesh. They live byhunting or predation, scavenging, and foraging.

Inferential classification offers the hobbyist, artist, or outdoorenthusiast a new way to understand animals and encourages adeeper appreciation for nature and her creatures.

I have actively collected bones since childhood, and over the pastsix years this interest has led me to assemble the bones of variousanimals into sculptures of new creatures. This has allowed me to geta better idea of how skeletal structure relates to function, a scientificdiscipline known as functional morphology.

My art, which has been featured both at galleries and on local newsprograms, has generated a great deal of interest. The barrage of bonestories and questions from persons of all ages and all walks of lifeindicates an almost universal fascination with this subject. At theprodding of an eleven-year-old friend, I tested this hypothesis byaccepting an offer from his middle-school science teacher to presenta lesson on basic skeletal structure and bone collecting to two sixth-grade science classes. This experience was extremely rewarding:The students' overwhelming response verified my initial conjecture

that the public is keenly interested in bones and skeletal structures.

Across North America many children and adults are fascinated bythe study of bones. Few, however, have the means or technicalresources to quickly identify them or comprehend what thestructures they find indicate about the environmental lifestyles of theanimals. Many publications that address osteology, the study ofbones, over-whelm the reader with a withering barrage of technicaland taxonomic terminology. While fine for professionals, thistechnical approach often hinders people not already familiar withthe subject. Therefore, I have written this book with a moregeneralized and understandable approach. Associated with commonenvironmental issues such as ecology, animal behavior, and eatinghabits, the information included is technical enough for educationaluse but basic enough for comprehension by a wide audience.



Page 3

Chapter 1Classification Systems

Our world is home to many animals. Without some organizationaltool, most people would find it extremely difficult to study andunderstand their vast diversity. Fortunately, scientists havedeveloped classification systems for this purpose, two of which arediscussed here: the species-specific view of traditional taxonomy, orsystematics, and the general-lifestyle view of inferentialclassification. Although both systems are helpful, inferentialclassification is used primarily in this book. To ease into thisapproach, let's first discuss traditional taxonomy.

Traditional Taxonomy

The biological science that deals with classification of animals asindividuals and groups is called zoology. Traditionally, this sciencehas used the tool of taxonomy to relate animals into anunderstandable pattern by grouping them according to similarities inskeletal and other biological structures. Taxonomy, or systematics, isdefined by Webster's New Collegiate Dictionary as "the orderlyclassification of plants and animals according to their presumednatural relationships." Many systems have been presented for theclassification of animals over the years. In the early eighteenthcentury, the gifted



Page 4Swedish naturalist and anatomist Carolus Linnaeus developed astandardized binomial classification system (which identifies genusand species) that has achieved universal acceptance.

The Linnaean system assumes that animals with similar bodyconstruction are members of the same classification group. Thissystem, though expanded and greatly elaborated since itsintroduction, provides the foundation for modern taxonomy.

Taxonomic Classification

Taxonomic classification employs a hierarchical succession ofgroupings called rank-categories, or taxa. Organized in descendingorder, the highest groupings contain many organisms that share verygeneral characteristics, while the lowest groupings contain fewermembers, which are identified by specific characteristics.

Implementation of this classification method begins with identifyingmajor groupings of organisms that share a broad similarity instructure. From these main groups subgroups are distinguished, eachcontaining organisms that exhibit increasing similarity of bodystructure. These subgroups may be subdivided still further, witheach successively lower group often consisting of progressivelymore, but smaller groups.* Usually, the lower a group's standing inthe system, the fewer its members. This cascading process ofsubdivision establishes a hierarchy of classification groups. (SeeFigure 1.1.)

Primary groupings within the Linnaean classification system arekingdom, phylum, group, class, order, family, genus, and species.

Each rank may also have super- and subranks, as shown in Table1.1.

To illustrate how this classification system works, Tables 1.21.5 listthe taxonomic classification for domestic dogs, woodchucks, andhumans. The first three taxonomic ranks, shown in Table 1.2, areshared by all three animals. Tables 1.3, 1.4, and 1.5 define the majorrank-categories of each.

*When a group is subdivided, successively lower groups do notalways contain more groupings. For example, a genus maycontain only one species.



Page 5

Figure 1.1.An illustration of the basic hierarchy of kingdom (K) to genus (G) rankings within

traditional taxonomic classification.

TABLE 1.1 TaxonomicRankings (in descending order)

MajorRanks

Subranks Superranks

Kingdom superphylumPhylum supergroupGroup subphylum superclassClass subgroup superorderOrder subclass superfamily

Family suborder supergenusGenus subfamily superspecies

Species subgenussubspecies

TABLE 1.2 TaxonomicRanks Shared by a Dog, aWoodchuck, and a HumanKingdomAnimaliaAll

animals.Phylum ChordataAnimals

withspinalcords andhollowvertebrae.

ClassMammaliaWarm-bloodedanimalswho havehair ontheir skin

andwhoseyoungarenourishedthroughmilkglands.



Page 6TABLE 1.3 TaxonomicRanking of a DomesticDogOrderCamivoraAnimals

whoseprimaryfoodsource isthe fleshof otheranimals.Canineteeth arelarge andconical,and otherteeth arespecializedfor thetearing offlesh. Feetareplantigrade(the entirefoot, toesand heel,touchingtheground) ordigitigrade(only thetoestouchingtheground).

FamilyCanidaeAnimalswhose diet isvaried andcan be partlyherbivorous.Incisors,canines, andpremolarteeth arespecializedfor cuttingand tearing,with at leasttwo grindingmolars stillintact. Feetaredigitigradewithnonretractableclaws, andlimbs arespecializedforlocomotionon theground.

Genus Canis Dog ordoglikeanimals.

SpeciesfamiliarisThemembers ofthe genusCanis whohave beendomesticatedby man. Thecommondog.

Latin Names

Classic Latin is the language of preference for nomenclature and terminology inclassification systems. There are four major reasons for this.

First, Latin is a ''dead" language, meaning it's no longer used for everyday speech.Therefore it can be reserved for a special purpose, such as scientific classification, andnot be subject to the changes in word definitions, grammar, and syntax that "live"languages experience.

Second, since Latin is the linguistic ancestor of Western languages such as French,Spanish, Italian, and English, people from many nations find it fairly easy to interpret.

Third, Latin nomenclature embodies scientific tradition. Latin has



Page 7TABLE 1.4 TaxonomicRanking of a WoodchuckOrderRodentiaHerbivorous

(sometimesomnivorous),gnawinganimals withone pair ofincisors(front teeth)in each jaw.

FamilySciuridaeRodentswith twoupperpremolarsand onelower, andnoinfraorbitalcanal forthemassetermuscle.This canalis anopening intherostrum, aportion ofthe skulljustforward oftheorbitals.

GenusMarmotaBurrowinganimalswithelaborateundergroundsocieties.

SpeciesmonaxThegrizzled,thicksetmarmot ofthenortheasternUnitedStates andCanada.

been used in this type of work for hundreds of years, and tradition is hard to change.

Finally, the use of Latin in taxonomy persists because of history. The science of Western civilization is

founded on the thought and culture of ancient Rome and Greece, and systematics was born of Westernculture. In medieval Europe, Latin was a survivor of the Holy Roman Empire, providing one of the few linkswith the principles of Old Rome and ancient Greece. The Roman Catholic Church wielded great power andinherited Latin as its primary language. In those days, since the church was the main source of education andscience, the majority of written works were composed in or translated into Latin.

It should be noted that Latin is not the only language used in modern taxonomic nomenclature, just theprimary one. French, Greek, Italian, Swedish, German, and other languages are also used but are usuallyLatinized. Appendix B provides further information on scientific naming, terminology, and word origins.



Page 8TABLE 1.5Taxonomic Rankingof a HumanOrderPrimateBasically

arboreal(treedwelling)or ofarborealancestry,animalswithfingers,flat nails,and areducedsense ofsmell.

FamilyHominidaeAnimals thatlive on thegroundMand walkupright ontwo legs.Their handsand feet aredifferentlyspecialized(hands forgrasping andfeet forwalking) andthey have afamily andtribal socialorganization.

GenusHomoOnlythoseanimalswith alargebrain,speechcapacity,and anextendedyouth.

SpeciessapiensAnimalswith aprominentchin, highforehead,thin skullbones,double-curvedspine, andsparsebody hair.Humans.

It's fairly easy to read scientific names once you understand the system. Each organism is given atwo-part name. The first name designates its genus and the second, its species. For example, a wolf'sscientific name is Canis lupus. In Latin the word Canis means dog and lupus means wolf. So Canis

lupus means dog wolf. A domestic dog's taxonomic classification is Canis familiaris. We alreadyknow that Canis is the Latin word for dog, and familiaris translates to the English word "familiar."So Canis familiaris means dog familiar.

Common Names

Few people spout Latin names and terminology during everyday conversation. Instead, most knowand refer to animals by their common names, which are often derived or taken directly fromlanguages native to the area where the animals live. For example, "chimpanzee" is taken fromchimpenzi in the Kongo dialect and "wolf" is derived



Page 9from the Old English Wulf and more directly from the old HighGerman Wolf. "Chipmunk" has its origins in the Algonquin wordchitmunk, "coyote" is taken from the word coyotl in the language ofthe Nahuatl Indians of western North America, and "woodchuck"comes from the Ojibwa word otchig, meaning fisher or martin, andfrom the Cree word otcheck.

The Arbitrary Nature of Taxonomic Classification

The animal kingdom comprises some two dozen phyla and at least1.5 to 2 million species. This book addresses the taxa found in thekingdom Animalia, phylum Chordata, class Mammalia. The readershould always remember that, save for species, there exists noprinciple, except perhaps genetics, by which taxonomicclassification categories may be absolutely defined.

Because of this, it is inevitable that genera, families, and so on asthey are presently identified by mammalogists do not exactlycompare to those used by ichthyologiststhose who study fishorentomologiststhose who study insects. These differences may reflecta lack of agreement among scientists or may be the result ofbiodiversity in our world. Whatever the cause of these differences,perhaps someday scientists in all fields will agree on all levels ofclassification.

If you pursue traditional taxonomic classification techniques, atheme beyond the scope of this book, beware of yourpreconceptions. For example, one of the greatest preconceptions ofcollectors and classifiers lies in size. While basic skull structureswithin a family may remain relatively constant, their sizes can vary

considerably. For example, the skulls of a domestic house cat and alion are quite similar in shape but differ greatly in size. A personused to thinking of members of the cat family, Felidae, as being thesize of a tabby may glance at a lion skull and erroneously identify itas a member of the bear family, Ursidae, without bothering to checkthe details.

The rigid specifics of traditional taxonomy can be somewhatoverwhelming for beginning collectors and hobbyists. Fortunately, amore broad-based method of animal identification, inferentialclassification, offers an alternative.

Inferential Classification

Inferential classification involves analyzing skeletal structures toinfer an animal's eating habits, or environmental lifestyle. Thissystem



Page 10encourages the student or hobbyist to develop an understanding ofthe relationship between skeletal structure and an animal's generalbehavior. This method doesn't supplant traditional systematics butrather is meant as a tool for people wishing to learn more about howanimal structures relate to their environment.

General Lifestyle Classifications

The theory of convergent evolution maintains that animals whoadapt to a certain environmental lifestyle develop similar bodystructures. This trend toward structural similarity is apparent in theskeletons, particularly the skulls, of animals that fill similarenvironmental nichesas either predator or prey. These structuralsimilarities may remain relatively constant across speciesboundaries.

Inferential classification assumes that associations of particularskeletal structures apply to certain environmental lifestyles. Whilesuch correlations can be made, it should be emphasized that no onestructure or combination of structures always indicates specificeating patterns. This is because lifestyle, unlike physicalconstruction, can change if necessary for the animal to survive.

For example, a polar bear, like its cousin the black bear, hasdentition necessary for an omnivorous lifestyle: cutting incisors,tearing canines, sharp bicuspids, and flat molars that are ideal forgrinding plant material. But since plants are scarce in its arctichabitat, the polar bear is left with little choice but to subsist entirelyon meat.

Most black bears, in contrast, live in temperate habitats amid athriving variety of plants and animals. With plant food as easilyavailable as animal flesh, or more so, black bears easily live anomnivorous, though primarily herbivorous, lifestyle.

Other animals that sometimes deviate from the lifestyle suggestedby their skeletal structure include rats, which, while classified asherbivores, will eat meat if their survival requires it. In all instances,environmental living conditions and available food supply exertpressures that affect an animal's lifestyle and behavior. Chapter 6discusses behavioral interpretation from skeletal structures at greaterlength.

As stated in the introduction, inferential classification groupsanimals into three environmental lifestyle categories: carnivores,herbivores, and omnivores. Keeping the previous discussion ofstructure versus lifestyle in mind, let's examine these lifestyles.



Page 11Carnivores and Insectivores

Carnivores subsist primarily upon the flesh of otheranimalsherbivores as well as smaller carnivores and omnivores.Speed, strength, specialized teeth, and body appendages such asclaws are familiar indicators of a lifestyle based on hunting, killing,and consuming prey.

Insectivores practice a lifestyle similar to that of carnivores butconsume insects rather than animal flesh. For the purpose of thisbook, insectivores and carnivores are grouped together.

Herbivores

Herbivores are animals whose primary, if not exclusive, source ofnourishment is plants. Specific structures, especially flat teeth, aredesigned to exploit this specialized food source by engaging in threegeneral modes of eating behavior: gnawing (rodents), browsing(ruminants), and cropping (perissodactyls).

Omnivores

Omnivores eat whatever food they can find, grazing on plants justas easily as they consume meat. These ultimate opportunists canoften be found scavenging among the leftovers of carnivore kills aswell as nibbling forage. This flexibility allows omnivores to adapttheir diets to available food sources. For example, when vegetationis plentiful, an omnivore's diet may consist primarily of plant mattersupplemented by animal flesh. When vegetation is scarce, theanimal may eat mostly meat.

This variable diet requires skeletal structures, especially the skull,

that combine herbivorous and carnivorous features. Interpretingsuch structures to infer an omnivorous lifestyle can be difficult,however. The only skeletal structures that can be used to reliablyinfer an omnivorous lifestyle are the presence of well-developedmolars in conjunction with a full complement of incisors, canines,and bicuspid teeth in both jaws. Outside of this, it is easier toascribe a carnivorous or herbivorous lifestyle to an animal's skeletalremains than an omnivorous one.

The Skeleton

Inferential classification uses observations of related structureswithin a skeleton, called function groups, to infer the probableenvironmental lifestyle of an animal. The three primary functiongroups are made up



Page 12of bones that work together within the larger skeletal system: theskull, the limbs, and the vertebrae and ribs.

The Skull

People are fascinated by skulls. Perhaps this is because the skulldefines the seeing-hearing-smelling-biting-eating end of a creatureand, therefore, its "personality." Regardless, this function groupoften becomes the focus of interest and study almost to theexclusion of the rest of the skeleton.

As defined in this book and discussed in detail in chapter 2, theskull function group consists of six easily recognizable structures:dentition, the jaw, the nasal cavity, the orbits (eye sockets), thezygomatic arch, and the cranium. These structures, along with thelocation of jaw muscle attachment positions, offer the greatestamount of immediate information concerning an animal'senvironmental lifestyle. (See Figure 1.2.)

The Limbs

When in their study of skeletal structure people emphasize thebiting end of an animal, they often disregard the animal's stepping,tromp-

Figure 1.2.The bold area indicates the skull function group.



Page 13ing, and clawing portion. In inferential classification, skeletalstructures used by a mammal to move itself across or through itshabitat are essential to forming a complete picture of itsenvironmental lifestyle.

The limb function group, detailed in chapter 4, comprises the frontand back legs. Each can be divided into three parts. The front leggrouping includes the front feet (claws and bones), the leg bones(radius, ulna, and humerus), and the shoulder blade. The back leg ismade up of the back feet (claws and bones), the leg bones (fibula,tibia, and femur) and the hipbone.

Analysis of these structures offers insight into the posture,locomotion, attack or escape capabilities, and probable terraincommon to the animal's environment. (See Figure 1.3.)

Vertebrae and Ribs

The vertebrae and ribs function group, detailed in chapter 5,provides the skeletal framework to which the other function groupsattach. The vertebral column protects the spinal cord and suppliesthe connecting structure that ties the entire skeletal system together.The ribs, in addition to protecting the

Figure 1.3.The bold areas indicate the limb function group.



Page 14heart and lungs, also provide the support platform to which thescapula, or shoulder blade, is attached.

The information derived from these structures is essential toassembling a complete picture of an animal's environmentallifestyle. Both can be used to infer posture, mass, and an animal'sdegree of flexibility during motion. (See Figure 1.4.)

Conclusion

Systematics and inferential classification are both useful inunderstanding animals, but they assume different levels ofknowledge on the part of the reader. Traditional taxonomy movesbeyond inference and into perceived specifics. To fully utilize thissystem requires exposure to systematics and a background inzoology or mammalogy. The inferential method is intended forpersons of any age who are unfamiliar with, or have just a basicknowledge of, concepts within this field of study. For these people,this book offers a practical introduction into the joys of skeletalinterpretation.

Figure 1.4.The bold area indicates the vertebrae and ribs function group.



Page 15A note of caution for would-be collectors: Be aware that fewskeletons are found complete. Although classifying an entireskeleton can be a complex procedure, identifying partial remains iseven more challenging. Before attempting to classify any skeletalremains, either through traditional taxonomy or inferentialclassification, take into account as many structural components aspossible. The more information you have to start with, the morelikely you are to reach correct conclusions.



Page 16

Chapter 2The Skull

More than any other skeletal feature, the skull is a great source ofinformation about an animal's environmental lifestyle. The term''skull" refers to the bony or cartilaginous case that forms theskeleton of the head. This case encloses and protects the brain aswell as the chief sense organs: eyes, inner ears, sinus, and tongue. Acomplete skull includes an immobile upper jaw, or maxilla, and amovable lower jaw, or mandible.

The many bones and plates of a mammal's skull fit together like ajigsaw puzzle. The jagged-edged surfaces along which these platesmeet are called sutures. Sometimes, as in birds, the plates fittogether so tightly that the sutures do not show. (See Figure 2.1.)

The study of skull construction, called craniology, is often limitedto human crania. Researchers in this field have identified more thanfifty separate structures that can be used to classify animals at thespecies level. For our purposes of inferential classification, however,we will look at major structural groups. It is important to rememberthat a skull must be considered as a whole during classification, asfew individual structures provide enough information to positivelyidentify the animal's environmental lifestyle. Six easily recognizableskull structures are especially useful for inferential classification of



Page 17

Figure 2.1.Top views of basic cranial suture lines in dog and horse skulls.

skulls: dentition, the jaw, the nasal cavity, the orbits (eye sockets),the zygomatic arch, and the cranium. The relationships among thesestructures and the attachment positions of jaw muscles also provideimportant clues. (See Figure 2.2.)

Dentition

Dentition refers to teeth and arrangement of teeth within an animal'sjaws. There are four basic types of teeth: incisors, canines,bicuspids, and molars. (See Figure 2.3.)

Incisors are the forward, or front, teeth within a jaw whose sharpedges provide excellent cutting surfaces. Their presence or absence

in



Page 18

Figure 2.2.The six basic skull structures used in inferential classification.

the upper jaw is a good indicator of the animal's environmentallifestyle.

Also called eyeteeth, canines are often conical, pointed teeth locatedbetween the incisors and the first premolars. They are ideal forgripping and tearing.

Also known as the first premolars, bicuspids have two conicalpoints and follow the canines. Like canines, they are used forgripping and tearing.

Molars follow the bicuspids and, depending upon the lifestyle of themammal, may be flat, for grinding, or serrated, for cutting. Molarform and structure will often determine an animal's aptitude for aparticular environmental lifestyle.

It can be argued that teeth are the most significant skull structuresused in classification. Their shape, positioning, and absence or pres-



Page 19

Figure 2.3.Human dentition. Note the four major dental groupings.

ence often indicate specific environmental lifestyles and eatinghabits. Following are discussions of dentition in each of the threeenvironmental lifestyle categories.

Carnivore Dentition

Since animal tissues are softer than those of plants, contain nocellulose, and tear fairly easily, carnivores have teeth with sharppoints and serrated edgesideal for tearing and cutting flesh.Carnivore


Page 20incisors are narrower and much smaller than the other teeth andsport beveled sharp edges, excellent for piercing and cutting. Thecanines (eyeteeth) are highly developed in carnivores and areusually longer than the other teeth. Their conical shape andpositioning in the jawoften pointing straight down from the maxillaand straight up from the mandibleare ideal for holding, tearing, andslashing.

Bicuspids (first premolars), capped with twin conical peaks, are alsoexcellent for cutting or shearing. In carnivores, these teeth alongwith the molars are often serrated and are called the carnassials, orcut-

Figure 2.4.

Views of common carnivore dentition.



Page 21ting blade teeth.In true carnivores, molars usually maintain a serrated, orjagged-edged, appearance that is perfect for cutting; this structuralconstruction is particularly noticeable in felines. Molars with flat grindingsurfaces are nonexistent or limited to one very small, almost vestigialnarrow molar in the far rear of the upper jaw. (See Figure 2.4.)

Herbivore Dentition

Features unique to nearly all herbivores are flat molars and the absence ofpointed canine teeth and bicuspids in both the maxilla and the mandible.But just because canines and bicuspids don't develop in most herbivoresas they do in carnivores doesn't mean they can't. For example, theherbivorous Malaysian musk deer, whose skull is shown in Figure 2.5,sports well-developed canine teeth. Also, some large North Americanherbivores such as elk and horses develop rudimentary canine teeth calledwolves teeth. (See Figures 3.26 and 3.30 in chapter 3.) Additional uniqueadaptations in dental structure reflect diverse methods of consuming foodas seen in the three groupings of herbivores: rodents, ruminants, andperissodactyls.

Figure 2.5.A side view of the skull of a Malaysian musk deer, which is not native to

North America. Notice the well-developed, tusklike canine teeth.


Page 22Rodents

Rodentssquirrels, rats, and so forthsport a single pair of long,curved, chisel-edged incisors in both their upper and lower jaws.Being the only incisors that develop in these animals, they are thesingle most indicative feature of a rodent skull. Well-developedmolars bevel inward and have a level, often corrugated surface. (SeeFigure 2.6.)

Ruminants

In ruminants, such as cows, incisors are present in the mandible butabsent in the maxilla and are wide with sharp, beveled edges. Theirmolarsflat, well formed, and slanting slightly inwardhave ridges ontheir grinding surfaces. (See Figure 2.7.)

Figure 2.6.

Views of herbivore dental construction common in rodents.



Page 23

Figure 2.7.Views of herbivore dental construction common in ruminants.

Perissodactyls

In striking contrast to ruminants, perissodactyls such as horses havewide, sharp-edged incisors in both their upper and lower jaws. Aswith ruminants and rodents, their flat-ridged molars bevel slightlyinwardexcellent structures for grinding plant materials. (See Figure2.8.)


Page 24

Figure 2.8.Views of herbivore dental construction common in perissodactyls.

Omnivore Dentition

Although omnivores come in a wide variety of sizes and shapes, thebasic structure of their dentition remains the same: a complete,welldeveloped complement of incisors, canines, bicuspids, andmolars in both the upper and lower jaws. As with other bodystructures of omnivores, their teeth reflect a combination of bothherbivore and carnivore structures.


Page 25

Figure 2.9.Views of omnivore dental construction from a pig.



Page 26

Figure 2.10.Views of omnivore dental construction from a dog.

Like carnivores and perissodactyl herbivores, omnivores haveincisors in both the maxilla and the mandible. Bevel-edged forcutting, these teeth may be wide or narrow and nearly the same sizeas or decidedly smaller than the canine teeth.

Omnivore canine teeth may be long and specialized, as in mostcarnivores, or short and unspecialized; they are often the samelength


Page 27

Figure 2.11.Views of omnivore dental construction from a bear.

as the surrounding teeth. Regardless of their size, however, theseteeth remain useful for tearing both plant and animal flesh.

Bicuspids, like the canine teeth, may be equal in size and shape tothose of true carnivores, or much flatter, though still similar instructure. These teeth sport sharp edges for tearing plant and animalflesh and sometimes shallow, flat areas for grinding.

When fully developed, omnivore molars have large, flat grindingsurfaces, but some omnivores (such as foxes) may also sport bothfull


Page 28and fractional flat grinding surfaces while retaining among somemolars the carnassial shape common to carnivores. (See Figures 2.3and 2.92.11.)

Jaws

A mammal's skull contains two jaws: The maxilla, or upper jaw, isfused to the main portion of the skull below the nasal cavity; themandible, or lower jaw, is movable and is attached at the hingejoints just forward of the ears. These structures mirror each other inshape and dimension. For example, if the maxilla is long andnarrow, the mandible will be long and narrow, too. If the mandibleis short and wide, the maxilla will be short and wide. (See Figure2.12.)

Jaws provide a foundation for leverage and gripping by the teeth.When working, the maxilla remains in its fixed position while themandible moves against it. These movements may be up and down,forward and back, or side to side. Powerful masseter and temporalismuscles attach the mandible to the cranium, providing crushing andgripping strength.

Figure 2.12.The maxilla and mandible of a human skull.



Page 29Like dentition, jaw shape is a good indicator of an animal'senvironmental lifestyle. Because its shape exhibits the greatestvariance among environmental lifestyles, however, the mandible canbe considered the better of the two jaw structures to use forinferential classification.

Carnivore Jaws

In carnivores the mandible is often at least slightly curved, allowinggreater pressure to be exerted at the front of the jaw, where thecanines and incisors reside. This gives the animal more strength forholding and tearing food. (See Figure 2.13.)

Figure 2.13.Typical carnivore mandibles. Notice the curved shape.


Page 30Herbivore Jaws

In the long, flat jaws common among many herbivores, themandible tapers from a wide back to a narrower front. Thisconstruction allows greater pressure to be exerted along the mid toback portions of the jaw than at the front. (See Figure 2.14.)

Not all herbivores share this lower jaw construction, however.Rodents have curved or slightly curved mandibles that allow bitepressure to be maximized at both the incisors and the molars. (SeeFigure 2.15.)

Omnivore Jaws

The lower jaws of omnivores share attributes of carnivore andherbivore mandibles and come in three basic shapes: short and flat,as in humans; long and flat to slightly curved, as in pigs and bears;and long and curved, as in dogs and opossums. (See Figure 2.16.)

Nasal Cavity

The sense of smell is vital to all mammals. The nasal cavity, hometo the olfactory organs, is the portion of the skull that houses andprotects the sinus membranes. It can be long and narrow, as in deerand wolves; long and wide, as in cows; short and flat, as in humansand cats; or short and narrow, as in otters.

The nasal cavity's size and shape often affects the placement of anddistance between the eye sockets of a mammal. Long-wide nasalstructures tend to space eye sockets farther apart and rotate them tothe side. Long-narrow and short-blunt nasal structures tend to space

eye sockets closer together and rotate them to face forward. (SeeFigure 2.17.)

Carnivore Nasal Cavity

In true carnivores, the nasal cavity, often short and blunt, as infelines, can also be short and narrow, as in otters. (See Figure 2.18.)

Herbivore Nasal Cavity

The nasal cavity in herbivores is usually long, housing an efficientsinus. The width of this structure differs greatly from species tospecies. For example, the nasal cavity of a cow is long and wide,but in a deer or squirrel, it is long and narrow, and in porcupines, itis short and somewhat pointed. (See Figure 2.19.)



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Figure 2.14.The long flat mandible shape typical of ruminant and perissodactyl herbivores.



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Figure 2.15.Rodent mandibles. Notice the curved shape.



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Figure 2.16.The range of omnivore jaw shapes.



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Figure 2.17.A comparison of four basic nasal structures.

Omnivore Nasal Cavity

Omnivore nasal cavities come in three general shapes: short andflat, as in humans; long and narrow, as in opossums; or long andmedium-wide, as in bears. (See Figure 2.20.)



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Figure 2.18.Examples of carnivore muzzles. Note the nasal structures and orbits.

Orbits

Orbits, or eye sockets, form the framework that supports andprotects the eyes. Their shape, size, and position in a skull canindicate the animal's environmental lifestyle. Eye-socket positions inmammal skulls range between two extremes: rotated facing forwardor rotated sideways facing outward from the side of the head.

Forward-facing eye sockets permit the fields of vision of each eyeto overlap. This parallax allows the brain to perceive the sameimage


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Figure 2.19.Examples of herbivore muzzles. Note the nasal structures and orbits.

from two different perspectives and so fix an object in space. Calledbinocular vision, this type of perception allows an animal to sensedepth, distances, and three-dimensional imagesvery handy whenattacking prey or dodging a predator. (See Figure 2.21.)



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Figure 2.20.Examples of omnivore muzzles. Note the nasal structures and orbits.

Eye sockets set on the sides of the skull require the eyes to faceoutward in opposite or near-opposite directions, a position in whichtheir fields of vision do not overlap. This results in monocularvision, which limits an animal's perception to flat, two-dimensionalimages, preventing the sensing of depth and distances. Although thismay seem less desirable than binocular vision, monocular visiondoes have advantages, including great peripheral vision. This allowsan animal


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Figure 2.21.The overlapping of sight fields that produces binocular vision, illustrated using the

orbital structures of an elephant shrew, a nonnative of North America.

to see farther to the rear and increases its ability to sense motionextremelyimportant if your enemies tend to sneak up from behind and use fast, quickmovements when they attack. (See Figure 2.22.)

Carnivore Orbits

The predominant position for carnivore orbits is facing forward or slightlyforward. This arrangement facilitates binocular vision and depth perception, bothessential for hunting and attack. (See Figure 2.18.)

Herbivore Orbits

Orbit position in herbivore skulls is often graded between forward facing and sidefacing and varies among animals. The eye sockets of most rodents are rotatedforward in the skull, allowing binocular vision. Bulky, often slow-moving animalssuch as cows and buffalo tend to have eye sockets rotated to the side in theirskulls for monocular vision. Faster-moving animals such as antelope and deerhave



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Figure 2.22.The independence of sight that produces monocular vision,

illustrated using the orbital structures of a bison.

orbitals rotated slightly forward, often far enough to provide limitedbinocular vision. (See Figure 2.19.)

Omnivore Orbits

Omnivores share the carnivore and rodent adaptation of forwardrotated or slightly forward rotated orbitals. This positioning allowsbinocular vision and good depth perception. (See Figure 2.20.)

Zygomatic Arches

The zygomatic arches are the portions of a skull that form thecheekbones and extend to the back along each side of the skull,attaching above and slightly forward of the ears. They are composedof two bones: The jugal bone, or cheekbone, connects with thesquamosal, which in turn connects to the cranium just above and in

front of the ears. The greatest distance between the outside edges ofthe zygomatic arches on either side of the cranium is called thezygomatic breadth.(See Figure 2.23.)



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Figure 2.23.Bold areas in this image reference the zygomatic arch and its component structures,

the jugal and the squamosal. Together these structures form the zygomatic arch.

Zygomatic arches are important for inferential classification because their size anddistance from the cranium indicate the relative size of the temporalis muscles,which pass between them and connect the back of the mandible to the cranium. Thelarger the opening, the larger and stronger the temporalis muscles, and the morelikely the animal is to exhibit carnivorous tendencies. (See Figure 2.24.)

The relationship between zygomatic breadth and cranium size and environmentallifestyle can best be shown by comparing the top view of the skulls illustrated inchapter 3. The figures in this chapter provide top and side views of carnivore,herbivore, and omnivore skulls.

Carnivore Zygomatic Arches

Carnivore skulls tend to have large zygomatic breadths. The zygomatic arches andthe ''hole" they form with the cranium accommodate the passage of well-developedtemporalis muscles. Although this arrangement provides greater space for thetemporalis muscles, it also provides a strong anchor position for the massetermuscles, which raise the lower jaw. (See Figures 3.13.10 of chapter 3.)



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Figure 2.24.A comparison of the zygomatic breadths of a horse and a wolf.

Herbivore Zygomatic Arches

The skulls of ruminants and perissodactyls have small zygomaticbreadths. While such an arrangement decreases the space betweenthe cranium and the zygomatic arches, offering less room for thetemporalis muscles, it does provide a stronger anchor position forthe masseters.

Rodent skulls, however, are similar to carnivore skulls in that theyhave large zygomatic breadths. Compare similarities and differencesamong herbivore arch structures by studying Figures 3.153.30 inchapter 3.

Omnivore Zygomatic Arches

In omnivores, the relative breadth and position of the zygomaticarches in relation to the cranium range between those of herbivore

and carnivore skulls. Although these structures can be large, as inbears and foxes, they can also be relatively small, as in humans andpigs. (See Figures 3.313.42 in chapter 3.)



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Cranium

The cranium, or dome, is the portion of the skull that protects andhouses the brain. This structure is important in classificationbecause its outward cross-sectional shape often varies according toan animal's environmental lifestyle. The back portion of the craniumcomprises two paired bones called the parietal bones. The sutureline joining these bones forms the sagittal crest, which runslongitudinally to the posterior or back of the skull. This crest can bepronounced (forming a peak), reduced (forming a slight bump), orsmooth (forming a rounded or flat surface). Whatever the case, thejoining of the plates that form the sagittal crest often determines thefinal appearance of the cranium.

Cranial shape indicates not only the surface area available to anchorjaw muscles but also muscle size and strength. Usually, the largerthe sagittal crest, the larger the temporalis muscles that attach alongits length; a smooth or flat cranium indicates smaller temporalismuscles that must anchor farther down its sides to maintainsufficient purchase. In cross-sectional appearance, three generalizedcranial shapes may be considered common among mammals:smooth-rounded, as in humans and deer; smooth-flat, as in cows;and peaked, as in dogs and cats. (See Figure 2.25.)

Figure 2.25.Three cross-sectional shapes common among mammal crania:

smooth-rounded, smooth-flat, and peaked.



Page 43Carnivore Crania

Carnivore crania often have a pointed appearance because of theirpronounced sagittal crest. This crest provides a secure anchor forlonger, more developed temporalis muscles. (See Figures 3.13.10 inchapter 3.)

Herbivore Crania

The skulls of ruminants and perissodactyls come in one of two basiccranial shapes: smooth-rounded and smooth-flat. These shapeshouse smaller temporalis muscles, as a reduced or smooth sagittalcrest doesn't provide the anchorage required by large, well-developed temporalis muscles. (See Figures 3.233.29 in chapter 3.)

Rodents are the exception to the herbivore rule. Rodent skulls canbe round and smooth or slightly peaked from a reduced sagittalcrest. (See Figures 3.163.22 of chapter 3.)

Omnivore Crania

Omnivore crania come in a variety of shapes, from the high peakscommon among carnivores to the smooth-round and smooth-flatdomes prevalent among herbivores. (See Figures 3.313.43 in chapter3.)

Muscle Attachment Positions

Two major muscle groups, the masseter and the temporalis, work toclose the lower jaw. They attach to the skull at the zygomatic arch,the cranium, and the lower jaw. The size and positioning of thesemuscles, when associated with other skull features, can help identify

an animal's environmental lifestyle.

Temporalis muscles attach along the rear of the lower jaw andanchor along the sides or top of the cranium. They provide power tothe forward portion of the jaws where the incisors, canines, andbicuspids reside.

Masseter muscles attach between the sides of the zygomatic archesand the rear portions of the lower jaw. They provide power for theback of the jaws, where the molars reside.

Carnivore Muscle Attachments

Muscle attachments in carnivore skulls are located where they willgive the greatest strength to muscles whose major function is to aidthe jaws in holding and crushing prey while the animal tears andrips



Page 44flesh. Therefore, the temporalis muscles attach to the rear portionsof the lower jaw, run beneath the zygomatic arches, extend up alongthe sides of the skull, and attach near the top of the cranium, usuallyat the sagittal crest. Their length and points of anchorage give atremendous amount of leverage and power to the front of the lowerjaw. In this arrangement, temporalis muscles are stronger thanmasseters.

Masseter muscles attach between the zygomatic arches and rearportions of the lower jaw. Usually smaller than the temporalismuscles, they produce the power for crushing and cutting with theback teeth, or molars. (See Figure 2.26.)

Figure 2.26.

Attachment points for the temporalis and masseter muscles on a European badger skull.



Page 45Herbivore Muscle Attachment Positions

Ruminant and perissodactyl skull structures are designed toaccommodate jaw muscles whose major function is to provide thepower for crushing and grinding plant materials with the rearportions of the jaws. (See Figure 2.27.) The temporalis musclesattach along the rear portions of the lower jaw and anchor the sidesof the cranium near the temple. Their relative shortness and cranialanchor positions limit the amount of leverage and power they cangive to the front of the relatively flat jaws common amongherbivores.

The masseter muscles attach between the zygomatic arches and theback of the lower jaw. In herbivores, these muscles are often largerand stronger than the temporalises. Strong masseter muscles greatlyenhance grinding side-to-side movements and crushing strength inthe rear portion of the jaw. Although smaller temporalis muscleslimit the total power of the front of the jaw, large masseter musclesoffer impressive leverage to the incisors of perissodactyls andruminants. Ask anyone who has been bitten by a horse. (See Figure2.27.)

Jaw muscle attachments in rodents are more like those of omnivoresthan those of other herbivores. A curved jaw, often reduced sagittalcrest, and forward-facing orbits all contribute to providingpositioning and development of strong, well-developed temporalisand masseter muscles. (See Figure 2.28.)

Omnivore Muscle Attachment Positions

Omnivore jaws are used to crush and grind plant material with theback of the jaws as well as tear and cut animal flesh and plantmaterial with the forward portion of the jaws, so their muscles mustbe attached where they can perform both tasks. The temporalismuscles attach to the rear portions of the lower jaw, run beneath thezygomatic arches, and finally extend and attach to the sides of thecranium. Along this route they commonly anchor in one of twocranial positions: lateral, as with herbivores, or dorsal, as withcarnivores.

A lateral attachment anchors temporalis muscles along the sides ofthe cranium near the temples. In this position, their limited lengthand cranial anchorage deliver a reduced, though more than adequate,amount of power to the front of the jaws. In this situation, thetemporalis muscles are often equal to or slightly weaker in strengththan the masseters.

A dorsal attachment anchors temporalis muscles along the sagittal



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Figure 2.27.Muscle attachment points for masseter and temporalis muscles

on ruminant and perissodactyl skulls.

crest near the top of the cranium. This position offers the musclessuperiority in length and anchorage, thereby giving a great amountof power to the forward portion of the jaws. In this arrangement,temporalis muscles are often stronger than or equal in strength tomasseters.

Omnivore masseter muscles attach between the zygomatic arches


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Figure 2.28.Muscle attachment points for masseter and temporalis muscles on rodent skulls.

and the rear portions of the lower jaw. In omnivores, these muscles range fromroughly equal in size and strength to somewhat larger and slightly stronger thanthe temporalis. Strong masseters greatly enhance grinding side-to-sidemovements and crushing strength in the rear portion of the jaw. (See Figure2.29.)



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Figure 2.29.Muscle attachment points for masseter and temporalis

muscles on an omnivore skull.



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Conclusion

When specifying which skull structures will be used forclassification, recognize that adaptive and environmental influencesoften encourage the development of similar structural shapes inmammals across lifestyle boundaries. Because of this, it is difficultto say with absolute certainty that specific structural shapes in askull indicate a particular environmental lifestyle. For example, anelongated muzzle is common to herbivores, carnivores, and four-legged omnivores. It is for this reason that inferential classificationconsiders no one structure definitive of a specific environmentallifestyle and instead suggests that structures be considered as awhole.



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Chapter 3Skulls Illustrated

This chapter presents a series of illustrations depicting skulls from avariety of North American land mammals. These images are dividedinto the three environmental lifestyle categories: carnivore,herbivore, and omnivore. An animal's common name and taxonomicfamily rank are provided with each entry. Appendix C lists completetraditional taxonomic order-to-species rankings for each mammalmentioned in this book.

Before presenting these illustrations, the following point must beclarified. This work classifies several animals as omnivores thattraditional taxonomy places in the order Carnivora. The long canineteeth generally associated with members of this order conjureimages of fanged creatures whose sole purpose in life is the rending,shredding, and consuming of animal flesh. Use of this term as agroup rank indicates a two-hundred-or-more-year-old preconceptionbased solely on the presence of these dental structures. Manymembers of this order also have flat, well-developed molars,however, indicating that vegetation is an important secondary foodsource. The relative length and width,* in centimeters, of skulls

*Width refers to the zygomatic breadth.



Page 51sketched for this chapter are presented in each figure caption. Thesemeasurements, provided for approximate scale, should not beconsidered absolutes. Relative dimensions will vary amongindividuals, depending on age and sex.

Carnivores and Insectivores

Carnivores and insectivores share similar environmental lifestylesbased on hunting and consuming prey, so they have similar skullstructures. Although their dentition is markedly different, with theteeth of insectivores being more serrated and undifferentiated thanthose of carnivores, the primary difference between these twogroups is size. Most insectivores are smaller than carnivores, andinsectivore skulls are often one-half inch or less in length.

Common Carnivore Skulls

From the vast number of carnivores in North America, membersfrom two prominent families have been chosen to provide a crosssection of common carnivore skulls: Felidae and Mustelidae.

Felidae

Domestic cats, lynx, bobcats, and cougars, or mountain lions, aremembers of the family Felidae. (See Figures 3.13.4.)

Mustelidae

Weasels, wolverines, skunks, badgers, river otters, and martens aremembers of the family Mustelidae. (See Figures 3.53.10.)

As discussed in chapter 1, an environmental lifestyle may beconsidered an interactive function of environmental and structural

constraints. Thus, an animal's actual lifestyle can be different fromthat suggested by its skull structures. For example, the polar bearmay be considered the only strictly carnivorous member of thefamily Ursidae. Its skull strongly resembles those from relatedomnivorous family members illustrated in Figures 3.313.33.Similarly, the arctic wolf may be considered the only trulycarnivorous member of the family Canidae. Its skull is similar tothose of the related omnivorous family members illustrated inFigures 3.343.38.



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Figure 3.1.Top and side views of a domestic cat skull. Length (8 cm), width (6 cm).



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Figure 3.2.Top and side views of a mountain lion skull. Length (20.5 cm) , width (14.1 cm).



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Figure 3.3.Top and side views of a lynx skull. Length (12.2 cm), width (9.1 cm).



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Figure 3.4.Top and side views of a bobcat skull. Length (12.5 cm), width (9.3 cm).



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Figure 3.5.Top and side views of a badger skull. Length (13 cm), width (8.2 cm).



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Figure 3.6.Top and side views of a pine marten skull. Length (8.5 cm), width (4.6 cm).



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Figure 3.7.Top and side views of a skunk skull. Length (6.3 cm), width (3.9 cm).



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Figure 3.8.Top and side views of a weasel skull. Length (5 cm), width (2.9 cm).



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Figure 3.9.Top and side views of a wolverine skull. Length (15.8 cm), width (10.7 cm).



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Figure 3.10.Top and side views of a river otter skull. Length (10.8 cm), width (7.3 cm).



Page 62Common Insectivore Skulls

Although many mammals, such as skunks and some rodents,include insects in their diets, only members of several specificorders and families lead strict insectivorous lifestyles. These includeSoricidae, Talpidae, Vespertilionidae, and Dasypodidae.

Soricidae

Shrews are members of the family Soriddae. (See Figure 3.11.)

Talpidae

Moles are members of the family Talpidae. (See Figure 3.12.)

Figure 3.11.Top and side views of a common shrew skull.

Length (2.1 cm), width (1 cm).


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Figure 3.12.Top and side views of an eastern mole skull.

Length (3.5 cm), width (1.8 cm).



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Figure 3.13.Top and side views of a big brown bat skull.

Length (2 cm), width (1.3 cm).



Page 65Vespertilionidae

Bats form many families in the order Chiroptera. Two prominentNorth American bats, the common big brown bat and the cave bat,are members of the family Vespertilionidae. (See Figures 3.13 and3.14.)

Figure 3.14.Top and side views of a cave bat skull.

Length (1.6 cm), width (1 cm).



Page 66Dasypodidae

Armadillos are members of the family Dasypodidae. Travelers in thesouthern United States have probably spotted these animalstrundling off into the undergrowth along roadsides or squashed flatin the roadway. (See Figure 3.15.)

Figure 3.15.Top and side views of an armadillo skull.




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Herbivores

A herbivorous lifestyle provides its practitioners with access to afairly reliable and diverse source of plant material. Although thevariety of plant life is often extensive, not all herbivores can eat allplants, and some plants have fairly effective defenses against theirwould-be consumers. Large amounts of cellulose make plant tissuestough and difficult to tear. As discussed in the previous chapter,herbivores sport dentition that can rasp, crush, and grind, allowingthem to exploit this food source.

Skulls of Common Herbivores

Most North American herbivores can be assigned to one of threebasic groups: rodents, ruminants, or perissodactyls.

Rodents

Rodents form the order Rodentia, which includes such mammals asmice, beavers, chipmunks, squirrels, and porcupines. (See Figures3.163.22.)

Rabbits are members of the order Lagomorpha. Since they havestrong similarities in skull structures and identical environmentallifestyles to rodents, this book groups them together. Because theirskull structures look similar, inexperienced collectors often confusethe two. To avoid misclassification, collectors should note whetherthe skull has large, open, weblike structures just forward of the eyes,along either side of the nasal cavity. If they're there, you have arabbit skull. (See Figure 3.23.)

Ruminants

Most ruminants belong to the order Artiodactyla, which includessuch mammals as cows, sheep, goats, and bison from the familyBovidae and antelope, deer, and elk from the family Cervidae. (SeeFigures 3.243.29.)

Perissodactyls

Perissodactyls form the order Perissodactyla, which includesmembers of the family Equidae, such as horses and mules. (SeeFigure 3.30.)



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Figure 3.16.Top and side views of a chipmunk skull. Length (3.8 cm), width (2 cm).



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Figure 3.17.Top and side views of a beaver skull. Length (12.8 cm), width (8.6 cm).



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Figure 3.18.Top and side views of a pocket gopher skull. Length (3.6 cm), width (2.1 cm).



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Figure 3.19.Top and side views of a muskrat skull. Length (6.5 cm), width (4.1 cm).



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Figure 3.20.Top and side views of a Wyoming ground squirrel skull.




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Figure 3.21.Top and side views of a porcupine skull. Length (9.8 cm), width (6.6 cm).



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Figure 3.22.Top and side views of a gray squirrel skull. Length (6.2 cm), width (3.5 cm).



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Figure 3.23.Top and side views of a rabbit skull. Length (6.5 cm), width (3.4 cm).



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Figure 3.24.Top and side views of a cow skull. Length (45.6 cm), width (20.5 cm).



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Figure 3.25.Top and side views of a deer skull. Length (26.3 cm), width (10.3 cm).



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Figure 3.26.Top and side views of an elk skull. Length (42 cm), width (17.2 cm).



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Figure 3.27.Top and side views of a goat skull. Length (21.9 cm), width (10.4 cm).



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Figure 3.28.Top and side views of a sheep skull. Length (26.7 cm), width (14 cm).



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Figure 3.29.Top and side views of a bison skull. Length (60 cm), width (45 cm).



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Figure 3.30.Top and side views of a horse skull. Length (49.5 cm), width (19.1 cm).



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Omnivores

An omnivorous diet consists of both plant material and animal flesh.Lack of a reliable single food source tends to encourage a diversity-based survival strategy where both plant and animal flesh proveimportant in an animal's diet. Fluctuations in environmentalconditions may have encouraged the development of omnivores,perhaps one reason why omnivore skulls sport structures similar tothose of both herbivores and carnivores.

Common Omnivore Skulls

An omnivorous lifestyle is shared by members from a wide varietyof orders and families. This lineage illustrates that, regardless ofclassic taxonomic groupings and differences in skull shapes, anomnivorous lifestyle is common. This section provides skullillustrations from six families.

Ursidae

Bears form the family Ursidae, and although most of its membersare omnivorous, the polar bear, as discussed earlier, is carnivorous.(See Figures 3.313.33.)

Canidae

Members of the family Canidae include domestic dogs, wolves,foxes, and coyotes. While bearing many structures adapted foreating meat, they also sport teethdeveloped flat rear molarsforgrinding plants and are known to regularly consume vegetablematter. (See Figures 3.343.38.)

Didelphidae

Opossums are the only member of the family Didelphidae. (SeeFigure 3.39.)

Procyonidae

Many of the skull adaptations in members of the family Canidaeexist in the skull structure of raccoons, who form the familyProcyonidae. (See Figure 3.40.)



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Figure 3.31.Side and top views of a black bear skull. Length (29.2 cm), width (16.6 cm).



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Figure 3.32.Side and top views of a brown bear skull. Length (31.8 cm), width (18.1 cm).



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Figure 3.33.Side and top views of a grizzly bear skull. Length (30.5 cm), width (14.2 cm).



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Figure 3.34.Side and top views of a coyote skull. Length (15.2 cm), width (7.5 cm).



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Figure 3.35.Side and top views of a domestic dog skull. Length (15.2 cm), width (7.5 cm).



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Figure 3.36.Side and top views of another domestic dog skull. Length (10.6 cm), width (8.6 cm).



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Figure 3.37.Side and top views of a fox skull. Length (12.3 cm), width (6.6 cm).



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Figure 3.38.Top and side views of a wolf skull. Length (26 cm), width (13.8 cm).



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Figure 3.39.Top and side views of an opossum skull. Length (12.1 cm), width (6.1 cm).



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Figure 3.40.Top and side views of a raccoon skull. Length (10.4 cm), width (6.4 cm).



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Figure 3.41.Side and top views of a human skull. Length (19.4 cm), width (17.2 cm).



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Figure 3.42.Side and top views of a pig skull. Length (23.8 cm), width (13 cm).



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Figure 3.43.Side view of a collared peccary skull. Length (23.6 cm), width (10.8 cm).



Page 97Homonidae

Humans are the only ''native" members of the family Homonidae inthe order Primate found in North America. Any supermarket willattest to their omnivorous nature. (See Figure 3.41.)

Suidae and Tayassuidae

Pigs and peccaries are omnivorous members of the orderArtiodactyla, families Suidae and Tayassuidae respectively. Theiromnivorous lifestyle contrasts sharply with the mostly herbivorousmembers from this order. (See Figures 3.42 and 3.43.)

An important point to remember is that not all animals are native tothis continent. Humans have introduced exotics into new ecosystemsas petsdogs, cats, and the European badgerand work/foodanimalshorses, oxen, and cows. Presented alongside nativeinhabitants, the animals depicted in this chapter represent anexcellent cross section of the current inhabitants of North America.



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Chapter 4The Limbs

A mammal uses its limbs primarily for locomotion and secondarilyfor defense and attack. The development and arrangement of bonesand structures within a limb affect an animal's ability to navigatevarious types of terrain, such as rocky areas, mountains, swamps,plains, and forested tracts.

The limb function group includes two structural assemblages: thefront limbs and the back limbs. These structures are usuallymodified to fit a mammal's particular mode of life. For example,bats have wings, ungulates, such as horses, have single-digit hooves,and humans have hands for grasping. (See Figure 4.1.)

Most mammals are tetrapods, or four-footed animals, while some,such as humans, are bipeds, or two-footed creatures. In both cases,the anterior, or front, limbs attach to the pectoral girdle, and theposterior, or rear, limbs connect with the pelvic girdle.

The limbs of all mammals have similar bone groupings andstructural divisions. Limb usage can vary greatly, however. Thefront and back limbs of the same animal are often quite different,depending on how they're used.

The front limb groupings (see Figures 4.2 and 4.3) include the nails,the front feet, the front legs, and the pectoral girdle. The front



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Figure 4.1.specialization required by bats for flying, by humans for grasping, and by horses for

running.



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Figure 4.2.Contrasted front limb structural groupings from a dog and a cow.



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Figure 4.3.A comparison of front limb structures of a dog, a pig, a horse, and a cow.

limbs tend to be used for a wider variety of functions than the hindlimbs, such as handling food, digging, climbing, or flying. In hoofedmammals such as deer, cows, horses, and pigs, however, the front limbsare used in conjunction with and perform nearly identical functions asthe rear limbs when walking or running.

The back limb grouping (see Figures 4.4 and 4.5) consists of the claws,back feet, back legs, and pelvic girdle, or hip. Hind limbs are usuallyassociated with the support and movement of the body. Since the pelvicgirdle is firmly anchored to the spinal column, the rear limbs often havemuch less freedom of movement than the front limbs.



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Figure 4.4.Contrasted back limb structural groupings of a dog and a cow.



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Figure 4.5.A comparison of back limb structures of a dog, a pig, a horse, and a cow.

Feet

The makeup of a mammal's footthe portion of the limb that actuallycomes in contact with the ground during locomotionprovidesinformation essential for inferential classification. The bone structure ofthe front and rear legs, along with the type of nails and digits, areimportant indicators of an animal's environmental lifestyle.

Before continuing, it's worth mentioning that the carpal and tarsalbones, which make up, respectively, the front and back ankles of thelimbs, have been excluded from discussion in this book. Although thereare approximately eight carpal and tarsal bones in each limb,



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Figure 4.6.Carpal and tarsal bones of a dog and an ox.

they are small and difficult to locate among scattered skeletalremains. When found, a nonexpert may find it very difficult toextrapolate environmental lifestyle information from their individualshapes. So that you may recognize their general shapes and position,however, Figure 4.6 illustrates the carpal and tarsal bones of a dogand an ox.



Page 105The Front Foot

A mammal's front feet have two major sets of bones: the phalangesand the metacarpals. Phalanges form the digits, or toes. A single digitis made up of a proximal, a middle, and a distal phalanx bone. Thefront feet of most mammals contain fourteen phalanges. Metacarpalsextend from the phalanges back to the carpals, or wrist bones, of thefront foot. Most mammals have five metacarpal bones in each frontfoot.

Figure 4.7.A comparison of front foot structural components of a dog and a deer.



Page 106The Back Foot

A mammal's back feet have two major sets of bones that are muchlike those of the front feet: phalanges and metatarsals. As in thefront feet phalanges make up the digits of the back feet. A singledigit consists of proximal, middle, and distal phalanx bones. Amammal's back foot, like its front foot, usually contains fourteenphalanges. The metatarsals extend from the phalanges back to thetarsals of the back foot. As in its front feet, most mammals have fivemetatarsal bones in each back foot.

Digits

The ease of associating environmental lifestyles with foot structuredepends on the number and relative size of toe bones found whencollecting. All carnivores, many omnivores, and most smallherbivores have five developed toes, sometimes with an opposabletoe for climbing, as with the opossum. Large herbivores, such ascows and deer, usually have two major toes, and horses have one.

The structural resemblance exhibited between foot bones of smallherbivores, carnivores, and omnivores can make it difficult to inferenvironmental lifestyles based solely on these structures. (SeeFigure 4.9.) It is much easier to use foot structure to separate largeherbivores such as deer and horses from large carnivores andomnivores such as mountain lions, humans, and wolves.Determining whether the metatarsals and metacarpals are fused orunfused is one effective indicator, as is the relative shape of thedistal phalanx bones of the digits. The metacarpals and metatarsalsin large herbivores, unlike those in carnivores and most omnivores,

are usually fused into what appears to be a single bone. (See Figures4.7 and 4.8.)

In addition, the digits of single- and double-toed foot structures,associated primarily with large herbivores, commonly havewedgeshaped distal phalanx bones. Nevertheless, the omnivorouspig has a similar foot structure and so breaks the rule of two-toedfoot structure being unique to herbivores. (See Figure 4.10.)

Nails

All mammals carry some sort of horny sheath-like structure on theend of every digita nail, a claw, or a hoof, depending on the animal.The nails of the front and back feet of an animal are usually similar,if not identical, but sometimes they can be very different. (SeeFigure



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Figure 4.8.A comparison of the front feet of a dog, a pig, a deer, and a horse.

4.11.) The form these structures take can be used to infer thecreature's environmental lifestyle.

Claws

Most carnivores, omnivores, and small herbivores have long,narrow, curved nails called claws. The two predominant claw types,retractable and nonretractable, refer to a claw's capacity formovement independent of the digit.

Nonretractable claws are firmly anchored to the distal phalanx andextend outward from it. (See Figure 4.12.) Nonretractable claws arecommon among omnivores, such as coyotes and raccoons:carnivores, such as weasels and otters; and small herbivores, such as

woodchucks and rabbits.



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Figure 4.9.The foot bones of small herbivores (squirrel and rabbit) compared with

small carnivores (weasel and marten) and small omnivores (raccoon and opossum).



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Figure 4.10.The foot bones of large herbivores (deer and horse) compared with a large

carnivore (mountain lion) and large omnivores (human, dog, and pig). Notice the uniquely shaped distal phalanx bones in the digits of the pig and the deer.



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Figure 4.11.Contrasts in nail shape between the front and back feet of a fox

(similar shapes), a beaver (dissimilar shapes), and a deer (similar shapes).

Retractable claws are anchored to the distal portion of a digit byflexible muscles and tendons. (See Figure 4.13.) This method ofattachment allows claws to be pivoted approximately 180 degrees ina slashing, scythelike motion. Retractable claws may indicate acarnivorous lifestyle and are clearly evident in members of the catfamily.

Claws come in a wide variety of shapes and sizes. Usually narrow,they can be sharply curved, slightly curved, or relatively flat. (SeeFigure 4.14.) Sharply curved claws, ideal for catching and holding

prey, are often associated with a carnivorous lifestyle. When movingbetween the shape ranges of curved to flat, however, lifestyle infer-



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Figure 4.12.The nonretractable claw of a domestic dog.

Figure 4.13.The retractable claw of a house cat.



Page 112ences become muddled. For example, the flat claw shown inillustration k of Figure 4.14 is the front claw of a badgera carnivore.Many omnivores, as can be seen in illustrations eh in Figure 4.14,sport sharply curved to slightly curved claws. This, as seen inillustrations i and j of Figure 4.14, can also be true of smallherbivores.

Hooves and Nails

In some mammalssuch as humansnails may be broad and flat ratherthan curved. Forms range from a shallow dish shape to a high, thicksingle hoof to a high double or split hoof. Flat dish-shaped nails aremost common among omnivores, such as humans. Hooves arecommon among large herbivores such as deer, antelope, elk, moose,

Figure 4.14.Examples of common curved claw shapes.



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Figure 4.15.Examples of the flat nail of a human, the double hoof of a cow

and the single hoof of a horse.

bison, horses, and cows. Hoofed animals are referred to as ungulates. (See Figure4.15.)

Feet and Locomotion

Mammals use three basic modes of locomotion, each related to that portion of thefeet that come in contact with the ground during the course of regular movement:unguligrade, digitigrade, and plantigrade. (See Figure 4.16.)

Figure 4.16.The three basic positions of animal feet, usually hind feet, used to define locomotion.



Page 114Unguligrade foot position places weight on the ends of thephalanges and movement uses only the distal phalanx portions,often of only two digits. Large herbivores, such as moose, elk,bison, deer, horses, and cows and omnivores, such as peccaries andpigs, rely on unguligrade locomotion. Digitigrade foot positionplaces weight on the phalanges and movement uses only the digits.Most carnivores, such as cats; omnivores, such as dogs; and smallherbivores, such as mice, squirrels, and woodchucks, often rely ondigitigrade locomotion. Plantigrade movement places weight on theentire foot, using the phalanges, metacarpals, and metatarsals.Omnivores such as humans and bears use plantigrade locomotion.

Although most mammals rely on digitigrade or unguligradelocomotion, some switch between digitigrade and plantigradelocomotion as circumstances warrant. For example, humans useplantigrade motion when walking and running but can quicklyswitch to digitigrade locomotion when sprinting.

Legs

The lower to upper-middle portions of an animal's front and backlimbs are each composed of three major bones. These bones areorganized in nearly identical patterns in both the front and the rear.

The Front Leg

Three bones compose the front legs: the radius, the ulna, and thehumerus. In quadruped mammals, these bones form the primaryweight-bearing supports for the front portion of the body. Thehumerus is the largest of the three leg bones and forms the upper

front leg. The radius and the ulna combine to form the animal'sforeleg. The radius is the larger of these two bones. (See Figures4.174.22.)

In mammals, the humerus always remains separate, while the radiusand the ulna are sometimes fused together. When the radius andulna have either fully or partially grown together, they are said to befused. This arrangement, although severely limiting an animal'sability to rotate its foreleg, creates a solid form that provides asecure foundation for primarily unguligrade movement. (See Figure4.23.)

In contrast, when the radius and ulna are completely separate andconnected by ligaments in an unfused arrangement, an animal isable to freely rotate its foreleg, greatly enhancing its flexibilityduring digitigrade and plantigrade movement. (See Figure 4.24.)



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Figure 4.17.The front leg bones of a human. Length: humerus (30 cm),

radius and ulna (25 cm).



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Figure 4.18.The front leg bones of a bear. Length: humerus (29 cm),

radius and ulna (27. 5 cm).



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Figure 4.19.The front leg bones of a lynx. Length: humerus (14.5 cm),

radius and ulna (15.1 cm).



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Figure 4.20.The front leg bones of a dog. Length: humerus (17.4 cm),

radius and ulna (21 cm).



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Figure 4.21.The front leg bones of an opossum.

Length: humerus (7 cm), radius and ulna (9 cm).



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Figure 4.22.The front leg bones of a deer. Length: humerus (17.3 cm),

radius and ulna (24.2 cm).



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Figure 4.23.The fused radius and ulna of a horse and an ox.



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Figure 4.24.The unfused radius and ulna of a human and a dog.



Page 123Large herbivores, such as deer, horses, and bison, and someomnivores, such as pigs and peccaries, have fused or semifusedforeleg bones. In most carnivores, omnivores, and smallerherbivores, the radius and ulna are usually unfused. Therefore, it canbe difficult to differentiate between the front leg bones of smallherbivores and those of small carnivores and omnivores.

The Back Leg

The relationship among bones in the back leg is nearly identical tothat in the front leg. The rear leg consists of three bones: the fibula,the tibia, and the femur. The femur is the largest of the three rear legbones and forms the thigh, or upper back leg. The tibia and thefibula combine to form the lower back leg. The tibia is the larger ofthese two bones. (See Figure 4.254.30.)

The bones of the back leg are organized much like those of the frontleg: the femur, like the humerus in the foreleg, is always separate,while the fibula and tibia, like the radius and ulna, can be eitherfused or unfused. Fused back legs are usually stronger, whileunfused limbs are more flexible. (See Figures 4.31 and 4.32.)

Weight Estimation

What can be inferred from the size of leg bones beyond the basicobservation that large animals have large leg bones and smallanimals have small leg bones? Leg bones of large animals, such as ahorse, must thicken disproportionately to provide the same relativestrength as the slender leg bones of a small creature such as aweasel.

Simply by growing larger, an animal will suffer a continueddecrease in relative surface area when its shape remains unchanged.In this situation, an animal's volume increases as the cube of length(length x length x length), while its surface increases as the squareof length (length x length). This means that as an animal grows andmaintains the same relative shape, such as a newborn coltdeveloping into an adult horse, its volume will increase morerapidly than its surface area.

This increase in volume usually translates into an increase inweight. As an animal's weight increases, so does the cross-sectionalarea of its leg bones. By measuring or calculating the diameter offemur and/or humerus leg bones at their narrowest point, amammal's weight may be estimated. (See Table 4.1.)



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Figure 4.25.The back leg bones of a human. Length: femur (46.6 cm),

fibula and tibia (34.6 cm).



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Figure 4.26.The back leg bones of a bear. Length: femur (33 cm),

tibia and fibula (25 cm).



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Figure 4.27.The back leg bones of a lynx. Length: femur (17 cm),




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Figure 4.28.The back leg bones of a dog. Length: femur (19 cm),




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Figure 4.29.The back leg bones of an opossum. Length: femur

(8.5 cm), fibula and tibia (8.9 cm).



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Figure 4.30.The back leg bones of a deer. Length: femur (23.2 cm),




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Figure 4.31.The fused fibula and tibia of a horse and an ox.



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Figure 4. 32.The unfused fibula and tibia of a human and a dog.



Page 132Measurements of bone diameter can be made with outside calipers,a measuring device with two thick legs, or jaws, that can beadjusted to determine thickness, diameter, and distances betweensurfaces. If you don't have access to such instruments, you can use acloth or vinyl tape measure to determine the circumference of thebone and then calculate its diameter.

The equation for calculating diameter from circumference is this: C+ Pi = D, where C is circumference, Pi is the constant 3.14, and Dis diameter. For example, if a bone's measured circumference is 4inches, then the bone's diameter would be: 4 + 3.14 = D, where D =1. 27 inches.

In North America, there exists more diversity among largeherbivores than omnivores and carnivores of similar bulk. Largermammals, such as elk, moose, deer, antelope, sheep, horses, andcows are predominantly herbivores, with large, less numerousomnivores, such as bears, and carnivores, such as mountain lions,coming in a distant second. This relationship is also true in smallermammals. In North America and probably the world, there existsgreater diversity among small herbivores than any other type ofmammal.

Pectoral Girdle

The pectoral girdle is anchored to the sternum (or breastbone),vertebral column, and ribs by muscles. This shoulder girdleprovides the power and foundation for the articulation, ormovement, of each front limb. The primary components of thisstructure are two clavicles and scapulas, one for each front limb.

(See Figure 4.33.)

Also called collarbones, clavicles link the sternum with thescapulas. Small or nonexistent on many running mammals such asdeer, these bones are much more developed in burrowing animalssuch as badgers and climbing animals such as raccoons andopossums. Members of the cat family have very small clavicles thatlie loose in the flesh between the scapula and sternum. Clavicles aregenerally difficult to find in the field because of scavengers,weathering, and general deterioration. For this reason, they will notbe addressed further in this chapter.

Scapulas, also known as shoulder blades, form the principalstructure of the pectoral girdle. Large, somewhat flat, oftentriangular shaped bones, scapulas are the easiest structures of theshoulder girdle to find and identify.



Page 133TABLE 4.1EstimatedWeight Basedon theAveragedDiameter ofHumerus andFibula

BoneDiameterin Inches

EstimatedWeight

inPounds

0.1 1.80.17 30.18 3.30.2 3.60.3 16

0.39 350.43 380.49 46.60.56 550.59 57.70.69 1600.79 2650.83 2800.89 3400.94 4501.08 5751.15 6971.18 7051.28 825

1.38 9451.48 10251.57 11251.67 12171.77 13251.87 14171.97 15002.07 16052.17 17002.26 18002.36 1900



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Figure 4.33.The two predominant bones, scapula and clavicle, of a pectoral girdle. The bold areas indicate these structures.

Scapula Structure

Visual references are often the best tools for describing specificstructures and relating their basic terminology. To this end, Figure4.34 uses a human shoulder blade to illustrate and label the twostructural components of a scapula, the acromion process andcoracoid process. Both are commonly used for inferentialclassification.

Scapula Shapes

Three general shapes are common among the shoulder blades ofmammals: isosceles triangle, paddle shaped, and curved edged, orblade shaped. (See Figure 4.35.) No one scapula shape may be

conclusively associated with a specific environmental lifestyle. Atbest only the fol-



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Figure 4.34.Two scapular structures used for inferential classification.

lowing broad generalizations concerning structural relationships canbe drawn.

Scapulas in large herbivores, such as cows, horses, elk, and deer, areoften shaped like a flat isosceles triangle with reduced acromion andcoracoid processes. (See Figures 4.364.39.)

In smaller herbivores, such as squirrels, woodchucks, and beavers,scapulas are often the general shape of a blunt curved blade or anisosceles triangle. In addition, these structures usually havepronounced acromion and coracoid processes. (See Figures4.404.44.)

Often carnivores and onmivores such as wolverines, bears, andwolves sport paddle- or curved-edged-shaped scapulas withpronounced acromion and coracoid processes. In some omnivores

such as pigs, however, the scapula is isosceles shaped with reducedacromion and coracoid processes. (See Figures 4.454.53.)



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Figure 4.35.Three common scapular shapes.



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Figure 4.36.Top and side views of a deer scapula.




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Figure 4.37.Top and side views of an elk scapula.




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Figure 4.38.Top and side views of a horse scapula.


Figure 4.39.Top and side views of a cow scapula.




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Figure 4.40.Top and side views of a beaver scapula.


Figure 4.41.Top and side views of a pocket gopher scapula.



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Figure 4.42.Top and side views of a gray squirrel scapula.


Figure 4.43.Top and side views of a Wyoming ground

squirrel scapula. Length (2.4 cm), width (1.1 cm).


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Figure 4.44.Top and side views of a western meadow mouse

scapula. Length (1.1 cm), width (0.3 cm).

Figure 4.45.Top and side views of a wolverine scapula.




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Figure 4.46.Top and side views of a lynx scapula.


Figure 4.47.Top and side views of a marten scapula.




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Figure 4.48.Top and side views of a dog scapula.

Length (14 cm), width (8 cm).



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Figure 4.49.Top and side views of a raccoon scapula.


Figure 4.50.Top and side views of an opossum scapula.




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Figure 4.51.Top and side views of a bear scapula.




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Figure 4.52.Top and side views of a human scapula.




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Figure 4.53.Top and side views of a pig scapula.


The Pelvic Girdle

The hipbone, or pelvic girdle, forms the foundation of a skeleton bysecurely anchoring to the sacrum, or base portion of the spine.Unlike the shoulder girdle, this structure moves only when the spineflexes, a firmness that offers support for power and movement bythe rest of the skeleton. The connection between the spine andpelvis, also discussed in chapter 5, is illustrated in Figure 4.54.

Because the pelvis forms the largest single skeletal structure, it isoften found when hunting bones. Although the pelvis has a distinctshape, people sometimes confuse it with a skull. When inverted orviewed from below, a hipbone can look like a skull without itslower jaw and cranium. (See Figure 4.55.)

A paleontology professor once told me of the time he and anotherprofessor received a call requiring their professional attention. ANew



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Figure 4.54.Two views, front and back, of a human pelvic girdle with the

attached sacrum and femurs of the rear limbs.

Mexico rancher firmly maintained that he had discovered numerousdinosaur skulls on his property and insisted that the professors cometo his farm and inspect them. He indicated his property was litteredwith them and didn't understand why folks said they were rare.Through perseveranceand the suggestion that he might donate theartifacts to the universitythe farmer persuaded the professors to visithis ranch. Upon examination, they discovered that the rancherowned an impressive collection of cow, horse, and bison hipbones.When informed of his identification error, the farmer, embarrassed,profusely apologized.

Basic Pelvic Structures

Three basic structures of the pelvic girdle are helpful in inferentialclassification. These consist of two general structures, the falsepelvis and the true pelvis, and a specific anatomical feature, theacetabulum. (See Figure 4.56.)

Also called the greater pelvis, the false pelvis is the broad,flangelike structure of the hip located just before, or above, the truepelvis. The opposing structures that constitute the false pelvis arecalled ilia. The true pelvis, or lesser pelvis, refers to the bones justbehind, or below, the false pelvis. It is composed of two opposingeye-holed structures



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Figure 4.55.Two views of a cow skull and hipbone. Notice their relative shapes

and consider how a hipbone could be misidentified as a skull or portion of a skull.



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Figure 4.56.Three basic pelvic structures used for inferential classification.



Page 152called ischia. (See Figure 4.56.) Also called the ball-and-socketjoint, the acetabulums are the two socketlike structures on the hipthat fit the ball of the femur, or thighbone. (See Figure 4.54.)

Posture

North American land mammals exhibit two basic hip shapes. (SeeFigure 4.57.) By analyzing the shapes of hipbones you find in thefield, you can infer the normal posture of a mammal, either erect orhorizontal, which in turn offers a clue as to the animal's usual modeof locomotion. An erect posture implies bipedal, or two-footed,means of locomotion, and a horizontal posture suggestsquadrupedal, or fourfooted, movement.

An animal's posture can be inferred from the relative position of

Figure 4.57.Posture as related to pelvic structure from a horizontal

quadruped (horse) and an erect biped (human).



Page 153the acetabulum, or ball-and-socket joint, on the hip as well as by theconstruction of the hipbone itself. Although all mammal hips sharesimilar construction, the human hip differs somewhat from thisnorm, as seen in Figure 4.57. (Also see Figures 4.584.60.)

Without a great deal of study and experience in the fields ofosteology and mammalogy, it is difficult to infer anything other thanposture from a hipbone, and even that can be tricky for theinexperienced collector. For our purposes it will suffice to keep inmind just one generalization: In North America, the only nativebipedal animals are humans. This means that all remainingherbivores, carnivores, and omnivores have pelvises constructed forquadrupedal posture.

Summary

The conclusive assignment of an animal to a specific environmentallifestyle based solely on its limb structures is impossible without ahigh level of knowledge and expertise. Until they have reached thatpoint, beginners would be wise to limit themselves to makinginferences based only on the following five generalizations. Whenassociated with the rest of the skeleton, limb structures can give thecollector a fuller view of an animal's environmental lifestyle.

Narrow, curved claws are common among omnivores, carnivores,and small herbivores; hooves are common among large herbivores.

Digitigrade locomotion is common among herbivores, carnivores,and omnivores; plantigrade locomotion is usually limited toomnivores and some carnivores; and unguligrade locomotion is

predominant among large herbivores.

Fused or semifused radius-ulna and fibula-tibia combinations arecommon among large herbivores and some omnivores, whereasunfused or separated radius-ulna and fibula-tibia bone structures arecommon among carnivores, omnivores, and small herbivores.

Scapula shape varies considerably across environmental lifestyles.An isosceles-shaped scapula is prevalent among large herbivoresand unusual among small herbivores. Curved-edged and paddle-shaped scapulas are common among carnivores, omnivores, andsmall herbivores.

The hipbones of most North American land mammals reflect theirquadrupedal, or four-legged, posture. Human hips differ in structureand indicate bipedal, or two-legged, posture.



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Figure 4.58.Hip structures of a Wyoming ground squirrel (2.5 cm), a rabbit (4.7 cm),

a marten (5.6 cm), a raccoon (8.1 cm), a coyote (9.7 cm), and a wolverine (12.3 cm). The measurements

refer to pelvis length.



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Figure 4.59.Hip structures of a wolf (18.4 cm), a mountain lion (21 cm), and

a deer (25 cm). The measurements refer to pelvis length.



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Figure 4.60.Hip structures of a bear (30 cm), a horse (35.8 cm), and a human (17 cm).

The measurements refer to pelvis length.



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Chapter 5The Vertebral Column and Ribs

An animal's vertebral column and ribs make up its skeleton'ssupporting framework. These structures alone usually will notprovide the nonexpert with enough information to identify theanimal's environmental lifestyle. However, through their size andshape these bones can give clues to an animal's posture and relativeflexibility during movement.(See Figure 5.1.)

The Vertebral Column

The vertebral column, or spine, shields the primary nerve conduit tothe brain, called the spinal cord, and supports the body. Amammal's spinal column contains individual bones calledvertebraeseventeen to sixty or more, depending on the species. Thevertebrae are kept from rubbing against each other by bony caps andcartilaginous disks.

Basic Structures of a Vertebra

Vertebrae vary somewhat in shape according to their location in thespinal column, but all vertebrae share six basic structures. (SeeFigure 5.2.)

Each vertebra has an opening in its center called the vertebralforamen, through which the spinal cord passes. The primary mass ofbone


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Figure 5.1.This portion of a dog skeleton demarcates the vertebral column/rib function group.

that makes up the vertebra is located below the vertebral foramen and is called thebody.The structure that projects vertically from the dorsal, or back, portion of avertebra is known as the spinous process.Its size and shape vary, depending on thespinal region occupied by a vertebra. Transverse processes are the structures thatproject laterally from either side of a vertebra. Like the spinous process, their sizeand shape vary, according to the vertebra's location in the spinal column. Articularprocesses are located at opposite ends of a vertebra. The inferior articularprocess, facing up on one end, and the superior articular process, facing down onthe other, overlap with their opposite counterparts, up to down and down to up, onfollowing and preceding vertebra. This overlap, illustrated in Figure 5.3, providesconnecting surfaces and allows movement between vertebrae.

Vertebral Division Structures

Within the vertebral column, individual vertebrae are separated by two structures:the intervertebral disk and the vertebral cap, which aid the smooth functioning andflexibility of the spine.

Intervertebral disks are relatively thick, cartilaginous structures that function aspadding and shock absorbers between vertebrae. When an animal dies and itsskeleton decays, the disks dry out. These are often found among the remains oflarge mammals such as deer, elk, and



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Figure 5.2.The six basic structures of a vertebra.



Page 160

Figure 5.3.The overlapping and movable connections of inferior and

superior articular processes.

Figure 5.4.Dried intervertebral disks.



Page 161cougars but can be difficult to locate among the remains of smallermammals. (See Figure 5.4.)

Vertebral caps are affixed to the ends of the vertebrae and provide asmooth surface between the vertebrae and intervertebral disks. As askeleton decays, these soft bony caps dry out and often fall off. Likeintervertebral disks, caps are easily found among the remains oflarge mammals but can be difficult to locate among the remains ofsmaller mammals. (See Figure 5.5.)

Spinal Regions

The vertebral columns of mammals are typically divided intocervical, thoracic, lumbar, sacral, and caudal regions. (See Figure5.6.)

Mammal spines typically contain seven cervical vertebrae, whichextend from the base of a skull to the first rib. Some mammals, suchas sloths and anteaters, however, have six or nine cervical vertebrae.(See Figure 5.7.)

Figure 5.5.Dried vertebral caps.



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Figure 5.6.Approximate positions of cervical, thoracic, lumbar, sacral, and

caudal regions within the vertebral column of a human and a dog.



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Figure 5.7.Cervical vertebrae from a human and a cow.

Not all cervical vertebrae are similar in shape. The first cervical vertebra that followsthe skull is called the atlas, and the second, the axis.These vertebrae have uniqueshapes, quite different from the rest of the cervical vertebrae. (See Figure 5.8.)

Figure 5.8.The first two cervical vertebrae: cow atlas and axis. Compare their unique shapes with

the cervical vertebrae illustrated in Figure 5.7.



Page 164Immediately following the cervical vertebrae, the thoracic vertebraecompose the structures that bear the ribs. Depending on themammal, there can be from nine to twenty-five of these vertebrae.Their often large spinous processes indicate the attachment of well-developed shoulder muscles, such as the trapezius. (See Figure 5.9.)

Lumbar vertebrae immediately follow the thoracic vertebrae in thespinal column; most North American land mammals have betweenfour and seven. This range should not be considered a globalconstant, however, since other mammals such as whales have asmany as twenty-five and some anteaters have as few as two. Therelatively large transverse processes of these vertebrae indicateattachment and support of well-developed back muscles such as thelatissimus dorsi. (See Figure 5.10.)

Following the lumbar vertebrae, sacral vertebrae normally fuse intoa composite structure called the sacrum.As shown in Figures 4.54and

Figure 5.9.A thoracic vertebra from a dog.

Notice the distinct dorsal fin shape given by the large

spinous process.



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Figure 5.10.A lumbar vertebra of a cow. Notice the unique wing shape

caused by a large transverse process.

4.57 of chapter 4, this solid arrangement of vertebrae attaches firmlyto the pelvic girdle along a portion of the ilium. (See Figure 5.11.)

Caudal vertebrae make up the tail of a mammal; how many ananimal has depends on the length of its tail. For example, amountain lion has a long tail and therefore many caudal vertebrae,but a bobcat's tail is very short and thus has only a few. Humans,who have vestigial tails, have no developed caudal vertebrae. (SeeFigure 5.12.)

Spinal Curvature

Because the spine is held together by cartilage, which decays ratherquickly, it is unusual to find an intact vertebral column amonganimal remains. Even if it is still intact, it is likely to be twisted intoan unnatural position. It's more common to find the vertebraeseparated and scattered about. In either case, it's difficult for anonexpert to accurately determine a spine's original shape.Fortunately, we can learn much about spinal shape by observing

living mammals.

When any animal moves quickly, its spine contracts, flexing towardthe back as the animal moves its hind feet forward and curvingtoward the abdomen when it stretches out, moving its hind feetbackward. Often, the greater the upward curvature in the spine whenan animal is standing still, the greater the flexibility in the spinewhen it moves. The spines of living North American land mammalsmay be categorized into three basic shapes: humped-back, flat, anddouble-curved.



Page 166

Figure 5.11.Two views of sacra of a horse and a dog. Parallel holes within these

structures mark vestigial remains of spaces between individual vertebrae lost when the sacral vertebrae fused.



Page 167

Figure 5.12.Caudal vertebrae of a cow. Notice the unique shape

of these structures when compared with other vertebrae.

Figure 5.13.Three shapes of spinal curves and their postural orientation.

Humped-back Spines

A spinal column whose lumbar and thoracic regions exhibit anupwardly curved shape is said to be humped-back. This formationof the vertebrae allows for the spine to act like a spring, resulting ingreater running or climbing speed. (See Figures 5.14 and 5.15.)

This shape is prevalent among carnivores, omnivores, and

herbivores. Antelopes and rabbits look humped-backed whenstanding still, but when they run, their fully stretched spines make aconcave



Page 168

Figure 5.14.The flexibility of a rabbit's humped-back spine while running.

Movement ranges through the spinal positions: stationary, contracted flexing up, and reverse-flexed.

arch. This flexibility affords greater power and distance in stride.Cat spines also have whiplike flexibility, allowing the felines to runand climb quickly and jump great distances both vertically andhorizontally. The hump in a weasel's spine is what allows itscharacteristic ''slinking" movement.



Page 169

Figure 5.15.The flexibility of a cat's humped-back spine while running.


Raccoons always look as if they are walking on their toes, not onlybecause they are, but also because of their upwardly arched spine.This feature greatly enhances their climbing ability. And, of course,who has not seen the back-arching profile of a greyhound? Built forspeed, these dogs are raced at tracks across the United States.

In every situation, a humped-back spine increases an animal'spotential for fast takeoffs, quick bursts of speed, and, for thoseadapted to it, enhanced climbing and jumping ability. This isadvantageous for hunter and prey alike.


Page 170Flat Spines

In flat-spined animals, the lumbar and thoracic regions of the spinalcolumns may be flat or very slightly humped. This constructionoften reduces a spine's flexibility and so limits an animal's speedand mobility when running. (See Figure 5.16.)

The spines of large herbivores such as horses, cows, bison, andmoose are flat when standing, although a horse's spine will oftenexhibit a slight upward arch. These animals' spines flex betweenslightly humped and slightly concave when they run, limiting theirstride power and distance.

A flat-spine construction does not mean an animal cannot movequickly, however. Anyone who has seen a stampede knows thatcows and bison can run fast, and the horse's potential for speed isevidenced every year at the Kentucky Derby. Like juggernautsslowly building up straight-line motion until traveling at a relativelygood clip, a flat spine offers long-term speed, usually at the expenseof quick takeoffs and agility.

Double-curved Spines

A spinal column whose thoracic region bows out while the lumbarregion bows inward is called double-curved. As with a flat spinethis construction limits an animal's running speed by reducing itsspringlike flexibility. (See Figure 5.17.)

In quadrupeds, a double-curved spine is debilitating, either the resultof a birth defect or due to the wear and tear of old age. This shapecan also be the result of affliction, as in swaybacked horses, whose

spines have become deformed by carrying too much weight forextended periods of time.

For bipeds, however, this spinal construction affords a balanced, in-line structure for upright posture and is indicative of only one NorthAmerican land mammal, the human. Although this spine shapelimits potential speed to some degree, it does compensate its uprightbearer with an increased potential for mobility and agility.

Vertebral Inferences

As mentioned earlier, it can be difficult for the inexperiencedcollector to infer environmental lifestyles from vertebrae alone. Sojust what can be learned from them?

When cervical vertebrae are the same size as or larger than lumbarand sacral vertebrae from the same skeletal remains, such as in



Page 171

Figure 5.16.The flexibility of a horse's flat spine while running.




Page 172

Figure 5.17.The flexibility of a human's double-curved spine while moving.


cows and deer, the neck is usually relatively long. This arrangementrequires long, strong muscles to hold both the skull and the neckupright, implying quadrupedal, or four-footed, posture.* (See Figure5.18.)

When the cervical vertebrae are the same size as or smaller thanlumbar and sacral vertebrae, the neck is often relatively short. Ashort

*This generalization works only with large mammals. Insmaller mammals, there often appears less difference in therelative sizes among vertebrae.


Page 173

Figure 5.18.Long necks of a horse and a cow as indicated by

cervical ertebrae that are larger than vertebrae from other spinal regions of the same animal.



Page 174neck, as in humans, requires smallerthough still strongmuscles tohold both skull and neck upright, implying bipedal posture.

Thoracic vertebrae often have spinous processes much larger andsharper than the spinous processes on vertebrae from other spinalregions. These vertical structures offer ideal support and attachmentpoints for large shoulder muscles such as the trapezius andrhomboideus, which anchor along this spinal region and provide theprimary strength for movement of the front limbs. Large spinousprocesses imply large shoulder muscles such as the trapezius andrhomboideus, which anchor along this spinal region and provide theprimary strength for movement of the front limbs.

Unlike other vertebrae that make up the spinal column, lumbarvertebrae sport large transverse processes. These lateral, orhorizontal, surfaces offer ideal support for long, large back musclessuch as the latissimus dorsi, which run along the back and providethe main strength and support for movement within this area. Aswith the spinous processes of the thoracic vertebrae, large transverseprocesses suggest large back muscles and are commondevelopments among all mammals, especially large herbivores.

The Ribs

Ribs attach to the thoracic vertebrae and sternum, or breastbone,forming a cagelike structure called the thorax, or rib cage. Thenumber of ribs varies with the species. For example, the rib cages ofhumans and domestic dogs contain approximately twenty-four ribs,whereas a horse has approximately thirty-six. The space betweenribs is called the intercostal space, and the cartilage that connects

ribs to the sternum is called costa cartilage.

The rib cage protects the heart and lungs and provides asemivacuum chamber necessary for the proper functioning of thelungs. Flexible rib connections at spine and sternum allow the ribcage to expand and contract during breathing.

It is difficult to infer environmental lifestyle from rib structurealone. What inference may be made by beginning collectors reliessolely upon rib size and relative degrees of rib curvature. This doesnot mean rib structure and shape can be ignored. Rather, collectors,so as not to confuse ribs with other bones, will find such knowledge



Page 175essential. The following story illustrates the importance of thisinformation and how a person, through lack or disuse of thisknowledge, can make mistakes with ribs.

I once collected cow bones with a man who had a degree in naturalresource conservation, a field of study that incorporates mammalcomparative structural anatomy. As we rooted through autumnleaves, gathering and placing bones in small piles, he mistakenlyidentified one of the first vertebrosternal ribs, discussed below, as aleg bone. When I corrected him he was greatly embarrassed andconfided that he had not used his education for over fifteen years.Since then this person has reeducated himself in comparativeanatomy and now uses this information as a regular hobby.

Basic Rib Structures

Ribs, regardless of their position within a rib cage, exhibit fourbasic features: head, tubercle, neck, and body, or shaft. (See Figure5.19.)

The lower portion at the spinal end of a rib that attaches betweentwo vertebrae is called the head. This is the primary attachmentpoint of a rib to the spinal column. The rib structure adjacent to therib head that attaches to a vertebra is known as a tubercle. This isthe secondary attachment point of a rib to the spinal column. Theportion of a rib located between the head and tubercle is called theneck. Also called the shaft, the body curves away from the head andtubercle to form the major structure of a rib. The end of the body,opposite the head and tubercle end, attaches via a cartilageextension, costa cartilage, to the sternum. Not all ribs attach at both

ends. For example the floating ribs, discussed later, connect only tothe vertebrae. (See Figure 5.20.)

Rib Arrangement

In mammals, the rib cage can be divided into two basic groupings:true ribs and false ribs.

Also called vertebrosternal ribs, true ribs extend and attach alongthe thoracic region of the spine, anchoring to the sternum and endingat its base. False ribs include the vertebrochondral ribs and thevertebral, or floating, ribs. Starting from a location below androughly parallel to the base of the sternum, vertebrochondral ribs,which are similar in appearance to the true ribs, extend from andanchor along the remain-



Page 176

Figure 5.19.The four structural components of a rib important in

inferential classification.



Page 177ing portion of the spine's thoracic region and attach via cartilage tothe bottom of the sternum. Immediately following thevertebrochondral ribs, the vertebral ribs attach only to the finalthoracic vertebra. (See Figure 5.20.)

Lifestyle Inferences

As stated at the beginning of this chapter, using ribs to inferenvironmental lifestyles can be difficult without extensive study inthis field. Nevertheless, beginning collectors may use two generalrules of thumbrelated to rib size and rib curvatureto garner usefulinformation.

Rib Size

Larger rib bones mean larger animals and smaller rib bones meansmaller animals. In North America most large mammals such asdeer,

Figure 5.20.

The basic arrangement of ribs within a rib cage.



Page 178cows, bison, elk, horses, and moose are herbivores. (However, large carnivores andomnivores, such as bears and humans, also exist.) Statistically there are more largeherbivores than large carnivores and omnivores, so collectors often associate largeribs found alone in the wild with herbivores.

When ribs are found alone, a collector without proper anatomical awareness of ribshape and construction can confuse rib classes across species. For example, afloating rib from a large mammal may be confused with a vertebrochondral rib of amedium-sized mammal. For this reason, a collector may find the ability to discernbetween various rib types an important skill. This is best performed by recognizingthe patterns associated with the head, neck, and tubercles of the three basic ribtypes. (See Figure 5.21.)

Figure 5.21.Example transformation in relative shapes in rib head, neck, and tubercle structures when progressing from vertebrosternal to vertebrochondral to vertebral, or floating, ribs in a cow. (The progression starts at the upper left of the illustration and ends at

the lower right.)



Page 179Rib Curvature

Generally, rib curvature increases with body mass, producingrelative variation in rib cage shape. Often, the larger the mammal,the greater the apparent barrel shape of its chest. Please note,however, that without the presence of the costa cartilage thatconnects ribs with the sternum, actual chest shape is difficult todetermine. With this in mind, the following broad associations ofchest shape with body mass, including exceptions, can be made, butkeep in mind that without a great deal of experience, collectors willfind rib curvature to be an inadequate tool for inferentialclassification.

Large mammals, such as horses, bears, and cows, often sport roundto downward-pointing ovular chests.

Intermediate-sized mammals, such as deer, appear to have narrower,slightly pointed chests. Pigs have seemingly barrel-shaped chests,however, and humans have elliptical, flattened chests.

Smaller mammals, such as mice, chipmunks, weasels, andopossums, have round chests flattened slightly along the breast.

Rib shape can also be used to infer a mammal's posture. Allmammals in North America, except for humans, are quadrupedal.The curved or slightly curved ribs of most mammals that imply, aswith horses and deer, rounded and pointed chest shapes also suggesta quadrupedal posture. The sharply curved ribs associated with ahuman skeleton imply a flat chest and bipedal posture.


Page 180

Chapter 6The Significance of Skeletal Structures

From the skeletal structure of an animal you can learn much aboutits probable behavior and habitat. Each structure in a skeletal systemserves a unique purpose and influences the shape, size, andpositioning of every other. For example, the size and shape of thenasal cavity will affect the dimensions of the maxilla, or upper jaw.These combined structures in turn determine the relative size of thelower jaw and the positioning of the eye sockets. By evaluatingthese interrelated structures as a whole, it's possible to inferenvironmental lifestyles.

Carnivores are almost always considered hunters that stalk, attack,and kill their prey. As such, this lifestyle embodies an aggressiveattitude that is reflected in their skeletal features. However, manycarnivores are also scavengers, and while they may be morecautious than their strictly hunting brethren, they too are consideredaggressive.

Since plants don't usually threaten bodily harm and require littlestalking prowess on the part of their consumer, herbivores areconsidered primarily passive and defense oriented. Reflecting thisbehavior, the skeletal features associated with this lifestyle exhibitadaptations optimized for running, motion sensing, and consumingplants.

Omnivores consume animal flesh and plant material. Their behavior,as reflected through this diet and skeletal structures, ranges


Page 181between the aggressive, attack-oriented behavior of a carnivorouslifestyle and the passive, defense-oriented behavior of a herbivorouslifestyle.

You should keep in mind, however, that although an animal'sskeletal construction may indicate certain behavioral tendencies,most creatures can adapt their behavior to some degree if theirsurvival requires it. For example, rats are rodents and thereforeherbivores, but they have been known to attack other creatureswithout provocation when plant food was scarce.

With this in mind, let's begin our discussion of how skeletalstructure relates to behavior and habitat. Please note, however, thatthe interpretations presented in this chapter reflect the author'sknowledge, perspective, and opinions. They should not beconsidered absolute guidelines, as behavior and habitat vary greatlyamong individuals. Readers are urged to incorporate personalknowledge and perspective with the material presented in this bookto develop their own interpretations.

Carnivores

In many ecosystems, animal flesh provides the single mostconcentrated source of food. Since it consists largely of proteins andwater, this nourishment is heavy and slow to digest. For this reason,and because they tend to gorge themselves, carnivores are oftensluggish after eating.

Though proficient at both, carnivores generally prove more adept atoffense than defense. Since prey animals often run or put up a fight,

carnivores can expend enormous amounts of energy in pursuit andcapture. Since a carnivore can also be prey for other animals,however, it must be able to run or in some other way protect itselffrom being eaten. The form of skeletal structures such as orbits,dentition, the zygomatic arch, and limbs are designed to function inboth the attack and defense modes common to hunting andscavenging lifestyles. The following profiles discuss these structuresin three carnivores: the domestic cat, the badger, and the bat.

Profile of a Domestic Cat

In the area of south-central New York where I grew up, a large catpopulation was partly responsible for the demise of songbirds,squirrels, rabbits, and other small mammals. Domestic cats releasedin the



Page 182wild must revert to their hunting heritage to survive. I've seen feralcats, their lithe supple bodies slinking through the grass and brush,effortlessly leaping between tree branches in play and pursuit ofprey.

As efficient predators, domestic cats, like their wild cousins, arebuilt for hunting, catching, and devouring prey. Enamored as we areof their playful stalking, furniture-leaping, and string-swatting,many of us fail to recognize the aggressive hunting behaviorreflected by these actions. (See Figure 6.1.)

A cat's orbits face somewhat forward. (See Figure 3.1 in chapter 3.)This position, while providing the animal with binocular vision anddepth perception, allows excellent peripheral vision, essential forhunting, targeting, and ambushing prey.

Cat dentition, as shown in Figure 2.4 in chapter 2, includes narrowincisors, long canines, prominent bicuspids, and sharply serratedcarnassials, or molars. This construction allows the cat to eat bygripping prey with the front teeth and, with a tug of the head, tearoff chunks of flesh. Chewing and cutting are performed by thecarnassials.

The short, blunt shape of a cat's nasal cavity is mirrored by a short,slightly curved mandible. Prominent zygomatic arches house large,well-developed temporalis muscles that attach along an often-projecting sagittal crest. Together, these structures indicate that a catkills by gripping prey and crushing it with its jaws.

Cats have sharply curved, retractable claws, meant for aggressive

gripping and slashing during both attack and defense. The ability tohook and dig into an object also implies the claws' possibleemployment for climbing. Also implying ground-based or arborealhabitat is the cat's five-toed foot, an indicator of digitigradelocomotion. (See Figures 4.14 and 4.15 in chapter 4.)

In cats, the bones of the lower front legsthe radius and ulnaand thelower back legsthe fibula and tibiaare unfused, also indicatingground-based or arboreal habitat. Allowing relative freedom of limbflexibility, this bone association permits agility when running,walking, or climbing over uneven terrain.

Profile of a Badger

During one of my frequent backcountry sojourns, I encountered amountain park ranger in the course of his rounds. As we passed thetime of day, the conversation turned toward natural events we had



Page 183

Figure 6.1.A cat skeleton.

witnessed. After a slight pause, he related the tale of a confrontationbetween a badger and a bear.

He had first spotted the grizzly sauntering along the wooded edge ofan open field fifty yards upwind from where he stood. Remainingmotionless, the ranger watched through field glasses as the bearstopped to investigate a creature that was burrowing frantically inthe loamy soil. After giving the other animal an imperious nudgewith its foot, the bear quickly retreated from the snarling fury thatcharged from the shallow hole. Even at that distance the rangerrecognized the badger's telltale face stripes.

Once the bear had withdrawn a sufficient distance, the badgerreturned to its digging. Again the bear advanced; this time it nudgedthe badger with its muzzle. The badger turned in a frenzy andclamped its teeth into the bear's nose. Startled, the bear reared into

the air and stood for a moment on its hind legs, the badger danglingfrom its face. Then with a roar it shredded the little creature andretreated, nose streaming blood, but otherwise intact.



Page 184Stripe-faced and burrowing, wild badgers are known for theirsingle-minded pursuit of prey and bad temper when interrupted.Because of their combative and belligerent nature, few creaturesbother them. When kept as pets, badgers, though relatively docile,tend to be aggressively intolerant of abuse. Interpretation of badgerskeletal structures indicates that they exhibit strong aggressivebehavior toward their prey and vigorous attack-oriented defensivebehavior when confronted by predators. Leg, foot, and clawstructures imply a ground-based habitat, with burrowing abilityimportant to survival Development in orbits, teeth, and jaws suggestthat they are carnivores. (See Figure 6.2.)

As is common to many carnivores, badger orbits face somewhatforward, so the animal has limited binocular vision but excellentperipheral vision. This visual acuity is essential for active hunting.

Badger dentition consists of narrow incisors, long canines, sharpbicuspids, and serrated molars. This structure suggests that theanimal grips and tears with its front teeth while chewing and cuttingwith its side teeth.

Figure 6.2.

A badger skeleton.



Page 185The relatively long nasal cavity of a badger's skull reflects the shapeof its upper and lower jaws. Longer jaws mean that less power istransmitted to their forward positions, so they have a weaker grip.This is why small carnivores with long muzzles cannot effectivelykill large prey by gripping it with their jaws; instead they nip andslash. Smaller prey do quickly succumb to this crushing power,however.

The long, slightly curved, spadelike claws on a badger's front feet,as shown in Figure 4.14 of chapter 4, are designed for diggingrather than slashing or gripping, implying a ground-based habitat.The badger's five-toed foot structure indicates digitigradelocomotion, and its leg bones are unfused, allowing it agility whenrunning and walking over uneven terrain. Both of these features addto the case for a ground-based habitat.

Profile of a Bat

When I was a child, bats were a mystery. During the day squeaksand chitters emanated from underneath age-bulged shingles thatcovered the sides of the old farmhouse in which I grew up. I hadnever seen a bat except in flight, and that was only an erraticsilhouette at dusk. Curiosity engaged my seven-year-old mind and Ibecame determined to observe one at close range.

I had heard stories of people night-fishing for bats, a pastime thatreveals much about the human psyche. The procedure was simple:You tied a small bit of cloth to a fishing line and cast it into a bat'sflight path. Bats that took the lure were played like fish and finallygrounded with a sharp tug. After attempting this without success, I

hit upon another method.

Common wisdom of the day considered bats to be carriers of rabies.So, hands protected by heavy gloves, I used a garden hose to washan unlucky individual from its resting place beneath a shingle. Icaught the waterlogged bat as it fell to the ground, being careful notto tear its delicate wing membranes. Its open mouth emitted a silentstream of high-pitched squeals, and flashed an array of sharp whiteteeth. With black beady eyes staring straight ahead, the strugglingbat frantically twisted its leathery wings. It never once attempted tobite, only to escape.



Page 186Slowly I began to understand that I was terrifying and torturing thecreature, so I released it. The bat flew back to the house, swayed amoment, and then, using its wings and back legs, climbed into theshelter of an overhanging shingle.

Some people call them flying rats or mice with wings. Emerging atdusk from their resting places, they careen through night skiesseeking insect prey.* This nocturnal hunt requires keen perceptionand an erratic flying pattern to match that of their prey.

By examining a bat's skeletal structures, we can infer that batsexhibit aggressive behavior toward their prey but are relativelypassive with other creatures. The structures of their legs and feetindicate an aerial lifestyle with a primarily arboreal habitat whenresting. The form of their dentition, jaws, and claws implies thatthey are insectivorous. (See Figure 6.3.)

Although bats depend primarily on their sense of hearing to locateobjects and maneuver through space, they do have functional eyes.As with many carnivores, a bat's skull orbits, as seen in Figures 3.13and 3.14 of chapter 3, are rotated facing forward. This orientation,when the eyes are actively used, provides binocular vision and depthperception.

As is common among insectivores, bats sport undifferentiateddentition in the form of pointed incisors, long canines, and sharpsymmetrical molars. This structure suggests that bats grip and tearwith their teeth but don't really chew their food.

There are many families of bats, each exhibiting unique body sizes

and skull shapes. Among these groups nasal cavities may be longwith long mandibles or short with short mandibles. However,regardless of relative jaw size, all bats kill their prey by grippingand crushing it with their jaws.

Bats usually have one curved claw on each front limb that extendsfrom a thumblike digit on the wing. Like the claws present on theback feet, they are used for climbing and gripping. These structuresimply an arboreal habitat, while their rather limited use argues forpassive, defense-oriented behavior when the animal is threatened.

Bats have distinctive foot structures. The presence and orientation

*Not all bats are insectivorous. For example, large fruitbatscalled ''flying foxes"that live in the South Pacific andIndonesia are herbivores.



Page 187

Figure 6.3.A bat skeleton.

of elongated digits on their front limbs strongly suggest that theyhave wingsand of course, we know that they do. Naturally, thepresence of wings suggests an aerial lifestyle and an arborealhabitat.

As with most small mammals, the bones of the lower front legs andback legs of bats are unfused, a feature that enhances their agilityand flying ability.


Page 188

Herbivores

All herbivores have flat, well-developed molars, although manyappear to be missing canines and bicuspids. Herbivores are dividedinto three categories based on their dentition, particularly incisordevelopment: perissodactyl, ruminant, and rodent. In mostecosystems, plant food is easy to come by and consists largely ofcellulose and water. Because these products have little or no foodvalue, herbivores eat more and do so more often than other animals.Since plants do not run or put up a fight, herbivores tend to be moreadept in defense than in offense.

This tendency is reflected in skeletal structures that help herbivoresprotect themselves from predators. The implications of specific boneformations are discussed below for representatives of each herbivorecategory.

Profile of a Horse

Ridden for pleasure, sport, and work, domesticated horses havetoiled for thousands of years as beasts of burden. As grazing animalsthey are usually passive, but they can become quite aggressive whenthreatened, kicking and biting in defense. Their leg, foot, and hoofstructures indicate a relatively level ground-based habitat, and theform of their orbits, teeth, and jaws strongly suggests a herbivorouslifestyle. (See Figure 6.4.)

As illustrated in Figure 2.8 in chapter 2, the wide, well-developedincisors in a horse's upper and lower jaws prove ideal for croppingplants evenly. There is a full complement of large, flat molars,

which serve as excellent structures for grinding plant material. Thepresence of these dental structures and the absence of teeth capableof slashing and tearing (i.e., canines, bicuspids, and carnassials)indicates passive, defense-oriented behavior.

A horse's orbits, as seen in Figure 3.30 in chapter 3, are angledslightly forward while facing out from the skull. This orientationproduces a narrow band of binocular vision directly ahead of theanimal and allows excellent peripheral vision. This structure impliesan open habitat, such as sparsely wooded areas, open fields, andplains, where spotting movement and possible threats approachingfrom the sides and rear is essential to survival.

Horses have a long, narrow-to-wide nasal cavity and mandible.Their small zygomatic breadth suggests passage of relatively small



Page 189

Figure 6.4.A horse skeleton.

temporalis muscles and the presence of strong masseter muscles.This combination allows the horse to maximize pressure at the backof the jaws, where the molars reside, and effectively crush and grindstrong plant fibers.

As shown in Figure 4.15 in chapter 4, horses have single hooves.The presence of hooves eliminates the possibility of an arborealhabitat. Their broad hooves tend to limit the animal's geographicrange to hills and flat, dry areas, but since wide hooves distributeweight over a large area, horses may, in a somewhat limited fashion,negotiate marshy ground. A horse's single-toed foot structure, asshown in Figure 4.8 in chapter 4, implies digitigrade locomotionand a primarily passive running defense.

In horses, as in many other large herbivores, the bones in the



Page 190lower front and back legs are fused. This limits limb flexibility andfurther indicates a relatively flat ground-based habitat with runningand walking the primary means of locomotion.

Profile of Cattle and Sheep

Although their wild counterparts still roam in limited areas aroundthe globe, most cattle and sheep are domesticated as food animalsor, as in the case of oxen, yoked for work. Usually living in openfields and hills, these animals, particularly sheep, are passive. Theywould rather run from attack than fight. Their leg, foot, and hoofstructures provide conclusive proof that they inhabit relatively firmground. Their herbivorous lifestyle is reflected in the structure oftheir orbits, teeth, and jaws. (See Figures 6.5 and 6.6.)

As illustrated in Figure 2.7 of chapter 2, ruminants such as cattleand sheep have wide, well-developed incisors in the lower jaw only.The absence of incisors in the upper jaw requires plant material tobe torn or ripped during grazing and browsing. This process,accomplished with an upward flick of the head, uses the incisors inthe

Figure 6.5.A cow skeleton.



Page 191lower jaw as a stationary cutting edge. Absence of incisors in themaxilla as well as dentition capable of slashing and tearing (i.e.,canines, bicuspids, and carnassials) implies passive, defense-oriented behavior.

Orbital positions among ruminants range between the extremes offacing laterally from the skull, as with cowsproducing strictmonocular visionto facing slightly forward, as with sheepproducinglimited binocular vision. These positions allow excellent peripheralvision but little if any depth perception. This structure implies anopen environment where spotting movement and possible threatsapproaching from the rear is essential to survival. For example,sheep often live in both open plains and wooded or rocky areas;their eye sockets are rotated slightly forward. Buffalo and long-horned cattle, whose eye sockets face outward from the sides of theskull, live in open plains areas.

Cows have long, wide nasal cavities and mandibles, while sheephave long, narrow nasal cavities and mandibles. Their smallzygomatic breadth, a distinctive feature of both animals, suggestsrelatively

Figure 6.6.A sheep skeleton.



Page 192small temporalis muscles and strong masseter muscles. As discussedabove, this combination allows the animal to exert great pressure atthe back of the jaw and crush and grind cellulose with the molars.

The flat and/or horned cranium common to large herbivores such ascows indicates that the animal uses its head (literally) for defense.For example, musk oxen form a defensive circle, heads and hornslowered, facing outward to ward off attackers. Goats will buttattackers with their heads and hook them with their horns. Anyrodeo rider or bullfighter is familiar with the goring techniques ofbulls. Deer and elk will lower their heads when cornered,brandishing their antlers in the face of their attackers.

Cattle and sheep sport split hooves. (See Figure 4.15 in chapter 4.)The presence of hooves indicates a ground-based habitat andpassive, defense-oriented behavior.

Small split hooves, such as those on sheep and deer, indicate firm,dry habitats ranging from plains to mountains. Small-hoofedmammals would find boggy areas uninviting and potentiallyperilous because narrow hooves focus an animal's weight onto alimited surface area. This severely curtails their traction on soft wetground and can cause them to quickly sink into bogs and quagmires.

Larger hooves, such as those on cows, tend to limit an animal'sgeographic range to flat or hilly areas. While many large-hoofedmammals may find themselves endangered on boggy ground, largehooves offer an advantage of weight distribution over a greatersurface area, allowing them to sink less. For example, the round,splayed hoof of a moose allows it to traverse and navigate wetlands

and waterways that would be inaccessible to small-hoofed mammalssuch as deer.

The two-toed foot structure shared by cows and sheep indicatesunguligrade locomotion, further indication of a ground-basedhabitat. (See Figure 4.8 in chapter 4.) Cows and sheep also havefused lower leg bones, a structure common among large, ground-based herbivores.

Profile of a Rabbit

The world is so rich that more events occur in a day than I will everexperience in my entire life. Therefore, I listen when people relatetheir experiences and observations. I once struck up a conversationwith a retired dairy farmer who raised rabbits as a hobby. While weshared rabbit stories he told me of a fight he'd seen between a catand a wild rabbit.



Page 193It was spring, and the rabbit was lounging near its warren, nibblingfresh shoots of grass and plantain. Hunched, tail twitching, a barncat watched intently from behind a nearby fence post. Expecting aneasy meal, it slowly stalked forward while circling to the rabbit'srear. When close enough, it darted forward. The rabbit, sensing themotion, jumped to the side, narrowly avoiding the cat's lunge, andescaped by diving into its warren.

The cat broke its charge at the bolt-hole, but after smelling newbornrabbits insidea much easier mealit made as if to enter. The rabbitquickly emerged from her den and confronted the crouched cat.Leaping into the air, she brought both hind feet crashing down uponthe cat's head and killed it. A rabbit's legs, while used primarily forhopping and running, can muster a great deal of force. Uponexamination by the farmer, the cat was found to have a fracturedskull.

Figure 6.7.A rabbit skeleton.



Page 194This behavior was unusual, prompted by distress and maternalinstinct. Rabbits are usually passive and will run rather than fightwhen confronted by a predator. (See Figure 6.7.)

Rabbits and rodents, as illustrated in Figure 2.6 in chapter 2,develop a single pair of long, chisel-shaped incisors in the upper andlower jaws. The shape and construction of these teeth makesgnawing or flaking off pieces of plant material the only sensibleprocedure for consuming food. Since rodents are the only mammalswhose incisors continue to grow throughout their lives, they mustcontinually gnaw to keep the teeth worn down; otherwise theincisors would curve around and grow up through the skull.

Rabbit eye sockets are rotated somewhat forward, allowing bothbinocular vision and peripheral vision. This structure implies thatthe animal lives in habitats where the view might be obstructed suchas in tall grass and wooded areas. In such areas, the ability to judgethe distance of objects and spot movement from the rear is essentialto survival.

Rodents and rabbits share several traits: short-to-long narrow nasalcavities, curved or slightly curved mandibles, and a large zygomaticbreadth. Together these structures suggest large, well-developedtemporalis muscles and equally developed masseter muscles, thusallowing the animal to exert pressure at the front, side, and rearportions of the jaw. Pressure created by the temporalis at the front ofthe jaw where the incisors reside provides the power necessary forgnawing strength. The power provided by the masseter muscleshelps the animal crush and grind cellulose with its molars. This

combination of structures indicates defensive behavior.

Small herbivores often have curved or slightly curved to flatnonretractable claws. (See Figure 4.14 of chapter 4.) When curved,these structures indicate arboreal or ground-based habitats. Flatclaws, such as those on rabbits, are fairly conclusive of ground-based habitats.

Rabbits have five-toed front feet; long, over-developed back feetand unfused lower front and back leg bones, indicating a ground-dwelling habitat, with running and walking as the primary means oftravel.

Omnivores

Omnivores rarely consume equal proportions of plant and animalfood. Usually they will eat more of one than the other, depending on



Page 195what's available. In most ecosystems plants are plentiful, providing aconsistent source of sustenance. In environments such as desertswhere plant life is sparse, animal flesh offers a more reliable andconcentrated food source. The ability to consume materials fromthese divergent sources enhances an animal's survivability byallowing it independence from a single food source.

The hunting, foraging, and scavenging of an omnivorous lifestylegenerally require an animal to be adept at both offense and defense.Omnivores, like carnivores, can expend great amounts of energy inpursuit and capture of prey. As potential prey, they must be able torun or in some other way protect themselves from being eaten.Skeletal structures such as orbits, dentition, the zygomatic arch, andlimbs reflect the defensive and attack behaviors that are bothcommon to an omnivorous lifestyle. Three familiar omnivores arediscussed below: the domestic dog, the pig, and the human being.

Profile of a Domestic Dog

While I was growing up it seemed everyone had dogs. Most werewell treated, and their behavior expressed this. When hunting,threatened, on duty protecting, or abused, however, normallytranquil canines could suddenly become aggressive.

I once observed a malamute, which I had seen chase deer and catchrabbits, stoically endure the demanding advances of a young boy.Suffering a barrage of tweaked ears, yanked tail, and occasionalswats from the child, the dog steadfastly refused to be drawn intoplay. Ignoring requests by his mother and aunt to leave the dogalone, the frustrated child struck the dog in the eye with a piece of

firewood. Until this point the malamute had remained aloof andindifferent. Once struck, however, he reacted to the pain by bitingthe boy. Both dog and boy required stitches.

The moniker "man's best friend" leaves little doubt as to a dog'sstatus among humans. Domesticated from the same root stock astheir wild cousins, dogs have been used through the ages forpersonal property protection, companionship, and hunting. Sincethey retain skeletal attributes from their wild predatory/scavengingancestors, there are people who consider them aggressive. However,while this may be true of some dogs, most exhibit a greater degreeof passive than aggressive behavior. (See Figure 6.8.)

Dogs have narrow incisors, long canines, prominent bicuspids,



Page 196

Figure 6.8.A dog skeleton.

serrated carnassials, and partially developed flat molars. Thisdentition suggests that the animal kills by gripping and crushing itsprey with its front teeth. The dog then tugs its head to tear offchunks of animal flesh and plant material and chews and cuts it withthe side teeth or molars. This dental structure, illustrated in Figure2.10 in chapter 2, can be considered suggestive of strong attack anddefensive behaviors.

The slight curve of a dog's lower jaw, as shown in Figure 2.16 inchapter 2, allows the animal to use maximum pressure at both therear and forward portions of the jaws. In the front, where theincisors, canines, and bicuspids reside, this shape provides powerfor the cutting and tearing of both animal flesh and plant material. Inthe rear, where the carnassials and molars reside, this structureprovides power for cutting flesh as well as crushing and grindingcellulose. This structure, in combination with the teeth, indicates the

offensive and defensive behaviors necessary for a hunting,scavenging, and foraging lifestyle.

In canine skulls the orbits usually face somewhat forward, allowingboth binocular and peripheral vision. (See Figures 3.35 and 3.36 in



Page 197chapter 3.) Both are necessary for tracking and judging the distancebetween animals and objects before, during, and after attack. Thisorbital orientation, when associated with other skull features,implies an aggressive hunting lifestyle and a habitat where the fieldof vision is open or partially obstructed, such as tall-grass orwooded areas, mountains, hills, and plains.

Dogs have a prominent zygomatic arch that allows passage for largewell-developed temporalis muscles. When taken into account withthe often peaked cranium and slightly curved mandible, thesestructures imply that the animal eats by gripping and crushing withthe forward portion of the jaws. Since plants don't run away or fightback, it can be assumed that this gripping is for live animals,suggesting aggressive offense, rather than passive defense, behavior.

The sharp to slightly curved nonretractable claws sported by dogsimply a ground-based habitat where these structures are employedfor gripping while running and possibly for digging. (See Figures4.12 and 4.14 in chapter 4.) A dog's five-toed foot structure, asshown in Figure 4.7 in chapter 4, indicates digitigrade locomotion,and its lower leg bones are unfused. This indicates that the dog liveson the ground and is able to run and walk over uneven terrain.

Profile of a Pig

Both hunted and raised for meat, these large, primarily defense-oriented beasts can be very aggressive when hungry or provoked, afact substantiated by historical accounts of boar hunts. Hunting dogsbaying and men on horseback and afoot would give chase,attempting to overtake and kill the quarry. Once cornered, boars

might attempt escape from their harrying adversaries by charging,tusks slashing, through the wall of human, dog, and horse. At timesthe loss of life was staggering as a powerful animal broke throughtheir ranks. Today, though armed with high-powered weapons,hunters run similar risks when hunting these reluctant adversaries.

Pigs will eat whatever they can find. When I was younger, myfamily raised pigs for food. We fattened them on table scraps, fruit,overripe vegetables from the garden, and grain. They rarely missedan opportunity to supplement their diets by catching and consumingthe occasional chicken who entered the pen seeking grain left overfrom the pigs' dinner.

Wild in the woods or tame on the farm, pigs use their noses to



Page 198root the ground looking for edibles. Domestic pigs are occasionallyused for work. For example, because of their keen sense of smell,pigs are used to hunt truffles, a mushroom that grows underground.It's common in southern areas of the United States to have a pig ortwo in the yard to kill snakes. (See Figure 6.9.)

Pigs have large canines and well-developed, flat molars. Canineteeth can be used for tearing and shredding, while the molarsprovide excellent surfaces for grinding. Since animal flesh doesn'trequire grinding, the latter suggests a surface for handling plantmaterial. Pig dentition, illustrated in Figure 2.9 in chapter 2,indicates a stronger defense- than attack-oriented behavior and a dietwhere plants form the primary food source with meat an importantbut limited secondary source.

Although primarily long and flat, the slight curve of a pig'smandible maximizes pressure at both the back and front of the jaws.In the front, where incisors, tusklike canines, and bicuspids reside,this pressure provides power for the cutting and tearing of bothanimal flesh and plant material. In the rear, this pressure providespower for the molars to crush and grind cellulose. This combinationindicates primarily defensive, though impressive offensive, behaviornecessary for a primarily plant-foraging lifestyle supplemented byhunting and scavenging.

A pig's orbits are widely spaced and rotated slightly forward. Thisposition allows limited binocular vision and excellent peripheralvision. Both are necessary for tracking and judging the distance ofother animals and objects. This arrangement implies a ground-based

habitat, such as wooded areas, where the field of vision is partiallyobstructed.

In pigs, a flat, narrow cranium, smaller zygomatic arch, and long,narrow jaw indicate crushing and grinding with the back of the jawsto be of greater importance than tearing and cutting with the front ofthe jaws. This association strongly indicates a diet where plantmaterials play a greater role than meat.

A pig has two toes and narrow hooves, indicating unguligradelocomotion and defense-oriented behavior. (See Figure 4.8 inchapter 4.)

The bones in the lower legs are fused, implying a relatively flathabitat where running and walking are the primary modes oflocomotion. It also successfully argues, as it does for many largeherbivores



Page 199

Figure 6.9.A pig skeleton..

such as horses, cattle, and sheep, for passive defense- rather thanattack-oriented behavior.

Profile of a Human

From arctic to desert extremes, mountaintop to valley, humanswalk, run, hunt, work, and play in a wide range of environments.We're at once defensive and aggressive, frail and strong. Inprosperous countries, much of the population eats meat as readily asvegetable matter. In poorer countries, meat is a luxury and plants thedietary staple. (See Figure 6.10.)

Human teeth are relatively flat, with smaller canines, flat molars,and wide, even incisors. This dental arrangement and shape indicatea behavior pattern where defense supersedes attack.

A human's short, flat mandible allows pressure to be maximized atrear and forward portions of the jaws. In the forward area whereincisors, canines, and bicuspids reside, this power aids the cutting

and tearing of animal flesh and plant material. Along the sides andrear areas where the well-developed flat molars are, this jaw shapeprovides the necessary power for crushing and grinding cellulose.This jaw structure, in combination with the teeth, indicates strongdefense/offense behavior necessary for a primarily plant-foraginglifestyle supplemented with hunting and scavenging.



Page 200

Figure 6.10.A human skeleton.

In human skulls, orbits are rotated to the extreme of facing directlyforward, allowing wide-angle binocular vision ahead and to thesides while severely limiting peripheral vision. The resultant wide-angle depth perception provides the necessary means for long-



Page 201distance tracking of objects and animals. Forward-pointing orbitsimply habitats with open fields of vision such as plains, hills, ormountainous areas, and/or partially obstructed fields of vision suchas wooded areas and arboreal habitats.

The rounded cranium, reduced zygomatic arch, and short jaw ofhumans indicate that crushing and grinding with the rear portion ofthe jaws are more important than tearing and cutting with the frontof the jaws. (See Figure 3.41 in chapter 3.) This strongly indicates adiet where plants play a greater role in nutrition than meat andprimarily passive, defense-oriented behavior over aggressive-oriented behavior.

The flat, rough nails of humans, as shown in Figure 4.15 in chapter4, indicate ground-dwelling or arboreal habitats and a trend towarddefense-oriented behavior. Since humans have learned to create''sharp, retractable claws," this generalization, as is evident throughhistory and current events, tends to fall apart when human behavioris closely scrutinized.

The five-toed human foot structure, as with bears, indicatesplantigrade locomotion and a ground-based habitat. The five-fingered hand, as shown in Figure 4.10 in chapter 4, stronglyindicates a partially arboreal habitat.

In humans, bones in the lower front and rear limbs are unfused,indicating that they move freely over uneven terrain.

Summary

The behavioral inferences presented in this chapter should not be

considered solid empirical data, nor conclusions engraved in stone.Rather, they are intended to illustrate possibilities of behavioralinference through the study of skeletal structure. The reader isencouraged to investigate this subject further through side readings,direct observation of living animals, study of comparative anatomy,and especially, use of the imagination. Life, to a great extent, isunpredictable. No matter how grandiose the conclusion or final theinference, there are exceptions to every rule.



Page 202

Chapter 7Bone-Collecting Basics

The collection and study of bones is an important activity formammalogists and forensic scholars as well as a fascinating andenlightening hobby for laymen. This post-postmortem examinationallows researchers to determine an animal's physical attributes,probable environmental lifestyle, species rank, and sometimes theprobable cause of death. Besides, bonesespecially skullsmake greatconversation pieces.

So, other than procuring them from a retail outlet such as SkullsUnlimited International, where can bones be found?

Our world is built upon the remains of all the creatures who haveever lived. We find their skeletons fossilized in rock, ground up assand beneath our feet, and diluted in the air we breathe and thewater we drink. More recent casualties lie on or buried just beneaththe surface of the ground. Their remains are scattered everywhere:along roads, in fields, and in forests. But just how do you go aboutcollecting them? What precautions should you take? What situationsshould you avoid?

Successful bone collecting takes patience, practice, and anawareness of your surroundings. Although experience is the bestteacher, this chapter should help you get started.



Page 203

Collection Gear

The right equipment will make bone collecting both easier andsafer. A usable outfit for this adventure is simple and inexpensiveand should consist of the following five items:

Brightly colored clothing (hat, shirt, pants, or all three).

Gloves, either latex or cloth. Latex gloves offer a sure grip, arenonporous, and are impervious to disease, but they retain body heatand make your hands sweat. The main advantage of cloth over latexis that cloth gloves will not cause hands to sweat and are morecomfortable to wear over extended periods.

A container for transporting the bones you find. Plastic heavy-dutytrash bags are ideal. They are strong, lightweight, and easy to foldup and carry until needed. If you use cloth bags, wash them aftereach successful excursion.

A stick for probing remains.

Disinfectant to rinse your hands. A small bottle containing aminimum 10 percent solution of bleach and water will suffice.

The Ethics of Bone Collecting

Before collecting bones, it is important to understand the role theyplay in an ecosystem. Collectors should question their motives forgathering bones and consider the long-term effects of their removal.

An ecosystem does not waste bones. Rather, they provide food formany creatures. Oils and rancid fats, constantly secreted by bones

during decomposition and weathering, supply food immediately forinsects and mammals. Long after the oils have been exhausted,bones continue to furnish a source of calcium and minerals tomammals, such as rodents, who gnaw on them. With their finaldecomposition, much-needed elements and minerals are returned tothe earth. The removal of bones from an ecosystem will deprivesome organism, animal or vegetable, of an essential source of food.

That leads us to this question: Given their position in the food web,is it ethical to remove bones from their natural setting? If so, underwhat conditions?

Bones are routinely collected for study by colleges, museums, andnature centers. They are scavenged by amateur naturalists andhobbyists for private collections, as well as by artists who useskeletal structures in their work. Nature warehouses are also knownto sell items procured from the wild. Do any of these individuals ororgani-



Page 204zations have valid reasons for the gathering of bones from theirnatural setting?

Institutions, such as nature centers and museums, use bones forstudy and educational presentations. While these osteologycollections are often purchased through biological warehouses, theyare still augmented with specimens found in the field. Limiting oreliminating field collection would restrict an important source ofspecimens.

Profit is another motive. A business must sell its products. If theseproducts consist of items found in the wild, such as bones, then aconstant source of supply must be established and maintained.

Naturalists may find themselves on the horns of a dilemma, as theinclination to collect conflicts with the awareness of bones' role innature.

An artist needs supplies, especially if his or her art involves bones.Art supplies are not cheap, and found materials are the leastexpensive.

It is hard to tell a nine- or ten-year-old, let alone an adult, that he orshe cannot keep a found skull. For this person a whole new worldhas opened up.

Many find it difficult to resist the desire to possess, whether foreducational, personal, economic, or creative reasons. All collectorsmust face this issue. This book does not attempt to answer thisquestion or impose ethical constraints. These responsibilities liewith the individual collector. To a greater or lesser degree, ethics

plays a part in any endeavor. While engaged in bone collecting, youare encouraged to trust your own judgment and empathy for nature.

How to Find Bones

Bones in the wild can usually be spotted by sight if you trainyourself to notice unusual shapes and contrasting colors. Once youfind a bone, you can launch a search for other skeletal fragments.

Color

There are no colors quite like those of bones in the wild, so noticingcolor contrasts between them and their surroundings is the first stepto locating skeletal remains. Developing an eye for these contraststakes practice. At first you will investigate every white object yousee. From a distance it is easy to confuse a rock, paper, or piece ofwhitened wood with a real bone. It is also easy to dismiss slightcon-



Page 205trasts as not worth examining and thus pass over bones. Don't bediscouraged. Practice sharpens and trains the eye at spotting thesetreasures.

Shapes

Every bone in a skeleton has a unique shape. When Clearly seeneither from a distance or close up, specific bones, such as scapulasand vertebrae, can be quickly recognized by their profiles. Sincecomplete or partial burial by fallen grasses and other vegetation canobscure identifying contours, however, shape recognition is bestutilized as an auxiliary to color contrasts in the initial location ofbones. Once located through color contrasts, you can recognizeskeletal fragments by shape during the close-up work of patternsearches.

Search Patterns

Two basic search patterns, spiral and a linear zigzag, are used in thehunt for skeletal remains and can be effectively implemented byindividuals or groups. Each pattern has a geographic terrain forwhich its employment is best suited. (See Figure 7.1.)

Spiral Pattern

When using a spiral search pattern, slowly wind outward from thefirst bone discovered. If a major portion of a skeleton issubsequently discovered, begin the pattern again, this time using thenew find as the center position. This pattern is best suited for use onopen land. Depending on the terrain, one of two spiral patterns maybe used.

If you find bones on a slope, such as a gully wall or side hill, use anelliptical spiral patterneither oval or teardrop shapedthat opens andwidens faster downhill than uphill. On this terrain, bone scattering isprimarily a function of gravity, as carcasses have a tendency to rolldownhill or be pulled there by scavengers.

For bones located in a flat, wide area, such as an open field, use acircular spiral pattern that increases at an even rate in all directions.On this terrain gravity has less effect on skeletal scattering andscavengers are as likely to pull a carcass in one direction as another.

Linear Zigzag Pattern

With a linear zigzag search pattern, move slowly from side to sidewhile advancing in one direction. Once the likelihood of findingbones



Page 206

Figure 7.1.Three basic search patterns: elliptical spiral, circular spiral, and linear zigzag.

The crossed arrows to the right of each image indicate the relative increase and direction of search pattern expansion.

by traveling farther in that direction has diminished, return to the startingposition. Repeat the process in the opposite direction. This search pattern bestsuits the banks of watercourses and dry streambeds.

Where to Find Bones

Bones can be found anywhere, and every place should be investigated.Depending upon your proximity to water, however, some locations mayprove more likely prospects than others.

Bones are most often found near water sources. Explore along the edges oflarge bodies of water such as lakes, ponds, and oceans. Investigate dryhummocks in swampy areas and along the banks of streams and rivers.Seasonal sources of water, like dry streams, riverbeds, and arroyos, shouldalso be considered.

Bones can also be found away from water. Animals often seek shelter and diein places that are protected and out of the wind. Their bones can be foundscattered in areas such as depressions in large open fields or woods, theleeward sides of hills, gullies, and ravines.

Locating the bones of small mammals, such as rodents, is difficult. However,if birds of prey inhabit the collecting area, small mammal bones can often befound along cliff bases, under standing dead, trees, and beneath telephone

poles. These raptors prefer elevated



Page 207areas with a clear view when consuming their prey. Bones scatteredabout the ground may be intact or fragmented, but rarely formcomplete skeletons.

When to Collect Bones

Bone collecting can be done at any time of the year, but someseasons are better suited to this than others. The best season tocollect skulls and bones is late spring. After the snows have melted,when the previous year's vegetation is still matted down and beforenew plant growth has started, bones are easier to spot. Their colorcontrasts strongly with the darker background of dead vegetation inwhich they lie. At this time bones are often partially or completelyuncovered, allowing their shapes to be more pronounced.

Summer is a difficult time to find bones because the abundance ofstanding, color-shaded, fully leafed vegetation tends to obscurebones.

Because of the contrast of white bone against rusty leaves and deadgrass, fall is also a good bone-collecting season. Because dry,standing vegetation often covers and conceals them, however, bonesare more difficult to spot in the fall than in the spring.

Wintertime in northern climates is a bad time for bone collecting.Even a slight dusting of snow can obscure skeletal fragments. Bonesare hard to spot in a white-on-white world. If you live where there isno snow you may be in luck, however: The fall- or summerlikeconditions in these regions offer some hope for visual bonesightings.

Although winter is not the best time to find bones, it is a good timeto locate carcasses. Then you can return to the remains in the springto collect the bones, after nature and time have stripped them offlesh.

Searching around such a carcass will often turn up others. Duringwinter everything needs to eat, and carnivores, as well asomnivores, are not apt to pass up an easy meal. Since many animalswill be drawn to a carcass, it is not unusual to find the remains ofwould-be gourmands who were unlucky enough to meet up withlarger predators who were staking out the carcass in hopes offinding fresh meat.

Final Notes on Collecting

The hobby of bone collecting develops a cross-disciplinaryunderstanding of geography, mammalogy, physics, behavioralpsychology, and



Page 208ecology. Through such study a person may learn to infer an animal'sbehavior and general lifestyle and in this way develop tools forunderstanding nature and its complexity. The hints supplied in thischapter should make the search for bones easier. Hunting of any sortalways presents dangers to the hunter, however, and the followingsections discuss some of the hazards inherent in bone collecting.

Safety Precautions

Hazards to health and safety are inherent in any expedition. Sinceknowledge often alleviates fear, collectors will find it important todevelop an awareness of the hazards peculiar to bone collecting.The risks of many of the perils discussed in this chapter are low andall can be diminished, if not eliminated, with proper attention todetail.

When in pursuit of bones, safety should be the primary concern.Many dangers can befall unwary and unprepared collectors.Including the standard hazards associated with hiking and climbing,the most likely dangers arise from fellow humans, wild animals, andthe weather.

Roadside Safety

Many animals are killed along our nation's major transportationroutes. If you insist on examining roadkill, don't be stupid. At alltimes wear bright clothing, be alert to the sounds of any motorizedvehicle, and keep a close watch up and down the road or traintracks.

These precautions will only mitigate the danger. When crouched

down looking at a dead animal lying in or along the side of the roador train tracks, a person is difficult to see. Even if you're wearingbright clothing, a driver may not become aware of your presenceuntil it's too late.

The only sure way to not be hit is to stay out of and away fromroads. Remember, cars and trains are heavy machines that build upmomentum as they move. Often traveling in excess of fifty milesper hour, they take a while to stop when brakes are applied. Anautomobile may take twenty feet or more to come to a completestop. Since trains are heavier than cars, a suddenly braking trainmay slide hundreds of feet along a track before coming to a halt. Ascreech of rubber on asphalt, or steel on steel, and either you're safeor you're roadkill. Because of the danger presented by motorizedvehicles of any kind, leave the remains of road-killed animals alone.



Page 209Hunting Season

Searching for bones in the outdoors can be dangerous duringhunting season and the best advice is to stay out of the woods andfields at this time. Although many hunters are safe andconscientious, some are not. Unsafe hunters have been known tomake "sound shots"firing a gun in the general vicinity of a soundwithout actually seeing the targetor fire in rapid succession at ananimal without taking sharp aim. Both "hunting techniques" arereckless and dangerous.

Although good hunting practices and techniques mitigate thesedangers, even they produce an inevitable stray bullet.

Wild Animals

It is easy to become so engrossed in a search that you are unawareof events going on around you. With the increasing encroachment ofhumans into the habitat and territories of wild animals, it is notunlikely that a backyard or backcountry bone collector may findhimself face to face with a bear or mountain lion.

Usually this isn't a problem, since most animals tend to shy awayfrom humans. This response shouldn't be counted on, however.When faced with such a predicament the better part of valor isrecommended. Retreat, but don't act like prey. If additionalinformation is desired, most nature centers provide cautionarybrochures on actions a person should take when confronted byaggressive wild animals.

Weather Conditions

Humans often consider themselves superior and invulnerable tonatural events. Any number of outdoor casualties can attest thatnature is indifferent to our arrogance.

Since many hiking and outdoor books detail effective cautionarytactics, I will just say that on any excursion into the out of doors, beprepared. Each season and geographic region has both predictableand unpredictable weather patterns. Carry gear sufficient forexpected as well as inclement weather. But most of all, know yourlimits. Many people overestimate their physical capabilities andunderestimate the forces of nature.

Health Hazards

It should go without saying that you should not collect freshremains. It takes a while for nature to scour bones clean of flesh anddisease.



Page 210The larger the animal, the longer it takes. Depending on the age ofthe bones and whether the climate is humid or arid, you may beexposed to several types of viral or bacterial contamination.Therefore, wait until nature has removed the bulk of, if not all, fleshand sinew from the bones, then collect and clean them.

The Dangers of Decomposition

Once dead, all organisms decompose, with muscle and other softtissues decaying faster than bone. The speed at which this processoccurs is directly related to the amount of moisture in the air and onthe ground surface. The presence of moisture speeds updecomposition. Humidity keeps flesh somewhat moist, providing anideal environment for the organisms that cause tissues to breakdown and rot. An arid climate like a desert inhibits decay but doesnot stop it. The bacteria that promote decay, and other organisms,such as flesh-eating insects, are still active.

Decomposition does not happen overnight. Sometimes it takesseveral years for a carcass to skeletonize. Even after the flesh isremoved from the outside of bones, marrow is still sealed inside. Asoft fatty connective tissue, marrow usually takes a long time toempty from the hollow center and spongelike areas of a bone. In mybackyard, I have ten-year-old elk bones still full of marrow. (SeeFigure 7.2.)

Exposure to rotting flesh presents immediate hazards to health andwell-being. Although these risks drop in direct proportion to abone's cleanliness, they never go away completely. Three majorinfections may be caused by handling decaying remains without

proper precautions: blood poisoning, botulism, and tetanus.

Blood Poisoning

Also called septicemia, blood poisoning is an infection caused bythe invasion of the bloodstream by virulent bacteria. Onceintroduced through an open wound, such as a cut or deep scratch onyour hand, the infection spreads, swelling tissues and sendingpainful livid red streaks across afflicted body parts. Of the threerisks mentioned here, this is the greatest.

Botulism

Also called acute food poisoning, botulism is caused by botulin, atoxin secreted by the spore-forming bacterium Clostridiumbotulinum. Botu-



Page 211

Figure 7.2A split section of femur. Fats and marrow fill the center hollow and the spongelike

material at the bone ends. The enlarged cutout section on the right illustrates the porous nature of this material.



Page 212lin is transmitted through contact with the mucous membranes foundin your nose or mouth. You don't have to eat rotten flesh to beaffected. All you need to do is pick up a bone that still has someflesh clinging to it or rancid oils oozing from it and, with the handthat touched the rotten flesh, inadvertently wipe your nose or mouth.

Tetanus

An acute infectious disease, tetanus is caused by a toxin producedby the bacillus Clostridium tetani. The toxin, often introducedthrough an open wound, causes rapid spasms and prolongedcontraction of voluntary muscles. An early symptom of tetanus ischaracterized by the spasming of the jaw muscles that eventuallyresults in the inability to open the jaw. It is for this reason thatadvanced tetanus is also referred to as lockjaw.

Contagious Diseases

Death is not always the result of old age or accident. Animals, bothdomestic and wild, die from disease or fall prey to accidents due todebilitation caused by a disease. Regardless of how an animal dies,a pathogen can cling to decaying flesh, bones, or hair. The fresherthe carcass, the greater the danger of contamination to a collector.Four of the most common diseases are discussed here: distemper,rabies, bubonic plague, and anthrax.

Distemper and Rabies

Distemper is a highly contagious virus whose infection is marked byfever and respiratory and nervous symptoms. Rabies is an acuteviral disease of the nervous system of warm-blooded animals. These

are two of the most prominent diseases among animals. Both canmake an animal disoriented, causing it to wander into areas outsideits normal territory. If it wanders onto a road, it may be struck andkilled by a passing motor vehicle.

These diseases can be contracted or carried through the handling ofcarcasses. Although rabies is infectious to humans, distemper is not.Pet lovers beware, beware, because humans can act as carriers forthese diseases and infect pets and livestock.

Bubonic Plague

Also called the Black Death, this plague decimated Europe in thefourteenth century, killing approximately one quarter of its humanpopu-



Page 213lation. The disease, caused by the bacterium Pasteurella pestis, istransmitted through the bites of fleas that live on warm-bloodedmammals. In the Middle Ages it was a large rat population thathosted the fleas. Today the disease is still transmitted primarilythrough large populations of rodents such as squirrels and prairiedogs, but any mammal can be a carrier of plague-infested fleas.Although fleas require a live host to survive and do not live longafter a host is dead, do not take the chance of contracting thisdisease by handling fresh carcasses.

Anthrax

Although controlled, anthrax occasionally flares up in domesticlivestock and wild animals. It is an infectious disease of warm-blooded animals caused by the spore-forming bacterium Bacillusanthracis. It can be transmitted to humans through the handling ofinfected products such as hair.

Precautions You Can Take

There are a number of simple precautions you can take to guardyour health and safety. First, wear brightly colored clothes. The bestcolor is fluorescent orange, also called hunter's orange. This colorstands out well against most backgrounds, reflects light, is attentiongetting, and makes the wearer easy to see.

Next, wear cloth or latex gloves when handling skeletal remains toprotect your hands against possible contamination. Latex gloveshave the advantage of being nonporous and, as long as they remainundamaged, impervious to disease.

Clean all clothing after each successful collecting excursion. Soakall articles, including gloves, in a bleach-water solution, then washthem in warm soapy water.

After handling remains, avoid touching your eyes; body orifices,such as mouth and nose; and any cuts and abrasions. Preventcontagion by washing your hands with a 10 percent solution ofbleach* and water.

Disinfect collected bones by soaking them overnight in a solution ofnine parts water to one part bleach. When soaking time is up,

*The best bleach to use is Clorox. Other bleaches often containa high percentage of lye.



Page 214remove and, using a scouring pad or old toothbrush, wash them inwarm soapy water, then let them air dry. If you can, dry them in thesun, as ultraviolet radiation kills bacteria. If desired, use some formof lacquer, clear spray paint, or floral plastic spray to seal the bones.This will prevent possible infection from future handling. Chapter 8provides details on bone disinfection, preparation, and preservationtechniques.

Conclusion

Collecting bones can be fun, but you must be aware of the risks toyourself and others. Play it safe and stay off roads and train tracks.When hunting season comes around, do not go into the woods andfields. When collecting skulls and other bones, take the precautionsof wearing gloves and bright clothes. Remember to keep your ownlife and bones intact.



Page 215

Chapter 8Bone Preparation and Cleaning

Because of the health risks associated with bones found in the wild,specimens should always be sanitized. In fact, bone cleaning shouldbe considered one of the single most significant tasks undertaken bycollectors.

Many bones, even those weathered for several years, may still haveremnants of flesh and tendons attached to them. Collectors shouldremove these tissues to eliminate both possible disease sources andoffensive odors. Depending on your intended use, one of two typesof cleaning may be undertaken: home quality and museum quality.

Home-Quality Specimens

Most people do not gather bones for scientific purposes but ratherfor display in homes or private rooms. These collections oftenconsist of loose bones that may be strung together and mounted butmore often remain spread out along shelves or stashed in boxes. Theprimary concerns for cleaning home-quality specimens are hygieneand aesthetics. Home-quality cleaning requires that the followingfour conditions be met.



Page 216All muscle and ligament tissue must be removed from the bones.

Bones should be sterilized both inside and out.

All surface oils must be removed, leaving bones dry, not greasy, tothe touch.

Bones should be white, off-white, or slightly yellow in color.

The Cleaning Kit

The basic components of a home cleaning kit are readily availablewithin most homes, supermarkets, and hardware stores. Dependingon the specimens' conditionflesh-free or with flesh still attachedallor some of the following items may be used.

Safety goggles, to protect your eyes from splattering hot water,caustic chemicals, and chemical solutions.

Disposable latex gloves, to protect your hands from hot materialsand caustic cleaners.

Old clothes that cover your arms to the wrists and your legs to theankles.

A drop cloth or newspapers, used for drying specimens.

A large pot or five-gallon metal can used exclusively for boilingbones.

Preferably two, but at least one, three- to five-gallon plastic pailsused strictly for soaking and scrubbing bones.

Several cutting and scraping utensils such as scalpels, paring knives,old steak knives, toothpicks, or thin, flat, narrow-tipped pieces of

wood.

Several soft, abrasive scraping utensils such as a plastic dish-washing pad, plastic vegetable scrubber, or a toothbrush.

A kitchen stove, a camping stove, or an open fire with a grate, for''cooking" bones. Be aware that boiling bones, especially old ones,can produce noxious, foul-smelling fumes. When cleaning isperformed in the house, use of a range hood or exhaust fan isrecommended.

One or all of the following basic household cleaning chemicals:ammonia, Clorox bleach, or a degreaser. During the bone-cleaningprocess these chemicals must be used outdoors or in well-ventilatedareas.

Once this kit has been assembled the cleaning process can begin.Use only those items necessary for the job at hand. Once kit itemsare used for bone cleaning, they should never be used for any otherpurpose.



Page 217Initial Preparation

No matter how spotless bones may appear when found, they shouldalways be considered possible sources of infection. Therefore, allspecimens should be cleaned and disinfected before being broughtinto your home for display. Although this will not eliminate allinfectious agents, it will greatly reduce risks of contagion.

The preparation process discussed in this section assumes relativelyflesh-free specimens. If you have fleshed specimens, use a knife oryour gloved hands to remove as much muscle and ligament materialfrom the bones as possible, being careful not to cut or scratch them.

Next, cover the ground or floor with the drop cloth or newspapers.Then mix a 10 percent disinfectant solution of approximately 1.6cups bleach or ammonia to 1 gallon of water. Soak the specimensovernight. Wearing gloves and goggles, remove the bones one at atime and gently scrape away as much softened flesh and ligamentmaterial as possible. If the bones are already free of ligament andmuscle tissue, simply scrub them with a brush. When finished, laythe specimens on the drop cloth to dry.

If you're working with small bones, the above procedure shouldadequately clear them of fat and grease. If the bones are large,however, the cleaning process will require another step. Once thescrubbed and disinfected bones have dried, the larger leg and hipbones should be drilled at certain positions along their sides andends. This technique, illustrated in Figures 8.1 and 8.2, will help toclear marrow and other fatty substances from the bones.

Skulls require more preparation than other skeletal structures. Inaddition to the general preparation detailed above, assuring theremoval or absence of brain tissues from the skull is very important.If brains are not removed prior to prolonged soaking or cooking,they may expand and force the brain case apart.

If brains are still in the skull, first soak the skull in warm water andthen remove the brains with a bent wire or soft-ended implement.Do this gently, as the divisional plate of bone inside the brain caseis fragile. Once the major portion of brain material has beenremoved, rinse the brain case with warm water to remove anyremaining tissue.

Cleaning Methods

Cleaning bones is a relatively simple process. Two basic methodsare discussed here: maceration and boiling. Choose whichevermethod



Page 218

Figure 8.1.Illustrations of bone-drilling techniques used to evacuate marrow and other fatty substances from large leg bones during

the cleaning process.



Page 219

Figure 8.2.Illustrations of bone-drilling techniques used to evacuate marrow

and other fatty substances from large hip bones during the cleaning process.

you prefer, depending on available time and materials, as well asyour level of patience. You should also consider the sensibilities ofyour neighbors, parents, or spouse, as bone cleaning can be anodoriferous process.

Maceration

Maceration involves submerging bones in a covered bucket of 1.5percent ammonia waterin the proportion of two quarts water to oneounce ammonia. Clorox bleach may be substituted for ammonia.*Leave bones in the solution a few weeks or months until all tissuedecays. Then remove the bones from the solution, scrub themgently, rinse with warm water, and allow to dry thoroughly. Thesoaking

* Remember: Bleach and ammonia are extremely caustic.Immersion of specimens in strongly concentrated solutions ofthese chemicals will result in the deterioration of delicate bonestructures such as those of the sinus.



Page 220process can take weeks or months and generates offensive odors, soit's best done only in rural areas with distant neighbors. Macerationis certainly not the quickest method of cleaning bones, but it isperhaps the best home method for preserving delicate structures inboth large and small animals. For example, the most difficult bonesto clean and preserve are those in a skull that support the sinusmembranes. These waffled, honeycomblike structures are verydelicate. In fact, many people, even museum personnel, simplyremove these structures to facilitate cleaning. By using maceration,however, they can be nicely preserved.

Boiling

An alternative to maceration is boiling, simply cooking bones inwater or a weak bleach or ammonia solution. Because bones oftensmell bad when boiling, it is best to do this outside on a camp stove.You could try it on your kitchen stove, but even if you use anexhaust fan you're likely to drive everyone out of the house.

To prepare bones for boiling, soak them overnight in a 1.5 percentammonia solution (two quarts water to one ounce ammonia). Thissolution may be used for cooking the bones the next day. Tie a longstring to each specimen before immersing it so that it can be liftedand examined from time to time during cooking.

When you're ready to cook, add more liquid (water or solution) tothe pot if necessary so that the specimens are covered.* Bring theliquid to a rolling boil, then reduce to a gentle boil by lowering theheat. Stirring occasionally, cook the specimens until flesh andligaments separate easily from the bone. Allow larger bones to cook

longer, particularly those that have been drilled.

The basic problem with this cleaning method is that boiling canloosen bone joints, especially those in the skull.

Be very careful when boiling skulls, especially those of juvenilesand smaller mammals. If the skull does fall apart, you canreconstruct it by using epoxy glue, superglue, or even liquid solderin a tube. Be careful to position the joints exactly, because once theglue or solder has set you won't get another chance. Do thisoutdoors or in a well-ventilated area, and wear gloves.

* Note: To avoid adverse chemical reactions, do not add bleachsolution to ammonia solution when soaking or cooking bones.



Page 221Prolonged cooking of skulls often results in the softening andeventual disintegration of the cartilagelike material that holds teethin their sockets. Should this occur, carefully gather the teeth andlater reset them in their proper position using rubber cement,superglue, or epoxy glue.

Boiling can also crack teeth, especially those of larger mammals.This happens because sudden changes in temperature cause toothenamel to shrink at a different rate than the tooth's bony center. Tominimize tooth-cracking, limit sudden hot-to-cold temperaturechanges by immersing skulls in a bucket of hot water as soon as youremove them from the pot. If gentle scrubbing is required, do thiswhile the skull is still submerged. When the liquid has cooled,remove the skull and allow it to dry. To further prevent teeth fromcracking, coat them with polyurethane, clear fingernail polish, orparaffin wax during the final cleaning, as discussed below.

Final Cleaning

The final scraping and probing can be the most tedious part of thebone-cleaning process, but is essential to ensure that all tissue hasbeen removed. With gloved hands, remove specimens from themaceration bucket or use the strings to lift bones one at a time fromthe boiling pot. Immediately upon removal, use a small, hardinstrument to pick or scrape off all extraneous material from eachspecimen, occasionally rinsing the bones in a bucket of hot water.

When you have removed as much material as possible with the hardscraper, switch to soft scrubbing pads. Immerse the specimen in abucket of hot water and gently but thoroughly scrub as much of its

surface area as you can reach. Then set the specimen aside on thepaper or drop cloth and move on to the next.

When you have cleaned all of the bones, you need to degrease themwith a final rinse, since you pulled them through a thin layer of oilwhen removing them from the maceration bucket or boiling pot. Todo this, fill the bucket with a 10 percent solution of hot water andammonia or bleach (two quarts water to 6.4 ounces ammonia).Immerse the bones in this solution and let stand for one hour, oruntil the liquid has cooled. Fill another bucket or pot with a 10percent solution of ammonia or bleach and immerse the bones oneat a time. This time scrub them gently but thoroughly with a softpad or toothbrush. When finished, place the specimens on the paperor cloth and let dry



Page 222in a well-ventilated area, preferably outside in the sun, for twoweeks longer.

If you wish, bones can be whitened by simmering themapproximately six hours in a 10 percent solution of water andhydrogen peroxide or bleach. Check the bones frequently, asprolonged submersion can make the bones chalky and cause them tocrumble. Also, be careful not to make the solution too strong, asstrong solutions can cause severe and rapid bone deterioration.

Sealing Bones

Once cleaned and dried, specimens should be sealed for longerpreservation. Sealing home-quality specimens is important becausemost, if not all, of the bone's natural grease sealant has beenremoved during the cleaning process, thus leaving bones veryporous and subject to crumbling and splitting.

Most hardware stores and home hobby centers carry severalcommercial sealing products. Use these materials in open, well-ventilated areas. The following five products are easily obtainableand relatively simple to apply.

Bones can be sealed with a later of clear wax such as paraffin. Awax coating can be polished, but once it is rubbed in it attracts dust,is difficult to clean, and, like furniture, requires occasional upkeep.Researchers find this sealant a plus because it can be removed,allowing close study of the bone.

Available in most hardware and woodworking stores, the activelifespan of varnish is shorter than other lacquer-type sealants and it

can be difficult to apply an even coating to specimens. Varnish alsotends to crack and yellow with age, but for the short term it provideseasy upkeep.

Polyurethane, a permanent sealant, is available in hardware andwoodworking stores. With a long active lifespan, it is easy tomaintain and has a clear, durable finish that resists cracking withage. If kept in constant sunlight, however, it may yellow.

Available in home hobby centers, hardware stores, and even in largesupermarkets, clear enamel spray paint combines easyadministration and upkeep with long life. The application of aminimum of three coats is recommended on specimens to ensuretotal coverage.

Clear plastic floral spray is available in home hobby centers and



Page 223offers the advantages of easy upkeep and simple application withlong life. A minimum of three coats should be applied.

Museum-Quality Specimens

Museum-quality specimens differ from home-quality specimens inaesthetic appeal. Whereas home specimens are used for publichandson display and require extensive hygiene considerations,museum osteology specimens are used for research and require theuse of long-term preservation techniques. Therefore, museumspecimen preparation and cleaning is less stringent concerninghygiene, since lubricating oils and grease and connecting ligamentsare often left intact. This cleansing level requires that the followingtwo conditions be met:

All residual flesh should be removed but connecting cartilage andligaments should be left intact.

Internal fat sources, such as marrow in large bones, should beremoved, but bones can retain a certain amount of grease. Oilretention maintains bone flexibility, keeping them from cracking,though leaving them greasy and potentially odoriferous with time.

A researcher's comprehension of skeletal structure and speciesidentification requires the presence of all major connectiveligaments and structures. From this, the science of osteology, thestudy of bones, recognizes specimen skeletons as ligamentary ordisarticulated.

Small mammals up to the size of a fox are generally treated asligamentary skeletons. Their bones, too small and delicate for

mounting, are cleaned with their connecting ligaments attached. Thebones of mammals larger than foxes are separated and referred to asdisarticulated skeletons. The bones may then be drilled, wired, andbolted together for mounting.

Cleaning Methods

The cleaning and preparation of museum-quality specimens issimilar to that of home-quality specimens but with less stringenthygiene requirements. As mentioned above, for research purposesligaments are preferred intact and, when possible, still connected onmuseum specimens. Even when large bones are drilled to helprelieve marrow, all of the grease and oils are not removed from thebone. Rather, a substantial portion is left to prevent bones fromcracking and splitting



Page 224when drying. Although these specimens may be cleaned throughboiling or maceration, many museums prefer to use dermestid beetlelarvae for cleaning almost all specimen bones.

The various species of the genus Dermestes, known by severalnames including bacon beetle and buffalo bug, have historicallybeen rated as destructive pests that consume hides, pelts, driedmeats, and other animal products. (See Figure 8.3.)

Since it's the growing larvae that consume the greatest amount offood and are most useful as bone cleaners, a working colonyrequires a fair number of adult beetles for reproductive purposes. Asufficient number to start a colony can be found in decayingcarcasses, especially where the meat has dried up.

In-house colonies are placed in a sealed bugproof box to preventtheir escape and spread into areas where they can wreak havocamong stored animal products. Low temperatures make beetles andlarvae inactive, and vibrations disturb them, so it is best to keepthem

Figure 8.3.Three examples of dermestid beetles.



Page 225in a warm, quiet place. A constant temperature of 80 degreesFahrenheit is best.

When a large number of larvae are concentrated in a small space,such as the bugproof box, a diminishing food supply forces them toeat any new material that is introduced. Single layers of hard, driedflesh-coated bones are sandwiched between two layers of cotton inshallow cardboard boxes. These boxes are then placed in the boxcontaining the bugs. Depending on the amount of flesh remaining ona carcass, an active dermestid colony will usually clean small skullsin twenty-four to forty-eight hours.

Keeping a colony alive requires food in the form of dried meat to befurnished when unclean skulls or skeletons are not on hand.

Final Cleaning

Specimens "cleaned" by a colony of dermestid beetles undergo twoadditional cleansing steps. Once specimens have been removed, theyare allowed to soak for twelve hours in a 10 percent ammoniasolution (two quarts water to 6.4 ounces ammonia). The ammonialoosens any pieces of meat or cartilage missed by the beetles andremoves excess grease from the bone. Depending on size, specimensare then soaked in water for twenty-four hours or longer. After thewater has been poured off, specimens are rinsed in fresh water andthen set aside to dry. Once dry, museum specimens, unlike thosedestined for home display, are not sealed. Coverings of any kindlimit a researcher's access to the actual bone material.


Page 227

Glossary of Terms

A

AcetabulumThe cup-shaped socket joint of the hip that accepts theball-like structure of the femur, or thighbone.

AnimaliaThe kingdom that includes all animal organisms.

AnthraxAn infectious disease of warm-blooded animals caused bythe spore-forming bacterium Bacillus anthracis. This disease can betransmitted to humans through the handling of infected productssuch as hair. It is characterized by external ulcerating nodules or bylesions in the lungs.

Articular processesThe two structures located at opposite ends of avertebra. The inferior articular process, facing up on one end, andthe superior articular process, facing down on the other, overlapwith their opposite counterparts, up to down and down to up, onfollowing and preceding vertebrae. (See Figures 5.2 and 5.3.)

B

Bacillus anthracisThe spore-forming bacterium that causes anthrax.

BacteriaAny of a class of microscopic plants, Schizomycetes, havinground, rodlike, spiral, or filamentous single-celled or noncellularbodies. Present in soil, water, organic matter, and the bodies ofplants and animals, these organisms are essential to decay. Whilethey can be beneficial in nutrition and digestion, they can also bepathogens causing sickness and disease.


Page 228BicuspidsAlso called the first premolars, the two teeth positionedjust after the canines and just before the molars in the upper andlower jaws. Bicuspid refers to the shape of their tips, which end intwo conical points, or cusps.

Binocular visionThe type of vision in which both eyes focus on asingle object at the same time, forming one three-dimensionalimage.

Bipeds The term used to describe animals that walk upright on theirtwo hind feet.

Blood poisoningAlso called septicemia, an infection caused by theinvasion of the bloodstream by virulent bacteria.

BotulinA toxin secreted by the spore-forming bacterium Clostridiumbotulinum. Botulin is transmitted through the mucous membranesfound in the nose, mouth, and eyes.

BotulismThe medical name for acute food poisoning caused by thetoxin botulin.

BreastboneSee sternum.

Bubonic plagueThe disease caused by the bacterium Pasteurellapestis and transmitted to mammals through the bites of infectedfleas. This disease is also called the Black Death or simply theplague.

C

CanineOf or relating to dogs or the dog family.

Canine teethTeeth that are pointed and conical in shape andpositioned between the incisors and bicuspids.

CarcassThe body of a dead animal.

CarnassialRelated to or being the teeth of a carnivore specialized forcutting. The carnassial teeth include the bicuspids and the molars.

CarnivoreAn animal whose primary source of food is animal flesh.

Carpal bonesThe bones that make up the wrists of an animal's frontlegs.

CartilageA translucent, flexible, elastic tissue that composes most ofthe skeleton of embryos and young vertebrates. During growth anddevelopment the majority of this tissue is converted into bone inlarger vertebrates.

Caudal vertebraeThe final vertebrae in the spine, these structuresextend from the sacral vertebrae, forming the tail of a mammal.

Cervical vertebraeThe vertebrae that extend from the base of theskull to the first rib.

CheekboneThat portion of the zygomatic arch, also called the jugal



Page 229bone, that forms the lower portion of the orbit and extends backalong the side of the cranium, where it connects with thesquamosal bone.

ChordataThe phylum that includes animals with spinal cords.

ClassThe rank-category below phylum and above order in theLinnaean classification system.

ClavicleAlso called the collarbone, this bone links the scapula to thesternum.

Clostridium botulinumThe spore-forming bacterium that secretesbotulin, the toxin that causes botulism.

CoccyxThe tailbone of a human.

CollarboneSee clavicle.

Costa cartilageThe cartilage that connects the shaft of a rib to thesternum.

CraniologyThe study of skulls, particularly human skulls.

CraniumThe part of the skull that encloses the brain.

D

DecompositionThe process of breaking down organic material intosmaller and simpler compounds.

DentitionThe number, kind, and arrangement of teeth in upper andlower jaws.

Depth perceptionAssociated with binocular vision, the ability to

perceive relative locations of objects within one's range of vision.

Dermestid beetleA type of beetle used by many museums forcleaning flesh from bones.

DigitigradeWalking on the digits, or toes, with the wrist and/or heelbones held off the groundthe common mode of walking among mostfour-footed carnivores, omnivores, and small herbivores.

DigitsThe scientific term for toes and fingers.

Distal phalanxThe last, or end, bone of the phalanges, or toes.

DistemperA highly contagious viral disease characterized by feverand respiratory and nervous symptoms.

Double-curved spineThe name applied to spinal columns whosethoracic region bows out while the lumbar region bows inward. Thisspine shape is associated with humans.

E

EntomologyThe study of insects.

Eye socketThe bony cavity that holds the eyeball, also called theorbit.

EyeteethSee canine teeth.



Page 230

F

False pelvisAlso called the greater pelvis, this term refers to thebroad, flangelike structures of the hip located just above, or before,the true pelvis.

False ribsThese ribs collectively embrace the vertebrochondral ribsand the vertebral, or floating, ribs.

FamilyThe rank-category below order and above genus in theLinnaean classification system.

FelineOf or relating to cats or the cat family.

Felis catusThe scientific name for the domestic cat.

FemurAlso called the thighbone, the single large bone that forms theupper portion of the back leg.

FibulaThe smaller of the two bones that form the lower portion ofthe back leg.

Floating ribsSee vertebral ribs.

Food poisoningThe common name for botulism.

Foramen magnumThe opening at the rear or base of a skull throughwhich the spinal cord passes to become the medulla oblongata.

Functional morphologyThe field of science that studies andinterprets the functional aspects of anatomy, physiology, andosteology.

G

GenusThe rank-category below family and above species in theLinnaean classification system.

H

Head of the ribThe lower portion at the spinal end of a rib thatattaches between two vertebrae. This structure forms the primaryattachment point of a rib to the spinal column.

HerbivoreAn animal whose primary source of food is plant material.

HierarchyA graded or ranked series of objects or classificationgroups.

Home-quality specimensSpecimens intended for home display thatare cleaned with strict regard to health and hygiene considerations.

HumerusThe single large bone that forms the upper portion of thefront leg.

I

IchthyologyThe study of fish.

IliaThe broad flangelike structures that constitute the false pelvis.

IncisorsThe front cutting teeth, located forward of the canine teethin the upper and lower jaws.

Inferior articular processThe articular process that faces up on oneend of a vertebra and overlaps with its counterpart, the superiorarticular process, on preceding vertebrae. (See Figures 5.2 and 5.3.)



Page 231Intercostal spaceThe space between ribs in the rib cage.

Intervertebral diskThe relatively thick cartilaginous disks thatfunction as padding and shock absorbers between two vertebrae.

IschiaThe opposing eye-holed structures that constitute the truepelvis.

J

Jugal boneSee cheekbone.

K

KingdomThe primary rank-category in the Linnaean classificationsystem from which all other classification groups are subdivided.

L

LeewardFacing into the wind or the side opposite the direction ofthe wind.

Linnaean classification systemThe binomial classification systemdeveloped by Carolus Linnaeus, which classifies animals accordingto their structural similarity.

Lumbar vertebraeThe vertebrae immediately following the thoracicvertebrae and just prior to the sacral vertebrae in the spine. Thesevertebrae are associated with the lower back.

M

MacerationA method of cleaning bones in which specimens areimmersed in a weak ammonia solution until all flesh has decayed

from the bone.

MammaliaThe class that includes warm-blooded animals who havehair on their skin and nourish their young with milk secreted bymammary glands.

MammalogyThe study of mammals.

MandibleThe lower jaw.

MasseterThe muscle group that connects the back of the lower jawand the zygomatic arch. This muscle, along with the temporalis,raises the lower jaw.

MaxillaThe upper jaw.

MetacarpalsThe bones of the front foot that extend from thephalanges back to the carpals.

MetatarsalsThe bones of the back foot that extend from thephalanges back to the tarsals.

MolarsThe rear grinding teeth located behind the bicuspids in theupper and lower jaws.

Monocular visionThe type of vision in which each eye focuses on aseparate object, providing two individual two-dimensional images.

Museum-quality specimensSpecimens intended for professionalresearch and cleaned with strict regard to long-term preservation.Ligaments are purposely left intact.



Page 232

N

Neck of the ribThe portion of a rib that curves away from the headand tubercle to form the major structural body of a rib. The end ofthis structure, opposite the head and tubercle, attaches via costacartilage to the sternum.

O

OlfactoryOf, related to, or connected with the sense of smell.

OmnivoreAn animal that eats both plants and animals and can useeither of these as primary food sources.

OrbitAlso called the eye socket, the bony socket that holds theeyeball.

OrderThe rank-category below class and above family in theLinnaean classification system.

OsteologyThe scientific field that studies and classifies bones.

P

Parietal bonesThe two bony plates that fuse together to form the rearportion of the cranium.

Pasteurella pestisThe scientific name for the organism that causesbubonic plague.

Pectoral girdleThe structure composed of the scapula and claviclethat provides the power and foundation for the articulation, ormovement, of the front limbs.

Pelvic girdleAlso called the hipbone, this large structure anchors tothe base portion of the spine, called the sacrum, and forms thefoundation for the skeleton.

PerissodactylsNonruminant hoofed mammals that usually have anodd number of toes.

PhalangesThe bones that form the digits of the front and back feet.

PhylumThe rank-category below kingdom and above class in theLinnaean classification system.

PlantigradeWalking with the entire foot (the digits, wrist, and heelbone) held on the ground. The common method of walking amonghumans and bears.

PremolarsSee bicuspids.

R

RabiesAn acute viral disease of the nervous system of warm-blooded animals.

RadiusThe largest of the two bones that form the lower portion ofthe front leg.

Rib cageThe cagelike structure formed by the attachment of the ribsto the sternum and thoracic vertebrae. This construction issometimes referred to as the thorax.



Page 233RoadkillThe name given to animals killed on roads by motorizedvehicles.

RodentAny member of the order Rodentia. These gnawingmammals have single pairs of incisors in their upper and lowerjaws.

RostrumThe portion of the skull forward of the orbitals formed bythe nasal structure and maxilla.

RuminantsEven-toed hoofed, or ungulate, mammals that chew theircud (regurgitated grass) and have complex, three- or four-chambered stomachs.

S

Sacral vertebraeThe vertebrae immediately following the lumbarvertebrae and just prior to the caudal vertebrae. These structuresfuse together to form the sacrum.

SacrumThe structure created by the fusion of the sacral vertebra andthat anchors to the hip or pelvic girdle.

Sagittal crestThe raised suture formed by the fusion of the parietalbones of a skull.

ScapulaAn often triangular-shaped bone attached to the rib cage viamuscles and the sternum via the clavicle, this bone forms the majorportion of the pectoral girdle and joins with the humerus.

SepticemiaThe medical name for blood poisoning.

Shoulder bladeSee scapula.

SinusThe cavity formed by the bone of a skull that, in conjunctionwith the nostrils, forms the passage and filtration system for air. It isassociated with the mechanism for the sense of smell.

SpeciesThe last rank-category in the Linnaean ClassificationSystem.

Spinal cordThe primary nerve conduit that runs through thevertebral column to the brain.

SpineSee vertebral column.

Spinous processThe structure that projects vertically from avertebra.

SquamosalThe last bone of the zygomatic arch positioned after thejugal bone and that connects to the cranium.

SternumAlso called the breastbone, this compound bone connectsribs and/or shoulder girdle.

Superior articular processThe articular process that faces down onone end of a vertebra and overlaps with its counterpart, the inferiorarticular process, on following vertebrae. (See Figures 5.2 and 5.3.)

SuturesThe jagged or scribbled joint produced when two bones fusetogether.



Page 234SystematicsThe science of taxonomic classification.

T

Tarsal bonesThe bones that make up the ankle of the rear legs.

TaxonThe term applied to a single classification group, such asorder or genus, within a classification system.

TaxonomyThe orderly classification of plants and animals accordingto their presumed natural relationships.

TemporalisThe muscle positioned along the side of the skull thatruns between the zygomatic arch and the skull. This muscleconnects the rear portion of the lower jaw to the skull and, alongwith the masseter, raises the lower jaw.

TerrestrialOf or related to the earth or its inhabitants.

TetrapodsThe term used to describe animals that move about on allfour of their feet.

Thoracic vertebraeThe structures of the vertebral column alongwhich the ribs attach. These vertebrae follow the cervical vertebraeand are just prior to the sacral vertebrae.

ThoraxSee rib cage.

Transverse processesThe structures that project laterally from eitherside of a vertebra.

True pelvisAlso called the lesser pelvis, this term refers to thecupped, eye-holed structure of the hip located just below, or behind,the false pelvis.

True ribsAlso called the vertebrosternal ribs, true ribs extend alongthe thoracic region of the spine, attaching along and ending at thebase of the sternum.

TubercleThe portion of a rib above the rib head that attaches to avertebra. This structure forms the secondary attachment point of arib to the spinal column.

U

UlnaThe smaller of the two bones that form the lower portion of thefront leg.

UngulatesHoofed mammals.

UnguligradeWalking on the distal phalanx bones, or ends of thetoes, with all other bones of the foot held off the groundthe commonmethod of walking among most large four-footed herbivores.

V

VertebraeThe skeletal structures that when connected or stackedtogether form the vertebral column.

Vertebral bodyThe primary mass of bone often located below thevertebral foramen.



Page 235Vertebral capsThe caps that affix to ends of vertebrae in liveanimals, providing a smooth surface covering between the vertebraeand intervertebral disks.

Vertebral columnThe structure, composed of vertebrae, that shieldsthe spinal cord and forms the primary connecting structure of askeletal system.

Vertebral foramenThe central opening in a vertebra through whichthe spinal cord passes.

Vertebral ribsThe ribs that attach only to the thoracic vertebrae andfollow the vertebrochondral ribs.

Vertebrochondral ribsStarting from a spot parallel to the bottom ofthe sternum, vertebrochondral ribs extend along the thoracic regionimmediately following, and look remarkably like the true ribs.

Vertebrosternal ribsAlso called the false ribs, these ribs extendalong the thoracic region of the spine, attaching along and ending atthe base of the sternum.

VirulentExtremely poisonous and fast-acting.

VirusAny of a large group of submicroscopic infective agents thatare regarded as either the simplest microorganisms or extremelycomplex molecules.

Z

Zygomatic archThe bony arch, formed by the jugal and squamosalbones, that extends back from the cheekbone along the cranium andusually anchors just forward and above the ear on the cranium.

Zygomatic breadthThe widest point from the outside edge of onezygomatic arch of a skull to the outside edge of the oppositezygomatic arch.



Page 237

Appendix AThings to Do

This appendix provides several classification and hands-on exercisesdesigned to illustrate and instruct in the application of materialpresented in this book.

Skull Classification

Figures A.1A.3 show two views of three skulls. Using theinformation provided in chapters 2 through 5, classify each skullaccording to its probable environmental lifestyle: carnivore,herbivore, or omnivore.

Skull Structure Identification

Using the red fox skull illustrated in Figure A.4, locate and identifythe structures listed in the caption. Relate these structures with thoselabeled a to i in the figure. Can you associate these with structuresin your own skull?

Jaw Muscle Attachments

In this exercise you will learn to identify, locate the connectingpoints, and understand the function of masseter and temporalismuscles. The only materials required for this exercise are yourfingers.



Page 238

Figure A.1.



Page 239

Figure A.2.



Page 240

Figure A.3.



Page 241

Figure A.4.Match the following nine terms with the structures labeled a to i on

the illustrated red fox skull. The structural terms are as follows: cheekbone, cranium,

dentition, mandible, maxilla, sagittal crest, nasal structure, orbit or eye socket, and zygomatic arch.



Page 242The Masseter Muscle

Place your fingers along the back side of your jaw. Now, makingexaggerated movements with your jaw, open and close your mouth.Clench your teeth. The muscle moving beneath your fingertips is themasseter muscle.

While continuing to move your jaw, find the limits of this muscle'smovement. Moving up the side of your head, this muscle stopsmoving at the zygomatic arch. Moving down the side of your head,this muscle stops moving at the bottom of your lower jaw. Movingforward along your lower jaw, notice that this muscle stops movingat about half to one-third of the way along the mandible.

The Temporalis Muscle

Move your fingers to the side of your head directly above the backof your jaw, just above and behind your eyebrow. Now, makingexaggerated movements with your jaw, open and close your mouth.The muscle moving and rippling beneath your fingertips is thetemporalis muscle.

While continuing to move your jaw, find the limits of this muscle'smovement. Moving up the side of your head, this muscle stopsmoving at about eyebrow level between your eye socket and ear.Moving down the side of your head, this muscle can be felt movinguntil it passes behind the zygomatic arch. At this point its movementis cloaked by the movement of the masseter. Since temporalismuscles move only when the lower jaw moves, however, you cansafely assume they connect to the rear portions of your lower jaw.

Tooth Identification

In this exercise you will learn to identify your own teeth. A regularwall mirror or, preferably, a small hand-held mirror is all that'srequired.

Use Figure 2.3 in chapter 2 to identify the four basic tooth groups:incisors, canines, bicuspids, and molars. Now go to a mirror, openyour mouth wide, and examine the teeth of your lower jaw. If youhave a hand mirror, move it so you can see the roof of your mouthand your upper teeth. Compare your teeth with those illustrated inFigure 2.3. Can you identify these teeth in your own mouth?

Vision

This exercise illustrates the properties of and differences betweenbinocular and monocular vision. The only materials required are twocardboard tubes.



Page 243Binocular Vision

Close one eye and rotate the open eye as far to the right and left aspossible, then switch and repeat this procedure with the other eye.Open both eyes and notice that the vision of each eye overlaps. Thisoverlap produces binocular vision.

Now, with both eyes open look at some object in the room. Noticethat it's easy to tell the distance this object is from you. Thisdemonstrates the depth perception afforded by binocular vision.

Monocular Vision

Place one cardboard tube over each eye and angle the tubes awayfrom each other. Notice that each eye sees a separate image and thatthe images do not overlap. This separation of viewed imagesproduces monocular vision.

Now, close one eye and with the other eye look through a tube at anobject in the room. Notice the difficulty in determining the distancethis object is from you. This exercise demonstrates the lack of depthperception associated with monocular vision.

Jaw Strength

This section uses jaw models to illustrate gripping strengthassociated with basic general herbivore and carnivore mandiblestructures. For this exercise you will need the following materials:

An unbent paper clip or straight pin.

A pair of scissors.

A roll of tape.

A flat, one-square-foot piece of corrugated cardboard.

A rubber band.

A quarter.

From cardboard cut out the jaw shapes and notches as shown inFigure A.5. The labels in this figure mean the following:

a) The left side of the upper jaw

b) The right side of the upper jaw

c) The center of the upper jaw

d) An outline shape of a flat herbivore lower jaw

e) An outline shape of a curved carnivore lower jaw

f) The notch for muscle attachment in the lower jaws

g) A notch for the attachment of the temporalis muscle

h) A notch for the attachment of the masseter muscle



Page 244The same upper jaw will be used for both herbivore and carnivoremock jaws. Using their relative shapes, align the left, center, andright pieces of the mock upper jaw. Glue or tape the pieces together.

As shown in Figure A.6, insert the herbivore jaw (d) into the upperjaw. Take a straightened paper clip or straight pin and push itthrough the cardboard at the position marked by the black dot. Thisis where the lower jaw and upper jaw meet. Since the massetermuscle is the major jaw muscle in herbivores, fit a rubber band intonotch (f) on the lower jaw and notch (h), the masseter anchorposition in the upper jaw. The rubber band should be snug but nottoo tight.

As shown in Figure A.7, insert the carnivore jaw (e) into thecardboard representation of the upper jaw. Take a straightened paperclip or straight pin and push it through the cardboard where thelower jaw and upper jaw meet. To represent the temporalis, themajor jaw muscle in carnivores, fit a rubber band into notch (f) onthe lower jaw and notch (g), the temporalis anchor position in theupper jaw. Again, the rubber band should not be too tight.

Place a quarter between the mock jaws at the front where they

Figure A.5.The pieces needed for the construction of two mock jaws.



Page 245

Figure A.6.Diagram of cardboard outline of a

herbivore lower jaw.

come together. Turn the jaws over so they're facing down. Howeasily does the quarter fall out?

The curved jaw and temporalis muscle, as in carnivores, providesufficient power to the front of the jaws to hold the quarter securely.The quarter should remain held even with a few shakes.

The flat jaw and masseter muscle, as in herbivores, provide lesspower to the front of the jaws. The quarter will fall out either by itssheer weight or with a few slight shakes.

Experiment with tightening the rubber band on both structures. Howloose does the rubber band have to be to drop the quarter from themock carnivore jaw? How tight does the rubber band have to be tosecurely hold the quarter in the mock herbivore jaw?

Figure A.7.Diagram of cardboard outline of a

carnivore lower jaw.



Page 246

Answers to Earlier Exercises

In the exercise on skull classification the four skulls illustrated inFigures A.1A.3 are the following:

a) A carnivore (spotted skunk)

b) A herbivore (woodchuck)

c) A herbivore (moose)

In the exercise on skull structure identification the structures markedin Figure A.4 are as follows:

a) Orbit, or eye socket

b) Cheekbone

c) Mandible

d) Cranium

e) Zygomatic arch

f) Sinus cavity

g) Dentition

h) Maxilla

i) Sagittal crest



Page 247

Appendix BScientific Terms and Common Names

The origins of terms used in scientific nomenclature are many andvaried. While primarily of Latin derivation, many words alsodescend from Greek, German, Swedish, French, Spanish, Italian,and English. Latin is the root for many Western languages such asFrench and Italian and can be understood by many people.

Languages do not remain stable throughout history. At different agesa language takes on distinctive styles, forms, and patterns of speech.This is why languages are divided into different categories, eachbased on the time periods during which certain styles and forms ofspeech were common. For example, modern English and Germandiffer dramatically from those spoken 500 years ago. MiddleEnglish was spoken from 13001475 a.d. and Old English wasspoken from 7001000 a.d. The German language, too, has beendivided into the different ages of Middle German and Old HighGerman.

Since words are formed during various periods in a language'sdevelopment, this historical division of usage creates an importantguide for determining the relative genealogy of words or terms.

Scientific Terms

The following scientific names were used in the text of this book.They are listed in this section along with their language origins.


Page 248BovidaeA family name, this term is derived from the Latin wordbos, which means head of cattle.

CaballusA species name, this term is taken from the Spanish wordcaballa, meaning horse.

Canidae and CanisFamily and genus names respectively, thesewords are derivations from the Latin words caninus and canis,which mean of or relating to dogs or the dog family.

CervidaeA family name, this term is derived from the Latin wordcervinus, which means of a deer.

EquidaeA family name, this term is derived from the Latin wordequinus and the French word equus, which mean of or related to ahorse.

Felidae and FelisFamily and genus names respectively, these termsare derived from the Latin words felinus and fetis, which mean of orrelating to cats or the cat family.

HomoA genus name, this term is the Latin word for man.

InsectivoraAn order name, this term is derived from the Latin wordinsectus.

PerissodactylaAn order name, this term is derived from the Greekword perissos, meaning excessive or odd in number, and daktylos,which means finger or toe.

Procyonidae and ProcyonFamily and genus names respectively.These terms are derived from the Greek word Prokyon, whichmeans foredog or rising before the Dog Star.

RodentiaAn order name for rodents.

RuminantiaA suborder name for ruminants.

SapienA species name, this term is Latin for wise and intelligent.

ScrofaA species name, this term is Latin for breeding sow.

SusA genus name, this term is Latin for pig, swine, or hog.

UngulataAn order name for ungulates.

Ursidae and UrsusFamily and genus names respectively, these termsare taken from the Latin word ursus, which means bear.

Common Names

The following common names were presented in the text of thisbook. They are listed in this section along with their languageorigins.

ArmadilloTaken from the Latin word armatus and the Spanish wordarmado, which mean armed one.



Page 249BatAn alteration of the Middle English word bakke, which, in turn,probably had its origin in the Old Swedish word nattbakka, or bat.

BearDerived from the Middle English word here, the Old Englishbera, and is akin to the Old English word brun, which meansbrown.

BovineTaken from the Latin words bovinus and bos, which mean oxor cow.

CanineDerivation of the Latin words caninus and canis, which meanof or relating to dogs or the dog family.

CarnivoreDerived from the Latin word carnivorus, which meansflesh-eating animals.

CatDerived from the Latin words cattus and catta, the Old Englishword catt, and the Old High German word kazza.

DonkeyDerived from the Middle and Old English word dunn, whichmeans dull, drab, or having a neutral, slightly brownish dark grayappearance.

DogA Middle English word that has been passed down to thepresent day. It is derived from the Old English word docga.

HerbivoreThis term is derived from the Latin word herbivora,which means plant-eating mammals.

HorseThis name is derived from the Middle English word hors andthe Old High German word hros, both of which mean horse.

HumanThis word is derived from the Latin words humanus and

homo, which mean man, and/or relating to the characteristics ofman.

OmnivoreDerived from the Latin word omnivorus, which meansfeeding on both plants and the flesh of animals.

PigThis term is often attributed to the Middle English word pigge.

RodentThis term comes from the Latin words rodens and rodere,which mean to gnaw.

SwineThis name is taken from the Old English and Old HighGerman word swin, which means pig.

UngulateDerived from the Latin word ungulatus, which meanshaving hooves.



Page 251

Appendix CScientific Classification

This appendix lists the common names of animals and theirtaxonomic classification ranks of order, family, genus, and species.

Order: ArtiodactylaFAMILY GENUS SPECIES

Buffalo(bison):

Bovidae Bison bison

Domesticsheep:

Bovidae Ovis aries

Domesticgoat:

Bovidae Oreamnos americanus

Ox (cow): Bovidae Bos taurusPronghornantelope:

AntilocapridaeAntilocapra americana

Elk: Cervidae Cervus canadensisMoose: Cervidae Alces alcesMuledeer:

Cervidae Odocoileus hemionus

White-taileddeer:

Cervidae Odocoileusvirginianus

Domesticpig:

Suidae Sus scrofa

Collared Tayassuidae Tayassu taiacu

peccary:



Page 252Order: Carnivora

FAMILY GENUS SPECIESDomesticdog:

Canidae Canis familiaris

Coyote: Canidae Canis latransGray wolf: Canidae Canis lupusFox: Canidae Vulpes vulpesDomesticcat:

Felidae Felis catus

Cougar: Felidae Felis concolorLynx: Felidae Lynx lynxBobcat: Felidae Lynx rufusEuropeanbadger:

Mustelidae Meles les

Mink: Mustelidae Mustela visonMarten: Mustelidae Martes americanaPinemarten:

Mustelidae Martes martes

Riverotter:

Mustelidae Lutra canadensis

Stripedskunk:

Mustelidae Mephitis mephitis

Long-tailedweasel:

Mustelidae Mustela nata

Wolverine: Mustelidae Gulo luscusRaccoon: ProcyonidaeProcyon lotor

Brownbear

Ursidae Ursus arctos

Blackbear:

Ursidae Ursus americanus

Grizzlybear:

Ursidae Ursus horribilis

Polar bear: Ursidae Ursus maritimus

Order: ChiropteraFAMILY GENUS SPECIES

Bigbrownbat:

VespertilionidaeEptesicus fuscus

Littlebrownbat:

Vespertilionidae Myotis lucifugus

Cavebat:

Vespertilionidae Myotis velifer

Order: DidelphiidaeFAMILY GENUS SPECIES

Opossum:DidelphidaeDidelphisvirginiana



Page 253Order: Insectivora

FAMILY GENUS SPECIESEasternmole:

Talpidae Scalopus aquaticus

Elephantshrew:

SoricidaeElephantulus rozeti

Commonshrew:

Soricidae Sorex araneus

Order: LagomorphaFAMILY GENUS SPECIES

Americanhare:

Leporidae Lepus americanus

Desertcottontail:

Leporidae Sylvilagus auduboni

Easterncottontail:

Leporidae Sylvilagus floridanus

Nuttall'scottontail:

Leporidae Sylvilagus nuttallii

Europeanrabbit:

LeporidaeOryctolagus cuniculus

Order: RodentiaFAMILY GENUS SPECIES

Housemouse:

Muridae Mus musculus

Plainsmouse:

Muridae Mus flavescens

Brown rat: Muridae Rattus norvegicusColoradochipmunk:

Sciuridae Eutamias quadrivittatus

Wyominggroundsquirrel:

Sciuridae Spennophilus elegans Easterngraysquirrel:

Sciuridae Sciurus carolinensis

Beaver: Castoridae Castor canadensisWoodchuck: Sciuridae Marmota monaxSoutheasternpocketgopher:

Geomyidae Geomys pinetis Porcupine:ErethizontidaeErethizon dorsatum

Order. PerisscdactylaFAMILY GENUS SPECIES

Donkey: Equidae Equidae EquusHorse: Equus asinus caballus



Page 254Order: Primate

FAMILY GENUS SPECIESHuman: Homonidae Homo sapiens

Order: Xenartha*FAMILY GENUS SPECIES

Armadillo:DasypodidaeDasypusnovemcinctus* Xenartha is the new name for the order inwhich the armadillo resides. Edentata wasthe old name.



Page 255

Appendix DSuppliers

Not everyone desires or has time to collect specimens from the wild.This situation may be particularly true for those involved in scienceeducation. The following companies offer alternative sources forskeletal specimens, biological teaching supplies, and science-relatedequipment. Contact these organizations directly to receiveinformation regarding price structures, specimen variety, and relatedmaterials. Note that addresses and phone numbers are subject tochange.

Accent ScienceP.O. Box 1444Saginaw, MI 48605(517) 799-8103

Acorn Naturalists17300 East 17th StreetSuite J-236Tustin, CA 92680(714) 838-4888(800) 422-8886

Adventures Company435 Main StreetJohnson City, NY 13790(607) 729-6512(800) 477-6512

American Science and Surplus3605 Howard StreetSkokie, IL 60076(708) 982-0870



Page 256Analytical Scientific11049 Bandera RoadSan Antonio, TX 78250(210) 684-7373(800) 364-4747

Ben Meadows Company3589 Broad StreetChamblee, GA 30341(800) 241-6401

The Biology StoreP.O. Box 2691Escondido, CA 92033(619) 745-1445

Carolina Biological Supply Company2700 York RoadBurlington, NC 27215(910) 584-0381

Central Scientific Company (CENCO)3300 CENCO ParkwayFranklin Park, IL 60131(708) 451-0231(800) 262-3620

CHEMetrics, Inc.Route 28Calverton, VA 22016-0214

(703) 788-9026(800) 356-3072

Chem Scientific, Inc.67 Chapel StreetNewton, MA 02158(617) 527-6626

Connecticut Valley Biological Supply Company, Inc.82 Valley RoadP.O. Box 326South Hampton, MA 01073(800) 628-7748

Creative Teaching AssociatesP.O. Box 7766Fresno, CA 93747(209) 291-6626

Cuisenaire Company of America10 Bank StreetWhite Plains, NY 10606(914) 997-2600(800) 237-3142

Delta Education, Inc.P.O. Box 915Hudson, NH 03051-0915(603) 889-8899(800) 258-1302

Edmund Scientific Company101 East Gloucester PikeBarrington, NJ 08007

(609) 573-6270

Educational Instruments, Inc.11 Robinson LaneOxford, CT 06483(203) 888-1266

Etgen's Scientific Stuff3600 Whitney AvenueSacramento, CA 95821(916) 972-1871



Page 257Fisher ScientificEMD4901 West LeMoyne AvenueChicago, IL 60651(312) 378-7770(800) 955-1177

Flinn Scientific, Inc.131 Flinn StreetP.O. Box 219Batavia, IL 60510(800) 452-1261

Forestry Suppliers, Inc.205 West Rankin StreetP.O. Box 8397Jackson, MS 39284-8397(601) 354-3565(800) 647-5368

Frey Scientific905 Hickory LaneMansfield, OH 44905(800) 225-3739

Grau-Hall Scientific64016501 Elvas AvenueSacramento, CA 95819(916) 455-5258(800) 331-4728

Hawks, Owls, and WildlifeRD#1, Box 293Buskirk, NY 12028(518) 686-4080

Hubbard Scientific, Inc.3101 Iris AvenueSuite 215Boulder, CO 80301(303) 443-0020(800) 446-8767

Kons Scientific Company, Inc.P.O. Box 3Germantown, WI 53022-0003(414) 242-3636

Learning Alternatives2370 West 89ASuite #5Sedona, AZ 86336(602) 204-2172(800) 426-3766

Learning Things68A BroadwayP.O. Box 436Arlington, MA 02174(617) 646-0093

NASCOP.O. Box 901Fort Atkinson, WI 53538-0901

(414) 563-2446(800) 558-9595

NASCO ModestoP.O. Box 3837Modesto, CA 95352(209) 529-6957(800) 558-9595



Page 258National Teaching Aids, Inc.1845 Highland AvenueNew Hyde Park, NY 11040(516) 326-2555

National Wildlife Federation1400 16th St., N.W.Washington, DC 20036-2266(703) 790-4233

Nature Discoveries389 Rock Beach RoadRochester, NY 14617(716) 865-4580

Nebraska ScientificA Division of Cygrus Company, Inc.3823 Leavenworth StreetOmaha, NE 68105-1180(402) 346-7214(800) 228-7117

Northwest Laboratories, Inc.#20-255 Great Arrow DriveBuffalo, NY 14207(716) 877-4748

Northwest Scientific Supply Company, Inc.4311 Anthony Court, #700P.O. Box 305

Rocklin, CA 45677(916) 652-9229

Nurnberg Scientific Company6310 S.W. Virginia AvenuePortland, OR 97201(503) 246-8297

Parco Scientific Company Instrument Group316 Youngstown-KingsvilleRoad, S.E.P.O. Box 189Vienna, OH 44473(216) 394-1100(800) 247-2726

Sargent-Welch Scientific CompanyP.O. Box 1026Skokie, IL 60076-8026(800) 727-4368

Scavengers Scientific Supply CompanyP.O. Box 240009Dougals, AK 99824

Schoolmasters Science745 State CircleP.O. Box 1941Ann Arbor, MI 48106(313) 761-5072

Science Kit and Boreal Laboratories777 East Park DriveTonawanda, NY 14150

(800) 828-7777

SCI-MA Education, Inc.325 South Westwood, #4Mesa, AZ 85210(602) 464-5605



Page 259Skullduggery624 South B StreetTustin, CA 92680(714) 832-8488

Skulls Unlimited InternationalP.O. Box 6741Moore, OK 73153(405) 632-4200(800) 676-7585

Summit LearningP.O. Box 493Fort Collins, CO 80522(800) 777-8817

WARD'S Natural Science Establishment, Inc.5100 West Henrietta RoadP.O. Box 92912Rochester, NY 14692-9012(716) 359-2502(800) 962-2660



Page 261

Appendix ESocieties and Associations

The organizations listed in this appendix are involved withenvironmental studies, education, and conservation efforts. Many, ascan be seen by perusing the publications section of the bibliography,publish their own journals. For information regarding membershipand environment-related topics, contact these groups directly. Youcould also contact natural history museums, colleges, and local,regional, state, and government environmental agencies.

United States

AAAS/Project 2061c/o Oxford University Press200 Madison AvenueNew York, NY 10016

American Association for theAdvancement of Science (AAAS)1333 H Street, NWWashington, DC 20005

American Birding Association, Inc.P.O. Box 6599Colorado Springs, CO 80934

The American Nature Study5881 Cold Brook RoadHomer, NY 13077


Page 262American Society of Mammalogistsc/o State University of New York at OswegoDepartment of BiologyOswego, NY 13126

Biological Sciences Curriculum Study (BSCS)830 North Tejon Street,Suite 405Colorado Springs, CO 80903-4720

Colorado Division of Wildlife6060 BroadwayDenver, CO 80216

Colorado Wildlife Federation7475 Dakin Street, Suite 137Denver, CO 80221

Ecological Society of AmericaCenter for Environmental StudiesArizona State UniversityTempe, AZ 85287

Ethical Science Education CoalitionP.O. Box 16736Stamford, CT 06905

Fish and Wildlife Reference Service5430 Grosvenor Lane, Suite 110Bethesda, MD 20814-2158

National Audubon Society

950 Third AvenueNew York, NY 10022

National Geographic Society1145 17th Street, NWWashington, DC 20036

National Resources Information Council (NRIC)317 West ProspectFort Collins, CO 80526-2097

National Science Teachers AssociationExecutive Office1840 Wilson BoulevardArlington, VA 22201-3000

National Wildlife Federation1412-16th Street, NWWashington, DC 20036

The Nature ConservancyInternational Headquarters1815 North Lynn StreetArlington, VA 22209

NYZS/ The WildlifeConservation SocietyThe BronxNew York, NY 10460

The Scientist Center for Animal Welfare4805 St. Elmo AvenueBethesda, MD 20814


Page 263Sierra Club730 Polk StreetSan Francisco, CA 94109

Society for Conservation Biologyc/o Blackwell Scientific Publications, Inc.238 Main StreetCambridge, MA 02142

Society of Systematic Biologistsc/o National Museum of Natural HistoryNHB163Washington, DC 20560

Society of Systematic Zoologyc/o Smithsonian InstitutionDepartment of Invertebrate ZoologyNMNHWashington, DC 20560

The Southwestern Association of Naturalistsc/o Southwest Texas State UniversityDepartment of Biology601 University DriveSan Marcos, TX 78666

The Wildlife Society5410 Grosvenor LaneBethesda, MD 20814-2197

World Wildlife Fund

1250 24th Street, NWWashington, DC 20037

Overseas

Administration de la Recherche AgronimiqueManhattan Center 7e etageAvenue du Boulevard 21B-1210 BruxellesBelgium

AgricolturaUfficio delle Relazioni internazionali18, via XX SettembreI-00187 RomaItaly

Animal Behavior SocietyReproduction Research Information Service141 Newmarket RoadCambridge CB5 8HAUnited Kingdom

The Association for the Study of Animal BehaviourReproduction Research Information Service141 Newmarket RoadCambridge CB5 8HAUnited Kingdom

Australian Rangland SocietyP.O. Box 596Alice Springs, NT 0871Australia

Centre NaturopaBP 431 R6, F-67006 StrasbourgFrance



Page 264Department des Affaires EtrangeresContrada OmerelliPalazzo BegniVia Giacomini47031 San Marino

Deutscher Naturschutzring E. V.Kalkuhlstrasse 24Postfach 32 02 10D-5300 Bonn-Oberkassel 3Germany

Direction de la Protection de la Nature14, Boulevard du General-LeclercF-92524 Neuilly-sur-Seine CedexFrance

English NatureNorthminster HouseGB-Peterborough PE1 1UAUnited Kingdom

Hellenic Society for the Protection of Nature24, Rue NikisGR-10557 AthenesGreece

Liechtensteinische Gesellschaftfur UmweltschutzHeiligkreuz 52

FL-9490 VaduzLiechtenstein

Liga para a Proteccao da NaturezaEstrada do Calhariz de Benfica, 187P-1500 LisboaPortugal

Ligue Suisse pour la Protection de la NatureWartenbergstrasse 22CH-4052 BaleSwitzerland

Ministerio de Obras Publicas y UrbanismoPaseo de la Castellana 67E-28071 MadridSpain

Ministry of Agriculture and FisheriesDepartment for Nature ConservationEnvironmental Protection and Wildlife ManagementP.O. Box 20401NL-2500 Ek's-GravenhageThe Netherlands

Ministry of the EnvironmentM-BeltissebhMalta

Ministry of the EnvironmentMyntgaten 2P.O. Box 8013 DEPN-0030 Oslo1Norway


Page 265Ministry of the EnvironmentThe National Forest and Nature AgencySlotsmarken 13DK-2970 HorsholmDenmark

Ministry of the Environment5A Rue de PragueL-Luxembourg-VilleLuxembourg

Ministry of the EnvironmentP.O. Box 351H-1394 BudapestHungary

Ministry of the EnvironmentP.O. Box 399SF-00121 HelsinkiFinland

National Swedish Environment Protection BoardP.O. Box 1302S-17125 SolnaSweden

Nature Conservation CouncilHlemmur 3P.O. Box 5324ISL-125 Reykjavik

Iceland

Nature Conservation ServiceMinistry of Agriculture and Natural ResourcesCY-NicosiaCyprus

Naturopa-Zentrum AustriaStiftgasse 16Swarovski-Haus, 2. StockA-6020 InnsbruckAustria

Turkish Association for the Conservation of Nature and NaturalResourcesMenekse Sokak 29/4KizilayTR-AnkaraTurkey

U.K. Joint Nature Conservation CommitteeMonkstone HouseGB PeterboroughUnited Kingdom PE1 1JY

Wildlife ServiceOffice of Public WorksLeeson LaneIRL-Dublin 2Ireland



Page 267

Recommended Reading

Books

Allaby, Michael, ed. The Concise Oxford Dictionary of Zoology.Oxford: Oxford University Press, 1991.

Anderson, Rudolph M. Methods of Collecting and PreservingVertebrate Animals. National Museum of Canada, Bulletin No. 69,Biological Series No. 18, 1948

Anderson, Sydney, and J. Knox Jones, Jr., eds. Recent Mammals ofthe World: A Synopsis of Families. New York: The Ronald PressCo., 1967.

Banfield, A. W. F. The Mammals of Canada. Toronto: University ofToronto Press, 1974.

Barbour, R. W., and W. H. Davis. Bats of America. Kentucky: TheUniversity Press of Kentucky, 1969

Blackwelder, Richard E. Taxonomy: A Text and Reference Book.New York: John Wiley and Sons, 1967.

Burt, William H., and Richard P. Grossenheider. A Field Guide toMammals. The Peterson Field Guide Series. Boston: HoughtonMifflin Company, 1983.



Page 268Checklist of Vertebrates of the United States, the U.S. Territories,and Canada. Washington, DC: U.S. Department of the Interior,Fish and Wildlife Service, Resource Publication 166, 1987.

Cosgrove, Margaret. Bone for Bone. New York: Dodd, Mead andCompany, 1968.

DeBlase, Anthony F., and Robert E. Martin. A Manual ofMammalogy: With Keys to Families of the World. Dubuque, Iowa:William C. Brown Company Publishers, 1981.

Gittleman, John L., ed. Carnivore Behavior, Ecology, andEvolution. Ithaca, N.Y.: Comstock Publishing Associates (CornellUniversity Press), 1989.

Glass, Bryan P. A Key to the Skulls of North American Mammals.2nd ed. Stillwater, Okla.: Oklahoma State University, 1973.

Gotch, A. F. Mammals: Their Latin Names ExplainedA Guide toAnimal Classification. Poole Dorset, U.K.: Blandford Press Ltd.,1979.

Gould, Stephen Jay. Ever since Darwin: Reflections in NaturalHistory. New York: W. W. Norton and Company, 1977.

. The Flamingo's Smile: Reflections in Natural History. New York:W. W. Norton and Company, 1985.

. Hen's Teeth and Horse's Toes: Reflections in Natural History.New York: W. W. Norton and Company, 1983.

. The Panda's Thumb: Reflections in Natural History. New York:W. W. Norton and Company, 1985.

Grant, Lesley. Discover Bones: Explore the Science of Skeletons.Reading, Mass.: Addison-Wesley Publishing Co., 1992.

Grzimek, H. C. Bernhard. Grzimek's Animal Life Encyclopedia.New York: Van Nostrand Reinhold, 1978.

Hall, Raymond E. The Mammals of North America, 2nd ed. 2 vols.New York: John Wiley and Sons, 1981.

Hildebrand, Milton. Analysis of Vertebrate Structure. New York:John Wiley and Sons, 1974.

Honachi, James, Kenneth Kinman, and James Koeppl, eds. MammalSpecies of the World: A Taxonomic and Geographic Reference.Lawrence, Kans.: Allen Press, Inc., and The Association ofSystematic Collections, 1982.

Jones, J. Knox, Jr., and Richard W. Manning. Illustrated Key toSkulls of Genera of North American Land Mammals. Lubbock,Tex.: Texas Tech University Press, 1992.



Page 269Livaudias, Madeleine, and Robert Dunne. The Skeleton Book: AnInside Look at Animals. New York: Walker Publications, 1972.

Malam, John, and John Creming. Dinosaur Skeletons. New York:Dell Publishing, 1991.

Matthiessen, Peter. Wildlife in America. New York: VikingPenguin, Inc., 1987.

Mayer, Ernst. Principles of Systematic Zoology. New York:McGraw-Hill, 1969.

Miller, Gerrit S., Jr., and Remington Kellogg. SmithsonianInstitutionList of North American Recent Mammals. Washington,D.C: U.S. Government Printing Office, 1955.

Nowalk, Ronald M., and John L. Paradise. Walker's Mammals ofthe World. Baltimore: The Johns Hopkins University Press, 1983.

Parker, Steve. Skeleton. Eyewitness Books. New York: Alfred A.Knopf, 1988.

Pasquini, Chris, and Tom Spurgeon. Anatomy of Domestic Animals:Systemic and Regional Approaches. La Porte, Colo.: SUDZPublishing, 1967.

Rose, Kenneth Jon. Classification of the Animal Kingdom: AnIntroduction to Evolution. New York: David McKay Company, Inc.,1980.

Rothschild, Lord. A Classification of Living Animals. New York:John Wiley and Sons, 1961.

Rubenstein, Daniel I., and Richard W. Wranham, eds. EcologicalAspects of Social Evolution: Birds and Mammals. Princeton, N.J.:Princeton University Press, 1986.

Spence, Alexander P., and Elliott B. Mason. Human Anatomy andPhysiology. New York: The Benjamin/Cummings PublishingCompany, Inc., 1979.

Vaughan, Terry A. Mammalogy. Philadelphia: Saunders CollegePublishing, 1978.

Weisz, Paul B. The Science of Zoology. 2nd ed. New York:McGraw-Hill, 1973.

Whitfield, Philip. The Hunters. New York: Simon and Schuster,1978.

World Wildlife Fund. The Official World Wildlife Fund Guide toEndangered Species of North America. 2 vols. Washington, D.C.:Beacham Publishing, Inc., 1990.

Young, J. Z. The Life of Vertebrates. 3rd ed. Oxford: OxfordUniversity Press, 1981.



Page 270

Periodicals

The American Midland Naturalist. University of Notre Dame, NotreDame, IN 46556.

Animal Behaviour. Academic Press Ltd., High Street, Foots CraySidcup, Kent DA14 5HP, United Kingdom.

Colorado Outdoors. Colorado Department of Natural Resources,Division of Wildlife, 6060 Broadway, Denver, CO 80216.

Ecological Applications. Ecological Society of America, Center forEnvironmental Studies, Arizona State University, Tempe, AZ85287.

Ethics in Research on Animal Behavior. Academic Press Ltd., HighStreet, Foots Cray Sidcup, Kent DA14 5HP, United Kingdom.

The Great Basin Naturalist. 290 MLBM, Brigham YoungUniversity, Provo, UT 84602.

International Wildlife. National Wildlife Federation, 1412 16thStreet, NW, Washington, DC 20036.

The Journal of the Society for Conservation Biology. BlackwellScientific Publications, Inc., 238 Main Street, Cambridge, MA02142.

The Journal of Wildlife Management. The Wildlife Society, 5410Grosvenor Lane, Bethesda, MD 20814-2197.

National Wildlife. National Wildlife Federation, 1412 16th Street,NW, Washington, DC 20036.

Natural History. American Museum of Natural History, CentralPark West at 79th Street, New York, MY 10024.

Nature: International Weekly Journal of Science. MacmillionMagazines, Ltd., 4 Little Essex Street, London, WC2R 3LF, UnitedKingdom.

Nature: International Weekly Journal of Science. MacmillionMagazines, Ltd., P.O. Box 1733, Riverton, NJ 08077-7333.

Nature Canada. Canadian Nature Federation, 1 Nicholas Street,Suite 520, Ottawa, Ontario, Canada K1N 7B7.

Nature Conservancy Magazine. Nature Conservancy, 1815 NorthLynn Street, Arlington, VA 22209.

Nature Study Journal. The American Nature Study, 5881 ColdBrook Road, Homer, NY 13077.

Naturopa. Centre Naturopa of the Council of Europe, BP 431 R6,F67006 Strasbourg, Cedex, France.

The Rangeland Journal. Australian Rangeland Society, P.O. Box596. Alice Springs, NT 0871, Australia.

Ranger Rick. National Wildlife Federation, 1412 16th Street, NW,Washington, DC 20036.



Page 271Science. American Association for the Advancement of Science,1333 H Street, NW, Washington, DC 20005.

The Science Teacher. National Science Teachers Association(NSTA), 1840 Wilson Boulevard, Arlington, VA 22201-3000.

Scientific American. Scientific American, Inc., 415 MadisonAvenue, New York, NY 10017-1111.

The Southwestern Naturalist. The Southwestern Association ofNaturalists, Southwest Texas State University, Department ofBiology, 601 University Drive, San Marcos, TX 78666.

Systematic Biology. Society of Systematic Biologists, c/o NationalMuseum of Natural History, NHB163, Washington, DC 20560.

Systematic Zoology. Society of Systematic Zoology, c/oSmithsonian Institution, Department of Invertebrate Zoology,NMNH, Washington, DC 20560.



Page 273

Index

A

Acetabulum, 149, 151, 152, 153, 227

Acromian process, 134, 135

Anthrax, 213, 227

Articular process, 158, 159, 160, 227

B

Bacteria

Bacillus anthracis, 213, 227

Clostridium botulinum, 210, 229

Clostridium tetani, 212

Pasteurella pestis, 213, 232

Badger, profile of, 182-185

Ball-and-socket joint, 152, 153

Bat, profile of, 185-187

Behavior, skeletal interpretation of

carnivore, 181-87

herbivore, 188-94

omnivore, 194-201

Bicuspid, 18, 20, 24, 27, 228

Binocular vision, 36, 37, 38, 39, 228, 243

Biped, 98, 152, 153, 174, 179, 228

Black Death, 212-213

Blood poisoning, 210, 228

Bone cleaning

home use, 215-23

kit, 216

methods, 217-22, 223-25

museum use, 223-25

preparation, 217

sealing, 222

Bone collecting

ethics, 203-04

gear, 230

methodology, 204-08

precautions, 208-14

Botulism, 210-12, 228

Breastbone, 132, 174, 175, 228

Bubonic plague, 212-13, 228

C

Canine teeth, 18, 20, 21, 24, 26, 27, 228

Carnassial, 20, 228

Carnivore, 2, 10, 11, 106, 107, 108, 109, 112, 114, 132, 135, 153,167, 178, 180, 228

behavioral interpretation, 181-87



Page 274crania, 43

dentition, 19-21

environmental lifestyle, 2, 11, 51, 181

jaws, 29, 43-44

jaw strength, 243-44

nasal cavity, 30

orbits, 38

skull illustrations, 51-66

zygomatic arch, 40

Carpal bones, 103, 104, 105

Cat, profile of, 181-82, 183

Caudal vertebrae, 165, 228

Cervical vertebrae, 161-63, 170, 172, 228

Cheekbone, 39, 228

Classification systems, 3-15

inferential, 1, 3, 9-15

Linnaean, 4, 231

systematics, 3, 234

taxonomy, 3-9, 234

Clavicle, 132, 134, 229

Claw, 101, 105, 106, 107-112

non-retractable, 107, 111

retractable, 110, 111

Collarbone, 132, 134, 229

Common names, 8-9, 248-49

Convergent evolution, 10

Coracoid process, 134, 135

Costa cartilage, 174, 175, 177, 229

Cow, profile of, 190-92

Craniology, 16, 229

Cranium, 42-43, 229

bones of 42

carnivore, 43

herbivore, 43

omnivore, 43

shapes of, 42

Cutting blade teeth, 20

D

Decomposition, 210, 229

Dentition, 17-28, 229

carnivore, 19-21

herbivore, 21-24

omnivore, 24-28

See also Teeth

Depth perception, 36, 229

Dermestid beetles, 224-25, 229

Digits, 105, 106, 107

Digitigrade, 114, 229

Diseases, 210-13

anthrax, 213, 227

botulism, 210-212

bubonic plague, 212, 228

distemper, 212-13, 229

rabies, 212, 232

septicemia, 210, 233

tetanus, 212

Dog, profile of, 195-97

Double-curved spine, 165, 170, 172, 229

E

Environmental lifestyle, 2, 9, 10-11, 16, 18, 19, 35, 43, 180

carnivore, 2, 11, 51, 181, 228

herbivore, 2, 11, 67, 188, 230

omnivore, 2, 11, 83, 194, 232

Eye socket, 35, 229

Eye teeth, 20, 229

F

False pelvis, 149, 151, 230

False ribs, 175, 177, 230

Feet, posture during movement

digitigrade, 114, 229

plantigrade, 114, 232

unguligrade, 114, 234

Femur, 123, 230

Fibula, 123, 230

Flat spine, 165, 167, 170, 171

Floating ribs, 175, 178, 230

Food poisoning, 210-12, 230

Functional morphology, 2, 230

G

Girdles

pectoral, 98

pelvic, 98, 101

shoulder, 132

Greater pelvis, 149

H

Herbivore, 2, 10, 11, 106, 107, 108, 109, 112, 114, 132, 135, 153,197, 170, 178, 180, 230, 249



Page 275behavioral interpretation, 188-94

crania, 43

dentition, 21-24


jaws, 30, 31, 32, 45-47, 243-244

nasal cavity, 30

orbits, 38-39

perissodactyl, 11, 21, 23, 26, 31, 41, 43, 45, 46, 67, 188

rodent, 11, 21, 22, 30, 32, 41, 43, 45, 47, 67, 181, 194

ruminant, 11, 21, 22, 31, 41, 43, 45, 46, 67, 191

zygomatic arch, 41

Hipbone, 148

See also Pelvis, structures of

Home quality cleaning, 215-23, 230

Hooves, 101, 112-13

Horse, profile of, 188-90

Human, profile of, 199-201

Humerus, 114, 230

Humped-back spine, 165, 167-69

I

Ilium, 149, 230

Incisor, 17, 20, 22, 23, 26, 230

Inferential classification, 1, 3, 9-15

Inferior articular process, 158, 230

Intercostal space, 174, 177, 231

Intervertebral disk, 158, 160, 161, 231

Ischium, 152, 231

J

Jaws, 28-30

carnivore, 29

herbivore, 30, 31, 32

masseter muscles of, 28, 43-48, 234

omnivore, 30, 33

temporalis muscles of, 28, 40, 43-48, 234

Jugal, 39, 231

L

Leg bones, 98, 123, 124-31

femur, 123, 230

fibula, 123, 230

humerus, 114, 230

illustrations of, 115-22, 124-31

radius, 114, 232

ulna, 114, 234

tibia, 123

Lesser pelvis, 149

Limb groupings, 98-156

back, 13, 101, 102, 103

front, 13, 98, 100, 101

Linnaeus, Carolus, 4

Linnaean classification, 4, 231

Locomotion

bipedal, 174, 179, 228

digitigrade, 114, 229

plantigrade, 114, 232

quadrupedal, 172, 179

unguligrade, 114, 234

Lockjaw, 212

Lower jaw, 28

Lumbar vertebrae, 164, 174, 231

M

Maceration, 219-20, 231

Mandible, 20, 21, 28, 29, 30, 231, 243

Masseter, 28, 43-48, 231, 242, 243, 244

Maxilla, 20, 21, 22, 28, 231

Metacarpals, 105, 231

Metatarsals, 106, 231

Molars, 18, 21, 22, 23, 24, 27, 231

Monocular vision, 37, 38, 39, 231, 243

Museum quality cleaning, 223-225, 231

N

Nails, types of, 106-113

claw, 101, 105, 106, 107-112

flat, 103, 112

hoof, 101, 112-13

Naming techniques

common, 8-9, 248-49

taxonomic, 6-9, 247-48, 251-54

Nasal cavity, 30, 34

carnivore, 30

herbivore, 30

omnivore, 34



Page 276

O

Omnivore, 2, 10, 11, 83, 97, 108, 109, 112, 114, 132, 135, 153,197, 170, 178, 180, 232, 249

behavioral interpretation, 194-201

crania, 43

dentition, 24-28


jaws, 30, 33, 45-48, 243-44

nasal cavity, 34

orbits, 39

skull illustrations, 83-97

zygomatic arch, 41

Orbit, 35-39, 232

carnivore, 38

herbivore, 38-39

omnivore, 39

Osteology, 223, 232

P

Parietal bones, 42, 232

Pectoral girdle, 98, 132, 134-48, 232

Pelvic girdle, 98, 101, 148-53, 232

illustrations, 154-56

Pelvis, structures of, 149-53

acetabulum, 149, 151, 152, 153, 227

ball-and-socket joint, 152, 153

false pelvis, 149, 151, 230

greater pelvis, 149

ilium, 149, 230

ischium, 152, 231

lesser pelvis, 149

true pelvis, 149, 151, 234

Peripheral vision, 37

Perissodactyl, 11, 21, 26, 41, 43, 67, 188, 232, 248

dentition, 23, 24

jaws, 31, 45, 46

Phalanges, 105, 106, 232

Phalanx bones

distal, 105, 106, 229

middle, 105, 106

proximal, 105, 106

Pig, profile of, 197-99

Plantigrade, 114, 232

Premolars, 20, 232

Q

Quadruped, 152, 172, 179

R

Rabbit, profile of, 192-94

Rabies, 212, 232

Radius, 114, 232

Ribs, 174-179

arrangement of, 175-78

false ribs, 175, 177, 230

floating ribs, 175, 178, 230

true ribs, 175, 177, 234

vertebral ribs, 175, 178, 235

vertebrochondral ribs, 175, 178, 235

vertebrosternal ribs, 175, 178, 235

Rib cage, 174, 232

Rodent, 11, 21, 30, 32, 67, 181, 194, 233, 248, 249

crania, 43

dentition, 22

jaws, 3, 45, 47

orbits, 38

zygomatic arch, 41

Ruminant, 11, 21, 41, 43, 67, 191, 233, 248

dentition, 22, 23

jaws, 31, 45, 46

S

Sacral vertebrae, 164, 170, 172, 233

Sacrum, 148, 164, 166, 233

Sagittal crest, 42, 233

Scapula, 132-48, 233

common shapes, 134-36

illustrations of, 135-48

structures of, 134, 135

Septicemia, 210, 233

Sheep, profile of, 190-92

Shoulder blade, 132, 233

See also Scapula

Shoulder girdle, 132

Skeleton

disarticulated, 223

ligamentary, 223

< previous page page_277

Page 277Skull structures, 16-49

cranium, 42-43, 229

dentition, 17-28, 229

illustrations, 51-97

jaw, 28-30, 31-33

nasal bone, 30, 34

orbits, 35-39, 232

zygomatic arch, 39-41, 235

Spine, 157, 233

Spinal column, 165, 167, 174

Spinal cord, 157, 233

Spinal curvature, 165-70

double-curved spine, 165, 170, 172, 229

flat, 165, 167, 170, 171

humped-back, 165, 167-69

Spinous process, 158, 174, 233

Squamosal, 39

Sternum, 132, 174, 175, 177, 233

Superior articular process, 158, 233

Sutures, 16, 233

Systematics, 3, 234

T

Tarsal bones, 103, 104, 234

Taxa, 4, 234

Taxonomic classification, 4-9

naming, 6-8, 247-48

nomenclature, 251-54

ranks, 4, 5, 6

Taxonomy, 3-9, 234

Teeth, 18-27

bicuspid, 18, 20, 24, 27, 228

canine, 18, 20, 21, 24, 26, 228

carnassial, 20, 228

cutting blade, 20

eye teeth, 20, 229

incisor, 17, 20, 22, 23, 26, 230

molar, 18, 21, 22, 23, 24, 27, 231

premolar, 20, 232

wolf's teeth, 21

Temporalis, 28, 40, 43-48, 234, 237, 242, 243, 244

Tetanus, 210

Tetrapods, 98, 234

Thoracic vertebrae, 164, 174, 234

Thorax, 174, 234

Tibia, 123

Transverse process, 158, 174, 234

True pelvis, 149, 151, 234

True ribs, 175, 177, 234

U

Unguligrade, 114, 234

Ulna, 114, 234

Upper jaw, 28

V

Vertebra, structures of, 157-65, 166

body, 158, 234

cap, 161, 235

foramen, 157, 235

inferior articular process, 158, 230

spinous process, 158, 174, 233

superior articular process, 158, 233

transverse process, 158, 174, 234

Vertebral groupings, 161-74

caudal, 165, 228

cervical, 161-63, 228, 170, 172

lumbar, 164, 174, 231

sacral, 164, 170, 172, 233

thoracic, 164, 174, 234

Vertebral column, 157-74, 235

Vertebral ribs, 175, 178, 235

Vertebrochondral ribs, 175, 178, 235

Vertebrosternal ribs, 175, 178, 235

Vision

binocular, 36, 37, 38, 228

monocular, 37, 38, 39, 231

peripheral, 37

W

Weight estimation, 123, 132, 133

Z

Zygomatic arch, 39-41, 235

carnivore, 40

herbivore, 41

omnivore, 41

structures of, 39

Zygomatic breadth, 39, 235

< previous page page_277

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