Department of Geological Sciences | Indiana University (c) 2011, P. David Polly

G404 Geobiology

Leopard skull (P. David Polly)

Reading Benton Chapter 5

Introduction to the Skull

Department of Geological Sciences | Indiana University (c) 2011, P. David Polly

G404 Geobiology

(from Kardong 1995, Vertebrates) Photo credit

Developmental components of the vertebrate skullDermatocranium (pink)Chondrocranium or neurocranium (blue)Splanchnocranium or visceral arches (yellow)

Learn:Palatoquadrate cartilageMeckel’s cartilageHyomandibulaHyoid arch

Department of Geological Sciences | Indiana University (c) 2011, P. David Polly

G404 Geobiology

(Wake, D. B. 1979. In Hyman’s Comparative Vertebrate Anatomy, Univ. Chicago)

Early tetrapod skull

Department of Geological Sciences | Indiana University (c) 2011, P. David Polly

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(after Evans, Anatomy of the Dog)

Mammalian skull in lateral view

Department of Geological Sciences | Indiana University (c) 2011, P. David Polly

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(after Polly, 2007, Limbs in Mammalian Evolution)

Functions of the skullSupports special senses (sight, olfaction, taste, hearing and balance)

Supports and protects the brain

Conducts nerves to organs of the head

Department of Geological Sciences | Indiana University (c) 2011, P. David Polly

G404 Geobiology

(after Polly, 2007, Limbs in Mammalian Evolution)

Functions of the skullFood getting (lips, incisors, tongue)

Food processing (chewing movements, teeth, tongue)

Swallowing (hyoid apparatus)

Department of Geological Sciences | Indiana University (c) 2011, P. David Polly

G404 Geobiology

(after Polly, 2007, Limbs in Mammalian Evolution)

Functions of the skullSupports and protects arteries carrying blood to the head (carotid and vertebral arteries and their branches)

Supports and protects veins carrying blood away from the head (jugular vein and its branches)

Department of Geological Sciences | Indiana University (c) 2011, P. David Polly

G404 Geobiology

(from Kardong 1995, Vertebrates)

The brain and the cranial nerves

Department of Geological Sciences | Indiana University (c) 2011, P. David Polly

G404 Geobiology

The cranial nerves and their functions

On (I) Olfactory Smell *

Old (II) Optic Vision *

Olympus’ (III) Occulomotor Eye movement

Towering (IV) Trochlear Eye movement

Top (V) Trigeminal Facial sensation, tooth sensation, control of muscles for chewing *

A (VI) Abducens Eye movement

Finn (VII) Facial Taste, tears, salivation, facial expression (in mammals) *

And (VIII) Auditory Hearing and balance

German (IX) Glossopharyngeal Taste, salivation, innervation of the throat

Viewed (X) Vagus Swallowing, heart, gastrointestinal system, respiration

Some (XI) Spinal Accessory Muscles of the neck and shoulder

Hops (XII) Hypoglossal Tongue movement *

Department of Geological Sciences | Indiana University (c) 2011, P. David Polly

G404 Geobiology

Olfactory (I)

Optic (II) + muscles of eye (III, IV, VI)

Trigeminal (V)

Facial (VII)

Auditory (VIII) Vagus (X)

Spinal Accessory (XI)

Exterior openings of cranial nerves on human skull

Department of Geological Sciences | Indiana University (c) 2011, P. David Polly

G404 Geobiology

(from Kardong 1995, Vertebrates)

Exploded mammalian skull

Department of Geological Sciences | Indiana University (c) 2011, P. David Polly

G404 Geobiology

(Evans, Miller’s Anatomy of the Dog)

External features of the mammalian skullInfraorbital foramen: opening for division II of the Trigeminal Nerve (CN V). In mammals, related to vibrissae

Optic canal: opening for the Optic Nerve (CN II)

External acoustic meatus: opening of the ear canal, ends at the tympanic membrane

Occipital condyles: joint surface shared with the axis (cervical vertebra 1)

Foramen magnum: opening for spinal cord as it exits the brain

Department of Geological Sciences | Indiana University (c) 2011, P. David Polly

G404 Geobiology

External features of the mammalian skullPalatine fissure (or palatine foramen): opening for trigeminal nerve and vomeronasal organ

Jugular foramen: opening through which jugular vein drains, also the passage for several cranial nerves including the vagus

Hypoglossal canal (hypoglosal foramen): opening for the hypoglossal nerve (CN XI)

Department of Geological Sciences | Indiana University (c) 2011, P. David Polly

G404 Geobiology

(Evans, Anatomy of the Dog)

Carotid arteries and the basicranium

Department of Geological Sciences | Indiana University (c) 2011, P. David Polly

G404 Geobiology

Scientific papers for further readingEvans, H. E. 1993. Miller’s Anatomy of the Dog. W.B. Saunders Company: Philadelphia, Pennsylvania.

Hanken, J. and B. K. Hall. 1993. The Skull: Volume 2: Patterns of Structural and Systematic Diversity. University of Chicago Press: Chicago, Illinois.

Romer, A. S. 1966. Vertebrate Paleontology. University of Chicago Press: Chicago, Illinois.

Romer, A. S. and T. S. Parsons. 1977. The Vertebrate Body. W.B. Saunders Company: Philadelphia, Pennsylvania.

ONLINE RESOURCES

Skull Anatomy Tutorial: http://www.gwc.maricopa.edu/class/bio201/skull/skulltt.htm

Skull bones: http://www.youtube.com/watch?v=Nc5IRj3OJhE

Cranial anatomy of the dog: http://animaldiversity.ummz.umich.edu/site/topics/mammal_anatomy/index.html

Lab manual for mammalian skull anatomy (Hyman): http://books.google.com/books?id=qfoSAAAAYAAJ&lpg=PA116&ots=ZsVjj5RiYO&dq=mammalian%20skull%20anatomy&pg=PA116#v=onepage&q=mammalian%20skull%20anatomy&f=false