vertebrates emily reiss josie jacob-dolan tori willbanks-roos
TRANSCRIPT
VertebratesEmily Reiss
Josie Jacob-DolanTori Willbanks-Roos
What makes a vertebrate a vertebrate?• Internal bony skeleton• Backbone encasing spinal column, skull-encased brain• Deuterostomes
(ex: Fish, amphibians, reptiles, birds, mammals)
• Chordate vs. Vertebrate• Notochord• Dorsal, Hollow Nerve cord• Pharyngeal slits and clefts• Muscular, post- anal tail• Somites• Tunicates • Ex. humans, amphioxus
Chordate- have a notochord and a dorsal, hollow nerve cord
Craniates- chordates with a head
• Neural Crest• Heart with at least 2 chambers• Kidneys • Evolved during the Cambrian
explosion about 530 million years ago
• Ex. human, hagfish
To be or not to be...
Vertebrates- Craniates with a backbone• Originally most vertebrae were cartilage• In some cases additions to the notochord• Most times surrounded the notochord• Lampreys• Ex. Humans, pteraspis
Gnathostomes- Vertebrates with jaws• Gnathostome means "jaw mouth"
• Aquatic gnathostomes have a lateral line system
• Appear in the fossil record about 470 million years ago
• Placoderms-"plate-skinned"• Acanthodians• Chondrichthyans-"cartilage fish"
o These include sharks and rays
• Body structure/characteristics
Rays vs SharksSharks• streamlined body, swift swimmers;
don't not maneuver very well• movements of the trunk and the
caudal (tail) fin help to move them• are carnivores• have several rows of teeth• Oviparous vs. Ovoviviparous vs.
ViviparousRays• closely related to sharks• live on the bottom of the ocean• tails are whip-like
-The largest sharks and rays are suspension feeders that consume plankton-
Gnathostomes- Vertebrates with jaws, continued.• Osteichthyans- "bony fish"
• Most aquatic osteichthyans control their buoyancy with a swim bladder.
• They are covered by a protective bony flap called the operculum.
page 682
Ray vs Lobe Finned fishes
Ray:• originated in fresh water and spread to the
seas. • Some (salmon, sea–run trout) replay their
evolutionary round–trip from fresh water to seawater and back to fresh water during their life cycle.
• serve as a food source for some humans• ex: bass, trout, perch, tuna, and herringLobe:• rod–shaped bones surrounded by a thick layer
of muscle in their pectoral and pelvic fins. • only three lineages survive today • ex: coelacanths, lungfishes, and those that
gave rise to tetrapods
Tetrapods- Gnathostomes that have limbs and feet• Tetrapod means "four feet"• Derived characters• The Origin of Tetrapods
on page 685
• ex: Amphibians- meaning: "two lives"
• Types
Amphibians
• Ancestors were tetrapods• Moist skin• Respiration: gas exchange
through skin and lungs • Have a 3-chambered heart• Ectotherms• Reproduction: external
fertilization, external development
• Metamorphosis
Amniotes- Tetrapods that have a terrestrially adapted egg
• Amniotic egg• Extraembryonic membranes - specialized membranes,
protect the embryo but not part of the embryo itself• Different shells: more leathery and flexible (slows
dehydration, allows for living on land)• Came around in the Carboniferous
• Other adaptations:o less permeable skin,
ability to use the rib cage to ventilate the lungs.
• Clade of amniotes, (lizards, snakes, turtles, crocs, birds.)• Scales: create waterproof barrier, helps prevent
dehydration • Shelled eggs on land• "Cold blooded"
o Ectothermic- Not enough metabolic heat to have much effect on body temperature.
o Endothermic- Warmed by heat generated by metabolism. Used to maintain body temperature higher than external environment.
Reptiles!
• Parareptiles- Mostly large, stocky quadrupedal herbivores
• Diapsids- Distinguished by pair of holes on each side of the skull, includes lepidosaurs and archosaurs.
• Lepidosaurs- Includes lizards, snakes, etc.• Archosaurs- Includes crocodiles, alligators,
dinosaurs, and birds.• Pterosaurs- Winged reptile that lived during
the time of dinosaurs.• Dinosaurs-Member of an extremely diverse
group of ancient reptiles varying in body shape, size, and habitat.
• Theropod- A member of an ancient group of dinosaurs that were bipedal carnivores.
Birds
• Reptiles but features all in adapted for flight.o Wings, feathers, stronger muscles,
good eye sight• Better for hunting, migrating, defense • Endothermic • Flightless species - Ratites (Ostrich,
Kiwi, Emu, etc.)• Beaks and feet very adaptable
Mammals: Amniotes that have hair and produce
milk• Mammary glands - produce
milk for offspring • Hair - retain heat
o Endothermic • Teeth adapted for many
different foods• Bigger brains
Synapsids• Lacked hair, laid eggs• Temporal Fenestra (holes behind eye sockets) - still
present in humans• Not true mammals but adapted mammal like
characteristics
Eutherians
Marsupials
Monotremes
• Three major lineages:
Eutherians:• "Placental mammals" because placentas are
more complex • Longer pregnancies, born when fully
developed• Includes Primates
Monotremes: • Have hair, produce milk (from glands)• Lay eggs (unlike any other mammal)• Platypus, Echidnas (spiny anteaters)
Marsupials:• Give birth to live young• Embryo develops in placenta • Born early in development, matures in
pouch
Primates
• Hands and feet, digitso Opposable Thumb
• Big brains, flat faces• Three main groups of living primates:
o Lemurso Lorises and Pottos o Anthropoids
Great Apes Humans
Works Cited
Campbell, Neil A., and Jane B. Reece. Biology. 7th ed. San Francisco, CA: Pearson Education Inc, 2005. Print.
Campbell, Neil A., and Jane B. Reece. Biology. 7th ed. San Francisco, CA: Pearson Education Inc, 2005. eBook.