Zool 110 Lecture: Innovations in Reptiles and Amniotes (Lecture 33)

amniotes

reptiles, birds, mammals

complete the transition to land

amniotes were the first group to what

amniote egg

has tough shell preventing water loss and encloses amniotic sac

1. amnion 2. chorion 3. allantois 4. yolk sac

what are the four extraembryonic membranes of an amniotic egg

chorion and allontois

the _____ and the _____ work together for gas exchange in an amniotic egg

amnion

what layer of extraembryonic membranes is closest to the embryo

Non-Avian (reptile) epidermis

keratinized

negative pressure (aspiration)

do reptiles use negative or positive pressure for breathing

pulmonary and systemic

reptiles have a greater (but still incomplete) separation of _____ and _____ circuits

ectothermic

are reptiles endothermic or ectothermic

ectothermic

body temperature depends on environment

polyphyodont and homodont

reptiles can have _____ and ____ teeth

polyphyodont teeth

can shed teeth and grow new ones

homodont

teeth are all the same shape

vomeronasal organ

a portion of the mammalian olfactory system that is sensitive to pheromones

internal

do reptiles have internal or external fertilization

metanephric kidneys

kidneys of reptiles, birds, mammals, excrete uric acid

anthracosaurs

ancestors of amniotes

Synapsid

1 fenestra (opening behind orbit)

Diapsid

2 fenestrae (2 openings behind orbit)

Anapsid

no fenestrae (no extra openings)

Order Testudines (Turtles)

bony shell consisting of dorsal carapace and ventral plastron

Order Squamata (Lizards and Snakes)

lower temporal bar lost, enables internally moveable (kinetic) skull, males with hemipenes

Suborder Sauria (Order Squamata)

lizards, found worldwide, oviparous, ovoviviparous, or viviparous

Suborder Serpentes (Order Squamata)

snakes, skulls highly modified to swallow large prey, many have venom, infrared sense in pit vipers, use tongue and vomeronasal organ, many use constriction to suffocate prey

1. lateral undulation 2. concertina motion 3. rectilinear motion 4. sidewinder motion

what are the four main types of snake locomotion

Order Sphenodontra (Tuataras)

only two living species of lizard-like reptiles remaining from a extinct line of sphenodontids, have a well-developed parietal eye

Order Crocodilia (Alligators and Crocodiles)

23 species worldwide, part of the great archosaur radiation, diapsid skull, thecodont dentition, amphibious in saltwater and freshwater

thecodont

teeth sit down into sockets

piscivorous crocodiles

fish eating

Gharial and Caiman

Pterosaurs

extinct flying reptiles, first vertebrate flight

Mosasaurs, Icthyosaurs, and Plesiosaurs

all belong to extinct orders within Class Reptilia, marine predators, were viviparous (did not lay eggs)