Amniotes Flashcards
Which age is the “age of reptiles”
mesozoic
reptilian scales are _______ derived
epidermally
ectothermic
regulate body temperature via solar energy
reptiles regulate their body temperature _________
ectothermally
amphibians regulate their body temperature __________
endothermally
first fully terrestrial vertebrates
reptiles
What forms the carapace and plastron in turtles?
ribs, vertebrae, and epidermal plates modified to form carapace and plastron
where are the pectoral and pelvic girdles located in turtles
located inside ribs
T/F turtles have teeth
False, jaw bones covered in keratinized beak
what are synapsids?
proto-mammals, mammal-like reptiles with only infratemporal fenestra
Reptiles have ___ temporal fenestrae
2, infratemporal and supra temporal
what are lepidosaurians?
Lizards, snakes, amphisbaenia
Lepidosaurians have overlapping _________ derived scales
epidermally
T/F: Lepidosaurians have secondarily lost one or more temporal fenestrae
True
what are archosaurians?
crocodiles, dinosaurs, pterosaurs, ancestor of birds
what are scutes?
epidermally derived plates
what is a crop?
enlarged part of esophagus to store food
archosaurians have ________ and _________ fenestrae
antorbital and mandibular (openings in front of eyes and in lower jaw)
T/F: pterosaurs are dinosaurs
false
how were pterosaur wings formed?
by skin membranes attached to an elongated 4th digit
what is saurischian
lizard-hipped - pubis directed anteriorly and ischium directed posteriorly
what is ornithischian
bird-hipped - pubis and ischium parallel and directed posteriorly
T/F: avians are endothermic ornithischian dinosaurs with feathers
false, they are endothermic saurischian dinosaurs
what are some features of archaeopteryx?
long tail, thecodont tooth attachment, not well-developed synsacrum, trunk vertebrae not rigidly fused, feathers
what is a synsacrum?
a fusion of vertebrae in the pelvic region
what are neornithes?
modern birds
what are the synapomorphies of neornithes?
reptilian scales on legs and feet, keratinized beak, 4-chambered heart, modified diapsid skull, large cerebellum, pneumatic bones, reduced number of bones in the wrist, palm, and digits
what are pneumatic bones?
slender long bones containing air sacs from the lungs
How was the bird wing formed?
fusion of carpals with metacarpals forming the metacarpus, and fusion of digits - feathered
what are the mammal synapomorphies?
synapsid skull, hair, and mammary glands, 3 ossicle bones in the middle ear cavity, muscular diaphragm, sweat glands, heterodont dentition with 2 sets of teeth (milk and permanent), extensive development of cerebral cortex
Mammals are ________ amniotes
endothermic
What are monotremes?
first mammal
What is the function of the corpus callosum?
allows the 2 sides of the brain to communicate
What are some features of monotremes?
lay heavily yolked eggs, malleus and incus larger than other mammals, no corpus callosum, endothermic, cloaca
what is a cloaca?
common cavity for the reproductive system
what are metatherians?
marsupials
what is the marsupium?
maternal abdominal pouch that incubates and nurses young
what are some features of marsupials?
no cloaca, double vagina, bifurcated penis, choriovitelline placenta
what is a choriovitelline placenta?
an embryonic yolk sac in contact with the chorion
what are eutherians?
placentals, a.k.a true mammals
what is a chorioallantoic placenta?
chorion in contact with allantois
T/F: eutherian young are carried in uterus until fully developed
True
