week 11 Flashcards
what is an anapsid? what are its modern lineages?
amniotes w no skull fenestrae
turtles are a modern ex
what is an synapsid? what are its modern lineages?
amniotes w one pair of skull fenestrae, incl mammals and extinct close relatives
what is an diapsid? what are its modern lineages?
group of amniotes w two pairs of skull fenestrae (supratemporal and laterotemporal)
incl crocs, lizards, snakes, tuataras, dinosaurs, birds, etc
who is dimetrodon closer related to - spinosaurus, or us?
us - they were synapsids
what are lepidosauromorphs
diapsids with no fenestrae other than those which make them diapsids
lizards, snakes, tuataras
what are archosauromorphs?
diapsids with bonus fenestrae such as the mandibular and antorbital fenestrae
incl crocs, birds, dinos, and pterosaurs
what are avemetatarsalians?
archosaurs w ankles that flex like a hinge
incl dinos, pterosaurs, birds
what are pseudosuchians
archosaurs w ‘peg and socket’ ankle joints
incl crocs
tell me about gorgonopsids, cynodonts, and dicynodonts
some of the first synapsids around!
gorgonopsids got fucked by the permian ME.
dicynodonts managed to make it through the permian ME, but didn’t make it out the triassic.
cynodonts would eventually give rise to the mammals!
what caused the permian mass extinction?
we dont know
working theory is intense greenhouse effect compounded by siberian traps volcanoes going off, melting some methane hydrates in the ocean
the triassic had a lot of diversifying to do following permian ME. rapid fire go!
- phytosaurs
- aetosaurs
- rausuchids
- prestosuchians
- poposauroids
phytosaurs: semiaq dudes who looked like crocodiles
aetosaurs: heavily armored herbivs
rauisuchids + prestosuchians: terre pred w upright limbs
poposauroids: dudes w sail backs
what is the difference bw a dinosauria and dinosauromorphs?
dinosauromorphs were missing key traits such as the perforated acetabulum (hip socket w a hole in it)
basically the precursors for dinosaurs
there was a ME event at the end of the triassic. who lived/died?
many archosaurs died, but importantly, the dino archosaurs survived. the pseudosuchian crocodylomorphs survived, as well as the pterosaurs
ALSO some protomammals! this would be important for later
what were the first land animals?
tetrapods, which would give rise to both synapsids and diapsids. synapsids would diversify first in the permian
