Class Diapsida - Archosauria Flashcards
archosaurs - write out their line from class to orders
class reptilia subclass diapsida superorder archosauria order crocodilia dinos
when did archosaurs evolve
late permian, early triassic
are archosaurs still diapsid amniotes
yep
what are the 2 main clades of archosaurs
crocs, relative
pterosaurs, dinos + birds
what are the derived characters / synapomorphies of the archosaurs
teeth in sockets
anti-orbital and mandibular fenestrae aka skull
fourth trochanter (FEMUR)
The anti-orbital and mandibular fenestrae (skull) or archosaurs are designed for what…
help reduce weight of skull in early archosaurs
basically just openings in front of the eyes and jaw
what helped archosaurs develop that bipedal gait…
without this, dinos may have never even evolved
the fourth trochanter / femur
better muscle attachment
synapsids are mammal-like reptiles that were replaced by archosaurs after the permian extinction. Why did archosaurs do better than the synapsids in this time, leading to them being able to radiate in the triassic?
it was dryer and reptile have better water conservation than mammal-like reptiles
erect limbs
Crocodilians… write out the lineage
class reptilian
subclass diapsida
superorder archosauria
order crocodilian
crocodilians are descendants from..
thecodonts
the crocodilians are the only surviving what of the archosauria lineage
non avian reptiles
what gave rise to the mesozoic diversification of dinos and birds
crocodilians
order crocodilians differ littler from primitive croc in the early mesozoic.. what are some key features
teeth in sockets
long, reinforced skull + jaw muscles for strong bite
seocndary palate
crocodilians have a shared feature with mammals.. what is it
secondary palate
are crocs more closely related to birds or lizards
birds
part of superorder archosauria
are croc viviparous, ovivparous or ovoviviparous
oviparous
lay eggs in open nest sites
how is the croc sex determined
temp
opposite to turtles
high temp - males :-(
cold temp - females
what is a secondary palate
divide nasal cavity from mouth
what are the three families under order crocodilia
family crocodyliadae (crocs)
family alligatoridae (alligators + caimans)
family gavialidae (gharials)
what are caimans
family alligatoridae
small alligator-like, from south central america
what habitats do crocs live in
semi-aquatic
freshwater
tropics of Asia, Africa, Americas, Australia
what are the 2 species of alligator
american and Chinese alligators
what are gharials
one species native to india semi-aquatic thinner snout than crocs lack jaw strength to catch larger prey
what’s the difference between cros and gators
different families
croc = long, narrow V shaped snout (fish + mammals) gator = wider, U-shaped snouth (more crunch to eat turtles)
upper and lower jaws differ