CHAPTER 11 Flashcards
anapsids
Amniotes that completely lack fenestrae (modern turtles)
Synapsids
amniotes with one fenestra on each lateral side of their skull. All mammals are synapsids
diapsids
Amniotes with one set of fenestrae on the lateral sides of their skulls and one set on the top surfaces of their skulls
Diapsids are further subdivided into two groups, again based on fenestrae.
Lepidosauromorphs or lepidosaurs
and
Archosauromorphs or archosaurs
Archosauromorphs or archosaurs
are diapsids with an additional fenestra in front of each orbit (the antorbital fenestra) and an additional fenestra on the rear of the lower jaw (the mandibular fenestra).
examples of archosaurs
Crocodilians, birds, dinosaurs, and the extinct flying reptiles called pterosaurs are all archosaurs.
Lepidosauromorphs or lepidosaurs
are diapsids with no additional fenestrae.
examples of lepidosaurs
Modern lepidosaurs include lizards, snakes, and tuataras.
Avemetatarsalians
they are characterized by having ankles that flex like a hinge, while other archosaurs have ankles that rotate like a ball-and-socket.
what does the adaptation that Avemetatarsalians have give?
it gave stiffer ankles, which were better able to safely support their weight while running and were better suited to locomotion on upright (non-sprawling) limbs.
Pseudosuchian archosaurs:
which include today’s living crocodiles, their ancestors
Avemetatarsalian archosaurs:
which include dinosaurs and their immediate ancestors, pterosaurs, and birds.
Dinosaurs are
dinosauromorphan, avemetatarsalian, archosaurian diapsids.
who were the first groups to evolve into mega herbivores and carnivores in land during the beginning of Permian?
the synapsids
Dimetrodon
one of the earliest synapsids
gorgonopsids
Late in the Permian, large saber- toothed synapsids, called gorgonopsids, were the top predators.
tusked dicynodonts
were the top herbivores
which synapsid would go in to evolve into mammals
Cynodonts
probable causes of the mass extinction in the permian
- long lasting volcanic activity creating a greenhouse effect, increasing global temps.
what did an increase in global temp do to after the end of the permian?
Increased global temperatures = melting of frozen chemicals called methane hydrates deep in the ocean = more global warming and more melting of methane hydrates
didi a comet cause the permian extinction
no since no comet has been found.
who survived the permian extinction
synapsids.
Gradually, large archosaurs became more abundant, while large synapsids became less abundant.
pseudosuchians
- phytosaurs
- rauisuchids and prestosuchians
- poposauroids
- aetosaurs
phytosaurs
which were semiaquatic predators like their distant crocodile relatives
aetosaurs
the heavily armored and herbivorous aetosaurs ,
the rauisuchids and prestosuchians
which were terrestrial predators with upright limb posture;
poposauroids
some had sail-backs and demonstrated convergent evolution with the earlier Dimetrodon.
earliest dinosaur-like archosaurs were,
small and bipedal and looked a lot like the true dinosaurs
what did early archosaurs lack that all dinosaurs had ?
a hip socket with a hole through it
what do we call archosaurs because they lack the hip socket with a hole through it?
we call them dinosauromorphs
what are the earliest records of early carnivorous saurischian dinosaurs
Eoraptor, Eodromaeus, Herrerasaurus, and Panphagia
__________ is an early herbivorous ornithischian dinosaur
isanosaurus
what were more successful and diverse within early dinosaurs
carnivores
what was the most common predator
Coelophysis, Triassic theropod that has been found in large bonebeds in New Mexico
when did prosauropods evolve ?
late jurassic (Plateosaurus)
after the end Permian extinction, pseudosuchian archosaurs…
diversified and became very common, they began to evolve Dino like body plans.
was the end of the jurassic known?
NO
what happened in the jurassic mass extinction
hit many archosaurs but not Dinos, Dinos got lucky.
why did archosaurs die off and not dinosaurs ?
some aspect of their biology made them better able to survive the end-Triassic extinction than the pseudosuchians.
mandibular
an additional fenestra on the rear of the lower jaw
who evolved into the crocodiles
a line of archosaurs called pseudosuchians
