Lecture 14: Reptiles Flashcards
04/08/2025
Which reptile lineage leads to mammals?
Synapsid
Which reptile lineage leads to anapsids and diapsids?
Sauropsid
Can animals in the diapsid lineages have changes to the skull that alter their diapsid appearance?
Yes!
What are the two major divisions of the sauropods/diapsids?
Lepidosauromorpha
Archosauromorpha
What major groups make up Archosauromorpha?
Aves (birds)
Testudines (turtles)
Eusuchia/Crocodilians (crocs)
What major groups make up Lepidosauromorpha?
Extant snakes, lizards, and tuatara.
Squamata (Serpentes, Lacertilia & Amphisbaenia)
Rynchocephalia (tuatara)
What is unique about tuataras amongst terrestrial ectotherms?
Lives and forages under the coldest body temperature of any terrestrial ectotherm. (around 16*C)
Foraging at night is not unique.
Fish do it colder.
What group are legless lizards?
Amphisbaenia
What traits differentiate snakes from legless lizards?
- Snakes don’t have eyelids, lizards do
2.
What are some major changes that occur as we move into the archosaurs?
- Appearance of the first four-chambered heart in the crocodilians
- Two of the three evolutions of flight occur in this group (1. pterosaur, 2. bird, 3. bats in mammals).
Are pterosaurs the ancestors to modern avians?
No, dinosaurs are.
What does flight mean?
Using own power to control directional change movement in the air against wind currents. Gliding does not count.
What is the weight limit for self-powered flight?
What does this indicate about pterosaurs?
Around 50 lbs. More weight would require more muscle.
The likelihood of an animal being as big as a pterosaur and being able to fly is slim. They also support their wing with one “pinky finger.” The likely did not fly, but glided.
What is the largest group of terrestrial vetebrates?
Reptiles (including birds)
