Archosauromorph Specialization

Question 1

Q: How do non-dinosaur archosaurs’ ankles differ from dinosaurs’?

Answer 1

A: Non-dinosaur archosaurs have peg-and-socket (rotational) ankles, while dinosaurs have hinge-like ankles for an upright stance.

Question 2

Q: Why are pterosaurs not considered dinosaurs?

Answer 2

A: Despite having hinge-like ankle bones, their unique adaptations for flying place them outside the dinosaur family tree.