A number of Permian & Triassic gliding reptiles, but only two powered flying groups:

• Avialians (i.e., birds, a type of theropod dinosaur)
• Pterosauria (pterosaurs, probably the sister group to Dinosauromorpha within Ornithodira, but some consider them more primitive archosauriforms)

Pterosaurs:

• First appear in Late Triassic; died out at very end of Cretaceous
• Had simple hinge-like ankle and S-shaped neck of other ornithodirans, but perhaps not parasaggital stance
• Flew using extended manual digit IV (ring finger)
• Skin stretched between finger and body, between legs, and from arm to neck
• Wings reinforced by special internal fibres attached to muscles: could control shape of wing
• Body covered with hair-like structures
• Some used to think they walked bipedally, but most evidence suggests quadrupedal (almost gorilla-like), at least for the derived groups. (Primitive forms may not have been able to do much walking at all.)
• Active powered fliers with large muscle attachments
• Quite probably warm-blooded (insulated; very fast growth rates; active fliers)
• Ranged from 15 cm to 12-14 m wingspan!
• Babies seem to have been able to fly right after hatching!
• Earlier forms relatively small, short metacarpi, and long tails; later forms (Pterodactyloidea, the true pterodactyls) could be very large, had long metacarpi, and short tails and were better adapted at walking
• Variety of diets: insectivores, fish eaters, fruit eaters, etc.

No evidence of direct competition between birds and pterosaurs.

To Next Lecture.
To Previous Lecture.
To Lecture Schedule.

Last modified: 6 July 2017