[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index][Subject Index][Author Index]
Whoops. I sent GOs response to the dinonet all by it's lonesome.
Here is the response I was going to write:
I'm not sure I follow your reasoning. Are you saying that because
pterosaurs evolved flight, this is going to increase the likelyhood that
dinosaurs would as well? I'm not sure I buy the idea that archosaurs
were especially predisposed for flight because two seperate groups out of
three in tetrapod history that evolved it were archosaurs.
1) The archosaurs were in general a very big, diverse, and successful
group. I would imaging thier sheer numbers and diversity would increase the
likelyhood of a specialized feature appearing, or appearing more than
once just by statistics, rather than due to some structural predisposition.
2) Pterosaurs and birds developed flight by two pretty differrent
structural methods, the pterosaurs growing a humungous pinkie and big
skin flap, the birds by elaborating those funny scale derivatives called
feathers. Correct me if I'm wrong, but I'd say that structually and
functionally, pterosaurs had more in common with bats than birds (big
fingers, skin flap, no tail feather analogues)