[no subject]

[Jeffrey Martz <martz@holly.ColoState.EDU>]

     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)

LN Jeff