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Re: Feduccia (was: polarity of bipedality in dinosaurs)

Ronald Orenstein challenged us (9/23/96; 2:07p):

>[snip]...This raises the point I have made several times here 
>(and that no one seems to want to discuss!) that gliding
>quadrupeds may be very poor models for bird ancestors, as the 
>natural tendency in such a creature would be to keep the trunk 
>lengthy and the hind limbs involved in the gliding surface in 
>order to maximize the surface area of the gliding membrane...

I'll take a shot at that!

I know we've been discussing birds here, but my point relates to 
pterosaurs.  It seems that the same argument could be made for 

...that gliding quadrupeds would be poor models for pterosaur 
ancestors,...yadda yadda yadda.  

Of course, pterosaus have very short trunks, and the hind legs are not 
substantially involved in flight. Is there some other model for the 
ancestor of a pterosaur than a gliding quadruped?  If gliding quadruped 
is the model for pterosaurs, then could that not also be a model for 

Norman R. King                                       tel:  (812) 464-1794
Department of Geosciences                            fax:  (812) 464-1960
University of Southern Indiana
8600 University Blvd.
Evansville, IN 47712                      e-mail:  nking.ucs@smtp.usi.edu