Re: Debate Over the Wings of Pterosaurs

[ornstn@hookup.net (Ronald Orenstein)]

>FOSSIL FIND MAY REDRAW IMAGE OF PTEROSAURS
>By MALCOLM W. BROWNE

Oh, boy, here we go again!

>Paleontologists no longer believe that Sordes pilosus had hair, but its 
original
>name has stuck.

Is this accurate?  Everything I have read seems to suggest that the general 
view is that Sordes at least, and perhaps other pterosaurs as well, were 
covereed with hair (although this was probably not homologous with mamalian 
hair).  Have I missed something (eassy for an amateur to do)?

 The creature had long, membranous wings, in which an elongated
>string of bones equivalent to those in the fourth finger of a human hand served
>as the supporting structure. The animal probably lived on fish, but it is not
>known whether it could dive beneath the surface of the lakes where it hunted.

I'd like to see how it would get out again if it could!

>
>The latest volley in the debate over pterosaur wings was fired in a report in
>current issue of the British journal Nature. The article argued that 
pterosaurs,
>flying reptiles that were contemporaries (and relatives) of the dinosaurs, had
>fleshy membranes extending from their wing tips along their bodies all the way
>to their hind feet. The authors said a membrane extension, called a 
uropatagium,
>bridged the space between the animal's ankles, giving it a dive brake or flap
>useful for maneuvering in low-speed flight, but severely hampering the
>pterosaur's locomotion on the ground.

OK, now I'm confused.  I heard a paper at the 1993 SVP meeting in Toronto - 
I think it was by Dr. Unwin - that seemed to demonstrate the exact opposite.

Why, though, couldn't there have been variations on this within pterosaurs?  
They were a highly diverse group, at least in size and skull morphology - 
why should their wing membranes have been identical throughout the group?  
Surely there must have been differing aerodynamic concerns relating to 
flight by, say, sparrow-sized Anurognathus and a monster like Quetzalcoatlus?
--
Ronald I. Orenstein                           Phone: (905) 820-7886 (home)
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