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Re: Patagium attachment Was: Re: Pterosaur.net



On Jan 18, 2010, at 2:35 PM, Mike Habib wrote:

> On Jan 18, 2010, at 8:37 AM, David Peters wrote:
> 
>> For some reason a group of pterosaur experts have been applauding this sort 
>> of nonsense lately (pterosaur.net; Unwin, 2004). Sad.
>> You're right, Mike. The uropatagia were split, as in Sharovipteryx and 
>> Pterodactylus [phylogenetic bracketing tells us that if not good ole 
>> observation].
> 
> The bracket only predicts split uropatagia in basal pterosaurs if 1) your 
> outgroup is correct (and that is still quite contentious) 2) there are no 
> fossil taxa within the bracket that have a broad uropatagium.  As it turns 
> out, even if you decide to argue #1, the bracket fails on #2: several basal 
> taxa appear to preserve a broad uropatagium.  Brackets only give the null 
> model, they do not override existing anatomical evidence.

Send one example, please. 


> 
>> ... Add more meat to those thighs to match the extent of the ilia.
> 
> Mark's hindlimb builds seem to be quite reasonable to me.  There are traces 
> of the anterior thigh compartment in some specimens when viewed under UV 
> illumination (the most recent Anurognathus, for example) - these show that 
> the thigh musculature, while hardly scrawny, was not as thick as you suppose. 
>  In all likelihood, a very broad iliacus ran from the anterior edge of the 
> expanded ilium to the proximal femur, but the other anterior thigh muscles 
> seem not to have run that far anteriorly, so the overall thigh was not 
> terribly deep.  This is not actually a surprise, if one looks closely at the 
> particular part of the ilium which is expanded in pterosaurs.

If what you say holds true for Sharovipteryx (whatever it's relationship) it 
would have had sticks for legs. That would be untenable. 

With regard to "Anurognathus" What you're seeing in the UV images are the 
ventral muscles attaching to the pubis and ischium. The muscles attaching to 
the ilium would have been over the ribs, which are exposed, hence, no muscles 
preserved.

Seriously, send one example of a broard uropatagium, please.

Best regards, and thanks for the challenges. 

David


> 
> Cheers,
> 
> --Mike Habib
> 
> 
> Michael Habib
> Assistant Professor of Biology
> Chatham University
> Woodland Road, Pittsburgh PA  15232
> Buhl Hall, Room 226A
> mhabib@chatham.edu
> (443) 280-0181
> 
> 
>