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Re: ptero endothermy




David Peters wrote:
> 
> Longer ilia means larger thigh muscles. Big thigh muscles are used
> aerobically in dinosaurs -- burning more oxygen, which creates heat,
> yada yada. Endothermy. (How bad did I botch that scenario?)

Longer ilia can also mean more area to help accept the wingroot loads
into the torso.

????? Except that the longer ilia preceded the wings by thousands of 
generations. And the wings appeared only distal to the elbows at first. Not 
what you might expect. No 'flying squirrels' here. But still makes an 
interesting narrative.

> 
> Pterosaurs had big ilia and big thighs before they had wings 

I didn't realize any pterosaurs without wings were presently known in
the fossil record.

????? True. I should have said, "pre-pterosaurs".  Pterosaurs are defined by 
the size of their wings. Longisquama, the closest sister taxon, has winglets 
framed by an enlarged fourth finger equal to the sum of digits II and III and 
as robust as the two put together. Sharovipteryx has an identical hand, 
slightly smaller finger four, and the membrane, if present, is lost due to a 
matrix break on one side and layering of other elements  (a femur) on the 
other. 

David Peters
St. Louis