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Re: Wilkinson's new pterosaur paper, Cunningham, Habib



>
>> Time to remember: Theoretical wing shapes are not real even though they 
>> could be.
>
>Keep in mind that irregularities like holes behind the elbow can be due to 
>differential preservation.  Bacteria may preferentially like fat pockets? 
>Pneumatic areas degrade more easily?  Etc.
>
>I think the point that you are making may be that birds can be expected to 
>evolve for greater efficiency, while pterosaurs can't.
>
>JimC
>
>
>

If this indeed were differential preservation, then sometimes it would be 
preserved one way and sometimes the other. In pterosaurs the preservation is 
ALWAYS the same. Both wings the same. All taxa the same. A smooth uninterrupted 
curve from wingtip to just behind the elbow continuing posteriorly to the 
anterior thigh. 

By holes behind the elbow, I, of course, meant lack of wing membrane: matrix 
showing through. I am aware of 'holes' or pockets behind the elbow in certain 
Pterodactylus but even these are within the parameters listed above. 

I was making no point regarding bird evolution for greater efficiency vs. 
pterosaurs.

My whole point is 
1. strict unbiased observation (precise tracing); 
2. reconstruction in all configurations (folded, open, partially open); 
3. interpretations must be supported by data (evidence).

Just come up with a single specimen that does not follow the rule and I will 
grant you that variation in inboard wingshape can and does occur. 

David Peters
St. Louis