re: Flight of _Sharovipteryx

[David Peters <davidpeters@att.net>]

David Peters wrote:


> The key to this thread is long legs (longer tibia
> than femur) = cursor.


>>Refer to (and I guess you've already seen it, but it can't hurt to look 
>>again): Dyke, G.J., Nudds, R.L. and Rayner, J.M.V. (2006). Flight of 
>>_Sharovipteryx mirabilis_: the world's first delta-winged glider.  J. Evol. 
>>Biol. 19: 1040-1043.<<

>>>If the length of the femur is functionally constrained (especially if wing 
>>>shape is governed by femoral protraction, as Dyke &c propose), then 
>>>increased length of the wing could only be achieved by elongation of the 
>>>lower hindlimb.  Under this scenario, the intramembral proportions of 
>>>_Sharovipteryx's_ hindlimb have nothing to do with bipedal/terrestrial 
>>>locomotion, but are an adaptation to gliding.Cheers Tim<<

Point 1: DNandR never actually _found_ forelimb membranes or forelimbs(!) in 
Sharovipteryx. Their paper was entirely hypothetical. 

Point 2: The keyword "If" and "under this scenario" are not supported by 
evidence. If you disagree, simply provide evidence. I'd love to see it. 

Point 3: Pterosaurs also have uropatagia, they walk and run as evidenced by 
tracks, and their tibia are typically longer than their femora, but that is a 
pleisomorphic character going back to preflapping taxa, like sister taxon, 
Sharovipteryx.

David Peters
davidpeters@att.net