re: pteros have lift-off

[David Peters <davidpeters@att.net>]

MH: <<In this case, my argument is that starting with the position that most 
pterosaurs were quad launchers is probably the better option, at least at the 
moment. We may then find some exceptions to the trend as time goes along (which 
would be nifty in and of itself).>>

Mike, Let's go, waaay back, to the origin of pterosaurs. Mike, where do 
pterosaurs come from? And which one is the most basal known pterosaur? What do 
these taxa have to tell us about a quad launch vs. a biped launch? Short 
explanation will suffice (aka: big arms, big hips, whathaveyou).

Also, which is the most important articulation creating the most forelimb 
launch power? The humerus/antebrachium? humerus/shoulder? 
antebrachium/metatacarpus? Or all three?

Finally, in present day leapers, from frogs to kangaroos, sort of 'Z' fold gets 
created by the femur, tibia and tarsal/pedal elements. And lots of final push 
comes from the large pedal digits. Is there a z-fold analogy in the forelimb of 
pterosaurs. And is there lots of push coming from the manual digits? At 
present, I don't see either.

BTW, I'm not arguing a particular point. I just want to understand in lieu of 
measureable images and diagrams of a leaping pterosaur, which seem to be 
lacking. 

David Peters

davidpeters@att.net