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Re: bird arms



Gav wrote:
<< If the radius and ulna of these animals could not cross then surely the 
birdlike posture with the arms tucked back is not possible. >>
   Have a look at a chicken wing. It is not necessary to cross the radius and 
ulna at all to fold the wing. The semilunate carpal evolved to allow this 
flexion without mammalian style radius/ulna crossing.
   Mark Orsen and I made much of this in our Dinofest 98 paper, but it seems 
like the Symposium volume will never be published. 

Thomas P. Hopp