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Re: BADD BCF



In a message dated 95-12-02 12:22:17 EST, Robert.J.Meyerson@uwrf.edu (Rob
Meyerson) writes:

>I'll clarify what I'm talking about.  Unlike bats and pterosaurs, the=
> patagium on a bird faces forward.  If you look at a bird's skeleton, the=
> bones of the outstretched wing form a backwards facing V.  Also, there is
a=
> set of muscles (then tensor patagii longus et brevis) that connect the=
> shoulder and wrist (forming a triangular shape).  The patagium covers this=
> triangle.  To restate my original question, how does the evolution of this=
> feature figure in with bird evolution?

The first question I would ask is, does this surface serve as an airfoil in
extant birds (it's hard to tell, because it's covered with feathers)? The
second question is, do the patagial tensor muscles help draw the wing back
during a wingbeat? My guess is that the patagium is one of those features
that evolved as an adjunct to gliding or powered flight, because it seems too
restrictive for a strictly climbing or grasping forelimb.

A most interesting anatomical feature, by the way. I wonder whether
dromaeosaurids and other maniraptorans retained one.