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Re: Arms into wings
Thomas R. Holtz, Jr. said:
>However, the hands of _Archaeopteryx_ and even _Confusciusornis_ retained
>quite a bit of grasping ability (as various morphometric and morphological
>studies have suggested). After all, there are few morphological differences
>between the forelimbs of Archie and dromaeosaurids.
I think what might be bothering many folks on this list (me included) is
the transitional phase. Ornithothoracines lost the grasping/predatory
ability of the wing (hence the carpometacarpal fusion). Sure,
_Archaeopteryx_ and other non-ornithothoracines used their forelimbs for
both grasping and flying. But how and why did the forelimb take on this
additional function of flight? How did it begin?
I know this goes all the way back to Darwin and the Evolution of Incipient
Structures. What good is half a wing, etc? I'm not arguing against a
maniraptoran origin of birds - but for my own benefit what kind of changes
MAY have occurred in the design of the forelimb (especially externally -
i.e. feathers) between a non-flying basal "eumaniraptoran" and a flying
avian like _Archaeopteryx_? There must have been a "not-quite-flying"
phase somehere in the middle, so what was the forelimb used for during this