Re: New alvarezsaurid

[Dinogeorge <Dinogeorge@aol.com>]

In a message dated 98-03-25 15:24:10 EST, martz@holly.ColoState.EDU writes:

<< Can you show the maniraptorian hand makes a better flyer then a
 looser, shorter, more mobile hand?  Where are YOUR statistics? Flight
 efficiency studies among three fingered birds and flyers with four and
 five fingered hands....? >>

I haven't said that the maniraptoran hand makes for a better flier. I only
said that the maniraptoran hand is found in all avians and in many pre-avian
dino-birds. I've decided to refrain from making statements about whether
anatomical features are "better" for this or "better" for that purpose, since
such statements cannot presently be substantiated. All we can do is catalogue
the existence or nonexistence of these features in the specimens we have.

I can speculate, however, that because the less mobile, longer hand exists in
so many extant flying avians, whereas the more mobile, grasping hand of
earlier theropods does not, that the less mobile hand was an adaptation for
flight within the theropod clade--for reasons presently unknowable, at least
until someone actually performs wind-tunnel studies (real or computer-virtual)
on various accurately modeled theropod hands and compares their aerodynamic
characteristics.

Who knows? Perhaps the less mobile hand evolved to help the ur-maniraptoran to
scratch itself and preen better, and then all its descendants became stuck
with this kind of hand to use as a wing, even though the looser, shorter hand
would have made a "better" wing. If you think this is a ridiculous idea, show
me why.