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Re: Digit loss



> >Yes, they are opposable to a certain degree. All tyrannosauroids for
which
> >hands are known were capable of holding _something_ (whatever that was)
in
> >a hand, even though it appears that they didn't do that very often. Also,
> >finger II was longer than the thumb, which is not shown in any
tyrannosaur
> >picture I know.
>
> Curious. I suppose, even if Tyrannosaurids started out as flying forms,
> their claws must have served some limited grasping function for climbing
> about in trees, or they wouldn`t exist at all.

For climbing about in trees?!? They would have had lots of time to disappear
in this case -- neither *Eotyrannus* nor *Stokesosaurus* looks small enough
to have climbed!
(Frustrating that it's always easier to tell what something was _not_ used
for...)

> I wonder if some comparison
> has been made with the digits of Archaeopteryx as far as degree of
> opposability. Also, a comparison with Ornithischian digits, and their
> opposability might be useful, as the ornithischian manus was never part of
> an avian wing.

All I know is a chapter or less in the book Lowell Dingus & Timothy Rowe:
The Mistaken Extinction (which I don't have here). It finds this
"semi-opposable" thumb in IIRC all or most bipedal and semibipedal
dinosauromorphs.