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Re: Theropod hands (was Re: dromaeosaurid intelligence)



 Aspidel wrote, in part:

> --- I wonder... What kind of movements were raptors and troodons able to
do with their grasping hands?  Did they have strength in their hands?<

I don't know, but it seems to me that theropods whose forelimb anatomy
limited motion at the wrist to adduction would be somewhat compromised in
their ability to flex their fingers, except perhaps when the hand was fully
extended.  When the hand was extended, the flexor tendons would run in a
straight line from the flexor muscles of the forearm to their insertion
points on the fingers.  That arrangement works well for flexing the fingers.
But if the hand were adducted and held in the same plane as the forearm,
those same tendons would essentially be forced through a 90 degree (or so)
angle at the wrist.  It would seem to me that this configuration would
greatly limit the power that could applied to flex the fingers with the hand
adducted unless there was some additional bracing at the wrist to hold
everthing in place.

PTN