RE: Claw function in Deinonychus

[MICHAEL HABIB <habib@jhmi.edu>]

I would caution against assuming a single function for the enlarged inner claw 
in dromeosaurids and troodontids.  An enlarged claw on the hindlimb is useful 
for a number of functions, including dispatching large prey, 
pinning/dispatching smaller prey, and climbing sheer surfaces (ie trees).  It 
was probably used differently by different taxa, which would explain the 
differences in morphology and relative size of the pedal claw across 
dromeosaurids.  Note that in the largest-bodied taxa, the claw seems to be 
larger proportionately.  It would be interesting to take a phylogenetic 
approach, combined with some morphometric analysis, to try to determine the 
'original' use of the claw in ancestral dromeosaurids. 

Cheers,
--Mike Habib