Tyrannosaurid arms (was RE: Forelimbs of "Terror Birds")

["Williams, Tim" <TiJaWi@agron.iastate.edu>]

Dann Pigdon wrote:

>"Williams, Tim" wrote:

Yeah, I gotta change my name address.  This just won't do.  Darn server...

>Then there is my suggesting (it may not be original): that the forelimbs
>weren't used much at all in adults, but that they were relatively larger
>in juveniles. An adult tyrannosaur could pretty much rely on that
>awesome mouth. Juveniles, who may have had quite different hunting
>strategies while small (as with Komodo monitors), may have used their
>relatively larger forelimbs to a greater degree.

So adult tyrannosaurids outgrew their forelimbs?  This scenario begs the
question: why did tyrannosaurids have only two fingers?  (Setting aside, for
the time being, George's view that didactyly was an aerodynamic adaptation
in the tyrannosaurids' flying ancestors, a la BCF.)

And even your juvenile tyrannosaurids have rather short arms - at least by
coelurosaurian standards.

>Note that this isn't based on any actual research on my part. 

What!!??  People still do "research"?

Which brings me to the _Discover_ article on claw-winged phorusrhacids.
Like Nick, I found the original (scientific) article describing the manus
configuration of _Titanis_ - but found no mention of a manual claw.  I
assumed it had been described elsewhere, and so I kept on looking for the
source.  So far, no dice.  Maybe it's all just a leap of somebody's
imagination which, over time, has solidified into "fact".  It happens.




Tim