Re: T-rex arms

["Nicholas R. Longrich" <longrich@phoenix.Princeton.EDU>]

On Thu, 30 Nov 1995 DPterosaur@aol.com wrote:

> My response:
> T-rex arms have the same function that mononykid arms had, grappling mates.
>  They are good only in close proximity, they are very strong and (hopefully)
> they do not puncture.  
> 
> Comments?

        With the robust nature of those limbs, I think that Mononykus 
would be able to do more than just grip mates. They could probably rip 
them apart. As for T. rex arms, if I remember the numbers correctly, the 
male and female specimens found can respectively pull with 450 and 800 
lbs per arm. Why females would need to grapple with mates isn't 
explained. I saw a cast as well, and if memory serves, it was a female 
with a huge rugosity on the Humerus? from where it had pulled a muscle 
off the bone. It had done this, one of the Larsons said (don't remember 
which one) by holding onto something very big that pulled away from the 
T. rex. Certainly they could have been of some use for this, but they 
didn't evolve specifically for that function.