Re: Killing Claws

["Tim Williams" <T.Williams@cclru.randwick.unsw.edu.au>]

In response to Sam Girouard
 
> >Not if the sickle-clawed theropod struck at the soft underbelly.  A 
> >nice, swift evisceration, and down goes the prey.
> >
> >[ Are we being a bit too mammalocentric here?  Would an animal with a
> >  rib cage extending all the way to its pelvis have a "soft underbelly"?
> >  -- MR ]
> 
>         Mickey took the words right out of my mouth. To quote innumerable
> others, dinosaurs aren't mammals.

Yeah, yeah, you're both probably right.  Still, the claws need not 
necessarily have struck bone every time a dromaeosaurid slashed out 
its prey.  IMHO the claws weren't there to cripple any unfortunate 
herbivore that crossed the dromaeosaurid's path - they were put to 
lively (or deadly) use slashing through the victim's hide.  

>         Tim Williams responded:
> 
> >I believe one of the major reasons sickle clawed theropods are thought to 
> >have carried their claws above the ground is because they have peculiar 
> >articulations on the toe bones that seem to let the toe sit hyperextended.  
> >Also, the claw toes have been shortened.  One quite telling feature is that 
> >the other two walking toes have become nearly equal in length, presumably 
> >for 
> >stability, and the foot bones have been reinforced.  As far as I know, 
> >cassowaries and rheas have none of these additional modifications.

Actually, this wasn't me.  It's far too intelligent and well-
researched for anything I could have said.  And I deny 
responsibility for the other stuff Sam quoted as well - two-toed 
tracks on Palaeoworld, self-sharpening claws of moggies - for similar 
reasons.  (Although I had no idea that emus were so mean.  I can 
assure you Sam, from now on I'm going to keep well away from my 
compatriot _Dromaius novaehollandiae_ ;-).)

[ He's right (imagine that :-)  My records show that Peter Buchholz was
  the author of the above quoted text and the section about Paleoworld
  as well.  -- MR ]

Tim Williams