RE: Claw function in Deinonychus

[Tim Williams <twilliams_alpha@hotmail.com>]

Andrew Simpson wrote:

> Excellent points Richard. My own take is rather simple. Why have the thing 
> if it's so unnecessary? I
> don't think such a weapon would develop if it wasn't a very useful and 
> necessary tool. And it remained on every dromaeosaur and Troodont for as 
> long as they remain in the fossil record

Perhaps not *all* troodontids.  In _Borogovia_ this claw is straight, not 
sickle-shaped, and it's hard to imagine how useful it could have been as a 
predatory tool.  In _Tochisaurus_, the second metatarsal is reduced and very 
slender, so the second toe may have lacked a "killer-claw".

AFAIK, the idea that the deinonychosaurian sickle-claw was used as an 
eviscerating device goes back to John Ostrom and his studies on 
_Deinonychus_.  (Sorry if this has been mentioned before - I came in late to 
this discussion).

Finally, there is a contrarian view that the sickle-claw originally evolved 
as a tree-climbing aid, and was later exapted into a predatory instrument.

John Hunt wrote:

> The programme also starred Ken and a robotic Ankylosaur tail that was used
> to break all the ribs of a pig carcase and send turkeys (standing in for
> Velociraptor) flying across the room.

Sounds like a fun thing to do at Thanksgiving - except if you happen to be 
the poor turkey standing around waiting to be thagomized by a tail-club.  
Just dragging the bird to the chopping block is probably more humane, and 
much less messy.

Cheers

Tim