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Re: DROMAEOSAUR "SICKLE" CLAWS



I agree.  Tracy Ford says the really large claw (on Deinonychus) is known
from a single specimen.  And dromaeosaurus claws are nowhere near that big,
from what I can see.
----------
> From: Jonathon Woolf <jwoolf@erinet.com>
> To: gbabcock@best.com
> Cc: franczak@ntplx.net; dinosaur@usc.edu
> Subject: Re: DROMAEOSAUR "SICKLE" CLAWS
> Date: Thursday, September 04, 1997 6:26 AM
> 
> Ralph Miller III wrote:
> 
> > What, then, do <you> think the dromaeosaurs were doing with those big
> > claws?
> 
> I don't know what they were used for.  I only know that I don't really
> find any of the conventional explanations to be convincing.  The huge
> foot-claw in dromaeosaurs seems to me to be a case of extreme overkill
> in any predatory scenario.  Between foreclaws and teeth, a dromaeosaur
> already had as effective a set of killing weapons as any theropod, and
> more so than some, like the toothless _Oviraptor_.  If we argue by
> analogy with modern predators, then a dromaeosaur hunting alone could
> bring down anything its size or smaller with just foreclaws and teeth. 
> Dromaeosaurs hunting in packs could take down animals equal to their
> collective masses, four or five times the size of a single hunter.  So,
> why the big claw if they were already efficient predators without it?
> 
> Cats have four claws they use for raking.  Dromaeosaurs had one claw. 
> Four claws means the strength of the legs is split four ways.  One claw
> means the whole strength of the leg muscles is focused onto one point. 
> I can't articulate the argument very well, but there's something about
> how focusing more strength onto one point increases the chance of
> snagging and doing damage to the claw, and also increasing the clawee's
> resistance so that the lone claw actually does _less_ damage than the
> four.  So, the single big hind claw may not have been all that effective
> as a hunting weapon.  Also, the deeper the claw digs, the more
> resistance to pulling it lengthwise.  That big claw would have dug
> pretty deep.  What good is a raking claw if it tends to jam or catch in
> bones?  You'd wind up with a lotta droms trying to walk on sprained,
> wrenched, or dislocated legs. <g>
> 
> I suppose one could argue that the big claw developed as a sort of
> built-in piton, to dig into a large prey animal's body and hold on while
> the teeth and foreclaws did the killing damage.  Unlikely but possible.  
> 
> One of the suggestions I've heard that I liked a lot is that the claw
> was a sexual characteristic.  That would explain its exaggerated size. 
> Have any dromaeosaurs been found with proportionately much smaller
> claws, perhaps cases of sexual dimorphism?  
> 
> All in all, though, I find that the notion of the foot-claw as a primary
> weapon simply isn't convincing.  I think it was used for something else
> we haven't yet figured out.
> 
> -- JSW