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Re: DROMAEOSAUR "SICKLE" CLAWS



Jonathon Woolf wrote:
>
> Casey Tucker wrote:
>
> > 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.
> > > -- JSW
> >
> > Extreme overkill?  Nothing like the fangs on a Sabretooth cat,or a modern
> > Persian Leopard who has one of the proportionally larger sets of fangs of
> > any modern predator, or the amount of force per square inch in a
> > crocodile's bite.  There are many examples of predators with "weapons" that
> > seem like overkill.
> >
>
> Paleontologists aren't sure yet what sabercats used their sabers for.
> In fact, there seems to be as much debate over that as there is over
> dromaeosaur claws. <g> We only know that exaggerated fangs is a
> repetitive trend in felid evolution, with at least four separate lines
> yielding sabertooth or dirktooth forms.  The snow leopard is an
> incipient fifth longtooth form, but right now its fangs are simply
> unusually long for its size.  Nowhere near as exaggerated as
> _Smilodon_'s sabers or _Deinonychus_'s big claw.

Perhaps my info's outdated, but I thought it clear that _Smilodon_ used
its teeth to effectively hunt and kill juvenile mammoths.  It's build
certainly supports the idea, and there are some crazy lions and tigers
even today who hunt elephants, so the concept isn't completely unheard
of among felids (or their kin, as the case may be).

> As for crocs, the amount of force in a crocodile's bite is not
> overkill.  It's an adaptation that gives a higher chance that the croc
> will hold onto a catch.  A croc's teeth aren't especially sharp, so it
> needs brute force to drive them deep into a prey animal.  And even
> with that staggeringly powerful bite, it's still not unheard of for a 
> prey animal to break free and escape.

This, I think, should be a critical part of determining the hunting
behavior of Dromaeosaurs.  How much force can they exert with their
jaws?  Most of the discussion here's been centered around that one big
claw; before we can really talk about behavior, though, we have to see
what other characters might support a given lifestyle.  Force per unit
area exerted by the jaws is a huge part of that, at least in modern
carnivorous mammals (and birds?  Do raptors have especially powerful
jaw/beak muscles?); if that force isn't terribly great any notion of
pack hunting in these animals is kinda silly if the claws aren't used as
weapons.

Chris