Re: Dromaeosaur "sickle" claws

["Gigi Babcock or Ralph Miller III" <gbabcock@best.com>]

----------
> From: Jeffrey Martz <martz@holly.ColoState.EDU>
> To: Peter Von Sholly <vonrex@gte.net>
> Cc: Gigi Babcock or Ralph Miller III <gbabcock@BEST.COM>;
m_troutman@hotmail.com; dinosaur@usc.edu
> Subject: Re: Dromaeosaur "sickle"  claws
> Date: Wednesday, August 27, 1997 11:59 AM
> 
 > If you ever cut yourself with an x-acto knife or razor, you know
 > it's a clean smooth cut.  Cat scratches rip and rake and bounce over the
 > surface.  Yes, they can dig in and tear the skin, but not slice it, in
the
 > way I would define SLICING. 

Agreed.  I was trying only to point out that there is more than one way to
rip flesh; dromaeosaurs did not need serrations on their so-called "sickle
claws" to do this. I used the term "slicing" only in reference to swords
and scalpels in my post, but my lack of clarification led to the
regrettable implication that I believed scalpels and dromaeosaur claws were
apt analogs.  I apologize for the misunderstanding.
    
>      Exactly.  Curved knives and swords have the cutting edge on the
> convex side, presumably because it makes it easier to DRAW the edge along
> what is being cut, which makes it much easier to cut.  Try cutting a
> tomato just by pressing down, and then by slicing.  Dromeosaur claws
would
> have the same problem.  With the cutting edge on the concave side, it
> would be more difficult to draw the edge along the wound, and the
> likelyhood of the TIP of the claw getting snagged would be greater.

And in this respect, the claws of animals (dromaeosaurs included) are
decidedly unlike man-made blades.  Perhaps this is due in part to the need
to prevent the prey from escaping (just as a good many predators have
recurved teeth that keep the prey from exiting the mouth).  A convex blade
would also merely bounce off osteoderms, while a more hook-like claw might
be able to work its way between them (provided they are not too densely
packed together) and do some damage.  Furthermore, the narrow so-called
"sickle" claw would seem to be better suited to _lacerating_ flesh than a
claw that is rounder in cross-section.  The narrow aspect of the claw would
make it more "flesh-o-dynamic".  In my opinion, _lacerating_ and stabbing
would both be possible and desirable (for the predator, that is).  Either
way, it would be very messy!  And most unlike the trimming of stalks of
cultivated wheat.

Ralph Miller III <gbabcock@best.com>