Re: Dromaeosaur tracks (was: thanks for tracks & a question)

[Betty Cunningham <bettyc@flyinggoat.com>]

domestic cats have a keratin sheath covering around the claws that they
shed rather constantly.
I have several nearly perfect claw-shaped bits that I've picked out of
sharpening posts in the past.
This replacing of the blade-y bits seems to help keep the tips sharp
even with constant wear.  
 
Perhaps something like a sheddable sheath covered the sickle-claw and
could help reduce wear from incidental walking damage.

-Betty Cunningham

(Do all wild cats have a sheddable claw-sheath?  In particular I'm
wondering about cheetahs)

"Ralph W. Miller III" wrote:
> It surprises me that the tracks reveal the "terrible claw" at all;
> articulated dromaeosaur specimens have preserved the digit in a
> hyperflexed pose.  If the claw were habitually extended during
> locomotion, contact with the ground would cause wear on the tip,
> blunting the ungual phalanx and rendering it less useful as a weapon.
> For example, a dog's or cheetah's primary manual and pedal claws are
> quite dull compared to the claws of cats (excepting cheetahs), which
> extend their claws only for such purposes as climbing trees and
> fighting.  Similarly, the cheetah's dew claws, which do not contact
> the ground, retain their sharpness, and are reportedly used by the
> cheetah to bring down prey by hooking or snagging.


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