RE: Claws on deinonychosaurs

["Jaime A. Headden" <qilongia@yahoo.com>]

Ken Carpenter (Ken.Carpenter@dmns.org) wrote:

<With respect to Jamie, he forgets that the claw of the foot in the vicinity of
the throat is extended, the other toes curled back. That of the other foot is
not.  Thus, the claw was being engaged as a weapon. With a sample size of one,
we do not know whether  this was the normal place of attack, just that in this
instance it was. As Manning and I have independently noted, the sickle-claw was
used as a piercing weapon, not as a slicing-dicing Ginzu knife.>

  I have no problem with the extension of the lifted leg of the GIN 100/25
*Velociraptor*, as well as the extended toe claw. As noted in earlier examples
of defensive cats, they will extend their claws as well, both to rake with the
hindlimbs and grasp with the forelimbs, without ever intending to kill my arm.
The action seems incidental to the action undertaken in a truly defensive
behavior, if the animals needed to eviscerate an attacker or more aggresive
cat. Cats are also typically neck and back biting attackers, with exception
given to cheetahs which attack the throat after tripping their prey, or
leopards which go for the head, so this "underbelly strike" is indeed purely
defensive.

  As for predatory behavior, it is just as likely to label a warthog,
*Phacoochoerus* spp. as a predator since as has been recorded to hunt lion
cubs. The tusks are also used to gouge defensively and can kill, but are not
neccessarily predator-related. While in a predator, *Velociraptor*'s claws
argue that they are aggressive, attacking machinery, but this does not mean all
uses for them are thus for killing, and that any association they are found in
means they were being used to kill prey. Their curved nature and inner
sharpened edge recalls the use of certain curved knives that are used to not
only pierce but slice open the throats of victims of the Sikh and Thuggee
assassins in the Hindu-Kush. In the studies of "sabre" use for killer cats, a
similar experiment on a dead bison used sabres to simulate how the piercing
equippment actually slice open, and eventually cut through the interventing
flesh, causing a jagged "rent". The shapes of these sabres are a LOT less
curved than those of most dromaeosaur claws, save for the foot sickle, which
actually has a relatively uncurved profile compared to the manus unguals. Thus
their action would require a constant flexure to perform the same action
sabretooth cats use. However, their position given the foot-based rather than
jaw-based equipment allows them to be "atop" the victim to perform this action,
since being below on the ground, while also allowing them the same vantage, put
them into a far greater vulnerable position for attack from above. I thus think
it unlikely the GIN 100/25 *Velociraptor* was attacking the *Protoceratops*.
This speaks little, in fact, of whether *Velociraptor* was capable of hunting,
and as above may note, was probably just as effective at it as sabretooth cats
were. I am arguing only about the behaviors inferred for a particular
assemblage, the Fighting Dinosaurs.

  Cheers,

Jaime A. Headden

"Innocent, unbiased observation is a myth." --- P.B. Medawar (1969)


                
__________________________________ 
Yahoo! FareChase: Search multiple travel sites in one click.
http://farechase.yahoo.com