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Re: New Velociraptorine



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> Again, IF the new dromaeosaur is a juvenile, then this may explain the
> supposed poor development of part of its sickle claw. Is better to wait for
> the specimen to be described in detail than to speculate about it.

I found no fault in the sickle claw per se of this particular specimen.
My point was more general, namely, that I think the general perception
is of the sickle claw tendons supplying their own power to slice into
prey. I find that supposition, if it exists, suspect, and propose
instead that the joint could be locked into position while the leg
muscles drive the claw into the prey.

An additional argument if favor of this considers how to maintain
muscle tone in the muscle responsible for driving the claw into prey.
99% of the time, the opposing retractive muscle is actuated and the
main driving muscle relaxed (so the sickle claw is out of the way
and stays sharp). So the main driver muscle is has very little
opportunity to develop especially to the bulk required to be
a major factor, even if the tendon and joint are adequate.
[I doubt calisthenics were a dino strong point :)]

The relevance to the present specimen was mainly in hopes that
someone might actually look at it to assess the quality of the
bearing surfaces in the sickle claw's joint. The ability to lock
the sickle claw joint may be characteristic of some or all
dinosaur species possessing a sickle claw.

Russ Andersson





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