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Re: Campbell's even crazier than a MANIAC? (archeopteryx climbing)

David Marjanovic wrote:

<Don't crampons work side-to-side? Sickle claws worked top-down and probably 
had a cutting edge. They were not round in cross-section.>

  Who says they had a cutting edge? Not all dromaeosaurid claws have a tomial 
ridge on the ventral edge. In fact, only that of *Utahraptor* has this feature, 
and that holotypic claw is crushed mediolaterally, exaggerating the degree to 
which the claw seems narrowed. The sharpened ventral margin is an inferrence 
that's been applied to them _because_ they were assumed to be cutting devices.

  Do recall in the TV spot that the experimentalists using ONLY the bony cores 
of *Deinonychus* pdII-3s were unable to acheive a cutting action in soft 
material, which is why the "crampon" idea has received more attention recently.


Jaime A. Headden

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