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RE: Arms into wings

At 12:40 PM 3/4/99 -0500, Tim Williams wrote:

>But seriously folks - this "predatory strike" would have to be damaging to
>the wing feathers of pre-bird maniraptorans.  It would be lost well before
>the forelimbs became aerodynamic.
>Therefore, I'm assuming the predatory functions (if any) of proto-birds
>would be executed by the jaws and feet, not the arms.  The hands would be
>used for grasping and stuffing the food into the mouth and/or for climbing
>the trunks of trees - not for killing or maiming.

I think perhaps you misunderstand the idea behind the predatory strike.  No
one is claiming that the forelimbs would be the primary instruments of
destruction.  The hands would be used for seizing the prey, but the dispatch
of the prey would primarily be the jaws and foot claws (a la modern felids,
or the "fighting dinosaurs" _Velociraptor_).  Remember that the physical act
of predation is a multi-stage event: prey must be located, acquired,
dispatched, and eaten.  Different predators use different techniques for
these various stages.

And, as Orenstein et al. have suggested, those maniraptorans who preyed on
large animals (i.e., dromaeosaurids) would probably have reduced their arm
feathers, but those which fed on smaller forms might not be that damaging to
their arm feathers.

Thomas R. Holtz, Jr.
Vertebrate Paleontologist     Webpage: http://www.geol.umd.edu
Dept. of Geology              Email:tholtz@geol.umd.edu
University of Maryland        Phone:301-405-4084
College Park, MD  20742       Fax:  301-314-9661