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Re: CNN: how first birds flew



At 12:36 PM 5/7/99 +1000, Dann Pigdon wrote:
>I'd have thought that the last thing you'd want to do if being
>pursued by a predator would be to stick your arms out. Wouldn't this
>actually slow you down?

So I would have thought, and so did most people, which is why a lot of folks
thought that it was biomechanically unfeasiable.  The point of the paper in
question is to show that, contrary to expectations, a running
_Archaeopteryx_ or other primitive protobird flapping its wings actually
adds thrust, and thus becomes faster.  Goofy sounding, but that's what their
model shows.  Find a flaw in their model, and get your paper published as a
Correction!

>I've always thought that Archae's feet
>carried recurved claws adapted for perching and grasping. Wouldn't
>these also present a problem to a fast runner? Sort of like trying
>to run in golf shoes...

Archie's foot claws are not curved to the same degree as many perching
birds, and in fact its toe proportions are about the same as primitive
terrestrial dinosaurs such as _Eoraptor_ and _Coelophysis_.  The consensus
of Hopson and Zhou was that it was kind of an all-puporse foot: good for
perching, but also for running.

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