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Re: How did dromaeosaurs use their arms?
In a message dated 5/10/00 3:45:42 PM EST, email@example.com writes:
<< Research has shown that feathers, even simple covert-type feathers,
significantly decrease aerodynamic drag over a surface. That's a significant
aerodynamic effect which is not just relevant for flight but also for ground
based manueverability. >>
I can think of no extant cursorial animals whatsoever that have featherlike
or hairlike forelimb structures for ground-based maneuverability that didn't
already have them because they're descended from flying ancestors--and such
forelimb structures are usually vestigialized. Simply using the feet against
the substrate is >far!< more effective for ground-based maneuverability than
any kind of aerodynamic integumentary structures or forearm flailing.
Hypothesis rejected: is awkward, doomed attempt to figure out >some kind< of
farfetched way that feathers might have appeared in ground-dwelling cursors
without having them simply go up into the trees and fly/glide first.