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Re: Lemurs and Feathers
In a message dated 6/19/01 2:44:01 PM, david.marjanovic@gmx.at writes:
<< Underwater flight provides a scenario in which the flapping movement (and
the aero-/hydrodynamic wing shape etc.) can be perfected >>
The problem with underwater flight is lack of fossil evidence. The
progression from non-avian to avian forelimb occurred in animals that ALL had
long thin hind limbs. They were not swimmers (other than when forced to,
perhaps) -- they were born to run.
<<flight in air is apparently next to impossible with symmetrical and
asymmetrical wing feathers>>
So some people say.
Here's a hypothesis: ALL fossilized dinofeathers have SOME degree of
asymmetry. Hard to disprove, right? Poorly preserved, right? Ever plucked a
chicken? There's hardly a symmetrical feather on it. Why assume dinofeathers
started out symmetrical? Their scales already weren't. Most integumentary
structures in nature are quite asymmetrical, including scales, scutes, hairs,
feathers, claws, teeth . . . um, have I missed any? The accusation of
theropods having symmetrical feathers seems likely to fade away with the
first specimen preserved well enough to give clear measurements of such
details.
Based on a simple look around the animal kingdom, why not go with the
majority? Asymmetry is plesiomorphic for MOST vertebrate structures, period.
Thomas P. Hopp
Author of DINOSAUR WARS, a science fiction novel published by iUniverse
Now Humans are the Endangered Species! http://members.aol.com/dinosaurwars