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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