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RE: four winged Archaeopteryx

So why exactly did Archie have feathers on the tail?

-----Original Message-----
From: owner-DINOSAUR@usc.edu [mailto:owner-DINOSAUR@usc.edu] On Behalf Of
Dann Pigdon
Sent: 30 September 2006 09:10
Subject: Re: four winged Archaeopteryx

Graydon wrote:
> Feathers started as insulative structures, not aerodynamic structures.
> All known birds can fluff their insulative feathers, and it's very
> hard to see how a non-mobile insulative structure could survive
> selection pressure, so the least hypothesis is that the proto-feather
> could move.  Not a lot, but there would have to be some mechanism to
> raise and lower it to control the amount of trapped air.

Feathers are only raised to help a bird to cool down. I doubt that a
long thin appendage like a bony tail - with likely little flesh and a
huge surface area to volume ratio - would specifically need cooling down
(in fact, the opposite is more likely). Therefore tail feathers in early
volant theropods may never have had any insulatory mobility to begin


Dann Pigdon
GIS / Archaeologist         http://heretichides.soffiles.com
Melbourne, Australia        http://www.geocities.com/dannsdinosaurs