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Re: ABSRD BAND on Sinornithosaurus feathers



----- Original Message -----
From: <Dinogeorge@aol.com>
To: <dinosaur@usc.edu>
Sent: Thursday, March 15, 2001 5:27 PM
Subject: Re: ABSRD BAND on Sinornithosaurus feathers


> In a message dated 3/15/01 10:20:24 AM EST, kinman@hotmail.com writes:
>
> << If every stage in the
>  evolution of a morphological structure has to be adaptive, then it is
>  difficult to fathom how a simple hollow cylinder or a pine needle-like
>  branching structure can be functional in an animal. >>
>
> As usual, they overlook the obvious solution to this conundrum: the
feathers
> of Sinosauropteryx and some of the other Liaoning theropods are derived
from
> more birdlike feathers such as those seen in the earlier Archaeopteryx.

There is an even simpler, IMHO even more obvious, solution: just about any
shape is perfect for getting rid of excess sulphur-rich protein, and
hairlike shapes are, as we know, just fine for insulation.

Weight reduction in a solid plate might (if it would occur at all, which is
counterintuitive in a surface used for gliding) produce a net-like shape,
but not an open branched one.

HP Thomas R. Holtz answered:

> Actually, they are ignoring something even more fundamental, which is the
> actual way feathers develop in living birds.  [...] see, for example,
>
http://www.bioone.org/bioone/?request=get-document&issn=0003-1569&volume=040
&issue=04&page=0513
> [...] Feathers are really a lot
> weirder than you think they are in the way they grow: a strange
> conveyer-belt like mechanism that adds the accessory structures onto the
> main shaft during development.

Great article! Thanks a lot for the link!!!