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Re: Feathers on Bloody Everything



At 6:23 PM +0000 5/27/99, luisrey wrote:

>After seeing the article and photographs in Nature just a few hours ago, I
>think Martin will go for the fact that there is no space between the fibers
>and the bones (unlike Sinosauropteryx). Even if this can be easily
>explained at the conservation level, ABC News has already something about
>it (that is: Martin putting down the therizinosaur fibers as collagen
>fibers).

I talked with Larry Martin and that's exactly what he said. I pointed out
that the filaments were much longer than those of Sinosauropteryx, and
Larry noted that Beipiaosaurus is a larger animal.

>The problem here is pattern and branching of the fibers and that again they
>are observed as hollow...it must have been a thick coat indeed.

>From the photo (I have a color version from Xu Xing), they look more like
filaments dangling from the bottom of the arm, as if they formed a frill. A
close look shows a central depression, as if they were hollow -- a critical
link to feathers, as Alan Brush pointed out. Otherwise, he says they look
very 'Sinosaupteryx-like'. There is no clearly discernible branching
structure, but there may be some splitting of the filaments at the end, a
bit like split ends on hairs, as if they had frayed.

Some of the Nature paper is devoted to a cladistic analysis of dinosaur
lines, trying to place the therizinosaurs with respect to other dinosaurs.
I get the impression from comparing these analyses that there was a rapid
branching of several groups at roughly the same time, which makes tracking
the origins of feathers all the more complicated. These divergence patterns
may in fact be an even more intersting question than the origin of feathers
because they reflect on evolution as a whole, not just the particular (and
fascinating) question of the origin of feathers. -- Jeff Hecht

(Yes, New Scientist has a brief story on Beipiaosaurus; I'm not sure if
it's on the web. I just got back from a three-day trip and am digging out.)

Jeff Hecht     Boston Correspondent    New Scientist magazine
525 Auburn St.,          Auburndale, MA 02466             USA
tel 617-965-3834 fax 617-332-4760 e-mail jhecht@world.std.com
URL: http://www.sff.net/people/Jeff.Hecht/
see New Scientist on the Web: http://www.newscientist.com/