Re: no feathers on Pelicanimimus

[Nick Longrich <longrich@phoenix.Princeton.EDU>]

I heard this one a few days ago, and my thoughts are:
No, it does not disprove feathers in Pelicanimimus. It pretty firmly
establishes that there were no feathers on the *head and neck* of
pelicanimimus. It is not ridiculous to suppose that the rest of he body of
Pelicanimimus was covered in insulation, actually, since this is just what
you find in various avians including some storks, old and new world
vultures, cassowaries I believe, and some species of ibis, to name a few.
You can debate, of course, what evidence there actually is for this.
Sinosauropteryx may or may not have borne feathers (in the sense that all
modern birds have complex, branched structures), but it seems likely that
it did bear some kind of hairlike insulatory somethings. If they are
simple, unbranched structures, in the end- bristles or fur- then whether
it is "feathered" becomes just a decision of what a "feather" is. I don't
think there's any official way to establish this but you could either
define a feather to be "insulatory structures of dinosauria and their
derivatives" or the branchy things we see in all birds including
"degenerate" things like ratites (less branchy but still branchy). 
However, there is some indirect evidence that the common ancestor of
troodonts, dromaeosaurs, and oviraptors did have honest to goodness
avian-style feathers. 

Nick L.

On Mon, 9 Jun 1997 Pieter.Depuydt@rug.ac.be wrote:

> Perhaps this is old news for most of you, but I didn't read anything about it 
> on the list so here it is:
> 
> from Science 30 May 1997, Random Samples:
> 
> 'No Feathers on Spanish Dino'
> 
> 'Last year, Chnese paleontologists stirred up an ongoing controversy 
> when they suggested that the fossil of a birdlike dinosaur foud in 
> China had a featherey mane (...). But since then, there has been no 
> further evidence to support the theory that some dinos had feathers. 
> Now a birdlike dino found in Spain offers some negative evidence:
> A detailed mold of skin from its head suggests that this 
> particular creature was featherless. (...)
> The first birdlike dino to be found in Europe, the animal had a 
> pelican-like throat poach and a soft tissue crest on its head. 
> Microscopic examination of the skin showed that its surface was 
> wrinkled and "bore no evidence of any structures such as feathers or 
> enlarged scales", according to Derek Briggs of Bristol Universtiy, 
> who, with Jose Luis Sanz of Universidad Autonoma de Madrid, has been 
> studying the fossil.'
> 
> Further according to the Science report, the full research will be 
> published in the July issue of the Journal of the Geological Society, 
> London.
> 
> The generic name of the dinosaur is not mentioned in the Science 
> report, but I guess it's the ornithomimosaur Pelicanimimus...
> 
> Pieter Depuydt
> 
>