Re: no feathers on Pelicanimimus

[nino@uam.es]

At 18:15 9/06/97 -0400, you wrote:
>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.

We actually have the anterior part of the Pelecanimimus (say, from the
anterior end of the ilium to the head, with both forelimbs), and there is no
remains of any kind of insulation. It has a naked skin, without any remains
of scales, hair of feathers.

>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.

The hairlike structures we though could be feathers or something like that
become muscular remains (I think it could be the same in Sinosauropteryx)and
the wrinkled skin.So, Pelecanimimus has no insulatory structures in the
anterior part of the body.
Nino.
Bernardino P. Perez-Moreno                      E-mail: Nino@uam.es
Unidad de Paleontologia                         Fax: 34-1-3978344
Departamento de Biologia
Facultad de Ciencias
Universidad Autonoma de Madrid
28049 - Madrid
SPAIN