Caveat (was:Re: SAUROPOD FEATHERS)

[Silvio Renesto <renesto@mailserver.unimi.it>]

At 14.41 16/02/02 -0800, you wrote
>  Cosesaurus
> has a "dorsal frill", Sharovipterx has scales on the tail and snout, but
> smooth neck skin.

and David Marjanovic wrote:

> Sharovipterx has scales on the tail and snout, but
> smooth neck skin.
Really? Cool.

Dear all
Not strictly on topic (dino feathers): but I feel that something like 
"according to...."  should be added to statements about these two critters. 
In fact there are lots of divergent opinions . The first describer, 
Ellemberger, saw "feather-like" impressions in Cosesaurus ( he thought it 
was a *bird* ancestor), subsequently David Peters saw "dorsal frills" and 
other similar structures (he considers  it as a *pterosaur*-related 
taxon)  while others (Sanz, for instance) saw "nothing" at all (they think 
it is simply a prolacertiform). . As far as I know  and have seen, the 
preservation is quite peculiar and it is extremely difficult to state what 
there really is, and I for one, would share the third group (this does not 
mean I dismiss Dave Peters hypothesis), to me, the impressions if ever 
present, are of nothing else than sedimentary structures. For what concerns 
Sharovipteryx, Unwin et al. wrote : "The integument covering the skull 
,NECK  (emphasis is mine) trunk .... bore small tubercular or keeled 
scales".  On the other hand Dave Peters has a different opinion (AFAIK he 
is working on this, thus I cannot tell more) . I do not know the reference 
for the naked neck (?), and having not seen Sharovipteryx first hand I do 
not have any personal opinion.
What I mean here,  however, is this: while we have  lots of hypotheses on 
these animals, the revidence is really scarce or at least highly 
controversial, thus it might be advisable to be dubitative when quoting 
about their features or using them to support any assumption.
All the best,

                                        Silvio Renesto


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"The Wise Man is like a bamboo tree;
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                                                Lao Tzu

Silvio Renesto

Dipartimento di Scienze della Terra
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