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Re: OVIRAPTOROSAURIA! Part One [Overview]



 Ray Stanford <starsong@prodigy.net> writes:
>     Richard W Travsky asked,
> >Feathered? Just out of curiosity, were any ground surface impressions
> >preserved at this site? Impressions that would indicate feathers?

>     No, there have not been any feather impressions noticed, BUT...
> 
>     The dry, highly wind-vulnerable situation involved would not readily
> lend itself to feather impressions.  --SNIP--
>     If an Oviraptor had been deposited in the kind of environment that
> preserved Confuciusornis sanctus, the remains might show us
well-feathered
> arms (wings).

Yes, but perhaps actual feather keratin could be preserved, as Mary Higby
Schweitzer has proposed for a (Cretaceous) specimen of _Shuvuuia deserti_
collected in the Gobi desert of Mongolia by the American Museum of Natural
History.  Schweitzer examined the delicate 3-nanometer-diameter hollow
white fibers associated with the head and neck of the _Shuvuuia_ fossil,
and performed  tests which produced results consistent with the proteins
found in bird feathers.  She revealed her results both at the 1997 SVP
meeting and at the 1998 Dinofest symposium.  Quoting the Dinofest abstract
volume:

"Microscopic and chemical analyses eliminated plant material or fungal
hyphae as a source for these fibers.  Antibodies specific for beta keratin
reacted strongly with these fibers, while antibodies against alpha keratin,
antibodies present in normal sera, and antibodies raised against a
non-relevant protein were negative for binding, a pattern consistent with
modern feathers."

I hope that she publishes a paper on this work in the near future!  On a
related topic, she also discussed the presence of keratin proteins
recovered from the claw sheath of _Rahonavis ostromi_ from Madagascar.

In contrast to the above, Larry D. Martin presented a talk, entitled
_Information on the Soft Tissues of Dinosaurs_, in which he stated that SEM
analysis of carbonized feathers (such as those associated with
_Confuciusornis_) reveals that the fossils preserve "keratin-loving
bacteria" rather than the original feather keratin.  This would mean that
there were feathers on the living animal, but the original proteins
themselves are no longer present.

In any case, it would appear that although feather or integument
impressions are unknown from the Cretaceous Gobi desert fossils, more
preserved keratin structures such as feathers could be discovered among the
Gobi fossils at some future date.  On the other hand, such structures are
exceedingly rare in the fossil record, so the absence of fossil evidence
does not prove that _Oviraptor_ was featherless.  If skin impressions are
to be found at some point, tracks should be present among the fossils as
well.  Have any fossilized tracks been found in the region?  

-- Ralph Miller III     gbabcock@best.com