Re: feathered coelurosaurs

[tholtz@geochange.er.usgs.gov]

>>But more to the point, the only potential case of feathers or feather-like
>>structures in nonavian dinosaurs known at present are the integumentary
>>features of the recently described Pelecanimimus.  These consist of two
>>series of fibres, one oriented perpendicular to the body, the other
>>parallel.  Unforutnately, the photographs do not show them very well, and I
>>haven't seen them in person yet.
>
>This is very interesting; can you give more details?  

I wish I could, but as of yet I still haven't seen the real thing, nor a
decent micrograph.

>I was also under the 
>impression that there  was a print, possibly made by a bipedal dinosaur 
>resting its forelimbs on the ground, that somone had claimed showed the 
>imprint of what could be feathers. I have no details, though - sorry.

I seem to remember this.  One problem with such things is that impressions
can be misleading - sometimes the "backwash" from a bipedal dinosaur
breaking into a run can look "feathery".  Still, a really good bodyprint
should be able to show feathers, since many footprints show clearly the
scales on the bottoms of the toes.

>Has it not also been claimed that the forelimb of Avimimus has a ridge that 
>might have served as an anchor point for featjers (I recall feeling dubious 
>about it when I read it)?  

I am dubious about this as well, since the structure which Kurzanov
described is not found in modern, feathered birds.

>Perhaps more to the point, there are very few 
>fossils of genuine, unquestionable birds that show feather imprints; we were 
>just lucky with Archaeopteryx.

This is very true.  A side note: there is almost no possibility that
feather impressions will help determine if Protoavis is a bird or not.  It
was found disarticulated in a medium-grained dirty sandstone, which is not
conducive to feather impressions.  Ah, well...
                                     
Thomas R. Holtz, Jr.
Vertebrate Paleontologist in Exile
U.S. Geological Survey
Branch of Paleontology & Stratigraphy
MS 970 National Center
Reston, VA  22092

email:  tholtz@geochange.er.usgs.gov 
Phone:  703-648-5280
FAX:            703-648-5420