Sinosauropteryx fibers (was Lizard Frills and Chimeras)

["Ralph Miller III" <gbabcock@best.com>]

Scott Robert Ladd <srladd.dino@juno.com> wrote:
> I asked Feduccia about Sinosauropteryx; he stated that the fibers along
> the fossil's spin are not feathers, but collegen fibers that supported a
> frill. I've heard him make this claim before, altho he tells me that "it
> will all come out soon." Is there any conclusive evidence as to the
> nature of these "fibers?" Not having access to the fossil myself, I can
> only go by the rather small pictures I've seen (the best was in
> Scientific American a few months back). If anyone has a large,
> high-quality picture, I'd love to see it.

I didn't know anyone still regarded the "sea snake or marine iguana frill"
hypothesis as having any viability whatsoever, but there you are.  At the
same SVP meeting where Nicholas Geist proposed the unconvincing aquatic
frill collagen hypothesis (Chicago, October 1997), Philip J. Currie
presented his assessment of the three _Sinosauropteryx prima_ specimens
which he had personally examined during his three trips to China.  You can
read several reports in the archives of this list dating from that time
period.

Currie described the fibers (which didn't remotely resemble the collagen
fibers Geist projected) as running not only all along the neck, the back,
and the top and bottom of the tail, but also between ribs 2 and 3 (meaning
under the ribs, and therefore representing integument of the bottom side of
the fossil slab), behind the humerus, behind the tibia, and between
(behind) the haemal spines.  He has also stated that the fibers are layered
(piled on top of each other) and so do not represent a single midline row. 
Furthermore, the head is tilted in the first specimen, rather than being in
profile, so the fibers running along the top of the head don't represent a
midline frill, either.  These descriptions of the fibers are also
interpreted to mean that the fibers could not possibly be internal
features.  The third specimen of _Sinosauropteryx_ has not yet been
formally written up in Western journals, and some of Currie's observations
are derived from studying this third specimen.

Philip J. Currie has also found evidence to suggest that the fibers were
hollow structures, as the Chinese authors of the description in _Nature_
also believe.  And Currie claims to have seen a branching organization to
some of the fibers.  Even if these latter two observations are not
corroborated by further studies, the chance would still be zero % that the
fibers are in any way comparable to the internal collagen features of a sea
snake or a marine iguana.

For fabulous color photos of _Sinosauropteryx prima_, see _Audubon_, April
1997.  For the first paper on the animal published in English, see
_Nature_, January 8, 1997.  More information on the fibers will be offered
at the Dinofest symposium in Philadelphia next month.

-- Ralph Miller III     gbabcock@best.com