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Re: Psittacosaurid hair & Sauropod Spikes



> >From: "Zoe Heraklides" <z_heraklides@hotmail.com>
>
> >I recall that integument/epidermally derived spikes were recorded for a
> >sauropod (?Diplodocid?) specimen from N. America.  Can anyone confirm?

As Jordan Mallon writes, the "Skin" article in Currie's & Padian's
_Encyclopedia of Dinosaurs_ describes and illustrates these features found on
the tail of a sauropod said to be most like _Diplodocus_ and _Barosaurus_,
excavated at Howe Quarry in northern Wyoming by Kirby Siber, a private Swiss
collector, starting in 1990.  It makes you wonder where the specimen end up...

Please note, however, that the sauropod spines do not resemble the putative
_Psittacosaurus_ integumentary features.  Czerkas describes the the sauropod
structures as "...dermal spines, much like those on the back of iguanas and
crocodile tails..."  They do not resemble "hairs" or "quills" at all.  In
addition to the narrow pointed spines which apparently straddled the dorsal
midline, wide, blunt spines appear to have decorated the animal's flanks.  It
is proposed that the spines were made of keratin, as they lacked bony cores.
This is not surprising, as feathers, horn sheaths, scales, and the
aforementioned reptilian spines are all made of keratin.

See also the DINODATA Reference Base on Czerkas at
<www.dinodata.net/Refs/C/CZERKAS.htm> for the complete references to Czerkas'
papers on the sauropod spines from _Geology_ 20, pp. 1068-1070 and _Gaia_ No.
10.

The illustration of the reconstructed skeleton against a silhouette of the
restored animal also appeared in a brief report in _Science News_, February
20, 1993 and an article in the Dinosaur Society's _Dino Times_ (date
unknown).  A newspaper article on the sauropod spines (with the same
illustration), "Familiar Dinosaurs May Take New Shape," by John Noble Wilford,
is reprinted on pp. 45-47 in the _New York Times Book of Fossils and
Evolution_.

The skeleton and the silhouette profile must be regarded with caution,
however, as the specimen has not even been assigned to a genus (suggesting the
fossil is far from complete), and the spines are illustrated along the full
postcranial dorsal midline (whereas they are only known from the tail).

As for the _Psittacosaurus_?  All I know is what I have seen in cyber space
(for what it's worth)!  It is either an amazing new find or another galling
example of the art of "creative prep work" Liaoning style.

-- Ralph W. Miller III   ralph.miller@alumni.usc.edu

"Does she or doesn't she?  Only her hair dresser knows for sure."