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Re: Return from SVPCA



> More than teeth? Would be great to see some real _bones_
> of a late Jurrasic tyrannosauroid.

One such bone has been known for quite some time now.

Oliver W. M. Rauhut: The dinosaur fauna from the Guimarota mine, 75 -- 82
in:
Thomas Martin & Bernard Krebs (eds): Guimarota -- A Jurassic Ecosystem, Dr.
Friedrich Pfeil 2000

p. 79:
"The genus *Stokesosaurus* is the only taxon of theropods that is
represented by identifiable skeletal material in the Guimarota mine. A small
right ilium, which is only 8.5 cm long (Fig. 11.13 [a very good photo of the
almost complete bone]), can be referred to this genus, which was originally
also described on the basis of an isolated ilium from the Late Jurassic
Morrison Formation of North America (MADSEN 1974). The ilium of
*Stokesosaurus* is characterized by a well-developed, sharply defined
vertical ridge over the acetabulum and the extremely broad and short pubic
peduncle (Fig. 11.13). The specimen from Guimarota differs from the type
specimen of *Stokesosaurus clevelandi* from the Morrison Formation, which is
almost twice as large, mainly in the proportions; however, it cannot be
determined at present, [sic] whether these differences indicate the presence
of a different species, or if they are only due to ontogenetic variation.
Although known only from fragmentary material, the genus *Stokesosaurus* is
also of great interest. A vertical ridge above the acetabulum, as it is
found in this taxon, is otherwise almost exclusively known from
tyrannosaurids (MOLNAR et al. 1990); thus, *Stokesosaurus* has repeatedly
been interpreted as the oldest known possible tyrannosaurid (MADSEN 1974,
BRITT 1991). This theory is now supported by the presence of several
tyrannosaurid-like teeth in the Guimarota mine, including two of the
diagnostic, stout premaxillary teeth, which are D-shaped in cross-section
(Fig. 11.14; ZINKE 1998). Together with the discovery of a tyrannosaur-like
braincase in the Morrison Formation (CHURE & MADSEN 1998) the material from
Guimarota thus indicates that the origin of tyrannosaurids also reaches back
to at least the early Late Jurassic. Furthermore, it seems that the first
tyrannosaurids were rather small animals, and only their Late Cretaceous
representatives grew to giant size, such as the well known *Tyrannosaurus
rex*. This theory is in general accordance with the assumption that the
tyrannosaurids belong to the generally rather small coelurosaurs (HOLTZ
1994)."

One has to read the expensive books, too. I got mine as a review copy. If
only I remembered my username so that I could check if it is published on
the website of the Dinosaur Society... but currently www.dinosociety.com
that site doesn't quite exist and www.dinosaursociety.com, as well as both
versions of -org, don't exist at all. <grumble> ~:-(

In any case I can recommend the book. It's great. The text is very detailed,
and the photos are breathtaking. (They, along with the incredibly heavy
paper, probably make up most of the hefty price.)