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New papers on the dinosaur formerly known as Syntarsus (no more "Megapnosaurus")
Today I got my hands on the December 2004 issue of PALAEONTOLOGICA AFRICANA,
with two dinosaur papers that I haven't seen mentioned online yet. Both
papers describe the same specimen and originate from Anthea Bristowe's M.Sc.
disseration at the University of the Witwatersrand, Johannesburg.
"Syntarsus" *rhodesiensis* and "S." *kayentakatae* are reclassified as
species of *Coelophysis*. The first paper mentions "Megapnosaurus" as a
junior synonym of *Coelophysis*, but with surprisingly brief comment...
"Analysis of the newly discovered skull has demolished each of these
purported characters, leading us to concur with Paul (1988 1993) that i)
*Syntarsus* is a junior synonym of *Coelophysis*, and ii) that the recently
proposed facetious replacement name for *Syntarsus* (*Megapnosaurus* Ivie,
Slipinski & Wegrzynowicz, 2001) should not stand."
Bristowe, A. & M.A. Raath, 2004. A juvenile coelophysoid skull from the
Early Jurassic of Zimbabwe, and the synonymy of *Coelophysis* and
*Syntarsus*. Palaeont. Afr. 40: 31-41.
ABSTRACT: Several authors have drawn attention to the close similarities
between the neotheropod dinosaurs *Coelophysis* and *Syntarsus*.
Reconstruction and analysis of a skull from a juvenile specimen of
*Syntarsus* (collected from the Forest Sandstone Formation of Zimbabwe)
shows thar cranial characters previously used to distinguish these taxa and
justify their generic separation (namely the presence of a 'narial fenestra'
in *Syntarsus* and the length of its antorbital fenestra), were based on
erroneous reconstructions of disassociated cranial elements. On the basis
of this reinterpretation we conclude that *Syntarsus* is a junior synonym of
*Coelophysis*. Variations are noted in three cranial characters- the length
of the maxillary tooth row, the width of the base of the lachrymal and the
shape of the antorbital maxillary fossa- that taken together with the
chronological and geographical separation of the two taxa justify separation
at species level.
Bristowe, A., A. Parrott, J. Hack, M. Pencharz & M. Raath, 2004. A
non-destructive investigation of the skull of the small theropod dinosaur,
*Coelophysis rhodesiensis*, using CT scans and rapid prototyping. Palaeont.
Afr. 40: 159-163.
ABSTRACT: To solve preparation problems encountered in an exceptionally
fragile skull of the small theropod dinosaur, *Coelophysis rhodesiensis*, CT
scans were taken of the partially prepared skull, from which a
three-dimensional wax model was built using a 'reverse engineering' rapid
prototyping technique. The resulting wax model was then consulted to trace
and describe cranial elements of the dinosaur that were otherwise concealed
by the matrix or overlying bones, which could not be removed without risk of
damage to the original fossil bone.