New Paper and a few comments

[christian farrell kammerer <cfkammer@midway.uchicago.edu>]

There's a new paper in Neus jarbuch fuhr Geologie und Palaontologie Abh.
that may be of interest to many of you. It is:
Harris, J.D., S.G. Lucas, J.W. Estep, J. Li. 2000. A new and unusual
sphenosuchian (Archosauria: Crocodylomorpha) from the Lower Jurassic
Lufeng Formation, People's Republic of China. N. Jb. Geol. Palaont. Abh.
215(1): 47-68
It describes the bizarre  crocodylomorph Phyllodontosuchus lufengensis, so
named because of the leaf-shaped mid and caudal maxillary teeth. The teeth
as a whole are just plain weird--they are VERY heterodont, with the
rostralmost first five being recurved and short while the rest are "leaf
or spade-shaped". The latter are not denticulate but do have "extremely
fine crenelations on their caudal margins". Unfortunately, this skull is
very poorly preserved (not as much fragmentary as it is crushed and
beaten-up), but it seems to show a long, somewhat slender snout. 
This paper should be of interest to dinosaur aficionados, as it seems that
most of the paper consists of the authors arguing why Phyllodontosuchus is
a sphenosuchian and not some sort of herbivorous dinosaur! The authors
note that the leaf-shaped teeth in this animal especially resemble
Lesothosaurus, Scutellosaurus, Pekinosaurus, and Tecovasaurus.
Phyllodontosuchus is found to be demonstably un-Ornithischian because of
the lack of a predentary (too poorly preserved to tell for sure, but
implied by by the fact that the dentaries are closely appressed along the
rostral fifth of their length), constant size of the phylloform teeth
(whereas ornithischian teeth have a maximum size near the central or
caudal part of the maxillary and dentary tooth rows), and the presence of
the short, recurved teeth, whose morphology is sufficiently different from
those of Lesothosaurus and the heterodontosaurids. These recurved teeth
also eliminate prosauropod as an option. Other options such as
megalancosaurid and choristoderan are also thrown out. Finally, and
perhaps most interestingly, the authors address the fact that this animal
could have some relation to the Lufeng "therizinosaurid dentary". However,
they eliminate this possibility on the basis of the tooth denticles found
on the "therizinosaurid" jaw as well as on the fact that the
"therizinosaurid" teeth have definable, central cingula. The dentary teeth
of Phyllodontosuchus are unknown due to the poor preservation of the skull
and thus could possibly match the "therizinosaurid", but "such a vast
differentiation of the postcaniniform maxillary and dentary teeth would be
unprecedented, even within the heterodont Crocodylomorpha. It seems
unlikely that the ["therizinosaurid"] jaw described by Zhao & Xu belongs
to Phyllodontosuchus". 

On a completely different topic, since there is currently much talk of
basal ornithopod biogeography on the list, I would like to bring up the
assignment of UCMP 49611, a right dentary tooth from the Late Jurassic
(Kimmeridgian) of England, to Bugenasaura sp. by Galton (1999). If this
assignment is correct, it adds further support to the established North
Americo-European faunal link already evidenced by allosauroids and
iguanodontians. However, I feel that the ramifications of this assignment
should be taken with a grain of salt. Firstly, this assignment would make
Bugenasaura a DANG long-lived genus. The problem here is the extremely
sketchy nature of the collection data (is it really from England? Who
collected it?), a fact noted by Galton, who puts forth mislabeling as a
definite potential. 

-Christian Kammerer