Ken Carpenter said:
That, regrettably, was not the best SVP poster and should be taken with
a grain of salt. I know the depression in question.
That isn't the only such report, however:
Fernandes, M.A., dos Reis Fernandes, L.B., and de Figueiredo Souto, P.R.
2004. Occurrence of urolites related to dinosaurs in the Lower Cretaceous
of the Botucatu Formation, Paraná Basin, São Paulo, Brazil. Revista
Brasileira de Paleontologia 7(2):263-268.
ABSTRACT: The geological units that correspond to the Mesozoic in the
Paraná basin, São Paulo State, are included in São Bento Group, by
correlation with the Pirambóia, Botucatu and Serra Geral formations. The
Botucatu Formation's age is bracketed between the Upper Jurassic and the
Lower Cretaceous (Neocomian). The Botucatu Formation is composed of
aeolian sandstones showing cross-stratification from medium to large
scale, a typical trait of migrating dunes. Ichnofossils were collected in
the São Bento Quarry, located in the city of Araraquara, São Paulo State.
Samples MPA-002 e MPA-003, respectively, are the negative epirelief and
positive hyporelief of the same trace fossil. MPA-001 is a negative
epirelief. These features show a removal of sedimentary material, in
contrast to the morphology of ornithopod and theropod dinosaur tracks,
where compression and deformation of unconsolidated sedimentary layers
occurs. These trace fossils show a pattern corresponding to erosion caused
by evacuation of liquid wastes and are classificated as urolites, because
this term has already been applied to the occurrence of ichnofossils of
this type in France and Germany. The morphostructure of these urolites is
very similar to the erosional geometry produced in the substrate by
expelled liquid waste of modern ratite birds, such as Struthio camelus
(ostrich). These urolites are the first records in Brazil of this type of
ichnofossil, and is also one of the first examples of trace fossils
attributed to liquid waste expulsion by dinosaurs.
The paper even has a nice sequence of photos of a zoo ostrich excreting a
rather large-ish stream of very liquid waste they call urine. (They don't
address its possible implications for the evolution of theropod or
ornithuran physiology.) I don't know what the French specimens referred
to are (the paper cited is a very old one [1844]; this apparently is the
paper that erects the term "urolite"), and some of the German specimens
were attributed to, of all things, ichthyosaurs (don't know how that's
supposed to work); the others just to "reptiles" (I don't have the papers
to which they refer, not that I can read much German, anyway). They are:
Duvernoy, G. 1844. Sur l'existence des urolithes fossiles, et sur
l'utilite que la science des fossiles organiques pourra tirer de luer
distinction d'aves les coprolithes, pour la determination de restes
fossiles de Sauriens et d'Ophidiens. Comptes Rendus Hebdomadaires des
Seances de l'Academie des Sciences 19: 255-260.
Leydig, F. 1896a. Koprolithen und Urolithen. Neues Jahrbuch fuer Geologie
und Palaeontologie, Monatshefte 2: 139-140.
Leydig, F. 1896b. Koprolithen und Urolithen. Biologisches Centralblatt 16:
101-103.
Voigt, E. 1960. Uber einen mutmasslichen fossilen Harnstein (Urolith) aus
der Oberen Kreide. Mitteilungen aus dem Geologischen Staatinstitut Hamburg
29: 85-95.
Hey, if anyone tracks these down and feels like making extra copies, I'd
love some -- thanks!
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Jerry D. Harris
Director of Paleontology
Dixie State College
Science Building
225 South 700 East
St. George, UT 84770 USA
Phone: (435) 652-7758
Fax: (435) 656-4022
E-mail: jharris@dixie.edu
and dinogami@gmail.com
http://cactus.dixie.edu/jharris/
"Actually, it's a bacteria-run planet, but
mammals are better at public relations."
-- Dave Unwin