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Dinosaur Genera List corrections #46



Two interesting new works came in today, one with a new (well, not entirely
new) dinosaur, the other with a new non-dinosaurian archosaur:

(1) Kellner, A. W. K. & Campos, D. de A., 1996. "First Early Cretaceous
theropod dinosaur from Brazil with comments on Spinosauridae," Neues Jahrbuch
fuer Geologie und Palaeontologie Abhandlungen 199(2): 151-166.

This paper formally describes the dinosaur _Angaturama limai_, featured last
year on a Brazilian postage stamp. Here's the abstract:

"The discovery of the first theropod dinosaur from the Early Cretaceous of
Brazil is reported here. The material consists of the anterior portion of a
skull and represents a new taxon, _Angaturama limai_ n.g., n.sp. This
dinosaur has an extremely laterally compressed rostrum with a well developed
premaxillary sagittal crest. Several synapomorphies suggest that _Angaturama_
is related to the unusual theropods attributed to Spinosauridae, known from
Cretaceous strata of different localities in Africa, and _Baryonyx_, known
from the Early Cretaceous of England."

The material is, as noted, pretty scanty, but the premaxillae have 7 teeth
(like those of _Baryonyx_ and the Niger material from Gadoufaoua described by
Taquet), and the teeth are typically spinosaurid, with round cross-sections
and unserrated carinae (at least, the preserved portions of the carinae are
unserrated). The relatively tall premaxillae are surmounted by a thin, low
parasagittal crest, as noted by the authors unique among theropods. As in
_Baryonyx_ and _Irritator_, the nares must have been situated some distance
back from the tip of the snout. The premaxillae "overhang" the front of the
snout, as in _Dilophosaurus_, and there is a well defined gap in the tooth
row between the premaxillary and maxillary teeth.

The whole specimen, including premaxillae, rostral parts of the maxillae, and
the corresponding segments of the palate, is about 18 cm long. I have no idea
how big the skull might have been, but it seems to have been of comparable
size to those of _Baryonyx_, the Gadoufaoua baryonychids, and _Irritator_.

The specimen is from the well-known Santana Formation, Romualdo Member
(Albian).

It is just possible to compare the caudal portion of the specimen with the
rostral portion of the incomplete skull of _Irritator_, and they in my
opinion do not resemble each other enough to warrant synonymizing
_Angaturama_ with _Irritator_. This means there were two baryonychid-like
theropods in the Santana dinosaur fauna.

The generic name is from the aboriginal Brazilian Tupi language, and it means
"noble." The species epithet honors Dr. Murilo Rodolfo de Lima, noted
Brazilian paleontologist, who discovered the specimen in a concretion and
brought it to the attention of the senior author.

[Thanks to Alex Kellner for sending a copy of the paper.]

(2) Sennikov, A. G., 1995. _Ranniye tekodonti Vostochnoi Yevropy_ [_Early
thecodonts of Eastern Europe_], _Trudy_ [_Transactions_] _of the
Paleontological Institute 263_, Nauka Publishers, Paleontological Institute,
Russian Academy of Sciences, Moscow: 141 pp. [in Russian with short English
abstract].

The author presents a massive overview of all known proterosuchian and other
early archosaur taxa (euparkeriids, rauisuchids, etc.), among which he
introduces the new genus _Uralosuchus_ (named after the Ural region of
central Russia) for the erythrosuchid species _Erythrosuchus magnus_ Ochev,
1980. Several higher-level taxa (tribes, subfamilies) are also introduced.
The work includes numerous figures of the known material, lengthy comments on
stance and gait of early archosaurs, a phylogeny of early archosaurs (but not
a cladistic analysis), and remarks on the ecology of early archosaurs.
Essentially, it is Sennikov's doctoral dissertation in published form.

[Thanks to Andrej Sennikov for forwarding a copy of this monograph.]

Regarding the Dinosaur Genera List, we may now remove the [Anonymous] 1995
[nomen nudum] notation from _Angaturama_ and rewrite it as

_Angaturama_ Kellner & Campos, 1995

Genera count remains stable at 785.