[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index][Subject Index][Author Index]

Therocephalians from Lower Triassic of Antarctica.

From: Ben Creisler

Some DML apparently members don't like non-dino postings, but I think
new papers that provide insights into the climate, ecosystems, and
amniote fauna of the Mesozoic may interest some. Here's a new
paper--the pdf will be available for free in a day or so:

Adam K. Huttenlocker and Christian A. Sidor (2012)
Taxonomic Revision of Therocephalians (Therapsida: Theriodontia) from
the Lower Triassic of Antarctica.
American Museum Novitates Number 3738 :1-19. 2012

Not yet posted for free download on the AMNH site. Check here:

We reevaluate the taxonomic status of therocephalian fossils recovered
from the lower Fremouw Formation (Lower Triassic) of the central
Transantarctic Mountains, Antarctica. The material, which includes
mostly fragmentary juvenile specimens, is reidentified using an
apomorphy-based approach. We recognize the presence of three
higher-level taxa: Eutherocephalia, Akidnognathidae, and Baurioidea.
The only genus-level identification is for a partial lower jaw and
pterygoid tentatively attributed to the baurioid, Ericiolacerta parva.
An indeterminate theriodont partial skull is reassigned to the
therocephalian family Akidnognathidae. The holotypes of Pedaeosaurus
parvus and Rhigosaurus glacialis are represented by indeterminate
juvenile baurioids and, in the absence of clear autapomorphies, are
considered nomina dubia. The results of the taxonomic revision
indicate that the therocephalian fauna of Antarctica lacks endemic
genera and thus corresponds to that of the Triassic Lystrosaurus
Assemblage Zone fauna of South Africa's Karoo Basin. More generally,
we consider the southern Gondwanan basins of South Africa and
Antarctica to sample a broadly distributed Lower Triassic tetrapod
fauna, although the latter basin documents the first occurrence of
several taxa (e.g., Kombuisia, Palacrodon). More precise (i.e.,
species-level) identifications are needed to better constrain the
biogeographic signal for therocephalians, but the presence of
juveniles strongly suggests that this group of therapsids, like
dicynodonts, were year-round high-latitude inhabitants during Early
Triassic times.