Taxonomic revision of therocephalians (Therapsida, Theriodontia) from the Lower Triassic of Antarctica

Title Variants

Alternative: Therocephalians from Antarctica

Related Titles

Series: American Museum novitates, no. 3738

By

Huttenlocker, Adam K.

Sidor, Christian A.

Type

Book

Material

Published material

Publication info

[New York], American Museum of Natural History, c2012

Notes

Caption title.

"March 5, 2012."

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.

Subjects

Antarctica , Dispersal , Paleontology , Reptiles, Fossil , Therapsida , Therocephalia , Transantarctic Mountains , Triassic

Call Number

QL1 .A436 no.3738 2012

Language

English

Identifiers

OCLC: 779190253