Eriphostoma, gorgonopsian from Permian of South Africa

[Ben Creisler <bcreisler@gmail.com>]

Ben Creisler
bcreisler@gmail.com


A new online paper:

Christian F. Kammerer, Roger M. H. Smith, Michael O. Day and Bruce S.
Rubidge (2015)
New information on the morphology and stratigraphic range of the
mid-Permian gorgonopsian Eriphostoma microdon Broom, 1911.
Papers in Palaeontology (advance online publication)
DOI: 10.1002/spp2.1012
http://onlinelibrary.wiley.com/doi/10.1002/spp2.1012/abstract


New specimens of the oldest gorgonopsian taxon Eriphostoma microdon
from the Pristerognathus Assemblage Zone (AZ) of South Africa
significantly improve our understanding of the anatomy of this taxon.
The new specimens consist of nearly complete skulls and lower jaws and
allow for a more complete diagnosis of Eriphostoma than was possible
based on the poorly preserved holotype. In addition to the
characteristic palatal dentition and delta-shaped palatine bosses
previously recognized for Eriphostoma, this taxon can be diagnosed by
the presence of three close-packed upper postcanines occupying an
indented margin of the maxilla, a large, tetragonal-to-rounded
preparietal bone, and large, paired interorbital depressions expanding
outwards in front of the pineal boss. The revised diagnosis permits
Eoarctops vanderbyli, Galesuchus gracilis, and Scylacognathus parvus
to be synonymized with Eriphostoma microdon, as previously suspected.
Among gorgonopsians, Eriphostoma is most similar to Aelurosaurus and
Gorgonops, although these similarities are likely plesiomorphic for
Gorgonopsia. Eriphostoma ranges from the Tapinocephalus AZ (where it
is the only valid gorgonopsian known from the Karoo Basin) through the
Pristerognathus AZ (where it co-occurs with Gorgonops).
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