Articles | Volume 18, issue 1
Foss. Rec., 18, 43–55, 2015
Foss. Rec., 18, 43–55, 2015

Research article 22 Jan 2015

Research article | 22 Jan 2015

Redescription of Digalodon rubidgei, an emydopoid dicynodont (Therapsida, Anomodontia) from the Late Permian of South Africa

C. F. Kammerer1, K. D. Angielczyk2, and J. Fröbisch1 C. F. Kammerer et al.
  • 1Museum für Naturkunde, Invalidenstraße 43, 10115 Berlin, Germany
  • 2Field Museum of Natural History, 1400 South Lake Shore Drive, Chicago, Illinois 60605, USA

Abstract. The Late Permian dicynodont Digalodon rubidgei Broom and Robinson, 1948, is redescribed based on reanalysis of the holotype and newly recognized referable specimens. Digalodon can be diagnosed by the presence of a long "beak" sharply demarcated from the caniniform process; an extremely tall zygomatic ramus of the squamosal, with a thickened, "folded-over" dorsal margin; raised parietal "lips" along the lateral edges of the pineal foramen; and a broad posterolateral expansion of the parietal, excluding the postorbital from the back of the skull roof. Inclusion of Digalodon in a recent analysis of anomodont phylogeny recovers it as a kistecephalian emydopoid, specifically as the sister taxon to the clade containing the remaining kistecephalians. Four definite specimens of Digalodon are known, but several additional specimens lacking tusks, the swollen pineal "lips", and a thickened zygoma may represent sexually dimorphic females or juveniles. Specimens of Digalodon are restricted to the central portion of the Karoo Basin, in the area around Graaff-Reinet, and are part of a characteristic fauna probably representing a limited time span.

Short summary
An overlooked taxon of Late Permian dicynodont, Digalodon, is redescribed. Based on new specimens, we recognize Digalodon as a valid taxon that fills an important gap in the record of latest Permian small-bodied herbivores.