Data from: Anatomy and relationships of the South African gorgonopsian Arctops (Therapsida, Theriodontia)

The gorgonopsian genus Arctops from the late Permian of South Africa is
revised and redescribed. The nominal species Arctops kitchingi and Arctops
watsoni are found to be junior synonyms of the type species Arctops
willistoni. A well-prepared specimen previously referred to Lycaenops
angusticeps and additional, previously undescribed specimens are also
referred to A. willistoni. The vomerine morphology of Arctops is highly
distinctive, supporting previous work highlighting the taxonomic
importance of this element. Arctops is restricted to the Cistecephalus
Assemblage Zone of the South African Beaufort Group. Inclusion of Arctops
in a phylogenetic analysis of gorgonopsian relationships recovers it as
the sister-taxon of Smilesaurus ferox, with the clade composed of Arctops
+ Smilesaurus positioned outside the Rubidgeinae.