preparietal, slender skull arches, narrow vomer, well developed palatal tuberosities, teeth on transverse apophyses, large ectopterygoids, slender mandible, [and] open symphysis". A. whaitsi First described by Robert Broom in 1911. The holotype of A. whaitsi is another skull, but mostly snout, with the main indicator being a flatter symphysis. Its classification went back and forth throughout the entire century since it has very few defining features, all of which could be juvenile features of other genera. A. polyodon First described by Broom in 1935. The holotype of A. polyodon is a crushed snout. Originally named Galerhinus polyodon, it was renamed Aelurosaurus polyodon in 1970. A. wilmanae First described by Broom in 1940. The holotype is a skull that is the best preserved of all the Aelurosaurus species. The defining feature is a larger snout compared to A. felinus, but overall the skull is still small at just 11 centimeters long. A.? watermeyeri First described by Broom in 1940. The holotype is a skull, and was originally named Scylacocephalus watermeyeri. The genus is still under debate, since it shares features with both Aelurosaurus (such as a large orbit and short snout) and Aloposaurus (such as larger preparietal and postfrontal). Geology/Paleoenvironment Aelurosaurus felinus was originally obtained in the Gough, of the Karoo Basin of South Africa, which includes the Tapinocephalus and Pristerognathus Assemblage Zones. These assemblage zones are a part of the Beaufort Group and span from the Middle Perimian to the Late Permian. The stratigraphic composition of the Beaufort Group include siltstone, mudstone, and sandstone beds, with evidence of rivers flowing across the land in semi-arid conditions. Findings of dense coprolites consisting of bones suggest that predators lived near these rivers. While most gorgonopsians have been recovered from the Karoo Basin in South Africa, there have been recent discoveries of gorgonopsians in Russia's Vyazniki Assemblage as well. References Gorgonopsia Prehistoric therapsid genera Lopingian synapsids of Africa Fossil taxa described in 1881 Taxa named by Richard Owen Lopingian genus first appearances Lopingian genus extinctions Beaufort Group