Rubidgea

Rubidgea is an extinct monospecificgenus of carnivorous therapsid from the Late Permian of South Africa and Tanzania. The genus was originally thought to have consisted of four species; the type species R. atrox, R. majora, R. kitchingi, R. platyrhina, and R. laticeps. However recent analysis suggested the three other species were synonymous to R. atrox. The generic name Rubidgea honours fossil hunter Sidney Rubidge. Its species name, atrox, is derived from Latin, meaning "fierce, savage, terrible". Rubidgea is part of the subfamily Rubidgeinae, a derived group of gorgonopsians. Gorgonopsians were a clade of saber-toothed predators that first appeared in the Middle (or Early) Permian, and were the first group of synapsids to have specialized saber-like canines. The largest specimen, BP/1/699, had a skull measuring 47.5 cm (18.7 in), making Rubidgea was one of the largest gorgonopsians. Rubidgea was likely one of the apex predators of its time and likely competed with large gorgonopsians such as Inostrancevia.

Rubidgea would go extinct shortly before the end of the Permian following a turnover event that separated the lower and upper Daptocephalus Assemblage Zone. This turnover event was thought to have been the result of aridification, with lacustrine floodplains being replaced by well-drained floodplains. The transition saw the disappearance of its prey which led to its extinction. Following its extinction, it was replaced by Inostrancevia in South Africa for the remainder of the Permian.