Inostrancevia

Inostrancevia is an extinct genus of large carnivorous therapsids which lived during the Late Permian in what is now European Russia and Southern Africa. The first-known fossils of this gorgonopsian were discovered in the context of a long series of excavations carried out from 1899 to 1914 in the Northern Dvina, Russia. Among these are two near-complete skeletons embodying the first described specimens of this genus, being also the first gorgonopsian identified in Russia. Several other fossil materials were discovered there, and the various finds led to confusion as to the exact number of valid species, before only two of them were formally recognized, namely I. alexandri and I. latifrons. A third species, I. uralensis, was erected in 1974, but the fossil remains of this taxon are very thin and could come from another genus. More recent research carried out in Southern Africa has discovered specimens identified as belonging to this genus, being classified within the species I. africana. The genus name honors Alexander Inostrantsev, professor of Vladimir P. Amalitsky, the paleontologist who described the taxon.

Possessing a skull measuring approximately long depending on the species, all for a body length reaching , Inostrancevia is the largest known gorgonopsian, being rivaled in size only by the genus Rubidgea. It has a broad and elongated skull equipped with large oval-shaped temporal fenestrae. It also has very advanced dentition, possessing large canines, the longest of which can reach and which may have been used to shear the skin of prey. Like most other gorgonopsians, Inostrancevia had a particularly large jaw opening angle, which would have allowed it to inflict fatal bites. Gorgonopsians in general would have been relatively fast predators, killing their prey by delivering slashing bites with their saber teeth. The skeleton is robustly constructed, but new studies are necessary for a better anatomical description and understanding about its paleobiological functioning.