Viatkogorgon

Viatkogorgon is a genus of gorgonopsian (a type of therapsid, the group that includes modern mammals) that lived during the Permian period in what is now Russia. The first fossil was found at the Kotelnich locality near the Vyatka River and was made the holotype of the new genus and species V. ivakhnenkoi in 1999. The generic name refers to the river and the related genus Gorgonops—the gorgons of Greek mythology are often referenced in the names of the group. The specific name honors the paleontologist Mikhail F. Ivakhnenko. The holotype skeleton is one of the most complete gorgonopsian specimens known and includes rarely preserved elements such as gastralia (abdominal ribs) and a scleral ring (a bony ring inside the eye). A larger, but poorly preserved specimen has also been assigned to the species.

The holotype specimen is about long, including the long skull, making Viatkogorgon a relatively small gorgonopsian. The assigned specimen is larger, with a long skull, and the holotype may have been young. As a gorgonopsian, it would have been skeletally robust with a somewhat dog-like stance, though with outwards-turned elbows. The snout was high, and the teeth were generally recurved (curved backward), pointed, and serrated. The canines (the saber teeth) were much larger than the incisors at the front and postcanines behind but relatively small for a gorgonopsian. Viatkogorgon was characterized by its unusually large eye socket and scleral ring. It was distinct from other gorgonopsians in that the lower end of the postorbital bar was narrow, and it had a very large sulcus (or furrow) at the back of the skull on each side. Since gorgonopsians have been described mainly from skulls, it is uncertain how widespread the postcranial features of Viatkogorgon were in other members of the group. The skeleton of Viatkogorgon was unusual in having gastralia, in that the tail was differentiated with a front and hind part, with the former less flexible, and in that some of the foot bones and its digits were reduced in size and interconnected.