Leogorgon

Leogorgon Temporal range: Late Permian,
Inostrancevia tooth (top) compared to a Leogorgon tooth (bottom)
Scientific classification
Kingdom:	Animalia
Phylum:	Chordata
Order:	Therapsida
Family:	†Gorgonopsidae
Tribe:	†Rubidgeini
Genus:	†Leogorgon Ivakhnenko, 2003
Binomial name
†Leogorgon kilmovensis Ivakhnenko, 2003

Leogorgon ("Leo's gorgon") is an extinct genus of rubidgeine gorgonopsians from the Late Permian of South Africa and Tanzania. Leogorgon was a 2m (6ft) predator that preyed on reptiles and smaller therapsids. It is a member of the tribe Rubidgeini.

In 2003, Mikhail Ivakhnenko described a new genus of large gorgonopsian from the Klimovo-1 locality of the Late Permian (Lower Vyatkian, c. 259-254 Ma) Sokolki Faunal Assemblage in Russia. Ivakhnenko named Leogorgon klimovensis based on an occiput fragment (PIN 4549/13) and a single incisor (PIN 4549/14). He assigned Leogorgon to the subfamily Rubidgeinae. The rubdgeines are robust-skulled gorgonopsians whose distribution had previously been restricted to Africa.

Based on the occiput, Ivakhnenko calculated a total skull length of 70 cm. In comparison, the largest known rubidgeine skull (GPIT K46) is around 50 cm in length, belonging to Rubidgea atrox from the Usili Formation of Tanzania (this specimen was formerly called Titanogorgon maximus). Rubidgea would have been around 3.5 meters in length; scaling up means that Leogorgon would have exceeded 4 meters. In that case Leogorgon would have been the largest known gorgonopsian, surpassing even Inostrancevia alexandri (which would have been similar in size to Rubidgea).

In 2016, Christian Kammerer published a revision of the Rubidgeinae. He found that the material that comprised Leogorgon was dubious. The incisor was identical to those of the contemporaneous Inostrancevia, and is likely referable to that genus. On the other hand, the occiput showed no distinguishable rubidgeine features; it could only be assigned to Gorgonopsia incertae sedis. Additionally, Kammerer noted that the occiput bore some characteristics of dicynodonts. The supposed giant gorgonopsian Leogorgon klimovensis is actually just a chimaera of fragmentary fossils.

References

• Golubev, V. (2000). The faunal assemblages of Permian terrestrial vertebrates from Eastern Europe. Paleontological Journal 34(Suppl. 2), 211-224.
• Ivakhnenko, M. F. (2003). Eotherapsids from the East European Placket (Late Permian). Paleontological Journal 37(Suppl. 4), 339-465.
• Kammerer, C. F. (2016). Systematics of the Rubidgeinae (Therapsida: Gorgonopsia). PeerJ 4:e1608.
• Maisch, M.W. (2002). Observations on Karoo and Gondwana vertebrates. Part 3: Notes on the gorgonopsians from the Upper Permian of Tanzania. Neues Jahrbuch für Geologie und Paläontologie Monatshefte 2002(4), 237-251.