en Gorynychus

Gorynychus; Temporal range: Mid Permian PreꞒ Ꞓ O S D C P T J K Pg N
	Holotype skull of G. masyutinae
Scientific classification
Domain:	Eukaryota
Kingdom:	Animalia
Phylum:	Chordata
Clade:	Synapsida
Clade:	Therapsida
Clade:	†Therocephalia
Genus:	†Gorynychus; Kammerer & Masyutin, 2018
Type species
	†Gorynychus masyutinae; Kammerer & Masyutin, 2018
Other species
	†G. sundyrensis Suchkova & Gobulev, 2019;

Gorynychus is a genus of therocephalian from the mid-Permian from Kotelnich, Russia. The genus contains two species, G. masyutinae and G. sundyrensis. It was named after the three-headed dragon Zmey Gorynych (Змей Горыныч) from Russian mythology.^[1]^[2]^[3]

Description

G. masyutinae, only known from its holotype, was wolf-sized and appears to have represented the largest predator in the Kotelnich fauna. Like many theriodonts, it had strongly developed and prominent canine teeth.^[1]

Paleoecology

The discovery of such a large therocephalian as the apex predator of its environment coupled with the discovery of a smaller gorgonopsid, the smaller and nocturnal Nochnitsa, in the same formation indicates that a faunal turnover was occurring at the time, with gorgonopsians taking over the therocephalians' role as the dominant predators in their environment.^[2]