Zygosaurus is an extinct genus of dissorophid temnospondyl from the Middle-Late Permian of Russia. It was described in 1848 by Eduard Eichwald, making it the first dissorophid to be described and is known from a single species, Zygosaurus lucius.[1] The location of the holotype, and only known specimen, is unknown,[2] and although casts are reposited in several institutions, little is known about this taxon beyond qualitative aspects of the skull (e.g., preorbital length twice as long as postorbital length; skull width greatest at mid-length of orbits).[3] The skull was estimated to be around 20 cm in length, making it one of the largest dissorophids, being only slightly smaller than Kamacops.