Erlianhyus is a genus of cetancodontamorph artiodactyl that lived during the Middle Eocene in China. It is monotypic and known from one species, E. primitivus.[1]
The holotype of Erlianhyus (IVPP V 28275) was discovered in strata from the Irdin Manha Formation. Its binomial name is derived from the Erlian Basin, in which it was discovered, and the suffix -hyus, which is often applied to bunodont artiodactyls. The species name, primitivus, refers to it bearing relatively primitive features. Erlianhyus was originally regarded as the sister taxon of a clade containing dichobunids, anthracotheriids and suoids. In 2023, Yu and colleagues performed a phylogenetic analysis that recovered it in a polytomy with Andrewsarchus and Achaenodon.
Erlianhyus is known from a partial maxilla that preserves teeth P3–M3. The molars are bunodont and bear weak cristae, similar to entelodontids. Similarly M1 in both Erlianhyus and entelodonts lacks lingual cingulum. However, the molars have a large and lingually-positioned metaconule and the postmetaconule crista on M1 and M2 are distinct, suggesting that it does not belong to that clade.[2]