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.
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 P<sup>3</sup>âÂÂM<sup>3</sup>. The molars are bunodont and bear weak cristae, similar to entelodontids. Similarly M<sup>1</sup> in both Erlianhyus and entelodonts lacks lingual cingulum. However, the molars have a large and lingually-positioned metaconule and the postmetaconule crista on M<sup>1</sup> and M<sup>2</sup> are distinct, suggesting that it does not belong to that clade.