Eosimias was a genus of early primates, first discovered and identified in 1999 from fossils collected in the Shanghuang fissure-fillings of the southern Jiangsu Province, China. It is a part of the family Eosimiidae, and includes three known species: Eosimias sinensis, Eosimias centennicus, and Eosimias dawsonae. It provides us with a glimpse of a primate skeleton similar to that of the common ancestor of the Haplorhini (including all simians). The name Eosimias is designed to mean "dawn monkey", from Greek eos "dawn" and Latin simius "monkey".