Eosimias is a genus of early primates, first discovered and identified in 1999 from fossils collected in the Shanghuang fissure-fillings of Liyang, the southern city of 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". Dating has proven this genus lived from 45 to 40 million years ago in the middle Eocene. The genus Eosimias is unique because of the presence of primitive and derived traits. It provides new insight into the phylogenetic relationships between simians and prosimians (especially the phylogenetic position of the haplorhine prosimian tarsiers). It can best be described as a likely tree dweller that relied on a steady diet of insects and nectar. Most eosimiid species are documented by unique or fragmentary specimens. This, as well as the strong belief that simians originated in Africa has made it difficult for many to accept the idea that Asia played a role in early primate evolution. Although some continue to challenge the anthropoid resemblances found in Eosiimidae, extensive anatomical evidence collected over the past decade substantiates its anthropoid status. Eosimias sinensis Eosimias sinensis (, ) was first discovered in China in 1992 by Christopher Beard. It was found in a mountain near Liyang City, Jiangsu province, China. The species is believed to have lived 45 million years before present, in the Eocene epoch. E. sinensis was tiny, as small as the smallest monkey presently, the pygmy marmoset (Cebuella pygmaea) of South America, and could fit in the palm of a human's hand. Its teeth are considered more primitive than those of early higher primates known from Africa, including Algeripithecus. Due to its highly primitive nature, some paleontologists consider E. sinensis to be evidence that higher primates may have originated in Asia rather than Africa. Christopher Beard was the lead member of the team that discovered Eosimias sinensis in 1994. Beard recovered a right mandible, cataloged as IVPP V10591, which preserved P4–M2 and roots or alveoli for C1, P2–3, and M3. Although it retains primitive characters such as a small body size (mean estimates range from ) and an unfused mandibular symphysis, it appears to