Eosimiidae[2] Temporal range:45–30 Ma PreꞒ Ꞓ O S D C P T J K Pg N Middle Eocene–Early Oligocene[1]
Life restoration ofEosimias sinensis
Scientific classification
Domain:	Eukaryota
Kingdom:	Animalia
Phylum:	Chordata
Class:	Mammalia
Order:	Primates
Suborder:	Haplorhini
Infraorder:	Simiiformes
Family:	†Eosimiidae Beard et al., 1994
Genera
†Anthrasimias †Bahinia †Eosimias †Phenacopithecus †Phileosimias? †Nosmips?

Eosimiidae is the possible family ofextinctprimates believed to be the earliestsimians.

When they were discovered, the possibility that Eosimians were outside and ancestral to Simians was considered (Culotta 1992), but subsequent work showed them to be Simians (Kay et al. 1997, Ross et al. 1998).^[3] Some scholars continue to question whether the eosimiids are simians, as they seem closer toTarsiiformes - Gunnell and Miller (2001), for instance, found that eosimiid morphology didn't match up to anthropoid (simian) morphology.^[4] However, most experts now place Eosimians as stem simians - Williams, Kay and Kirk (2010) note this is because more and more evidence points in that direction.^[5]

Williams, Kay and Kirk note that (as at late 2009), accounting for all proposed species, there would be 11 species in total in 6 genera (Amphipithecidae,Anthrasimias,Bahinia,Eosimias,Phenacopithecus,Phileosimias).^[5] There appears to be a wealthy diversity of eosimiids in China.

With several genera, such asPhileosimias, andAnthrasimias, their classification as eosimiids appears to be unclear. Marivauxet al. (2005) suggest three definite groups of Eosimiidae:Bahinia,Phenacopithecus andEosimias. They announced their discovery of fossils of two new species,Phileosimias kamali andPhileosimias brahuiorum. They concluded thatPhileosimias are also early simians, and that the more modern simians may have emerged as their sister group.^[6] Williams, Kay and Kirk (2010) note that both Gunnell et al. (2008) and Kay et al. (2009) argue thatAnthrasimias should be classified asAdapiforms, and that Rosenberger and Hogg express doubts aboutBahinia pondaungensis. They also note that whilst most analyses linkAmphipithecidae to Anthropoids (i.e. simians), there is a lack of certainty as they show resemblances toadapiforms andomomyiforms as well as tocatarrhine simians.^[5]

Below is a phylogenic tree with some of the extinct simian species with the more modern species emerging within the Eosimiidae.Anthrasimias is not shown. The Simians originated in Asia while the crown simians were in Afro-Arabia.^{[7][8][4][9][10]} It is indicated approximately how many million years ago (Mya) the clades diverged into newer clades. In this tree, Eosimiidae as conventionally defined, shown as italic, is a paraphyletic, 'grade' or stem group in this assessment. Paraphyletic groupings are problematic, as one can not talk precisely about their phylogenic relationships, their characteristic traits and literal extinction.^[11][12]Cladistically the 'higher' monkeys are included. The Ekgmowechashaladea are usually placed in Tarsiiformes, in which case Eosimiidae may become equivalent to the Simians. Alternatively, with Phileosimias and Amphipithecidae placed outside of an Eosimiidaesensu stricto taxon would restore monophyly.

• Evolutionary biology
• Afrasia

• Beard KC, Wang J (Apr 2004). "The eosimiid primates (Anthropoidea) of the Heti Formation, Yuanqu Basin, Shanxi and Henan Provinces, People's Republic of China".J Hum Evol.46 (4):401–32.doi:10.1016/j.jhevol.2004.01.002.PMID 15066378.
• Kay RF, Ross C, Williams BA (Feb 1997). "Anthropoid origins".Science.275 (5301):797–804.doi:10.1126/science.275.5301.797.PMID 9012340.S2CID 220087294.

• Eocene primates
• Oligocene primates
• Eocene first appearances
• Oligocene extinctions
• Prehistoric mammal families
• Primate families
• Simians

• Articles with short description
• Short description is different from Wikidata
• Articles with 'species' microformats