Eosimiidae is the possible family of

extinct Extinction is the termination of a kind of organism or of a group of kinds (taxon), usually a species. The moment of extinction is generally considered to be the death of the last individual of the species, although the capacity to breed and ...

primate Primates are a diverse order of mammals. They are divided into the strepsirrhines, which include the lemurs, galagos, and lorisids, and the haplorhines, which include the tarsiers and the simians (monkeys and apes, the latter including huma ...

s believed to be the earliest

simian The simians, anthropoids, or higher primates are an infraorder (Simiiformes ) of primates containing all animals traditionally called monkeys and apes. More precisely, they consist of the parvorders New World monkeys (Platyrrhini) and Catarrhi ...

Taxonomy

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). Some scholars continue to question whether the eosimiids are simians, as they seem closer to

Tarsiiformes Tarsiiformes are a group of primates that once ranged across Europe, northern Africa, Asia, and North America, but whose extant species are all found in the islands of Southeast Asia. Tarsiers (family Tarsiidae) are the only living members of ...

- Gunnell and Miller (2001), for instance, found that eosimiid morphology didn't match up to anthropoid (simian) morphology.Primate Adaptation and Evolution: 3rd Edition, Ch. 13, p 279-281 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. 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 The Amphipithecidae were simian primates that lived in Late Eocene and Early Oligocene. Fossils have been found in Myanmar, Thailand, and Pakistan. The limited fossil evidence is consistent with, but not exclusive to, arboreal quadrupedalism. In ...

, ''

Anthrasimias ''Marcgodinotius'' is a genus of adapiform primate that lived in Asia during the early Eocene. It is a monotypic genus, the only species being ''Marcgodinotius indicus''. Another adapiform primate ''Suratius robustus'' was found in the same hori ...

'', '' Bahinia'', ''

Eosimias ''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 inclu ...

'', '' Phenacopithecus'', ''

Phileosimias ''Phileosimias'' ("''Eosimias'' ally") is an extinct genus of primates with two species, ''P. kamli'' and ''P. bahuiorum'', that are believed to be amongst the early simians. Marivaux ''et al.'' announced in 2005 their discovery of fossils of t ...

''). There appears to be a wealthy diversity of eosimiids in China. With several genera, such as ''Phileosimias'', and ''

'', their classification as eosimiids appears to be unclear. Marivaux ''et al.'' (2005) suggest three definite groups of Eosimiidae: '' Bahinia'', '' Phenacopithecus'' and ''

''. They announced their discovery of fossils of two new species, ''Phileosimias kamali'' and ''Phileosimias brahuiorum''. They concluded that ''

'' are also early simians, and that the more modern simians may have emerged as their sister group.
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Williams, Kay and Kirk (2010) note that both Gunnell et al. (2008) and Kay et al. (2009) argue that ''

'' should be classified as

Adapiforms Adapiformes is a group of early primates. Adapiforms radiated throughout much of the northern continental mass (now Europe, Asia and North America), reaching as far south as northern Africa and tropical Asia. They existed from the Eocene to the ...

, and that Rosenberger and Hogg express doubts about '' Bahinia pondaungensis''. They also note that whilst most analyses link

to Anthropoids (i.e. simians), there is a lack of certainty as they show resemblances to

adapiforms Adapiformes is a group of early primates. Adapiforms radiated throughout much of the northern continental mass (now Europe, Asia and North America), reaching as far south as northern Africa and tropical Asia. They existed from the Eocene to the ...

and omomyiforms as well as to

catarrhine The parvorder Catarrhini , catarrhine monkeys, Old World anthropoids, or Old World monkeys, consisting of the Cercopithecoidea and apes (Hominoidea). In 1812, Geoffroy grouped those two groups together and established the name Catarrhini, "Old ...

simians.

Phylogeny

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. 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.

Cladistically Cladistics (; ) is an approach to biological classification in which organisms are categorized in groups ("clades") based on hypotheses of most recent common ancestry. The evidence for hypothesized relationships is typically shared derived chara ...

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 Eosimiidae ''sensu stricto'' taxon would restore monophyly.

References

External links

* * {{Taxonbar, from=Q3055654 Eocene primates Oligocene primates Eocene first appearances Oligocene extinctions Prehistoric mammal families Primate families

Taxonomy

Phylogeny

See also

References

External links