Saimiri Fieldsi

''Saimiri fieldsi'' is an extinct species of New World monkey in the genus ''Saimiri'' (squirrel monkeys) from the Middle Miocene (Laventan in the South American land mammal ages; 13.8 to 11.8 Ma). Its remains have been found at the Konzentrat-Lagerstätte of La Venta in the Honda Group of Colombia.''Saimiri fieldsi''
at Fossilworks.org

Description

More than 200 fossil specimens of ''Saimiri fieldsi'', formerly described as ''Neosaimiri fieldsi'', were recovered from the Middle Miocene Villavieja Formation, that has been dated to the Laventan, about 13 to 12 Ma, during fieldwork in 1989 and 1990. The holotype of ''Saimiri'' which was recovered in 1949, is an incomplete mandible and dentition, while later materials include not only lower but also upper dentition and deciduous teeth.Takai, 1994

The fossils were differentiated from ''Saimiri'' in the proportions of tooth series, with smaller incisors and larger molars; in the structure of the P4 hypocone; and in the morphology of M1-2, which shows strong polymorphism. Also the species has been described as more robust than the extant ''Saimiri''.Defler, 2004, p.31 This led researchers to identify an independent genus, ''Neosaimiri'', as a Middle Miocene ancestor of ''Saimiri''. ''Laventiana annectens'', which was recovered at the same location in 1988, has been concluded to be a junior synonym of ''Neosaimiri'', placed later in the same genus as ''Saimiri annectens''.

The lower molars of the fossil ''Saimiri'' resemble those of ''Dolichocebus'', from Argentina.Tejedor, 2013, p.24 An estimated body mass of has been suggested for ''Saimiri fieldsi''.Pérez et al., 2013, p.9Silvestro et al., 2017, p.14

Evolution

The evolutionary split in New World monkeys between ''Cebus'' and ''Saimiri'' has been estimated at 16.7 Ma.Takai et al., 2001, p.304

Habitat

The La Venta Lagerstätte of the Honda Group, and more precisely the "Monkey Beds", are the richest site for fossil primates in South America.Rosenberger & Hartwig, 2001, p.3 It has been argued that the monkeys of the Honda Group were living in habitat that was in contact with the Amazon and Orinoco Basins, and that La Venta itself was probably seasonally dry forest.Lynch Alfaro et al., 2015, p.520 Other fossil New World primates uncovered from the same locality are ''Aotus dindensis'', ''Cebupithecia'', ''Mohanamico'' and ''Stirtonia tatacoensis''.Luchterhand et al., 1986, p.1753Wheeler, 2010, p.133Setoguchi et al., 1986, p.762

See also

* List of primates of Colombia
* ''Lagonimico''

References

Bibliography

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Further reading

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{{Taxonbar, from=Q55632351

†Saimiri
Prehistoric monkeys
Miocene first appearances
Miocene extinctions
Miocene primates of South America
Laventan
Neogene Colombia
Fossils of Colombia
Honda Group, Colombia
Fossil taxa described in 1951