''Stirtonia'' is an
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 ...
genus of
New World monkeys from the
Middle Miocene
The Middle Miocene is a sub-epoch of the Miocene Epoch made up of two stages: the Langhian and Serravallian stages. The Middle Miocene is preceded by the Early Miocene.
The sub-epoch lasted from 15.97 ± 0.05 Ma to 11.608 ± 0.005 Ma (million y ...
(
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
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Honda has been the world's largest motorcycle manufacturer since 1959, reaching a product ...
of
Colombia
Colombia (, ; ), officially the Republic of Colombia, is a country in South America with insular regions in North America—near Nicaragua's Caribbean coast—as well as in the Pacific Ocean. The Colombian mainland is bordered by the Car ...
. Two species have been described, ''S. victoriae'' and the
type species ''S. tatacoensis''.
[''Stirtonia victoriae'']
at Fossilworks
Fossilworks is a portal which provides query, download, and analysis tools to facilitate access to the Paleobiology Database
The Paleobiology Database is an online resource for information on the distribution and classification of fossil animals ...
.org[''Stirtonia tatacoensis'']
at Fossilworks
Fossilworks is a portal which provides query, download, and analysis tools to facilitate access to the Paleobiology Database
The Paleobiology Database is an online resource for information on the distribution and classification of fossil animals ...
.org Synonyms are ''Homunculus tatacoensis'', described by
Ruben Arthur Stirton in 1951 and ''Kondous laventicus'' by Setoguchi in 1985.
[Setoguchi et al., 1986a, p.2] The genus is classified in
Alouattini as an ancestor to the modern
howler monkeys.
[McKenna & Bell, 1997][Takai et al., 2001, p.290]
Etymology
''Stirtonia'' is named after the scientist who first discovered it, Ruben Arthur Stirton. The two species, ''S. tatcoensis and S. victoriae'', are named after the locations in which they were found: ''S. tatacoensis'' gets its name from the Tatacoa desert; and ''S. victoriae'' gets its name from the village “La Victoria” near its discovery site.
[
]
Description
The genus is the largest primate found at La Venta,[Defler, 2004, p.33] with estimated body masses of ''S. tatacoensis'' at and of ''S. victoriae'' at .[Silvestro, 2017, p.14] ''Stirtonia tatacoensis'' and ''S. victoriae'' are known by several teeth, a mandible and a maxilla that closely resemble, and are almost indistinguishable from, the living '' Alouatta''.[Pérez et al., 2013, p.4]
Fossil teeth found in the Solimões Formation at the Acre River in the border region of Brazil and Peru may belong to ''Stirtonia''.[Tejedor, 2013, p.30]
Fossil record
A lower mandible fossil of ''S. tatacoensis'' was discovered during fieldwork between 1944 and 1949,[Hershkovitz, 1970, p.1] in the Honda Group
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Honda has been the world's largest motorcycle manufacturer since 1959, reaching a product ...
, that has been dated to the Laventan, about 13 Ma.
Upper jaws and other cranial material of the large primate ''Stirtonia victoriae'' from the Perico Member of the La Dorada Formation, Honda Group were discovered in 1985 and 1986. Based on stratigraphic position, more than below the ''Stirtonia tatacoensis'' type locality, this was the oldest primate material known until 1987 from Colombia.[Kay et al., 1987, p.173]
Evolution
The evolutionary split between Atelidae, of which ''Stirtonia'', and Pitheciidae plus '' Callicebus'', has been placed at 17.0 million years ago.[Takai et al., 2001, p.304]
Habitat
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] From the same level as where ''Stirtonia tatacoensis'' has been found, also fossils of '' Aotus dindensis'', '' Micodon'', '' Mohanamico'', '' Saimiri annectens'', '' Saimiri fieldsi'' and '' Cebupithecia'' have been uncovered.[Luchterhand et al., 1986, p.1753][Wheeler, 2010, p.133][Setoguchi et al., 1986b, p.762] ''Stirtonia'' reinforced the notion that leaf-eating was an
enduring and essential aspect of the howler monkey's ecophylogenetic biology.[Rosenberger et al., 2015, p.24]
See also
* List of primates of Colombia
The primates of Colombia include 41 extant species in 13 genera and five families. Additionally, 12 fossil species in 10 genera and five families have been identified in Colombia, mainly at the La Venta (Colombia), La Venta Lagerstätte of the Hond ...
* ''Miocallicebus
''Miocallicebus'' is an extinct genus of New World monkeys from the Middle Miocene (Laventan in the South American land mammal ages; 13.8 to 11.8 mya). Its remains have been found at the Konzentrat-Lagerstätte of La Venta in the Honda Group ...
''
* '' Mohanamico''
References
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Further reading
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{{Taxonbar, from=Q7617627
Prehistoric primate genera
Prehistoric monkeys
Miocene genus first appearances
Miocene extinctions
Miocene primates of South America
Laventan
Neogene Colombia
Fossils of Colombia
Honda Group, Colombia
Neogene Brazil
Fossils of Brazil
Fossil taxa described in 1970