New World monkey

New World monkeys are the five families of primates that are found in the tropical regions of Mexico, Central and South America: Callitrichidae, Cebidae, Aotidae, Pitheciidae, and Atelidae. The five families are ranked together as the Ceboidea (/səˈbɔɪdi.ə/), the only extant superfamily in the parvorder Platyrrhini (/plætɪˈrn/).[3]

New World monkeys
Temporal range: Early Oligocene-Holocene, 31–0 Ma
BrownSpiderMonkey (edit2).jpg
Brown spider monkey
Scientific classification e
Kingdom: Animalia
Phylum: Chordata
Class: Mammalia
Order: Primates
Suborder: Haplorhini
Infraorder: Simiiformes
Parvorder: Platyrrhini
E. Geoffroy, 1812[1][2]
Type species
Cebus capucinus

Incertae sedis

sister: Catarrhini

Platyrrhini means broad-nosed, and their noses are flatter than those of other simians, with sideways-facing nostrils. Monkeys in the family Atelidae, such as the spider monkey, are the only primates to have prehensile tails. New World monkeys' closest relatives are the other simians, the Catarrhini ("down-nosed"), comprising Old World monkeys and apes. New World monkeys descend from African simians that colonized South America, a line that split off about 40 million years ago.[4]

Evolutionary historyEdit

About 40 million years ago, the Simiiformes infraorder split into the parvorders Platyrrhini (New World monkeys—in South America) and Catarrhini (apes and Old World monkeys—in Africa).[5] The individuals whose descendants would become Platyrrhini are currently conjectured to have migrated to South America either on a raft of vegetation or via a land bridge. There are two possible rafting routes, either across the Atlantic Ocean from Africa or across the Caribbean from North America; however, there is no fossil record to support the hypothesis of a migration from North America. The land bridge hypothesis relies on the existence of Atlantic Ocean ridges and a fall in the sea level in the Oligocene. This would have produced either a single land bridge or a series of mid-Atlantic islands to act as stepping stones for the migration. The latter is now the favoured land bridge hypothesis.[6]

At the time the New World monkeys split off, the Isthmus of Panama had not yet formed, ocean currents and climate were quite different, and the Atlantic Ocean was less than the present 2,800 km (1,700 mi) width by about a third; possibly 1,000 km (600 mi) less, based on the current estimate of the Atlantic mid-ocean ridge formation processes spreading rate of 25 millimetres per year (1 in/year).[citation needed]

However, the non-platyrrhini Ucayalipithecus of Amazonian Peru who might have rafted across the Atlantic between ~35–32 million years ago, are nested within the Parapithecoidea from the Eocene of Afro-Arabia.[7] Parvimico and perupithecus from Peru appear to be at the base of the Platyrrhini.[8]

The chromosomal content of the ancestor species appears to have been 2n = 54.[9] In extant species, the 2n value varies from 16 in the titi monkey to 62 in the woolly monkey.

A Bayesian estimate of the most recent common ancestor of the extant species has a 95% credible interval of 27 million years ago-31 million years ago.[10]


The following is the listing of the various platyrrhine families, as defined by Ryland & Mittermeier (2009),[2] and their position in the Order Primates:[1]


New World monkeys are small to mid-sized primates, ranging from the pygmy marmoset (the world's smallest monkey), at 14 to 16 cm (5.5 to 6.5 in) and a weight of 120 to 190 g (4.2 to 6.7 oz), to the southern muriqui, at 55 to 70 cm (22 to 28 in) and a weight of 12 to 15 kg (26 to 33 lb). New World monkeys differ slightly from Old World monkeys in several aspects. The most prominent phenotypic distinction is the nose, which is the feature used most commonly to distinguish between the two groups. The clade for the New World monkeys, Platyrrhini, means "flat nosed". The noses of New World monkeys are flatter than the narrow noses of the Old World monkeys, and have side-facing nostrils.

New World monkeys are the only monkeys with prehensile tails—in comparison with the shorter, non-grasping tails of the anthropoids of the Old World. Prehensility has evolved at least two distinct times in platyrrhines, in the Atelidae family (spider monkeys, wooly spider monkeys, howler monkeys, and wooly monkeys), and in capuchin monkeys (Cebus).[11] Although prehensility is present in all of these primate species, skeletal and muscular-based morphological differences between these two groups indicate that the trait evolved separately through convergent evolution.[12][13] The fully prehensile tails that have evolved in Atelidae allow the primates to suspend their entire body weight by only their tails, with arms and legs free for other foraging and locomotive activities.[14] Semi-prehensile tails in Cebus can be used for balance by wrapping the tail around branches and supporting a large portion of their weight.[15]

New World monkeys (except for the howler monkeys of genus Alouatta)[16] also typically lack the trichromatic vision of Old World monkeys.[17] Colour vision in New World primates relies on a single gene on the X-chromosome to produce pigments that absorb medium and long wavelength light, which contrasts with short wavelength light. As a result, males rely on a single medium/long pigment gene and are dichromatic, as are homozygous females. Heterozygous females may possess two alleles with different sensitivities within this range, and so can display trichromatic vision.[18]

Platyrrhines also differ from Old World monkeys in that they have twelve premolars instead of eight; having a dental formula of or (consisting of 2 incisors, 1 canine, 3 premolars, and 2 or 3 molars). This is in contrast with Old World Anthropoids, including gorillas, chimpanzees, bonobos, siamangs, gibbons, orangutans, and most humans, which share a dental formula of Many New World monkeys are small and almost all are arboreal, so knowledge of them is less comprehensive than that of the more easily observed Old World monkeys. Unlike most Old World monkeys, many New World monkeys form monogamous pair bonds, and show substantial paternal care of young.[19] They eat fruits, nuts, insects, flowers, bird eggs, spiders, and small mammals. Unlike humans and most Old World monkeys, their thumbs are not opposable[20] (except for some Cebids).

See alsoEdit


  1. ^ a b Groves, C. P. (2005). "Infraorder Simiiformes". In Wilson, D. E.; Reeder, D. M. (eds.). Mammal Species of the World: A Taxonomic and Geographic Reference (3rd ed.). Baltimore: Johns Hopkins University Press. pp. 128–152. ISBN 0-801-88221-4. OCLC 62265494.
  2. ^ a b Rylands AB, Mittermeier RA (2009). "The Diversity of the New World Primates (Platyrrhini): An Annotated Taxonomy". In Garber PA, Estrada A, Bicca-Marques JC, Heymann EW, Strier KB (eds.). South American Primates: Comparative Perspectives in the Study of Behavior, Ecology, and Conservation. Springer. ISBN 978-0-387-78704-6.
  3. ^ "Platyrrhini and Ceboidea". ChimpanZoo. 2005. Archived from the original on 2008-05-15. Retrieved 19 July 2009.
  4. ^ Sellers, Bill (2000-10-20). "Primate Evolution" (PDF). University of Edinburgh. pp. 13–17. Retrieved 2008-10-23.
  5. ^ Robert W. Shumaker & Benjamin B. Beck (2003). Primates in Question. Smithsonian Institution Press. ISBN 978-1-58834-176-1.
  6. ^ Alan de Queiroz, The Monkey's Voyage, Basic Books, 2014.
  7. ^ Seiffert, Erik R.; Tejedor, Marcelo F.; Fleagle, John G.; Novo, Nelson M.; Cornejo, Fanny M.; Bond, Mariano; de Vries, Dorien; Campbell Jr., Kenneth E. (2020). "A parapithecid stem anthropoid of African origin in the Paleogene of South America". Science. 368 (6487): 194–197. Bibcode:2020Sci...368..194S. doi:10.1126/science.aba1135. PMID 32273470. S2CID 215550773.
  8. ^ Vries, Dorien de; Beck, Robin M. D. (2021-10-22). "Total evidence tip-dating phylogeny of platyrrhine primates and 27 well-justified fossil calibrations for primate divergences": 2021.10.21.465342. doi:10.1101/2021.10.21.465342. S2CID 239770343. {{cite journal}}: Cite journal requires |journal= (help)
  9. ^ de Oliveira EH, Neusser M, Müller S (2012) Chromosome evolution in New World Monkeys (Platyrrhini). Cytogenet Genome Res
  10. ^ Perez SI, Tejedor MF, Novo NM, Aristide L (2013) "Divergence times and the evolutionary radiation of New World monkeys (Platyrrhini, Primates): An analysis of fossil and molecular Data". PLoS One 8(6):e68029.
  11. ^ Rosenberger, Alfred L. (1983). "Tale of tails: Parallelism and prehensility". American Journal of Physical Anthropology. 60 (1): 103–107. doi:10.1002/ajpa.1330600114. ISSN 1096-8644. PMID 6869497.
  12. ^ Xu, Emily; Gray, Patricia M. (2017-07-28). "Evolutionary GEM: The Evolution of the Primate Prehensile Tail". Western Undergraduate Research Journal: Health and Natural Sciences. 8 (1). doi:10.5206/wurjhns.2017-18.4. ISSN 1923-757X.
  13. ^ Lockwood, Charles A.; Fleagle, John G. (1999). "The recognition and evaluation of homoplasy in primate and human evolution". American Journal of Physical Anthropology. 110 (S29): 189–232. doi:10.1002/(SICI)1096-8644(1999)110:29+<189::AID-AJPA7>3.0.CO;2-3. ISSN 1096-8644. PMID 10601987.
  14. ^ Sehner, Sandro; Fichtel, Claudia; Kappeler, Peter M. (December 2018). "Primate tails: Ancestral state reconstruction and determinants of interspecific variation in primate tail length". American Journal of Physical Anthropology. 167 (4): 750–759. doi:10.1002/ajpa.23703. PMID 30341951. S2CID 53008537.
  15. ^ Emmons, L. H.; Gentry, A. H. (1983). "Tropical Forest Structure and the Distribution of Gliding and Prehensile-Tailed Vertebrates". The American Naturalist. 121 (4): 513–524. doi:10.1086/284079. ISSN 0003-0147. JSTOR 2460978. S2CID 85211169.
  16. ^ Jacobs, G. H.; Neitz, M.; Deegan, J. F.; Neitz, J. (1996). "Trichromatic colour vision in New World monkeys". Nature. 382 (6587): 156–158. Bibcode:1996Natur.382..156J. doi:10.1038/382156a0. PMID 8700203. S2CID 4305822.
  17. ^ Sean B. Carroll (2006). The Making of the Fittest. W.W. Norton and Company. ISBN 978-0-393-06163-5.
  18. ^ Pamela M Kainz; Jay Neitz; Maureen Neitz (December 1998). "Recent evolution of uniform trichromacy in a New World monkey". Vision Research. 38 (21): 3315–3320. doi:10.1016/S0042-6989(98)00078-9. PMID 9893843. S2CID 11967994.
  19. ^ New World Monkeys at Animal Corner
  20. ^ "The Primates: New World Monkeys".

Further readingEdit

External linksEdit