The simians, anthropoids, or higher primates are an infraorder (Simiiformes ) of primates containing all animals traditionally called

monkey Monkey is a common name that may refer to most mammals of the infraorder Simiiformes, also known as the simians. Traditionally, all animals in the group now known as simians are counted as monkeys except the apes, which constitutes an incomple ...

s and apes. More precisely, they consist of the parvorders New World monkeys (Platyrrhini) and Catarrhini, the latter of which consists of the superfamilies Cercopithecidae ( Old World monkeys in the stricter sense) and apes ( Hominoidea; including the genus '' Homo''). The simians are sister group to the tarsiers (Tarsiiformes), together forming the

haplorhines Haplorhini (), the haplorhines (Greek for "simple-nosed") or the "dry-nosed" primates, is a suborder of primates containing the tarsiers and the simians (Simiiformes or anthropoids), as sister of the Strepsirrhini ("moist-nosed"). The name is some ...

. The radiation occurred about 60 million years ago (during the Cenozoic era); 40 million years ago, simians colonized South America, giving rise to the New World monkeys. The remaining simians (catarrhines) split about 25 million years ago into

Cercopithecidae Old World monkey is the common English name for a family of primates known taxonomically as the Cercopithecidae (). Twenty-four genera and 138 species are recognized, making it the largest primate family. Old World monkey genera include baboons ...

and apes (including humans).

Taxonomy and evolution

In earlier classification, New World monkeys, Old World monkeys, apes, and humans – collectively known as simians or anthropoids – were grouped under Anthropoidea (; ), while the strepsirrhines and tarsiers were grouped under the suborder " Prosimii". Under modern classification, the tarsiers and simians are grouped under the suborder

Haplorhini Haplorhini (), the haplorhines (Greek for "simple-nosed") or the "dry-nosed" primates, is a suborder of primates containing the tarsiers and the simians (Simiiformes or anthropoids), as sister of the Strepsirrhini ("moist-nosed"). The name is some ...

, while the strepsirrhines are placed in suborder Strepsirrhini. Strong genetic evidence for this is that five

SINEs Sines () is a city and a municipality in Portugal. The municipality, divided into two parishes, has around 14,214 inhabitants (2021) in an area of . Sines holds an important oil refinery and several petrochemical industries. It is also a popular ...

are common to all haplorhines whilst absent in strepsirrhines — even one being coincidental between tarsiers and simians would be quite unlikely. Despite this preferred taxonomic division, " prosimian" is still regularly found in textbooks and the academic literature because of familiarity, a condition likened to the use of the metric system in the sciences and the use of

customary units United States customary units form a system of measurement units commonly used in the United States and U.S. territories since being standardized and adopted in 1832. The United States customary system (USCS or USC) developed from English units ...

elsewhere in the United States. In the Anthropoidea, evidence indicates that the Old World and New World primates went through parallel evolution. Primatology,

paleoanthropology Paleoanthropology or paleo-anthropology is a branch of paleontology and anthropology which seeks to understand the early development of anatomically modern humans, a process known as hominization, through the reconstruction of evolutionary kinship ...

, and other related fields are split on their usage of the synonymous infraorder names, Simiiformes and Anthropoidea. According to

Robert Hoffstetter Robert Julien Hoffstetter (11 June 1908 in Fargniers – 29 December 1999 in Gennevilliers) was a French taxonomist and herpetologist who was influential in categorizing reptiles. He described the snake families Bolyeriidae and Madtsoiidae Mad ...

(and supported by Colin Groves), the term Simiiformes has priority over Anthropoidea because the taxonomic term ''Simii'' by

van der Hoeven Van der Hoeven (Vanderhoeven) or Van der Hoeve is a surname of noble Dutch family. People with the name include: * Abraham Pruijs van der Hoeven (1829–1907), Dutch colonial governor of Aceh * Agnes van Ardenne-van der Hoeven (b. 1950), Dutch pol ...

, from which it is constructed, dates to 1833. In contrast, Anthropoidea by

Mivart St. George Jackson Mivart (30 November 1827 – 1 April 1900) was an English biologist. He is famous for starting as an ardent believer in natural selection who later became one of its fiercest critics. Mivart attempted to reconcile D ...

dates to 1864, while Simiiformes by

Haeckel Ernst Heinrich Philipp August Haeckel (; 16 February 1834 – 9 August 1919) was a German zoologist, naturalist, eugenicist, philosopher, physician, professor, marine biologist and artist. He discovered, described and named thousands of new sp ...

dates to 1866, leading to counterclaims of priority. Hoffstetter also argued that Simiiformes is also constructed like a proper infraorder name (ending in "iformes"), whereas Anthropoidea ends in -"oidea", which is reserved for superfamilies. He also noted that Anthropoidea is too easily confused with "anthropoïdes", which translates to "apes" from several languages. Extant simians are split into three distinct groups. The New World monkeys in parvorder Platyrrhini split from the rest of the simian line about 40 million years ago (Mya), leaving the parvorder Catarrhini occupying the Old World. This group split about 25 Mya between the

and the apes. Some lines of extinct simian also are either placed into the

Eosimiidae Eosimiidae is the possible family of extinct primates believed to be the earliest simians. Taxonomy When they were discovered the possibility that Eosimians were outside and ancestral to Simians was considered (Culotta 1992), but subsequent ...

(to reflect their Eocene origin) and sometimes in Amphipithecidae, thought to originate in the Early Oligocene. Additionally, '' Phileosimias'' is sometimes placed in the Eosimiidae and sometimes categorised separately.

Classification

The following is the listing of the various simian families, and their placement in the order Primates: * Order Primates ** Suborder

Strepsirrhini Strepsirrhini or Strepsirhini (; ) is a Order (biology), suborder of primates that includes the Lemuriformes, lemuriform primates, which consist of the lemurs of Fauna of Madagascar, Madagascar, galagos ("bushbabies") and pottos from Fauna of A ...

: non

tarsier Tarsiers ( ) are haplorhine primates of the family Tarsiidae, which is itself the lone extant family within the infraorder Tarsiiformes. Although the group was once more widespread, all of its species living today are found in Maritime Southeast ...

prosimians ** Suborder

: tarsiers and monkeys, including apes *** Infraorder Tarsiiformes ***Infraorder Simiiformes **** Parvorder Platyrrhini: New World monkeys ***** Family Callitrichidae: marmosets and tamarins ***** Family

Cebidae The Cebidae are one of the five families of New World monkeys now recognised. Extant members are the capuchin and squirrel monkeys. These species are found throughout tropical and subtropical South and Central America. Characteristics Cebid mo ...

: capuchins and squirrel monkeys ***** Family

Aotidae Night monkeys, also known as owl monkeys or douroucoulis (), are nocturnal New World monkeys of the genus ''Aotus'', the only member of the family Aotidae (). The genus comprises eleven species which are found across Panama and much of South Ame ...

: night or owl monkeys (douroucoulis) ***** Family Pitheciidae: titis, sakis, and uakaris ***** Family Atelidae: howler, spider, and woolly monkeys **** Parvorder Catarrhini ***** Superfamily Cercopithecoidea: Old World monkeys ****** Family

***** Superfamily Hominoidea ****** Family

Hylobatidae Gibbons () are apes in the family Hylobatidae (). The family historically contained one genus, but now is split into four extant genera and 20 species. Gibbons live in subtropical and tropical rainforest from eastern Bangladesh to Northeast India ...

: gibbons ****** Family

Hominidae The Hominidae (), whose members are known as the great apes or hominids (), are a taxonomic family of primates that includes eight extant species in four genera: '' Pongo'' (the Bornean, Sumatran and Tapanuli orangutan); ''Gorilla'' (the ea ...

: great apes, including humans **** † Amphipithecidae **** †

**** †'' Aseanpithecus'' Below is a cladogram with some of the extinct simian species with the more modern species emerging within the Eosimiidae. The simians originated in Asia, while the crown simians were in Afro-Arabia. It is indicated approximately how many Mya the clades diverged into newer clades. Usually the Ekgmowechashalidae are considered to be

, not Haplorhini. A 2018 study places Eosimiidae as a sister to the crown haplorhini. In 2020 papers, the

Proteopithecidae Proteopithecidae is an extinct family of primates which lived in the Priabonian (late Eocene) and probably early Oligocene periods. Fossils that have been found are in the Jebel Qatrani Formation in Egypt. Currently two genera are recognised, eac ...

are part of the Parapithecoidea, and ''

Nosmips aenigmaticus ''Nosmips aenigmaticus'' is a rare fossil primate known only from 12 teeth. Most teeth were found at a site in the Fayum Depression about outside Cairo, Egypt. ''Nosmips aenigmaticus'' probably lived 37 million years ago in Africa and has ...

'' (previously in Eosimidae) is a basal simian.

Biological key-features

In a section of their 2010 assessment of the evolution of anthropoids (simians) entitled "What is an Anthropoid", Williams, Kay, and Kirk set ou
a list of biological features common to all or most anthropoids
including genetic similarities, similarities in eye location and the muscles close to the eyes, internal similarities between ears, dental similarities, and similarities on foot bone structure. The earliest anthropods were small primates with varied diets, forward-facing eyes, acute color vision for daytime lifestyles, and brains devoted more to vision and less to smell. Living simians in both the New World and the Old World have larger brains than other primates, but they evolved these larger brains independently.

References

External links

BioMed Central Full text Gene conversion and purifying selection of a placenta-specific ERV-V envelope gene during simian evolution

Taxonomy browser (Simiiformes)

* ttps://web.archive.org/web/20121018195118/http://news.sciencemag.org/sciencenow/2010/10/mouse-sized-primates-shed-light.html Mouse-Sized Primates Shed Light on Human Origins {{Taxonbar, from=Q5452918 Primate taxonomy

Taxonomy and evolution

Classification

Biological key-features

See also

References

External links