Haplorhini (), the haplorhines (

Greek Greek may refer to: Greece Anything of, from, or related to Greece, a country in Southern Europe: *Greeks, an ethnic group. *Greek language, a branch of the Indo-European language family. **Proto-Greek language, the assumed last common ancestor ...

for "simple-nosed") or the "dry-nosed" primates, is a suborder of primates containing the

tarsiers 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 ...

and the simians (Simiiformes or anthropoids), as sister of the Strepsirrhini ("moist-nosed"). The name is sometimes spelled Haplorrhini. The simians include

catarrhines 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 W ...

(

Old World monkey 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 ...

s and

ape Apes (collectively Hominoidea ) are a clade of Old World simians native to sub-Saharan Africa and Southeast Asia (though they were more widespread in Africa, most of Asia, and as well as Europe in prehistory), which together with its sister g ...

s, including

human Humans (''Homo sapiens'') are the most abundant and widespread species of primate, characterized by bipedalism and exceptional cognitive skills due to a large and complex brain. This has enabled the development of advanced tools, cultu ...

s), and the platyrrhines (

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 ...

s). Haplorhini was proposed by Pocock in 1918 when he realized the tarsiers were actually sister to the monkeys rather than the lemurs, also following findings of

Hugh Cuming Hugh Cuming (14 February 1791 – 10 August 1865) was an English collector who was interested in natural history, particularly in conchology and botany. He has been described as the "Prince of Collectors". Born in England, he spent a number of y ...

80 years earlier and

Linnaeus Carl Linnaeus (; 23 May 1707 – 10 January 1778), also known after his ennoblement in 1761 as Carl von Linné Blunt (2004), p. 171. (), was a Swedish botanist, zoologist, taxonomist, and physician who formalised binomial nomenclature, the ...

160 years earlier. For Linnaeus, this ensemble of primates constituted a genus "''Simia''". For religious reasons, ''Homo'' constituted its own genus (which has remained). The extinct omomyids, which are considered to be the most basal haplorhines, are believed to be more closely related to the tarsiers than to other haplorhines. The exact relationship is not yet fully established – Williams, Kay and Kirk (2010) prefer the view that tarsiers and simians share a

common ancestor Common descent is a concept in evolutionary biology applicable when one species is the ancestor of two or more species later in time. All living beings are in fact descendants of a unique ancestor commonly referred to as the last universal comm ...

, and that common ancestor shares a common ancestor with the omomyids, citing evidence from analysis by Bajpal et al. in 2008; but they also note two other possibilities – that tarsiers are directly descended from omomyids, with simians being a separate line, or that both simians and tarsiers are descended from omomyids. Haplorhines share a number of derived features that distinguish them from the

strepsirrhine Strepsirrhini or Strepsirhini (; ) is a suborder of primates that includes the lemuriform primates, which consist of the lemurs of Madagascar, galagos ("bushbabies") and pottos from Africa, and the lorises from India and southeast Asia. Colle ...

"wet-nosed" primates (whose Greek name means "curved nose"), the other suborder of primates from which they diverged some 63 million years ago. The haplorhines, including tarsiers, have all lost the function of the terminal

enzyme Enzymes () are proteins that act as biological catalysts by accelerating chemical reactions. The molecules upon which enzymes may act are called substrates, and the enzyme converts the substrates into different molecules known as products ...

that manufactures

Vitamin C Vitamin C (also known as ascorbic acid and ascorbate) is a water-soluble vitamin found in citrus and other fruits and vegetables, also sold as a dietary supplement and as a topical 'serum' ingredient to treat melasma (dark pigment spots) ...

, while the strepsirrhines, like most other orders of mammals, have retained this enzyme. Genetically, five

short interspersed nuclear elements Retrotransposons (also called Class I transposable elements or transposons via RNA intermediates) are a type of genetic component that copy and paste themselves into different genomic locations (transposon) by converting RNA back into DNA through ...

(SINEs) are common to all haplorhines whilst absent in strepsirrhines. The haplorhine

upper lip The lips are the visible body part at the mouth of many animals, including humans. Lips are soft, movable, and serve as the opening for food intake and in the articulation of sound and speech. Human lips are a tactile sensory organ, and can be ...

, which has replaced the ancestral

rhinarium The rhinarium (New Latin, "belonging to the nose"; plural: rhinaria) is the furless skin surface surrounding the external openings of the nostrils in many mammals. Commonly it is referred to as the tip of the ''snout'', and breeders of cats and ...

found in strepsirrhines, is not directly connected to their nose or gum, allowing a large range of

facial expression A facial expression is one or more motions or positions of the muscles beneath the skin of the face. According to one set of controversial theories, these movements convey the emotional state of an individual to observers. Facial expressions are ...

s. Their brain-to-body mass ratio is significantly greater than the strepsirrhines, and their primary sense is vision. Haplorhines have a

postorbital The ''postorbital'' is one of the bones in vertebrate skulls which forms a portion of the dermal skull roof and, sometimes, a ring about the orbit. Generally, it is located behind the postfrontal and posteriorly to the orbital fenestra. In some ...

plate, unlike the postorbital bar found in strepsirrhines. Most species are diurnal (the exceptions being the tarsiers and the

night monkey 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 Am ...

s). All anthropoids have a single-chambered

uterus The uterus (from Latin ''uterus'', plural ''uteri'') or womb () is the organ in the reproductive system of most female mammals, including humans that accommodates the embryonic and fetal development of one or more embryos until birth. The ...

; tarsiers have a bicornate uterus like the strepsirrhines. Most species typically have single births, although twins and triplets are common for marmosets and

tamarin The tamarins are squirrel-sized New World monkeys from the family Callitrichidae in the genus ''Saguinus''. They are the first offshoot in the Callitrichidae tree, and therefore are the sister group of a clade formed by the lion tamarins, Goe ...

s. Despite similar gestation periods, haplorhine newborns are relatively much larger than strepsirrhine newborns, but have a longer dependence period on their mother. This difference in size and dependence is credited to the increased complexity of their behavior and natural history.

Etymology

The taxonomic name Haplorhini derives from the

Ancient Greek Ancient Greek includes the forms of the Greek language used in ancient Greece and the ancient world from around 1500 BC to 300 BC. It is often roughly divided into the following periods: Mycenaean Greek (), Dark Ages (), the Archaic p ...

' (, "onefold, single, simple") and ' ( ( genitive ῥινός), "nose"). It refers to the lack of a

or "wet nose", which is found in many mammals, including

primates.

Classification and evolution

Molecular estimates based on mitochondrial genomes suggest Haplorhini and its sister clade, Strepsirrhini, diverged 74 million years ago (mya), but no crown primate fossils are known prior to the beginning of the

Eocene The Eocene ( ) Epoch is a geological epoch that lasted from about 56 to 33.9 million years ago (mya). It is the second epoch of the Paleogene Period in the modern Cenozoic Era. The name ''Eocene'' comes from the Ancient Greek (''ēṓs'', " ...

, 56 mya. The same molecular analysis suggests the infraorder

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 o ...

, whose only remaining family is that of the tarsier (Tarsiidae), branched off from the other haplorhines 70 mya. The fossil '' Archicebus'' may be similar to the most recent common ancestor at this time. The other major clade within Haplorhini, the simians (or anthropoids), is divided into two parvorders: Platyrrhini (the

s) and

Catarrhini 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 ...

(the

s and

s). The New World monkeys split from catarrhines about 35 - 40 mya and have African origin, while the apes (

Hominoidea Apes (collectively Hominoidea ) are a clade of Old World simians native to sub-Saharan Africa and Southeast Asia (though they were more widespread in Africa, most of Asia, and as well as Europe in prehistory), which together with its sister g ...

) diverged from Old World monkeys (

Cercopithecoidea 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 ...

) about 25 mya. The available fossil evidence indicates that both the hominoid and cercopithecoid clades originated in Africa. The following is the listing of the living haplorhine families, and their placement in the Order Primates: * Order

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 ...

s ** Suborder Strepsirrhini: lemurs, lorises, galagos etc. ** Suborder Haplorhini: tarsiers + monkeys and apes *** Infraorder

**** Family Tarsiidae: tarsiers *** Infraorder

Simiiformes 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 Cata ...

: monkeys and apes **** Parvorder Platyrrhini: New World monkeys ***** Family Callitrichidae: marmosets, tamarins ***** Family Cebidae: capuchins, squirrel monkeys ***** Family Aotidae: night or owl monkeys (douroucoulis) ***** Family

Pitheciidae The Pitheciidae () are one of the five families of New World monkeys now recognised. Formerly, they were included in the family Atelidae. The family includes the titis, saki monkeys and uakaris. Most species are native to the Amazon region ...

: titis, sakis, uakaris ***** Family Atelidae: howler, spider, and woolly monkeys **** Parvorder

Old World anthropoids ***** Superfamily

****** Family Cercopithecidae: Old World monkeys ***** Superfamily

: apes ****** Family Hylobatidae: lesser apes (gibbons) ****** Family Hominidae: great apes and humans

Uncertain placement of extinct early haplorhines

The exact placement of early haplorhine families is uncertain owing to limited evidence. The following sets out a possible order put together by Williams, Kay and Kirk in 2010, based on cladograms put together by Seiffert et al (2005), Marivaux (2006) and Bajpai et al (2008), and should not be seen as definitive. They do not include

Propliopithecoidea Propliopithecoidea is a superfamily of catarrhine primates that inhabited Africa and Arabia during the Early Oligocene about 32 to 29 million years ago. Fossils have been found in Egypt, Oman and Angola. They are one of the earliest known famil ...

as they classify them as early catarrhines. Also included are Archicebidae, the discovery of which was announced by Ni et al in 2013. (but see notes below regarding placement). * Order

s ** Plesiadapiformes ** Strepsirrhini: lemurs, lorises, galagos and their ancestors **Haplorhini *** possible stem Haplorrhini - see explanation below ***

/ Omomyiformes Tarsiers and their ancestors **** Archicebidae **** Tarsiidae *** Anthropoidea/

**** Eosimiidae early anthropoids (or simians) ****

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 ...

****

Parapithecoidea Parapithecoidea is an extinct superfamily of primates which lived in the Eocene and Oligocene periods in Egypt. In some classifications all Parapithecoidea are placed within the family Parapithecidae. Seiffert ''et al.'' (2010) propose that Para ...

**** Proteopithecoidea ****

Oligopithecidae Oligopithecidae is an extinct basal Catarrhine family from the late Eocene of Egypt Egypt ( ar, مصر , ), officially the Arab Republic of Egypt, is a List of transcontinental countries, transcontinental country spanning the North Africa ...

****

Old World anthropoids **** Platyrrhini New World monkeys Sigé et al (1990) describe '' Altiatlasius'' as an Omomyiform, but also state that it could be an early anthropoid, with the latter view being supported by Godinot (1994) and Bajpai et al (2008). Kay et al (2004) point out that a case can be made for Amphipithecidae being placed either as

adapiformes 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 M ...

(i.e. early strepsirrhines) or as early anthropoids, noting in particular that they had a long evolution separate from other groups, and that key parts of their anatomy are missing from the fossil record. They conclude that either possibility is equally plausible.Callum F Ross, Richard F. Kay ''Anthropoid Origins: New Visions '', Springer, 2004, p. 114 Kay and Williams (2013, edited by Feagle and Kay), look at possible hypotheses about how oligopiths, parapiths and propliopiths relate to each other and catarrhines and platyrrhines:
- that parapiths and propliopiths are closely related, with their common ancestor being related to oligopiths, and the common ancestor of all three being related to the platyrrhines with extant catarrhines (i.e.

cercopithecoidea 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

hominoidea Apes (collectively Hominoidea ) are a clade of Old World simians native to sub-Saharan Africa and Southeast Asia (though they were more widespread in Africa, most of Asia, and as well as Europe in prehistory), which together with its sister g ...

) being descended from the propliopiths;
- or that parapiths and propliopiths are closely related but their common ancestor is closely related to the platyrrhines and the common ancestor of all three is related to the oligopiths, with extant catarrhines again being descended from the propliopiths;
- or that propliopiths and oligopiths are closely related, and parapiths are related to the common ancestor of both and the common ancestor of all three is related to the platyrrhines, with cercopithecoidea being descended from the parapiths and hominoidea being descended from propliopiths.
- finally, they also consider the hypothesis that oligopiths are adapiformes (i.e. early strepsirrhines rather than early haplorhines)Richard F. Kay, Blythe A Williams ''Anthropoid Origins: New Visions (Developments in Primatology: Progress and Prospects)'', Springer, 2013, p. 365 Ni et al, in announcing '' Archicebus achilles'' in 2013 as what they describe as the earliest known primate with such detailed remains, place it somewhat differently to the above as they place Omomyids within Tarsiiformes, with Omomyids and Tarsiidae sharing a common ancestor, and that common ancestor sharing a common Tarsiiform ancestor with the Archicebidae. Possible stem Haplorrhini are some species which are usually considered to be Strepsirrhini, such as the Notharctidae, and

Darwinius ''Darwinius'' is a genus within the infraorder Adapiformes, a group of basal strepsirrhine primates from the middle Eocene epoch. Its only known species, ''Darwinius masillae'', lived approximately 47 million years ago (Lutetian stage) based ...

References

Literature cited

* * ''Primate Taxonomy'' (Smithsonian Institution Press, 2001),

Colin Groves Colin Peter Groves (24 June 1942 – 30 November 2017) was a British-Australian biologist and anthropologist. Groves was Professor of Biological Anthropology at the Australian National University in Canberra, Australia. Education Born in Englan ...

() * ''Primates in Question'' (Smithsonian Institution Press, 2003), Robert W. Shumaker & Benjamin B. Beck ()
Neotropical Primates 10(3)
{{Taxonbar, from=Q82261 Primate taxonomy Extant Paleocene first appearances Taxa named by R. I. Pocock Taxa described in 1918