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 Southea ...

and the

simian 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 Catarr ...

s (Simiiformes or anthropoids), as sister of the

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 ...

("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 baboo ...

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 ...

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, culture, ...

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 Ceboid ...

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 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, ...

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

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 Southe ...

s 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 com ...

, 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. Co ...

"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 (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 a ...

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 The postorbital bar (or postorbital bone) is a bony arched structure that connects the frontal bone of the skull to the zygomatic arch, which runs laterally around the eye socket. It is a trait that only occurs in mammalian taxa, such as most s ...

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. Th ...

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

marmoset The marmosets (), also known as zaris or sagoin, are 22 New World monkey species of the genera '' Callithrix'', '' Cebuella'', '' Callibella'', and '' Mico''. All four genera are part of the biological family Callitrichidae. The term "marmose ...

s 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, Goel ...

s. Despite similar

gestation period In mammals, pregnancy is the period of reproduction during which a female carries one or more live offspring from implantation in the uterus through gestation. It begins when a fertilized zygote implants in the female's uterus, and ends once i ...

s, 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 pe ...

' (, "onefold, single, simple") and ' ( (

genitive In grammar, the genitive case ( abbreviated ) is the grammatical case that marks a word, usually a noun, as modifying another word, also usually a noun—thus indicating an attributive relationship of one noun to the other noun. A genitive can ...

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,

, 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'', "da ...

, 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 of ...

, 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

s (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 ...

) 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 babo ...

) 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 human ...

s ** Suborder

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

**** Family

Tarsiidae 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 Southea ...

: 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 Catarrh ...

: monkeys and apes **** Parvorder Platyrrhini: New World monkeys ***** Family

Callitrichidae The Callitrichidae (also called Arctopitheci or Hapalidae) are a family of New World monkeys, including marmosets, tamarins, and lion tamarins. At times, this group of animals has been regarded as a subfamily, called the Callitrichinae, of the f ...

: marmosets, tamarins ***** Family Cebidae: capuchins, squirrel monkeys ***** Family Aotidae: night or owl monkeys (douroucoulis) ***** Family Pitheciidae: titis, sakis, uakaris ***** Family Atelidae: howler, spider, and woolly monkeys **** Parvorder

Old World anthropoids ***** Superfamily

****** Family

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 babo ...

: Old World monkeys ***** Superfamily

: apes ****** 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 In ...

: lesser apes (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 ...

: 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 Plesiadapiformes (" Adapid-like" or "near Adapiformes") is a group of Primates, a sister of the Dermoptera. While none of the groups normally directly assigned to this group survived, the group appears actually not to be literally extinct (in ...

: lemurs, lorises, galagos and their ancestors **Haplorhini *** possible

stem Stem or STEM may refer to: Plant structures * Plant stem, a plant's aboveground axis, made of vascular tissue, off which leaves and flowers hang * Stipe (botany), a stalk to support some other structure * Stipe (mycology), the stem of a mushro ...

Haplorrhini - see explanation below ***

Omomyiformes Omomyidae is a group of early primates that radiated during the Eocene epoch between about (mya). Fossil omomyids are found in North America, Europe & Asia making it one of two groups of Eocene primates with a geographic distribution spanning h ...

Tarsiers and their ancestors **** Archicebidae ****

***

Anthropoidea 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 Catarrhi ...

****

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 ...

early anthropoids (or simians) **** Amphipithecidae **** Parapithecoidea **** Proteopithecoidea ****

Oligopithecidae Oligopithecidae is an extinct basal Catarrhine 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 t ...

****

Old World anthropoids **** Platyrrhini New World monkeys Sigé et al (1990) describe ''

Altiatlasius ''Altiatlasius'' ("High Atlas" from Latin altus, "high" + Atlas, "Atlas") is an extinct genus of mammal, which may have been the oldest known primate, dating to the Late Paleocene (c.57 ma) from Morocco. The only species, ''Altiatlasius koulc ...

'' 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 th ...

(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 babo ...

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 ...

) 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

, 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