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''Nakalipithecus nakayamai'' is an extinct species of
great ape 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 east ...
from Nakali, Kenya, from about 9.9–9.8 million years ago during the
Late Miocene The Late Miocene (also known as Upper Miocene) is a sub-epoch of the Miocene epoch (geology), Epoch made up of two faunal stage, stages. The Tortonian and Messinian stages comprise the Late Miocene sub-epoch, which lasted from 11.63 Ma (million ye ...
. It is known from a right jawbone with 3
molars The molars or molar teeth are large, flat teeth at the back of the mouth. They are more developed in mammals. They are used primarily to grind food during chewing. The name ''molar'' derives from Latin, ''molaris dens'', meaning "millstone to ...
and from 11 isolated teeth, and the specimen is presumed female as the teeth are similar in size to those of female
gorilla Gorillas are herbivorous, predominantly ground-dwelling great apes that inhabit the tropical forests of equatorial Africa. The genus ''Gorilla'' is divided into two species: the eastern gorilla and the western gorilla, and either four or fi ...
s and
orangutan Orangutans are great apes native to the rainforests of Indonesia and Malaysia. They are now found only in parts of Borneo and Sumatra, but during the Pleistocene they ranged throughout Southeast Asia and South China. Classified in the genus ...
s. Compared to other great apes, the canines are short, the enamel is thin, and the molars are flatter. ''Nakalipithecus'' seems to have inhabited a
sclerophyllous Sclerophyll is a type of vegetation that is adapted to long periods of dryness and heat. The plants feature hard leaves, short internodes (the distance between leaves along the stem) and leaf orientation which is parallel or oblique to direct ...
woodland environment.


Taxonomy

''Nakalipithecus'' was first described from a right jawbone, the
holotype A holotype is a single physical example (or illustration) of an organism, known to have been used when the species (or lower-ranked taxon) was formally described. It is either the single such physical example (or illustration) or one of several ...
KNM-NA46400, and eleven isolated teeth excavated in 2005 by a team of Japanese and Kenyan researchers in
mud flow A mudflow or mud flow is a form of mass wasting involving fast-moving flow of debris that has become liquified by the addition of water. Such flows can move at speeds ranging from 3 meters/minute to 5 meters/second. Mudflows contain a significa ...
deposits in the Nakali area of northern Kenya's former
Rift Valley Province Rift Valley Province ( sw, Mkoa wa Bonde la Ufa) of Kenya, bordering Uganda, was one of Kenya's eight provinces, before the Kenyan general election, 2013. Rift Valley Province was the largest and one of the most economically important provinces i ...
, hence the genus name ''Nakalipithecus'' ("Nakali ape"). The species name is in honour of the late Japanese geologist Katsuhiro Nakayama who worked on the expedition. The specimen dates to about 9.9–9.8 million years ago in the
Late Miocene The Late Miocene (also known as Upper Miocene) is a sub-epoch of the Miocene epoch (geology), Epoch made up of two faunal stage, stages. The Tortonian and Messinian stages comprise the Late Miocene sub-epoch, which lasted from 11.63 Ma (million ye ...
. The specimens are housed by the
National Museums of Kenya The National Museums of Kenya (NMK) is a state corporation that manages museums, sites and monuments in Kenya. It carries out heritage research, and has expertise in subjects ranging from palaeontology, archeology, ethnography and biodiversit ...
. The holotype preserves all 3 lower
molars The molars or molar teeth are large, flat teeth at the back of the mouth. They are more developed in mammals. They are used primarily to grind food during chewing. The name ''molar'' derives from Latin, ''molaris dens'', meaning "millstone to ...
, and the isolated teeth are: a left first
incisor Incisors (from Latin ''incidere'', "to cut") are the front teeth present in most mammals. They are located in the premaxilla above and on the mandible below. Humans have a total of eight (two on each side, top and bottom). Opossums have 18, whe ...
, a right first incisor, a right canine, a right third upper
premolar The premolars, also called premolar teeth, or bicuspids, are transitional teeth located between the canine and molar teeth. In humans, there are two premolars per quadrant in the permanent set of teeth, making eight premolars total in the mouth ...
, a left third upper premolar, a right left fourth upper premolar, a left fourth upper premolar, a right first upper molar, a right third upper molar, a left third upper molar, and a left fourth lower premolar. It is debated if great
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 siste ...
s evolved in Africa or Eurasia given the abundance of early fossil apes species in the latter and the paucity in the former, despite all modern great apes except the
orangutan Orangutans are great apes native to the rainforests of Indonesia and Malaysia. They are now found only in parts of Borneo and Sumatra, but during the Pleistocene they ranged throughout Southeast Asia and South China. Classified in the genus ...
being known from Africa. The first Miocene African ape, ''
Samburupithecus ''Samburupithecus'' is an extinct primate that lived in Kenya during the middle to late Miocene. The one species in this genus, ''Samburupithecus kiptalami'', is known only from a maxilla fragment dated to discovered in 1982 and formally descri ...
'', was discovered in 1982. It is unclear how ''Nakalipithecus'' is related to other apes. It is possible these Late Miocene African apes were
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 ...
great apes closely related to the
last common ancestor In biology and genetic genealogy, the most recent common ancestor (MRCA), also known as the last common ancestor (LCA) or concestor, of a set of organisms is the most recent individual from which all the organisms of the set are descended. The ...
of all modern African apes, which existed about 9–8 million years ago. ''Nakalipithecus'' and the 9 million year old Greek ''
Ouranopithecus macedoniensis ''Ouranopithecus macedoniensis'' is a prehistoric species of ''Ouranopithecus'' from the Late Miocene of Greece. See more detail at ''Ouranopithecus''. This species is known from three localities in Northern Greece. The type location is Ravin de ...
'' exhibit many similarities with each other, but ''Nakalipithecus'' has more basal (primitive) traits, which could indicate that it was the ancestor or closely related to the ancestor of ''Ouranopithecus''. ''Ouranopithecus'', in turn, is postulated to be closely related to
australopithecine Australopithecina or Hominina is a subtribe in the tribe Hominini. The members of the subtribe are generally ''Australopithecus'' (cladistically including the genus, genera ''Homo'', ''Paranthropus'', and ''Kenyanthropus''), and it typically in ...
s and the human line. This would show that apes evolved in Africa. However, evidence of common ancestry can also be interpreted as
convergent evolution Convergent evolution is the independent evolution of similar features in species of different periods or epochs in time. Convergent evolution creates analogous structures that have similar form or function but were not present in the last com ...
, with similar dental adaptations caused by inhabiting a similar environment, though ''Ouranopithecus'' seems to have consumed more hard objects than ''Nakalipithecus''. A 2017 study on
deciduous In the fields of horticulture and Botany, the term ''deciduous'' () means "falling off at maturity" and "tending to fall off", in reference to trees and shrubs that seasonally shed leaves, usually in the autumn; to the shedding of petals, aft ...
fourth premolars—deciduous teeth are less affected by environmental factors as they soon fall out and are replaced by permanent teeth—found that ''Nakalipithecus'' and later African apes (including australopithecines) shared more similarities with each other than to Eurasian apes, though drew no clear conclusion on the ''Nakalipithecus''–''Ouranopithecus'' relationship. ''Nakalipithecus'' has also been proposed to have been the ancestor to the 8 million year old ''Chororapithecus'', which possibly represents an early member of the
gorilla Gorillas are herbivorous, predominantly ground-dwelling great apes that inhabit the tropical forests of equatorial Africa. The genus ''Gorilla'' is divided into two species: the eastern gorilla and the western gorilla, and either four or fi ...
line; if both of these are correct, then ''Nakalipithecus'' could potentially represent an early gorilla.


Anatomy

''Nakalipithecus'' has an overall large size, with teeth similar in size to those of female gorillas and orangutans. The specimen is thus presumed female. The ''Samburupithecus'' specimen was also about the same size. Unlike other apes, the canines are short, and as long as they are wide—about in height and width respectively. For comparison, the left first incisor is . The premolars are elongated, and the
protoconid Many different terms have been proposed for features of the tooth crown in mammals. The structures within the molars receive different names according to their position and morphology. This nomenclature was developed by Henry Fairfield Osborn i ...
(the cusp on the tongue side) of the third premolar is oriented more cheekwards, which is a distinguishing characteristic of Miocene African apes from Miocene Eurasian apes. Compared to African apes contemporary with ''Nakalipithecus'', the
tooth enamel Tooth enamel is one of the four major Tissue (biology), tissues that make up the tooth in humans and many other animals, including some species of fish. It makes up the normally visible part of the tooth, covering the Crown (tooth), crown. The ...
on the
molars The molars or molar teeth are large, flat teeth at the back of the mouth. They are more developed in mammals. They are used primarily to grind food during chewing. The name ''molar'' derives from Latin, ''molaris dens'', meaning "millstone to ...
is thinner, and the cusps (which project outward from the tooth) are less inflated, creating a wider basin. In the holotype, the first, second, and third molars are , , and , respectively. Like modern and some contemporary apes, but unlike earlier East African apes, the first molar is relatively large, with a first molar to second molar ratio of 85%. Like ''Ouranopithecus'' and early ''
Sivapithecus ''Sivapithecus'' () (syn: ''Ramapithecus)'' is a genus of extinct apes. Fossil remains of animals now assigned to this genus, dated from 12.2 million years old in the Miocene, have been found since the 19th century in the Siwalik Hills The Si ...
'' (''Sivapithecus'' is known from the
Indian subcontinent The Indian subcontinent is a list of the physiographic regions of the world, physiographical region in United Nations geoscheme for Asia#Southern Asia, Southern Asia. It is situated on the Indian Plate, projecting southwards into the Indian O ...
), but unlike most contemporary and future apes, the third molar was much larger than the second, with a third molar to second molar ratio of 115%, though this ratio is smaller than that of the later Southeast Asian ''
Khoratpithecus ''Khoratpithecus'' is an extinct genus of pongin primates that lived during the late Miocene (7–9 million years ago) in Myanmar and Thailand. Three species belong to this genus: *''Khoratpithecus chiangmuanensis'' from Thailand (Chaimanee, ...
''. The mandible is less
robust Robustness is the property of being strong and healthy in constitution. When it is transposed into a system, it refers to the ability of tolerating perturbations that might affect the system’s functional body. In the same line ''robustness'' ca ...
(heavily built) than those of contemporary Eurasian Miocene apes, except for ''Ouranopithecus''.


Palaeobiology

During the Late Miocene, East Africa, the
Sahara , photo = Sahara real color.jpg , photo_caption = The Sahara taken by Apollo 17 astronauts, 1972 , map = , map_image = , location = , country = , country1 = , ...
, the Middle East, and Southern Europe all appear to have been predominantly seasonal
sclerophyllous Sclerophyll is a type of vegetation that is adapted to long periods of dryness and heat. The plants feature hard leaves, short internodes (the distance between leaves along the stem) and leaf orientation which is parallel or oblique to direct ...
evergreen In botany, an evergreen is a plant which has foliage that remains green and functional through more than one growing season. This also pertains to plants that retain their foliage only in warm climates, and contrasts with deciduous plants, which ...
woodland environments. Nakali appears to have been dominated by C3 (forest) plants. ''Nakalipithecus'' is known from the Upper Beds, which comprise lakeside or riverine deposits. Climate change caused the expansion of grasslands in Africa from 10–7 milling years ago, likely fragmenting populations of forest-dwelling primates, leading to extinction. Nakali has also yielded a
black rhino The black rhinoceros, black rhino or hook-lipped rhinoceros (''Diceros bicornis'') is a species of rhinoceros, native to eastern and southern Africa including Angola, Botswana, Kenya, Malawi, Mozambique, Namibia, South Africa, Eswatini, Tanzania ...
specimen, the pig ''
Nyanzachoerus ''Nyanzachoerus'' is an extinct genus of the pig family ( Suidae) belonging to the subfamily Tetraconodontinae. The several species of ''Nyanzachoerus'' lived in Africa from the Miocene to Pliocene The Pliocene ( ; also Pleiocene) is th ...
'', an
antelope The term antelope is used to refer to many species of even-toed ruminant that are indigenous to various regions in Africa and Eurasia. Antelope comprise a wastebasket taxon defined as any of numerous Old World grazing and browsing hoofed mammals ...
, the hippo ''
Kenyapotamus ''Kenyapotamus'' is a possible ancestor of living hippopotamuses that lived roughly 16 million to 8 million years ago during the Miocene epoch. Its name reflects that its fossils were first found in modern-day Kenya. Although little is known a ...
'', the rhino '' Kenyatherium'', the giraffe ''
Palaeotragus ''Palaeotragus'' ("ancient goat") is a genus of very large, primitive, okapi-like giraffids from the Miocene of Africa and Eurasia. ''Palaeotragus primaevus'' is the older species, being found in early to mid-Miocene strata, while ''P. germaini' ...
'', the horse ''
Hipparion ''Hipparion'' (Greek, "pony") is an extinct genus of horse that lived in North America, Asia, Europe, and Africa during the Miocene through Pleistocene ~23 Mya—781,000 years ago. It lived in non-forested, grassy plains, shortgrass prairie or st ...
'', the elephants ''
Deinotherium ''Deinotherium'' was a large elephant-like proboscidean that appeared in the Middle Miocene and survived until the Early Pleistocene. Although superficially resembling modern elephants, they had notably more flexible necks, limbs adapted to a mo ...
'' and (possibly) ''
Choerolophodon ''Choerolophodon'' is an extinct genus of proboscidean that lived during the Miocene of Eurasia and Africa. Fossils of ''Choerolophodon'' have been found in Africa, Southeast Europe, Turkey, Iraq, Iran, the Indian subcontinent, and China. ''Choer ...
'', and the
colobine The Colobinae or leaf-eating monkeys are a subfamily of the Old World monkey family that includes 61 species in 11 genera, including the black-and-white colobus, the large-nosed proboscis monkey, and the gray langurs. Some classifications spli ...
monkey ''
Microcolobus ''Microcolobus'' is an extinct genus of Old world monkey that lived in eastern Africa during the Late Miocene and is regarded as the first known member of the Colobinae. Taxonomy ''Microcolobus'' was described in 1986 from remains that were found ...
''. The third premolar of a small nyanzapithecine ape was also found in Nakali, and ''Samburupithecus'' was nearly contemporaneous with ''Nakalipithecus'', and was discovered to the north of Nakali.


See also


References


External links


Human Timeline (Interactive)
Smithsonian,
National Museum of Natural History The National Museum of Natural History is a natural history museum administered by the Smithsonian Institution, located on the National Mall in Washington, D.C., United States. It has free admission and is open 364 days a year. In 2021, with 7 ...
(August 2016).
"Mama, Is That You? Possible Ape Ancestor Found"
''
Discovery News Discovery, Inc. was an American multinational mass media factual television conglomerate based in New York City. Established in 1985, the company operated a group of factual and lifestyle television brands, such as the namesake Discovery Channe ...
''. Version of 2007-NOV-12. Retrieved 2007-NOV-13. Contains photo of fossil. {{Taxonbar, from=Q134742 Miocene primates of Africa Prehistoric apes Fossil taxa described in 2007 Monotypic prehistoric primate genera Prehistoric primate genera Miocene mammals of Africa Great Rift Valley