View source for Nakalipithecus

{{Short description|Extinct species of ape}}
{{good article}}
{{Use dmy dates|date=March 2020}}
{{Speciesbox
| fossil_range = [[Tortonian]], {{fossil range|9.9|9.8}}
| image = Nakalipithecus mandible.jpg
| image_caption = Top and side views of the ''Nakalipithecus'' [[holotype]], a jawbone and the [[molar tooth|molars]]
| display_parents = 3
| genus = Nakalipithecus
| parent_authority = [[Yutaka Kunimatsu|Kunimatsu]] et al., 2007
| species = nakayamai
| authority = [[Yutaka Kunimatsu|Kunimatsu]] et al., 2007
}}

'''''Nakalipithecus nakayamai''''', sometimes referred to as the '''Nakali ape''',<ref>{{cite web |url=http://www.enzimuseum.org/the-stone-age/the-first-ape-men/nakalipithecus |title=Nakalipithecus |last1=Kiarie |first1=Maina |access-date=8 Aug 2023 |website=Enzi Museum}}</ref> is an extinct species of [[great ape]] from [[Nakali, Kenya|Nakali]], Kenya from about 9.9–9.8 million years ago during the [[Late Miocene]]. It is known from a right jawbone with 3 [[molar tooth|molars]] and from 11 isolated teeth. The jawbone specimen is presumed female as the teeth are similar in size to those of female [[gorilla]]s and [[orangutan]]s. Compared to other great apes, the canines are short, the [[tooth enamel|enamel]] is thin, and the molars are flatter. '''''Nakalipithecus''''' seems to have inhabited a [[sclerophyllous]] woodland environment.

==Taxonomy==
{{cladogram|title=[[Hominidae]]|align=left|caption=Two hypotheses on ''Nakalipithecus'' taxonomy<ref name=Katoh2016/>
|cladogram=
{{clade
|1={{clade
 |1=''[[Kenyapithecus]]''
 |2={{clade
  |1='''''Nakalipithecus''''' (as a [[stem group|stem]] [[hominid]])
 |2={{clade
  |1={{clade
   |1='''''Nakalipithecus''''' (as a [[stem group|stem]] gorilla)
   |2={{clade
    |1=''[[Chororapithecus]]''
    |2=[[Gorilla]]s
    }}
   }}
  |2={{clade
   |1={{clade
    |1=[[Chimpanzee]]
    |2=[[Bonobo]]
    }}
   |2={{clade
    |1=''[[Ardipithecus]]''
    |2={{clade
     |1=''[[Australopithecus]]''
     |2=''[[Homo]]'' ([[human]]s)
     }}
    }}
   }}
}}}}}}}}}}
{{Human timeline}}

''Nakalipithecus'' was first described from a right jawbone, the [[holotype]] KNM-NA46400, and eleven isolated teeth excavated in 2005 by a team of Japanese and Kenyan researchers in [[mud flow]] deposits in the Nakali area of northern Kenya's former [[Rift Valley Province]], 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 specimens are housed by the [[National Museums of Kenya]]. The holotype preserves all 3 lower [[molar tooth|molars]], and the isolated teeth are: a left first [[incisor]], a right first incisor, a right [[canine tooth|canine]], a right third upper [[premolar]], 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.<ref name="Kunimatsu07">{{Cite journal|last1=Kunimatsu |first1=Y. |first2=M. |last2=Nakatsukasa |first3=Y. |last3=Sawada |first4=T. |last4=Sakai |year=2007 |title=A new Late Miocene great ape from Kenya and its implications for the origins of African great apes and humans |journal= Proceedings of the National Academy of Sciences |volume=104 |issue= 49|pages=19220–19225 |doi= 10.1073/pnas.0706190104 |pmid=18024593 |pmc=2148271|bibcode=2007PNAS..10419220K |doi-access=free }}</ref>

It is debated if great [[ape]]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]] being known from Africa. The first Miocene African ape, ''[[Samburupithecus]]'', was discovered in 1982.<ref>{{Cite journal|last1=Yasui|first1=Kinya|last2=Nakano|first2=Yoshihiko|last3=Ishida|first3=Hidemi|date=March 1987|title=Excavation at the Fossil-Hominoid-Bearing Locality, Site-SH22 in the Samburu Hills, Northern Kenya|url=https://repository.kulib.kyoto-u.ac.jp/dspace/handle/2433/68329|journal=African Study Monographs. Supplementary Issue|volume=5|pages=169–174|doi=10.14989/68329|issn=0286-9667}}</ref> It is unclear how ''Nakalipithecus'' is related to other apes. It is possible these Late Miocene African apes were [[stem group|stem]] great apes closely related to the [[last common ancestor]] of all modern African apes, which existed about 9–8 million years ago.<ref name="Kunimatsu07"/>

''Nakalipithecus'' and the 9 million year old Greek ''[[Ouranopithecus macedoniensis]]'' exhibit many similarities with each other, but ''Nakalipithecus'' has more [[basal (phylogenetics)|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]]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]], with similar dental adaptations caused by inhabiting a similar environment, though ''Ouranopithecus'' seems to have consumed more hard objects than ''Nakalipithecus''.<ref name="Kunimatsu07"/> A 2017 study on [[deciduous tooth|deciduous]] 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.<ref>{{cite journal|first1=W.|last1=Morita|first2=N.|last2=Morimoto|first3=Y.|last3=Kunimatsu|display-authors=et al.|year=2017|title=A morphometric mapping analysis of lower fourth deciduous premolar in hominoids: Implications for phylogenetic relationship between ''Nakalipithecus'' and ''Ouranopithecus''|journal=Comptes Rendus Palevol|volume=116|issue=5–6|pages=655–669|doi=10.1016/j.crpv.2016.10.004|bibcode=2017CRPal..16..655M |hdl=2115/71435 |hdl-access=free}}</ref>

''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]] line; if both of these are correct, then ''Nakalipithecus'' could potentially represent an early gorilla.<ref name=Katoh2016>{{cite journal|first1=S.|last1=Katoh|first2=Y.|last2=Beyene|first3=T.|last3=Itaya|display-authors=et al.|year=2016|title=New geological and palaeontological age constraint for the gorilla–human lineage split|journal=Nature|volume=530|issue=7589|pages=215–218|doi=10.1038/nature16510|pmid=26863981|bibcode=2016Natur.530..215K|s2cid=205247254}}</ref>

==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 {{cvt|10.7x10.5|mm}} in height and width respectively. For comparison, the left first incisor is {{cvt|10.8x8.6|mm}}. The premolars are elongated, and the [[protoconid]] (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]] on the [[molar (tooth)|molars]] is thinner, and the [[cusp (anatomy)|cusps]] (which project outward from the tooth) are less inflated, creating a wider basin. In the holotype, the first, second, and third molars are {{cvt|15.6x14|mm}}, {{cvt|16.2x15.8|mm}}, and {{cvt|19.5x15.1|mm}}, 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'' is known from the [[Indian subcontinent]]), 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]]''. The mandible is less robust (heavily built) than those of contemporary Eurasian Miocene apes, except for ''Ouranopithecus''.<ref name="Kunimatsu07"/>

==Palaeobiology==
During the Late Miocene, East Africa, the [[Sahara]], the Middle East, and Southern Europe all appear to have been predominantly seasonal [[sclerophyllous]] [[evergreen]] woodland environments. Nakali appears to have been dominated by [[C3 plant|C3]] (forest) plants. ''Nakalipithecus'' is known from the Upper Beds, which comprise lakeside or riverine deposits.<ref name="Kunimatsu07"/> Climate change caused the expansion of grasslands in Africa from 10–7 million years ago, likely fragmenting populations of forest-dwelling primates, leading to extinction.<ref name=Kunimatsu2017/>

Nakali has also yielded a [[black rhino]] specimen,<ref>{{cite journal|first1=N.|last1=Handa|first2=M.|last2=Nakatsukasa.|first3=Y.|last3=Kunimatsu|first4=H.|last4=Nakaya|year=2019|title=Additional specimens of ''Diceros'' (Perissodactyla, Rhinocerotidae) from the Upper Miocene Nakali Formation in Nakali, central Kenya|journal=Historical Biology|volume=31|issue=2|pages=262–273|doi=10.1080/08912963.2017.1362560|s2cid=135074081}}</ref> the pig ''[[Nyanzachoerus]]'', an [[antelope]], the hippo ''[[Kenyapotamus]]'', the rhino ''[[Kenyatherium]]'', the giraffe ''[[Palaeotragus]]'',<ref name=Benefit1986/> the horse ''[[Hipparion]]'',<ref>{{cite conference|first1=H.|last1=Nakaya|first2=K.|last2=Uno|first3=A.|last3=Fukuchi|display-authors=et al.|date=13 September 2010|title=Late Miocene paleoenvironment of hominoids—mesowear analysis of fossil ungulate cheek teeth from northern Kenya|journal=International Primatological Society|volume=26 |id=147|doi=10.14907/primate.26.0.147.0}}</ref> the elephant-like proboscideans ''[[Deinotherium]]'' and (possibly) ''[[Choerolophodon]]'',<ref name=Benefit1986>{{cite journal|first1=B. R.|last1=Benefit|first2=M.|last2=Pickford|year=1986|title=Miocene fossil cercopithecoids from Kenya|journal=Physical Journal of Anthropology|volume=69|issue=4|pages=441–464|doi=10.1002/ajpa.1330690404}}</ref> and the [[colobine]] monkey ''[[Microcolobus]]''.<ref>{{cite journal|first1=M.|last1=Nakatsukasa|first2=E.|last2=Mbua|first3=Y.|last3=Sawada|display-authors=et al.|year=2010|title=Earliest colobine skeletons from Nakali, Kenya|journal=Physical Journal of Anthropology|volume=143|issue=3|pages=365–382|doi=10.1002/ajpa.21327|pmid=20949609}}</ref> The third premolar of a small [[Nyanzapithecinae|nyanzapithecine]] ape was also found in Nakali,<ref>{{cite journal|first1=Y.|last1=Kunimatsu|first2=M.|last2=Nakatsukasa|first3=Y.|last3=Sawada|year=2016|title=A second hominoid species in the early Late Miocene fauna of Nakali (Kenya)|journal=Anthropological Science|volume=124|issue=2|pages=75–83|doi=10.1537/ase.160331|doi-access=free}}</ref><ref name=Kunimatsu2017>{{cite journal|first1=Y.|last1=Kunimatsu|first2=Y.|last2=Sawada|first3=T.|last3=Sakai|display-authors=et al.|year=2017|title=The latest occurrence of the nyanzapithecines from the early Late Miocene Nakali Formation in Kenya, East Africa|journal=Anthropological Science|volume=125|issue=2|pages=45–51|doi=10.1537/ase.170126|doi-access=free}}</ref> and ''Samburupithecus'' was nearly contemporaneous with ''Nakalipithecus'', and was discovered {{cvt|60|km}} to the north of Nakali.<ref name="Kunimatsu07"/>

== See also ==
{{columns-list|colwidth=25em|
*[[Timeline of human evolution]]
* ''[[Afropithecus]]''
* ''[[Anoiapithecus]]''
* ''[[Danuvius guggenmosi|Danuvius]]''
* ''[[Dryopithecus]]''
* ''[[Graecopithecus]]''
* ''[[Hispanopithecus]]''
* ''[[Khoratpithecus]]''
* ''[[Lufengpithecus]]''
* ''[[Oreopithecus]]''
* ''[[Pierolapithecus]]''
* ''[[Sivapithecus]]''
}}

==References==
{{Reflist}}

==External links==
* [http://humanorigins.si.edu/evidence/human-evolution-timeline-interactive Human Timeline (Interactive)] – [[Smithsonian Institution|Smithsonian]], [[National Museum of Natural History]] (August 2016).
* [http://dsc.discovery.com/news/2007/11/12/ape-gorilla-ancestor.html "Mama, Is That You? Possible Ape Ancestor Found"]. ''[[Discovery Channel|Discovery News]]''. Version of 2007-NOV-12. Retrieved 2007-NOV-13. Contains photo of fossil.

{{Human Evolution}}
{{Haplorhini|Ho.}}
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[[Category:Hominidae]]
[[Category:Miocene primates of Africa]]
[[Category:Prehistoric apes]]
[[Category:Fossil taxa described in 2007]]
[[Category:Monotypic prehistoric primate genera]]
[[Category:Great Rift Valley]]