''Samburupithecus'' is an extinct

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 huma ...

that lived in

Kenya ) , national_anthem = "Ee Mungu Nguvu Yetu"() , image_map = , map_caption = , image_map2 = , capital = Nairobi , coordinates = , largest_city = Nairobi , ...

during the middle to late

Miocene The Miocene ( ) is the first geological epoch of the Neogene Period and extends from about (Ma). The Miocene was named by Scottish geologist Charles Lyell; the name comes from the Greek words (', "less") and (', "new") and means "less recen ...

. The one species in this genus, ''Samburupithecus kiptalami'', is known only from a

maxilla The maxilla (plural: ''maxillae'' ) in vertebrates is the upper fixed (not fixed in Neopterygii) bone of the jaw formed from the fusion of two maxillary bones. In humans, the upper jaw includes the hard palate in the front of the mouth. The t ...

fragment dated to discovered in 1982 and formally described by . The type specimen KNM-SH 8531 was discovered by the Joint Japan-Kenya Expedition at the SH22 fossil site in the

Samburu District Samburu County is a county in the former Rift Valley Province, Kenya. It covers an area of roughly 21,000 km2 (8,000 mi2) in northern Kenya where the Samburu, Turkana and many other tribes live. It stretches north from the Wuaso Ng' ...

, a locality where several other researchers found no ape fossils. ''Samburupithecus'' lived during the so-called "African ape gap" , a period from which very few hominoid fossils have been found in Africa until relatively recently. This apparent gap, however, is now populated by a diversity of apes such as ''

Nakalipithecus ''Nakalipithecus nakayamai'' is an extinct species of great ape from 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, and the ...

'', ''

Chororapithecus abyssinicus ''Chororapithecus'' is an extinct great ape from the Afar region of Ethiopia roughly 8 million years ago during the Late Miocene, comprising one species, ''C. abyssinicus''. It is known from 9 isolated teeth discovered in a 2005–2007 survey of ...

'', ''

Otavipithecus ''Otavipithecus namibiensis'' is an extinct species of ape from the Miocene of Namibia. The fossils were discovered at the Berg Aukas mines in the foothills of the Otavi mountains, hence the generic name. The species was described in 1992 by G ...

'', and ''

Nacholapithecus ''Nacholapithecus kerioi'' was an ape that lived 14-15 million years ago during the Middle Miocene. Fossils have been found in the Nachola formation in northern Kenya. The only member of the genus ''Nacholapithecus'', it is thought to be a key g ...

''.

Characteristics

''Samburupithecus'' was approximately and was most likely a

frugivorous A frugivore is an animal that thrives mostly on raw fruits or succulent fruit-like produce of plants such as roots, shoots, nuts and seeds. Approximately 20% of mammalian herbivores eat fruit. Frugivores are highly dependent on the abundance and ...

terrestrial Terrestrial refers to things related to land or the planet Earth. Terrestrial may also refer to: * Terrestrial animal, an animal that lives on land opposed to living in water, or sometimes an animal that lives on or near the ground, as opposed to ...

quadruped Quadrupedalism is a form of locomotion where four limbs are used to bear weight and move around. An animal or machine that usually maintains a four-legged posture and moves using all four limbs is said to be a quadruped (from Latin ''quattuor' ...

. Paleoenvironmental reconstructions indicate that ''Samburupithecus'' most likely lived in a wooded habitat surrounded by

savannah A savanna or savannah is a mixed woodland-grassland (i.e. grassy woodland) ecosystem characterised by the trees being sufficiently widely spaced so that the Canopy (forest), canopy does not close. The open canopy allows sufficient light to rea ...

. Defining cranial traits of this genus include low, broad zygomatics, straight

alveolar process The alveolar process () or alveolar bone is the thickened ridge of bone that contains the tooth sockets on the jaw bones (in humans, the maxilla and the mandible). The structures are covered by gums as part of the oral cavity. The synonymous ter ...

and large

maxillary sinus The pyramid-shaped maxillary sinus (or antrum of Highmore) is the largest of the paranasal sinuses, and drains into the middle meatus of the nose through the osteomeatal complex.Human Anatomy, Jacobs, Elsevier, 2008, page 209-210 Structure It is ...

. Defining dental traits include three-rooted

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 ...

s, thick enamel and

bunodont 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 ...

cusps. The teeth in the ''Samburupithecus'' type maxilla are comparable in size to those of the type mandible of ''

'', roughly the size of a modern female gorilla. The upper premolars of both are elongated mesiodistally (along the row of teeth), but those of ''Samburupithecus'' have more inflated cusps that are positioned more centrally, so that occlusal foveae and basins (depressions at top of teeth) are very restricted. This suggests that ''Samburupithecus'' was strongly specialized compared to other Miocene and extant apes. Another distinguishing feature between the two is the higher relief of the

dentine Dentin () (American English) or dentine ( or ) (British English) ( la, substantia eburnea) is a calcified tissue of the body and, along with enamel, cementum, and pulp, is one of the four major components of teeth. It is usually covered by ena ...

/ enamel junction in ''Samburupithecus''. These elongated teeth are unlike many other Miocene hominoids, linking ''Samburupithecus'' the taxon to

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 ...

chimpanzee The chimpanzee (''Pan troglodytes''), also known as simply the chimp, is a species of great ape native to the forest and savannah of tropical Africa. It has four confirmed subspecies and a fifth proposed subspecies. When its close relative th ...

s and

hominin The Hominini form a taxonomic tribe of the subfamily Homininae ("hominines"). Hominini includes the extant genera ''Homo'' (humans) and '' Pan'' (chimpanzees and bonobos) and in standard usage excludes the genus ''Gorilla'' (gorillas). The t ...

s, but its relationships within this

clade A clade (), also known as a monophyletic group or natural group, is a group of organisms that are monophyletic – that is, composed of a common ancestor and all its lineal descendants – on a phylogenetic tree. Rather than the English term, ...

is at present unclear. Because of this mixture of primitive and derived traits in the KNM-SH 8531 specimen, it has been proposed that ''Samburupithecus'' lived before the gorilla-chimpanzee-hominin split and, therefore, that it is 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 ...

to these primates alongside ''

Ouranopithecus ''Ouranopithecus'' ("celestial ape" from Ancient Greek οὐρανός (ouranós), "sky, heaven" + πίθηκος (píthēkos),"ape") is a genus of extinct Eurasian great ape represented by two species, ''Ouranopithecus macedoniensis'', a late M ...

''.

Notes

References

* * * * * * * * {{Taxonbar, from=Q28683 Miocene mammals of Africa Prehistoric apes Miocene primates of Africa Fauna of Kenya Fossil taxa described in 1997 Monotypic prehistoric primate genera Prehistoric primate genera

Characteristics

See also

Notes

References