| Afropithecus | |
|---|---|
 | |
| Skull cast | |
Scientific classification | |
| Domain: | Eukaryota |
| Kingdom: | Animalia |
| Phylum: | Chordata |
| Class: | Mammalia |
| Order: | Primates |
| Suborder: | Haplorhini |
| Infraorder: | Simiiformes |
| Superfamily: | Hominoidea |
| Family: | †Afropithecidae |
| Genus: | †Afropithecus Leakey &Leakey, 1986 |
| Species: | †A. turkanensis |
| Binomial name | |
| †Afropithecus turkanensis | |
Afropithecus is a genus ofMiocenehominoid with the sole speciesAfropithecus turkanensis, it was excavated from a small site nearLake Turkana calledKalodirr in northernKenya in 1986 and named byRichard Leakey andMeave Leakey.[1] The estimated age ofAfropithecus is between 16 and 18 million years old, which was determined withradiometric dating techniques and the geological studies conducted by Broschetto and Brown from theUniversity of Utah.[1] In total there are 46 recovered specimens from Kalodirr relating toAfropithecus consisting ofcranial,mandible,dentition and post-cranial remains. Thetype specimen ofAfropithecus turkanensis is KNM-WK 16999.[1]
Richard Leakey and Meave Leakey first describedAfropithecus turkanensis to be a large hominoid which appeared to have relatively thick enamel.[2] Leakey suggested thatA. turkanensis shared postcranial features with the speciesProconsul nyanzae, which is the best known Miocene genus with literally hundreds of fossils having been found representing almost allskeletal elements, and sharing cranial features withAegyptopithecus zeuxis andHeliopithecus which had two weatheredmolars that indicated a general distinction from known large earlycatarrhines, and later concluded thatA. turkanenensis was a primitive, arborealquadruped similar toP. nyanzae, and thatA. turkanensis had primitive facial morphology and derived dental characteristics that would suggest a diet of hard fruits. Leakey also synonymisedHeliopithecus withAfropithecus.[3]
The type specimen, KNM-WT 16999 is composed of a long distinctsnout, the facial skeleton,frontal, much of thecoronal structure, most of thesphenoid, and relatively unwornadult dentition; the right orbit (virtually complete), the rightzygomatic, thepterygoid, most of the sphenoid and lesser wings, themaxilla andpremaxilla, and adult dentition with procumbentincisors. The surface on the right side maxilla and premaxilla along with theenamel on the right molars has been lost over time and has been replaced with calcite crystals, which only provide the general shape and not the details.[1]
From dentition it is known that the palate, which is almost completely calcified, ofA. turkanensis is shallow, long and narrow with tooth rows that converge posteriorly, and it is probable the tooth rows were originally nearly parallel. A. turkanensis had a 6.5mmdiastema between its very procumbent second incisor (KNM-WT 16999 had large, broad incisors) and thecanine.[4]
The thickness of the enamel on the molars is often reported when fossils are being recorded and used to make comparisons across taxa. The thickness is referred to either as "thin" or "thick" and is commonly assessed as a linear measurement of the enamel on worn or naturally fractured teeth. From enamel testing it has been suggested thatA. turkanensis is the oldest known thick-enamelled hominoid, which is what would distinguish it fromKenyapithecus.[4]
Post cranial remains such as KNM-WK 16901, includes an associated right fibula (lacking the proximal portion, and is approximately the same size asPan troglodytes; 184 mm), a right proximal thirdmetatarsal, a right fourth metatarsal lacking the head, and an incomplete first metatarsal head.[1]
Other post-cranial remains include: KNM-WK 17016P a large rightulna, and foot or hand bones: KNM-WK 17008, KNM-WK 18395.[1]
Morphological analysis of the teeth and palate ofAfropithecus suggests that it utilized a sclerocarpic foraging diet similar to members ofPitheciidae, in contrast to that ofMorotopithecus.[5]
