Кениядағы ежегі homininнің жаңа қазбасы

Postulated early hominin discovered in Kenya

Orrorin is an extinct genus of primate within Homininae from the Miocene Lukeino Formation and Pliocene Mabaget Formation, both of Kenya. The type species is O. tugenenesis, named in 2001, and a second species, O. praegens,

If Orrorin proves to be a direct human ancestor, then according to some paleoanthropologists, australopithecines such as Australopithecus afarensis ("Lucy") may be considered a side branch of the hominid family tree: Orrorin is both earlier, by almost 3 million years, and more similar to modern humans than is A. afarensis. The main similarity is that the Orrorin femur is morphologically closer to that of Homo sapiens than is Lucy's; there is, however, some debate over this point. This debate is largely centered around the fact that Lucy was female and the Orrorin femur it has been compared to belonged to a male. In contrast, "Orrorin shares several apomorphic features with modern humans, as well as some with australopithecines, including the presence of an obturator externus groove, elongated femoral neck, anteriorly twisted head (posterior twist in Australopithecus), anteroposteriorly compressed femoral neck, asymmetric distribution of cortex in the femoral neck, shallow superior notch, and a well developed gluteal tuberosity which coalesces vertically with the crest that descends the femoral shaft posteriorly." Based on the structure of its femoral head it still exhibited some arboreal properties, likely to forage and build shelters. An analysis of the BAR 10020' 00 femur showed that Orrorin is an intermediate between Pan and Australopithecus afarensis. The current prevailing theory is that Orrorin tugenensis is a basal hominin and that bipedalism developed early in the hominin clade and successfully evolved down the human evolutionary tree. It is clear that the phylogeny of Orrorin is uncertain, however, the evidence of the evolution of bipedalism is an invaluable discovery from this early fossil hominin.