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The fossils of Orrorin tugenensis shares no derived features of homin great-ape relatives. "In contrast,Orrorin shares several apomorphic features  with  humans  and  some  with  australopithecines,including the presence of an obturator externus groove,elongated  femoral  neck,  anteriorly  twisted  head  (posterior twist in Australopithecus), antero-posteriorly compressed femoral neck, asymmetric distribution of cortexin the femoral neck, shallow superior notch, and a well developed gluteal tuberosity which coalesces verticallywith  the  crest  that  descends  the  femoral  shaft  poste-riorly." According to recent studies Orrorin tugenensis is a basal hominid that adapted an early form of bipedalism. Based on the structure of it's femoral head it still exhibited some arboreal properties, likely to forage and build shelters. O. tugenensis shares an early hominin feature in which their iliac blade is flared to help counter the torque of their body weight, this shows that they adapted bipedalism around 6 MYA. These features are shared with many species of Australopithecus. It has been suggested by Pickford that the many features Orrorin shares with modern humans show that it is more closely related to Homo sapiens than to Australopithecus. This would mean that Australopithecus would represent a side brand in the homin evolution that does not directly lead to Homo. Another study conducted by Almecija suggested that Orrorin is more closely to early hominins than to Homo. An analysis of the BAR 10020' 00 femur showed that Orrorin is an intermediate between Pan and Australopithecus afarensis. It is clear that the phylogeny of Orrorin is uncertain, however the evidence of the evolution of bipedalism is an invaluable discover from this early fossil hominin.

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