Sarmiento, Esteban E.2005-10-062005-10-061987http://hdl.handle.net/2246/521444 p. : ill. ; 26 cm.Includes bibliographical references (p. 36-43)."Since Oreopithecus was first described, its systematic position has been a subject of controversy. Despite the hominoid specializations in its postcrania, those classifications emphasizing the peculiarities in its dentition have arrived at numerous and varied interpretations. A review of the dental features of Oreopithecus, living catarrhines, and some known fossil catarrhines shows that those dental traits which may be used to classify Oreopithecus as either a hominoid, cercopithecoid, or early catarrhine exhibit a large degree of variability. Although only true hominoids exhibit the variability which encompasses all of the features of the Oreopithecus dentition, an early catarrhine or cereopithecoid could have possibly arrived at a similar dentition. The postcrania of Oreopithecus, however, shows conclusive evidence as to its hominoid affinities. As in hominoids, Oreopithecus exhibits the joint complex for forearm and shoulder rotation, both parts of a forelimb specialization which allows hominoids to climb vertical supports of large diameters. The large number of anatomical elements incorporated into this specialization and the one-to-one correspondence of these elements in Oreopithecus and hominoids strongly argue for a uniquely shared evolutionary history. Furthermore, Oreopithecus shares a strikingly large number of traits with a hypothetical ancestor of the pongid-hominid lineage more than any other known fossil form. Nevertheless, the position of Oreopithecus within the hominoids is uncertain. Many of the traits it shares with hylobatids may be expected in an early forerunner of the pongid-hominid lineage. On the other hand, many of those traits it shares with pongids may be expected in a large hylobatid which, due to its size, emphasized slow climbing aspects of its locomotor behavior"--P. 2.8320932 bytesapplication/pdfen-USQL1 .A436 no.2881, 1987Oreopithecus.Hominoidea -- Origin.Primates -- Phylogeny.Primates, Fossil.The phylogenetic position of Oreopithecus and its significance in the origin of the Hominoidea. American Museum novitates ; no. 2881text