ABSTRACT
Various workers have made use of sub-family divisions within the two families, placing the gibbons and their fossil relations in a sub-family called Hylobatinae. The difficulty concerning the correct placing of Oreopithecus within the accepted classification pattern of the Hominoidea has forced several authors to consider the setting up of a full family to accommodate Oreopithecus. The earlier classification of the super-family into only two families Pongidae and Hominidae seems to be no longer tenable, unless leading authorities insist upon carrying the process of “lumping” to an extreme degree. It can be argued that the differences between the extremes which are, at present, grouped in the Pongidae, are no greater than those which are placed in the single family Equidae. The criteria accepted for membership of the family Hominidae include certain dental characters, certain cranial characters, the structure of the limb bones and pelvic girdle, the nature of the lower third pre-molars and the morphology of the canines.
