The quantitative variables related to aspects of prehistoric populations of Patagonia and Fueguía were analyzed.Skulls from adult individuals of both sexes, 100 deformed and 100 undeformed ones, were studied.Thirty-four linear and angular variables described by Herrera Fritot (1964) based on the sagittal profile were recorded.Data matrices, one for each sample (deformed and undeformed), were computed.Both samples were analyzed by principal components analysis and cluster techniques.Variables with major discriminatory power for each sample were obtained.Results were compared and four sets of variables were delimited.The first one consisted of variables which shared discriminatory power between both the deformed and undeformed skulls;the second set includes those which deal with the variation for undeformed skulls;the third set with the variation for deformed skulls, and the fourth set did not provide any important contributions dealing with the intrasample variation. Differences among variables by region were also analyzed.
Nyanzapithecus is a genus of East African Miocene apes, which has been suggested to be an ancestral stock of oreopithecids.A new species of this genus, Nyanzapithecus harrisoni, is described in this article.The description is based on the material discovered from Nachola, a middle Miocene fossil locality (ca.15 m.y.a.) in northern Kenya.N.harrisoni is slightly smaller than the previously known N. pickfordi and N.vancouveringorum, but shares with them such unique dental characters as elongated molar crowns, quite inflated cusps, and restricted occlusal basins and foveae. The presence of the new Nyanzapithecus species in Nachola has expanded the distribution and diversity of this genus, and suggests that oreopithecids may have been a relatively common element in the middle Miocene primate fauna of East Africa.