Dental Evolutionary Trends of Relevance to the Origin and Dispersion of the Platyrrhine Monkeys

Abstract

The evolutionary history of the platyrrhine primates has been the subject of considerable controversy. Comparative studies of extant Old and New World higher primates suggest that these forms and the platyrrhines are each monophyletic, but the nature and origin of common ancestral groups remains in doubt. It has been hypothesized that the Platyrrhini evolved from a lemuroid stock (Liedy, 1873; Loomis, 1911; Gregory, 1920, 1921; Gingerich, 1973, 1975, 1977), a tarsioid stock (Wortman, 1904; Gazin, 1958; Simons, 1961, 1972; Hoffstetter, 1969, 1974; Orlosky and Swindler, 1975; Szalay, 1976) or a monkey stock (Stirton, 1951; Olson, 1964; Hershkovitz, 1969; Sarich, 1970; Cronin and Sarich, 1975). Most of the above authors assumed that the South American primates were derived from some North American or Central American primate group. However, some have hypothesized that an African stock might have been ancestral to the platyrrhine primates (Sarich, 1970; Hoffstetter, 1972, 1974; Lavocat, 1974; Cronin and Sarich, 1975). Indeed, recent geological evidence (see Tarling, this volume) indicates that an immigration of primates into South America from Africa would be quite as feasible during the late Eocene to early Oligocene as a North American origin for these primates.