ABSTRACT
This chapter explores the various hypotheses and scenarios that concern the paleobiogeographic source of origin of the Platyrrhini. It addresses specific questions which include: From what geographical region or regions were the immediate ancestors of the New World monkeys derived? When and by what means did these first platyrrhines reach the island continent of South America? What influence did continental drift have on the geographic source of origin and mode of dispersal of the Platyrrhini? The chapter presents a consensus-oriented maximum-parsimony model of platyrrhine origins and dispersal. There are two basic geographic sources from which to derive the immediate ancestors of the Platyrrhini: the North American continent; and the African continent. The African-origin model of the Platyrrhini attempts to derive the ancestral New World monkeys directly from the African continent via a sweepstakes route across a much less expansive Eocene South Atlantic Ocean.
