Platyrrhine Evolution and Paleobiogeography revisited

TEJEDOR, MARCELO; NOVO, NELSON

Primatology in Argentina

Sociedad Argentina para el Estudio de los Mamiferos, series A

Año: 2017;

Abstract. The evolutionary history of platyrrhines, today widely distributed in the Neotropical Region, presents various controversial issues that have been debated and discussed during the last three decades. The notable increase in the fossil record has reoriented our previous hypotheses in benefitting from a better knowledge of the diversity, distribution and phylogeny of the platyrrhines in the past, as well as their relationships with the living forms. These advances led to alternative interpretation of the platyrrhine fossil record and evolutionary history, particularly regarding the early to middle Miocene Patagonian forms that were often discussed as a distinctive stock with primitive appearance, difficult to integrate with the living clades. Another more advanced group of primates appears in the middle Miocene La Venta region, Colombia. Their affinities are in several ways comparable to the Patagonian forms. In light of the new oldest record of South American primates, from the late Eocene of Santa Rosa, Peru, the scenario changes notably and new evidence strongly supports the inclusion of all Patagonian forms into the crown Platyrrhini, as they exhibit even more advanced morphologies than previously thought. The proposal presented here suggests the possible existence of a western paleobiogeographic corridor that may have connected the areas where platyrrhines inhabited, from the austral regions to the northernmost Neotropics. Fossiliferous sites in western Argentina, Chile, and Peru, ranging from the early to late Miocene, reinforce the idea of this paleobiogeographic region facilitating the dispersion of the Patagonian primates, especially when considering that Santa Rosa is also located to the west and its primates are possibly part of an extensive radiation that certainly occurred during pre-Miocene times.