Platyrrhine evolution and paleobiogeography revisited

TEJEDOR, M.F.; NOVO, N. M.

Primatology in Argentina- La Primatología en Argentina

SAREM

Año: 2017; p. 25 - 48

The evolutionary history of platyrrhines, today widely distributed in the NeotropicalRegion, presents various controversial issues that have been debated and discussed during the lastthree decades. The notable increase in the fossil record has reoriented our previous hypotheses inbenefitting from a better knowledge of the diversity, distribution and phylogeny of the platyrrhinesin the past, as well as their relationships with the living forms. These advances led to alternativeinterpretation of the platyrrhine fossil record and evolutionary history, particularly regarding theearly to middle Miocene Patagonian forms that were often discussed as a distinctive stock withprimitive appearance, difficult to integrate with the living clades. Another more advanced group ofprimates appears in the middle Miocene La Venta region, Colombia. Their affinities are in severalways comparable to the Patagonian forms. In light of the new oldest record of South Americanprimates, from the late Eocene of Santa Rosa, Peru, the scenario changes notably and new evidencestrongly supports the inclusion of all Patagonian forms into the crown Platyrrhini, as they exhibiteven more advanced morphologies than previously thought. The proposal presented here suggeststhe possible existence of a western paleobiogeographic corridor that may have connected the areaswhere platyrrhines inhabited, from the austral regions to the northernmost Neotropics. Fossiliferoussites in western Argentina, Chile, and Peru, ranging from the early to late Miocene, reinforce the ideaof this paleobiogeographic region facilitating the dispersion of the Patagonian primates, especiallywhen considering that Santa Rosa is also located to the west and its primates are possibly part of anextensive radiation that certainly occurred during pre-Miocene times.