Disparate data sets resolve squirrel monkey (Saimiri) taxonomy:: Implications for behavioral ecology and biomedical usage

Squirrel monkeys (Saimiri spp.) are the most commonly used neotropical (platyrrhine) monkeys in biomedical research; however no consensus exists as to the phylogenetic relationships amongst geographic variants or whether these variants represent species or subspecies. Here we report a strongly supported squirrel monkey phylogeny, congruent across multiple data sets, including new field data and the first molecular (mtDNA) cladogram. These data support species-level classification for the three major groups in this study Approximately the same amount of molecular divergence exists among Saimiri oerstedii, S. sciureus, and S, boliviensis, The S. sciureus/S. oerstedii ancestor diverged from S. boliviensis and shortly thereafter S, sciureus and S, oerstedii diverged. Until now, lack of a robust taxonomy has hindered exploitation of the massive potential of Saimiri for comparative studies, No other primate genus displays such widely divergent, genetically-based social behaviors. Our taxonomy also provides robust support for previous warnings against the widespread use of hybrid squirrel monkeys as research models.