Filogenia e história biogeográfica do grupo Saguinusmystax (Primates: Callitrichidae)

The present study sought to contribute to the elucidation of the evolutionary and biogeographic history of the Saguinus mystaxgroup through morphological, molecular and biogeographic data. Eighteen cranial characters and six coat characters were established from the examination of 208 specimens deposited in Brazilian institutions and from the literature. From these data a morphological phylogeny was obtained by parsimony, which resulted in a clade formed by S. imperator, S. mystaxand S. labiatus, supported by four synapomorphies,while four other synapomorphies supported the inclusion of S. inustusin the S. mystax group, a hypothesis previously postulated by molecular data, but still lacking morphological support. Phylogenies with molecular and concatenated data were obtained from the morphological data and from 40 GenBank markers. In both,S. mystaxand S. labiatusform a clade with S. inustus,while S. imperatormore distantly related. Estimates using relaxed molecular clock date the diversification of the S. mystaxgroup between6 and 12 million years. The first divergence would have been of S. imperator(3-9 ma), followed by S. inustus(1.8 to 6.7 ma) and S. labiatusand S. mystax(0.7 to 4.7 ma). To test the hypothesis of diversification by Hershkovitz(1977), we optimized the facial bleaching character by parsimony and maximum likelihood and both suggest that this character does not constitute an adequate basis for proposing an evolutionary hypothesis for these species. In the biogeographic analyzes carried out in Bio-GeoBEARS, the DIVAj model pointed to the ancestor area of Saguinusand S. mystaxgroup in the western Amazon, from where the group would have dispersed, made possible by changes in the Amazonian landscape in the early Miocene, of particular importance being the end of the system of lakes known as the Pebas System and the beginning of the establishment of the present fluvial systems, that today are known to delimit the distribution of species of Saguinus