Phylogeny of the titi monkeys of the Callicebus moloch group (Pitheciidae, Primates).

Callicebus is a Neotropical primate genus of the family Pitheciidae, which currently comprises 34 recognized species. Based on their morphological traits and geographic distribution, these species are currently assigned to five groups: the C. moloch, C. cupreus, C. donacophilus, C. torquatus, and C. personatus groups, although in the past, alternative arrangements have been proposed based on the analysis of morphological data. The principal disagreements among these arrangements are related to the composition of the C. moloch group. In the present study, we tested the different taxonomic proposals for the C. moloch group, based on the molecular analysis of nuclear markers (Alu insertions and flanking regions) and three mitochondrial genes (16S, COI, and Cyt b), with a total of approximately 7 kb of DNA sequence data. Phylogenetic reconstructions based on maximum likelihood and Bayesian inference methods indicated that the species of the current C. cupreus group should be reintegrated into the C. moloch group. In addition, our results corroborated previous studies suggesting that the species of the current C. personatus group form a distinct species group. We also observed a relatively subtle level of divergence between C. dubius and C. caligatus. While the known diversity of Callicebus is considerable, these findings indicate that the relationships among groups and species may still not be completely understood, highlighting the need for further research into the biological, geographic, and genetic variability of these primates, which will be fundamental to the effective conservation of the genus. Am. J. Primatol. 78:904-913, 2016.