Traditional classifications of Platyrrhini monkeys, based mainly on morphological features, are being contested by recent molecular data. The subfamily Callitrichinae (Platyrrhini, Primates) consists of a diverse group of species, many of them considered endangered. Our analysis of two DNA regions, a mtDNA gene (ND1) and a nuclear gene (intronic regions of the transferrin gene), suggests that Callithrix pygmaea may have sufficient variability to justify the existence of subspecies or even separate species. Phylogenetic dendrograms based on the ND1 region show that this species is more closely related to Amazonian than to Atlantic forest marmosets. These results reopen the discussion about diversity and conservation programs based exclusively on traditional classifications.
