How many genera and species of woolly monkeys (Atelidae, Platyrrhine, Primates) are there? The first molecular analysis of Lagothrix flavicauda, an endemic Peruvian primate species.

We sequenced COI and COII mitochondrial genes of 141 Neotropical woolly monkeys to provide new insights concerning their phylogeography and phylogenetic relationships. For the first time, eight individuals of the endemic and extremely rare Peruvian yellow-tailed woolly monkey (flavicauda) were sequenced at these genes and compared with other Lagothrix taxa (poeppigii, lagotricha, lugens and cana). There were four main results. (1) L. flavicauda showed a gene diversity of zero, whereas poeppigii and lugens showed high levels of gene diversity and lagotricha and cana showed more modest levels of gene diversity. The absence of gene diversity found for L. flavicauda strongly supports that it is one of the 25 more endangered primates on earth; (2) Our genetic distance and phylogenetic analyses, which included many cases of genetic introgression and recent hybridization, suggest that all woolly monkeys could be included in one unique genus, Lagotrix, divided into two species: L. flavicauda and L. lagotricha. The last species is divided into at least four subspecies. Our molecular results agree with Fooden's (1963) classification, but do not support the classification proposed by Groves (2001). (3) Poeppigii was the first taxon within L. lagotricha to experience a mitochondrial haplotype diversification, while cana and lagotricha experienced more recent mitochondrial haplotype diversification; (4) Poeppigii and lagotricha were the taxa which showed the greatest evidence of population expansions in different Pleistocene periods, whereas lugens experienced a population declination in the last 25,000 YA.