Invalidation of taxa within the silvery wooly monkey (, Atelidae, Primates).

The systematics of the Humboldt's wooly monkeys (; Atelidae) is essential to preserve this Neotropical primate species. Traditionally, four morphological subspecies have been described, which recently have been molecularly confirmed. However, no population genetics studies have been carried out throughout the geographical distribution of one of these subspecies, . For this reason, we analyzed nine mitochondrial genes of mainly collected from the Ecuadorian and Peruvian Amazon in order to better understand the evolutionary history of this taxon. The mitochondrial genetic diversity levels (haplotype and nucleotide diversity) we estimated are likely the highest yet reported for Our results did not detect important genetic structure within . Furthermore, our phylogenetic analyses did not detect any relevant molecular cluster in the area where Groves hypothesized the existence of . Therefore, based on these data, is not a valid taxon from a molecular perspective. The most differentiated subpopulation within was from Morona-Santiago province (Ecuador) and had a genetic distance of 0.8-1.2% relative to the other subpopulations studied. However, this genetic distance range is within the variability found within a population. We estimated the mitochondrial temporal diversification within to have occurred during the Pleistocene, 1.8-1.2 million years ago. Similarly, all our analyses detected a strong Pleistocene female population expansion for this taxon. Diverse spatial genetic analyses, perhaps with the exception of Monmonier's Algorithm, did not detect differentiated taxa within the area analyzed for . These genetics results could be of importance to conservation efforts to preserve this taxon as one unit.