Saguinus ursulus was described in 1807 by the German zoologist
Johann Centurius Hoffmannsegg. It was later synonymised, first with
S. midas and then with
S. niger. In 2013,
S. ursulus was revalidated based on differences in coat color and morphological divergences, which were corroborated by molecular data. As a consequence of the genetic divergence, as well as minor differences in pelage color, the population east of the Tocantins River was recognised as a separate species. == References ==