Range Description

Field research since the publications of Hershkovitz (1977) and Rylands et al. (1993) has diminished the supposed distribution of the Santarém marmoset. Hershkovitz’s (1977) range is now divided into four, being occupied by marmosets now considered distinct species: M. mauesi, M. saterei and M. acariensis besides M. humeralifer. According to our current understanding, M. humeralifer occurs south of the Rio Amazonas, between the Rio Maués (and possibly its tributary the Rio Parauari) in the west, and the Rio Tapajós in the east. The southern limit is not known, but may be in the region of the Rio Paracari. The southernmost locality for the Santarém marmoset plotted by Hershkovitz (1977) was Vila Braga, 4º25'S, on the Transamazon highway, just north of the Amazonia National Park.