Range Description

Very poorly known species that occurs in a sliver south of the Rio Amazonas, between the Rios Madeira and lower Aripuanã in the west and the Rio Canumã (= Cunumã) in the east (Hershkovitz 1977; Silva Jr. and Noronha 1996; Ferrari 2008). It occurs on the north (left) bank of the Paraná Urariá (M. mauesi. Silva Jr. and Noronha (1996) observed M. chrysoleucus at Santa Bárbara on the left bank of the Rio Canumã. The southernmost locality is Prainha, a short distance north of the mouth of the Rio Roosevelt, on the east (right) bank of the Rio Aripuanã. It is probable that Prainha is near to the southern limit to its distribution, which may be marked by the headwaters of Rio Sucundurí, Serra do Sucundurí towards 8ºS.