13156 Mawayana 10-99 Ethnologue has two codes for apparently a single language, Madipian [mpw] in Brazil (with alternate name Mawayana) and Mawayana [mzx] for Guyana -- both said to be 50 people living with the Waiwai.

Mawayana [mzx]: 50 in Guyana (1986 C. Howard); population total all countries: 60;
Mapidian [mpw] (Mahuayana, Maiopitian, Maopityan, Mawayana): 10 in Brazil (Moore 2006).
Ethnologue: Languages of the World, 16th Edition (2009) Off 50? 10-99