This species is known with certainty only from southern Brazil, mostly from the state of Sao Paulo, but also from south-western Minas Gerais State and south-western Rio de Janeiro State. It used to be found at the biological station at Boraceia in Sao Paulo, but can no longer be found there, having last been seen around 1980, despite subsequent searches. It is, however, still found in other places. Its altitudinal range is 500-2,000m asl. It has also been recorded from the Argentinean province of Misiones (a single specimen from 1961), but this record probably refers to another species.
Habitat and Ecology
This diurnal species occurs in and near rocky streams, in which it breeds, or marshy areas with slow-flowing water, in primary and secondary forest. It does not occur in open areas.
This species is uncommon. The population at Boraceia disappeared, despite apparently having suitable habitat remaining. This decline is reminiscent of disappearances of stream-breeding, high-altitude frog species in other parts of the wet tropics.
The major threats are probably related to habitat loss due to logging and human settlement. It is perhaps also affected by soil and water pollution due to agricultural and industrial practices. However, it appears that this species might also have experienced some unexplained declines in areas of suitable habitat, and chytridiomycosis cannot be ruled out as the cause.
This species occurs in some protected areas. Surveys are urgently needed to determine whether or not it is declining even where suitable habitats survive, and whether or not chytridiomycosis is involved.
Red List Status
Data Deficient (DD)
Esteban Lavilla, Oswaldo Luiz Peixoto 2004. Crossodactylus dispar. In: IUCN 2014