This species occurs in Paraná, Santa Catarina, and Rio Grande do Sul states, Brazil, at 200-1,000m asl. Populations from Argentina (M. spectablis) and Paraguay (M. fulvoguttatus) formerly ascribed to this species are now considered distinct species.
Habitat and Ecology
It occurs in open areas and forest. Reproduction is explosive and occurs in temporary pools.
The population status is unknown because it is very difficult to survey this species.
Deforestation, cattle ranching and water pollution are threats to this species. It is also potentially threatened by the international pet trade.
It might occur in private reserves.
The forms spectabilis and simplex were elevated to species status by Caramaschi and Cruz (2002). These authors also resurrected the species Melanophryniscus pachyrhynus, formerly considered a synonym of M. tumifrons.
Paulo Garcia, Magno Vicente Segalla, Esteban Lavilla, Diego Baldo 2004. Melanophryniscus tumifrons. In: IUCN 2014