Description
Female: 29-32 mm, Male: 22-25 mm. Dorsum greyish dark brown with many small ocher or yellowish spots. The belly and chest are orange, with irregular dark blotches. As all the species in the M. tumifrons group, this toad has a conspicuous frontal swelling.

Distribution and Habitat

Country distribution from AmphibiaWeb's database: Uruguay

View distribution map in BerkeleyMapper.

This species is only know from a few localities in southern Uruguay. The habitat is at the top of hills, in rocky soils.

Life History, Abundance, Activity, and Special Behaviors
Little is know about the natural history of this species. Females with mature eggs were found during cold months (May to August). These toads seem to be explosive breeders with diurnal activity after heavy rains. This species exhibits the typical defensive behavior of the genus "Unkenreflex".

Trends and Threats
The populations of M. orejasmirandai could be threatened by consequence of habitat loss.

Possible reasons for amphibian decline

General habitat alteration and loss
Habitat modification from deforestation, or logging related activities
Habitat fragmentation

References

Achaval, F., and Olmos, A. (2003). Anfibios y reptiles del Uruguay Ed. Graphis. Serie Fauna N°, Montevideo, Uruguay.

Klappenbach, M. A., and Langone, J. A. (1992). ''Lista sistemática y sinonímica de los anfibios del Uruguay con comentarios y notas sobre su distribución.'' Anales del Museo Nacional de Historia Natural de Montevideo (2a Serie), 8, 163-222.

Langone, J. A. (1994). Ranas y sapos del Uruguay (reconocimientos y aspectos biológicos). Museo Damaso Antonio Larrañaga 5, Serie de Divulgación

Maneyro, R., and Langone, J. A. (2001). ''Categorización de los anfibios del Uruguay.'' Cuadernos de Herpetología, 15(2), 107-118.

Núñez, D., Maneyro, R., Langone, J. A. and De Sá, R. O. (2004). ''Distribución geográfica de la fauna de anfibios del Uruguay.'' Smithsonian Herpetological Information Series, 134, 1-34.

Prigioni, C. M., and Langone, J. A. (1986). ''Melanophryniscus orejasmirandi n. sp. un nuevo Bufonidae (Amphibia, Anura) de Uruguay, con una clave para las especies del grupo tumifrons.'' Comunicaciones Zoologicas del Museo de Historia Natural de Montevideo, 159, 1-11.

Prigioni, C. M., and Langone, J. A. (1990). ''Descripción de la larva de Melanophryniscus orejasmirandi Prigioni & Langone 1986 (Amphibia, Anura, Bufonidae).'' Comunicaciones Zoologicas del Museo de Historia Natural de Montevideo, 173, 1-9.

Species Account Citation: AmphibiaWeb 2006 Melanophryniscus orejasmirandai <https://amphibiaweb.org/species/347> University of California, Berkeley, CA, USA. Accessed May 11, 2025.

Citation: AmphibiaWeb. 2025. <https://amphibiaweb.org> University of California, Berkeley, CA, USA. Accessed 11 May 2025.

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