''Oligoryzomys rupestris'' is a species of

rodent Rodents (from Latin , 'to gnaw') are mammals of the order Rodentia (), which are characterized by a single pair of continuously growing incisors in each of the upper and lower jaws. About 40% of all mammal species are rodents. They are n ...

in the genus ''

Oligoryzomys ''Oligoryzomys'' is a genus of rodents in the tribe Oryzomyini of family Cricetidae. Many species are known as pygmy rice rats or colilargos.Musser and Carleton, 2005 The genus is found from Mexico to Tierra del Fuego and includes approximately 1 ...

'' of family

Cricetidae The Cricetidae are a family of rodents in the large and complex superfamily Muroidea. It includes true hamsters, voles, lemmings, muskrats, and New World rats and mice. At almost 608 species, it is the second-largest family of mammals, and h ...

. It is known only from eastern

Brazil Brazil ( pt, Brasil; ), officially the Federative Republic of Brazil (Portuguese: ), is the largest country in both South America and Latin America. At and with over 217 million people, Brazil is the world's fifth-largest country by area ...

, where it has been found in several localities in the

campos rupestres The ''campo rupestre'' ("rupestrian grassland") is a discontinuous montane subtropical ecoregion occurring across three different biomes in Brazil: Cerrado, Atlantic Forest and Caatinga. Originally, ''campo rupestre'' was used to characterize th ...

montane Montane ecosystems are found on the slopes of mountains. The alpine climate in these regions strongly affects the ecosystem because temperatures fall as elevation increases, causing the ecosystem to stratify. This stratification is a crucial ...

savanna A savanna or savannah is a mixed woodland- grassland (i.e. grassy woodland) ecosystem characterised by the trees being sufficiently widely spaced so that the canopy does not close. The open canopy allows sufficient light to reach the ground to ...

ecoregion An ecoregion (ecological region) or ecozone (ecological zone) is an ecologically and geographically defined area that is smaller than a bioregion, which in turn is smaller than a biogeographic realm. Ecoregions cover relatively large areas of ...

. This is a small ''Oligoryzomys'' species with a gray head, a yellow-brown back and gray belly and tail. Of the two karyotypic forms described by Silva & Yonenaga-Yassuda in 1998, species 1 is probably identical to ''O. rupestris'', while the other (species 2) is closely related. Its karyotype has 2n = 46 and FNa = 52.

References

Mammals of Brazil Oligoryzomys Mammals described in 2005 Taxa named by Marcelo Weksler {{Oligoryzomys-stub