The montane Atlantic Forest rat (''Delomys collinus'') is a

South America South America is a continent entirely in the Western Hemisphere and mostly in the Southern Hemisphere, with a considerably smaller portion in the Northern Hemisphere. It can also be described as the southern Subregion#Americas, subregion o ...

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

species A species () is often defined as the largest group of organisms in which any two individuals of the appropriate sexes or mating types can produce fertile offspring, typically by sexual reproduction. It is the basic unit of Taxonomy (biology), ...

of the 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 over 870 species, it is either the largest or second-largest family ...

. It is endemic to part of the Atlantic Forest region of southeastern

Brazil Brazil, officially the Federative Republic of Brazil, is the largest country in South America. It is the world's List of countries and dependencies by area, fifth-largest country by area and the List of countries and dependencies by population ...

, where it is found at elevations from 1000 to 2700 m in noncontiguous mountain ranges. Its

karyotype A karyotype is the general appearance of the complete set of chromosomes in the cells of a species or in an individual organism, mainly including their sizes, numbers, and shapes. Karyotyping is the process by which a karyotype is discerned by de ...

, like that of closely related ''

Delomys dorsalis The striped Atlantic Forest rat (''Delomys dorsalis'') is a rodent species from South America. It is found in Argentina and Brazil Brazil, officially the Federative Republic of Brazil, is the largest country in South America. It is the wor ...

'', has 2n = 82, but the

fundamental number A karyotype is the general appearance of the complete set of chromosomes in the cells of a species or in an individual organism, mainly including their sizes, numbers, and shapes. Karyotyping is the process by which a karyotype is discerned by de ...

s of the two species differ. While it is not thought to be in present danger of extinction,

habitat destruction Habitat destruction (also termed habitat loss or habitat reduction) occurs when a natural habitat is no longer able to support its native species. The organisms once living there have either moved elsewhere, or are dead, leading to a decrease ...

and grassland fires are considered to be threats.

References

Delomys Rodents of Brazil Endemic mammals of Brazil Mammals described in 1917 Taxa named by Oldfield Thomas {{Cricetidae-stub