Ruschi's rat or Ruschi's spiny mouse (''Abrawayaomys ruschii'') is a

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 na ...

species In biology, a species is the basic unit of classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of organisms in which any two individuals of the appropriate s ...

found in

Argentina Argentina (), officially the Argentine Republic ( es, link=no, República Argentina), is a country in the southern half of South America. Argentina covers an area of , making it the second-largest country in South America after Brazil, th ...

and

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 ...

. Some cranial features suggest it may be an archaic relative of the

paramo Oldfield mouse The paramo Oldfield mouse (''Thomasomys paramorum'') is a species of rodent in the family Cricetidae. It is found only in Ecuador Ecuador ( ; ; Quechua: ''Ikwayur''; Shuar: ''Ecuador'' or ''Ekuatur''), officially the Republic of Ecuado ...

(''Thomasomys paramorum''). The upper parts are greyish yellow with a darker head and yellowish-white underparts. Fine hairs are mixed with flattened and grooved spines that are most numerous on the back.Walker's Mammals of the World (6th Edition, 1999) by Ronald M. Nowak, The Johns Hopkins University Press, Baltimore and London.

Taxonomy

This rat was first described by Cunha and Cruz in 1979 and is named in honour of the Brazilian naturalist Augusto Ruschi (1915 - 1986).

Description

A medium-sized rodent, Ruschi's rat has a broad head and rounded ears. Adults have a total length of between , about half of which is the tail. The fur is short and dense. Some of the hairs are slender while others are spiny, especially on the back and rump; each spiny hair is flattened and stiff, with a longitudinal groove, and is broadest in the middle. The fur is

agouti The agouti (, ) or common agouti is any of several rodent species of the genus ''Dasyprocta''. They are native to Middle America, northern and central South America, and the southern Lesser Antilles. Some species have also been introduced else ...

(banded in light and dark), and there is little difference in shade between the greyish-yellow upper parts of the animal and the slightly paler underparts.

Distribution

Ruschi's rat is native to eastern South America. The type locality is

Espírito Santo Espírito Santo (, , ; ) is a state in southeastern Brazil. Its capital is Vitória, and its largest city is Serra. With an extensive coastline, the state hosts some of the country's main ports, and its beaches are significant tourist attra ...

in southeastern Brazil, and it is also known from several locations in

Misiones Province Misiones (, ''Missions'') is one of the 23 provinces of Argentina, located in the northeastern corner of the country in the Mesopotamia region. It is surrounded by Paraguay to the northwest, Brazil to the north, east and south, and Corrientes ...

in northeastern Argentina, and from near

Rio de Janeiro Rio de Janeiro ( , , ; literally 'River of January'), or simply Rio, is the capital of the state of the same name, Brazil's third-most populous state, and the second-most populous city in Brazil, after São Paulo. Listed by the GaWC as a b ...

and in

Santa Catarina State Santa Catarina (, ) is a state in the South Region of Brazil. It is the 7th smallest state in total area and the 11th most populous. Additionally, it is the 9th largest settlement, with 295 municipalities. The state, with 3.4% of the Brazili ...

. The precise extent of its range is unknown.

Ecology

This species is poorly known. It has been caught in traps set on the ground so it is probably terrestrial rather than arboreal, and this is borne out by its anatomy. Observations of one individual feeding suggests that the diet is mainly fruits, seeds and foliage.

Status

''A. ruschii'' is found in forests in southeastern Brazil and northern Argentina. Although some of the forest is fragmented, the rat has a wide range and no particular threats have been identified. The

International Union for Conservation of Nature The International Union for Conservation of Nature (IUCN; officially International Union for Conservation of Nature and Natural Resources) is an international organization working in the field of nature conservation and sustainable use of natu ...

has assessed its conservation status as being of

least concern A least-concern species is a species that has been categorized by the International Union for Conservation of Nature (IUCN) as evaluated as not being a focus of species conservation because the specific species is still plentiful in the wild. T ...

References

{{Taxonbar, from=Q1633510 Thomasomyini Rodents of South America Mammals of Argentina Mammals of Brazil Mammals described in 1979 zh:闊面倉鼠屬