The Chalchalero viscacha rat or Chalchalero vizcacha rat (''Tympanoctomys loschalchalerosorum'') is a species of

caviomorph Caviomorpha is the rodent parvorder that unites all New World hystricognaths. It is supported by both fossil and molecular evidence. The Caviomorpha was for a time considered to be a separate order outside the Rodentia, but is now accepted as ...

rodent in the family

Octodontidae Octodontidae is a family of rodents, restricted to southwestern South America. Fourteen species of octodontid are recognised, arranged in seven genera. The best known species is the common degu, ''Octodon degus''. Octodontids are medium-sized ...

. It was formerly considered to be

monotypic In biology, a monotypic taxon is a taxonomic group (taxon) that contains only one immediately subordinate taxon. A monotypic species is one that does not include subspecies or smaller, infraspecific taxa. In the case of genera, the term "unisp ...

within the genus ''Salinoctomys'', but has been shown by genetic analysis to nest within ''

Tympanoctomys ''Tympanoctomys'' is a genus of rodent in the family Octodontidae. There are three extant species in the genus: ''Tympanoctomys barrerae, T. barrerae'', ''Tympanoctomys kirchnerorum, T. kirchnerorum'' and ''Tympanoctomys loschalchalerosorum, T. l ...

'', and in particular, within the variation of '' T. barrerae''. The species is

endemic Endemism is the state of a species being found only in a single defined geographic location, such as an island, state, nation, country or other defined zone; organisms that are indigenous to a place are not endemic to it if they are also foun ...

to a small area of northwestern

Argentina Argentina, officially the Argentine Republic, is a country in the southern half of South America. It covers an area of , making it the List of South American countries by area, second-largest country in South America after Brazil, the fourt ...

, where it lives in

shrubland Shrubland, scrubland, scrub, brush, or bush is a plant community characterized by vegetation dominance (ecology), dominated by shrubs, often also including grasses, herbaceous plant, herbs, and geophytes. Shrubland may either occur naturally o ...

s bordering the salt flats of the

Salinas Grandes The Salinas Grandes ('Salina' is a spanish word for salt flat) is a large salt flat in central-northern Argentina, spanning the borders of four provinces (Córdoba, Catamarca, La Rioja and Santiago del Estero), at an average altitude of above ...

. Its diet consists of

halophyte A halophyte is a salt-tolerant plant that grows in soil or waters of high salinity, coming into contact with saline water through its roots or by salt spray, such as in saline semi-deserts, mangrove swamps, marshes and sloughs, and seashores. ...

plants. It is named after an Argentine musical group, Los Chalchaleros, whose songs were popular with its discoverers.

Description

The Chalchalero viscacha rat is a

nocturnal Nocturnality is a ethology, behavior in some non-human animals characterized by being active during the night and sleeping during the day. The common adjective is "nocturnal", versus diurnality, diurnal meaning the opposite. Nocturnal creatur ...

medium-sized species of rat. Its dorsal fur is dark brownish black while its underparts are white. The hairs on its back are about long and have a grey base, a brown band and a black tip, and the guard hairs are a uniform darkish brown. This viscacha rat reaches a head-and-body length of with a tail length of . The tail is relatively long, clad with hair along its entire length and ends with a black tassel. The soles of the feet have six pads, and there is a fringe of hairs around the feet.

Status

It is only found within an area totalling less than and it actually occupies only about one tenth of that area. It lives among the salt-loving plants that grow between the salt pans and the dense thorn scrub typical of the surrounding area. Its population is decreasing and the

International Union for Conservation of Nature The International Union for Conservation of Nature (IUCN) is an international organization working in the field of nature conservation and sustainable use of natural resources. Founded in 1948, IUCN has become the global authority on the stat ...

has rated its conservation status as "

critically endangered An IUCN Red List critically endangered (CR or sometimes CE) species is one that has been categorized by the International Union for Conservation of Nature as facing an extremely high risk of extinction in the wild. As of December 2023, of t ...

References

External links

SAREM Photograph and Type Specimen Repository
for the Chalchalero viscacha rat (in Spanish) {{Taxonbar, from=Q1059502 Mammals described in 2000 Mammals of Argentina Tympanoctomys