Mountain viscacha rat | |
---|---|
Scientific classification | |
Domain: | Eukaryota |
Kingdom: | Animalia |
Phylum: | Chordata |
Class: | Mammalia |
Order: | Rodentia |
Family: | Octodontidae |
Genus: | Octomys Thomas, 1920 |
Species: | O. mimax |
Binomial name | |
Octomys mimax Thomas, 1920 | |
The mountain viscacha rat or mountain vizcacha rat (Octomys mimax), historically viscacha rat or vizcacha rat, is a species of rodent in the family Octodontidae. [2] It is endemic to Argentina. [1]
It is the only living species within the genus Octomys. [3] This diploid genus (2n = 56) may be ancestral to the two unusual suspected tetraploid species Tympanoctomys barrerae and Pipanacoctomys aureus . [4] However, some genetic studies have rejected any polyploidism in mammals as unlikely, and suggests that amplification and dispersion of repetitive sequences best explain the large genome size. [5]
The mountain viscacha rat is a rat-like animal with a head-body length of about 11 to 18 centimetres (4.3 to 7.1 in) and weighing from 85 to 121 grams (3.0 to 4.3 oz). The feet are relatively long, while the tail measures 12 to 16 centimetres (4.7 to 6.3 in). It has light brown fur with white underparts and a bushy tail. [3]
Unusual features of the viscacha rat include greatly enlarged auditory bullae, and the presence of numerous whiskers on the roof of the mouth behind the incisor teeth. The exact function of the whiskers is unclear, but they may enable the animal to sense the position of food inside the mouth. [6]
Mountain viscacha rats are found only in the Monte Desert region of northwestern Argentina, [1] specifically in the provinces of Catamarca, La Rioja, San Luis, San Juan. They inhabit rocky desert and semidesert environments up to 800 metres (2,600 ft) above sea level. [3]
Mountain viscacha rats are nocturnal and solitary, spending the day sheltering in rock crevices. Although it does not construct burrows, it may place pieces of cactus close to crevice entrances to help protect against predators. [3] Individuals occupy large home ranges of around 12,300 square metres (3.0 acres), often overlapping with those of their neighbours. [7] They are herbivorous, feeding on the leaves and seeds of shrubland vegetation. During the dry season, their diet consists largely of the leaves of Prosopis trees, supplemented by caperbushes and alkaliweeds. During the wet season, they eat more seeds and fruit, including those from plants such as Maytenus and boxthorn shrubs. [3]
Kirchner is an occupational surname of German origin, derived from the Middle High German word kirchenaere. Notable people with the name include:
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 a genuine part of the rodents. Caviomorphs include the extinct Heptaxodontidae, the extinct Josephoartigasia monesi and extant families of chinchilla rats, hutias, guinea pigs and the capybara, chinchillas and viscachas, tuco-tucos, agoutis, pacas, pacaranas, spiny rats, New World porcupines, coypu and octodonts.
Chinchilla rats or chinchillones are rodents of the family Abrocomidae. This family has few members compared to most rodent families, with only nine known living species. They resemble chinchillas in appearance, with a similar soft fur and silvery-grey color, but have a body structure more like a short-tailed rat. They are social, tunnel-dwelling animals, and live in the Andes Mountains of South America. They are probably herbivorous, although this is not clear.
Abrocoma is a genus of abrocomid rodents found in the Andes of South America, from southern Peru to central Chile. The genus contains eight species, most of which are found in isolated mountain ranges in northwestern Argentina. The oldest fossil record for the Caviomorpha appears at the late Eocene-Early Oligocene transition. The Abrocoma has an interesting body structure for example within its own head it has a sac that contains a liquid that is not named by Janet K. Braun and Michael A. Mares(894). They also have feet that are padded which helped to completely say with certainty that it is a rock dweller but also a rock climber.(896).
The golden viscacha rat or golden vizcacha rat is the single species of the genus Pipanacoctomys of the rodent family Octodontidae. It has 92 chromosomes and has been regarded as tetraploid. This octodontid and its sister-species, the plains viscacha rat, may have arisen from the diploid mountain viscacha rat, as a result of the doubling and subsequent loss of some chromosomes. However, some genetic studies have rejected any polyploidism in mammals as unlikely, and suggest that amplification and dispersion of repetitive sequences best explain the large genome size.
The Atlantic bamboo rat, or southern bamboo rat, is a spiny rat species found in humid tropical forests in Argentina, Brazil and Paraguay. It is the only member of the genus Kannabateomys.
Pittier's crab-eating rat is a species of semiaquatic rodent in the family Cricetidae. It is endemic to Venezuela. The natural habitats of this species are rivers and swamps. Its karyotype has 2n = 92 and FNa = 98. This was previously thought to be the highest chromosome number known for a mammal, but it has since been found that the plains viscacha rat or red viscacha rat has 4x = 2n = 102.
The northern viscacha is a species of viscacha, a rodent in the family Chinchillidae. It is known from Peru and Chile, at elevations from 300 to 5000 m, and may also be present in Bolivia.
The plains viscacha or plains vizcacha is a species of viscacha, a rodent in the family Chinchillidae. It is the only living species within the genus Lagostomus. It is found in Argentina, Bolivia, and Paraguay. The plains viscacha is the largest species in its family. They construct elaborate burrows that house successive colonies for decades.
The prehensile-tailed hutia is a small, furry, rat-like mammal found only in forests on Cuba. It is the only member of the genus Mysateles. It climbs and lives in trees where it eats only leaves, and it is threatened by habitat loss. The prehensile-tailed hutia is a member of the hutia subfamily (Capromyinae), a group of rodents native to the Caribbean that are mostly endangered or extinct.
The plains viscacha rat, plains vizcacha rat, red viscacha rat, or red vizcacha rat is a species of rodent in the family Octodontidae native to Argentina. It is one of three species in the genus Tympanoctomys.
Tympanoctomys is a genus of rodent in the family Octodontidae. There are three extant species in the genus: T. barrerae, T. kirchnerorum and T. loschalchalerosorum. T. loschalchalerosorum was formerly considered to be monotypic within the genus Salinoctomys, but has been shown by genetic analysis to nest within the variation of T. barrerae.
Viscacha rats are a group of rodents in the family Octodontidae. All species are found in Argentina. They are placed in the following genera:
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.
The Chalchalero viscacha rat or Chalchalero vizcacha rat is a species of caviomorph rodent in the family Octodontidae. It was formerly considered to be monotypic within the genus Salinoctomys, but has been shown by genetic analysis to nest within Tympanoctomys, and in particular, within the variation of T. barrerae. The species is endemic to a small area of northwestern Argentina, where it lives in shrublands bordering the salt flats of the Salinas Grandes. Its diet consists of halophyte plants. It is named after an Argentine musical group, Los Chalchaleros, whose songs were popular with its discoverers.
The 2000s witnessed an explosion of genome sequencing and mapping in evolutionarily diverse species. While full genome sequencing of mammals is rapidly progressing, the ability to assemble and align orthologous whole chromosomal regions from more than a few species is not yet possible. The intense focus on the building of comparative maps for domestic, laboratory and agricultural (cattle) animals has traditionally been used to understand the underlying basis of disease-related and healthy phenotypes.
Kirchner's viscacha rat or Kirchner's vizcacha rat is a species of rodent in the family Octodontidae described in 2014. It is one of three species in the genus Tympanoctomys. That species is endemic to Chubut Province in the central western Argentina, where it has a fragmented range. Its natural habitat is desert scrubland, dunes and salt flats, where it eats halophyte plants. It is a solitary, nocturnal rodent that constructs large mounds with complex burrows. The species was named in honor of both Cristina Fernández de Kirchner and Néstor Kirchner, presidents of Argentina.
The Argentine Monte (NT0802), or Low Monte, is an ecoregion of dry thorn scrub and grasslands in Argentina. It is one of the driest regions in the country. Human settlements are mainly near water supplies such as rivers or oases. Deforestation and over-grazing around these settlements have caused desertification.
Echimyinae is a subfamily of rodents belonging to the spiny rats family Echimyidae. It contains 14 arboreal genera—all the members of the tribe Echimyini, plus Callistomys—a few terrestrial genera, and a subaquatic genus (Myocastor).
The High Monte is a montane grasslands and shrublands ecoregion in Argentina.