The Golden Vizcacha Rat (Pipanacoctomys aureus) is the single species of the genus Pipanacoctomys of the rodent family

Family (biology)

In biological classification, family is* a taxonomic rank. Other well-known ranks are life, domain, kingdom, phylum, class, order, genus, and species, with family fitting between order and genus. As for the other well-known ranks, there is the option of an immediately lower rank, indicated by the...

 Octodontidae

Octodontidae

The Octodontidae are a family of rodents, restricted to south-western South America. Thirteen species of octodontid are recognised, arranged in nine genera. The best known species is the Degu, Octodon degus....

. This animal is tetraploid and has 4x

Ploidy

Ploidy is the number of sets of chromosomes in a biological cell.Human sex cells have one complete set of chromosomes from the male or female parent. Sex cells, also called gametes, combine to produce somatic cells. Somatic cells, therefore, have twice as many chromosomes. The haploid number is...

 = 2n = 92 chromosome

Chromosome

A chromosome is an organized structure of DNA and protein found in cells. It is a single piece of coiled DNA containing many genes, regulatory elements and other nucleotide sequences. Chromosomes also contain DNA-bound proteins, which serve to package the DNA and control its functions.Chromosomes...

s. This species and its sister-species Tympanoctomys barrerae (4x = 102) appear to have arisen from the diploid Mountain Vizcacha Rat

Viscacha Rat

The viscacha rat , or mountain viscacha rat, is a species of rodent in the family Octodontidae. It is endemic to Chile and Argentina.It is the only living species within the genus Octomys...

, Octomys mimax (2x = 2n = 56) as a result of doubling and then loss of some chromosomes.

The species is known from Catamarca Province

Catamarca Province

Catamarca is a province of Argentina, located in the northwest of the country. The province has a population of 334,568 as per the , and covers an area of 102,602 km². Its literacy rate is 95.5%. Neighbouring provinces are : Salta, Tucumán, Santiago del Estero, Córdoba, and La Rioja...

 of northwestern Argentina

Argentina

Argentina , officially the Argentine Republic , is the second largest country in South America by land area, after Brazil. It is constituted as a federation of 23 provinces and an autonomous city, Buenos Aires...

, where specimens are known only from the Salar de Pipanaco, a salt flat. It feeds on halophyte

Halophyte

A halophyte is a plant that grows where it is affected by salinity in the root area or by salt spray, such as in saline semi-deserts, mangrove swamps, marshes and sloughs, and seashores. An example of a halophyte is the salt marsh grass Spartina alterniflora . Relatively few plant species are...

 plants. The genus is named after the locale, with “octo” being a reference to the figure-eight ridge on its cheek tooth

Tooth

Teeth are small, calcified, whitish structures found in the jaws of many vertebrates that are used to break down food. Some animals, particularly carnivores, also use teeth for hunting or for defensive purposes. The roots of teeth are embedded in the Mandible bone or the Maxillary bone and are...

.

It is threatened by conversion of its very restricted habitat to agricultural use.