Ricardo Ojeda's degu (''Octodon ricardojeda'') is a species of

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 n ...

in the

family Family (from la, familia) is a group of people related either by consanguinity (by recognized birth) or affinity (by marriage or other relationship). The purpose of the family is to maintain the well-being of its members and of society. Idea ...

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 is found in a small portion of eastern

Chile Chile, officially the Republic of Chile, is a country in the western part of South America. It is the southernmost country in the world, and the closest to Antarctica, occupying a long and narrow strip of land between the Andes to the east a ...

and western

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 ...

, being the only degu found outside of Chile. It was named after Argentine mammalogist Ricardo Ojeda. It was formerly thought to be a population of Bridge's degu (''O. bridgesii)'' but in 2020, a genomic study found it to be a distinct species. Phylogenetic evidence supports it being the sister species to the Pacific degu (''R. pacificus''), from which it diverged during the early

Pleistocene The Pleistocene ( , often referred to as the ''Ice age'') is the geological epoch that lasted from about 2,580,000 to 11,700 years ago, spanning the Earth's most recent period of repeated glaciations. Before a change was finally confirmed in ...

, about 1.97 million years ago.

Fossil A fossil (from Classical Latin , ) is any preserved remains, impression, or trace of any once-living thing from a past geological age. Examples include bones, shells, exoskeletons, stone imprints of animals or microbes, objects preserved ...

records of this species are known from Holocene archaeological sites in

Neuquén Neuquén (; arn, Nehuenken) is the capital city of the Argentine province of Neuquén and of the Confluencia Department, located in the east of the province. It occupies a strip of land west of the confluence of the Limay and Neuquén river ...

and Río Negro, Argentina; this indicates that the species had a slightly wider distribution in prehistoric times. In

it inhabits semiopen areas in

southern beech ''Nothofagus'', also known as the southern beeches, is a genus of 43 species of trees and shrubs native to the Southern Hemisphere in southern South America (Chile, Argentina) and Australasia (east and southeast Australia, New Zealand, New Gui ...

forests, such as those found in Lanín National Park, as well as sandy hillocks within patches of '' Chusquea'' bamboo. Although it is a primarily terrestrial species, it can climb. It is not as of yet known if it excavates the burrows that it inhabits or only occupies those dug by other animals. Due to its small range and being known only from a few localities (although potential unsurveyed habitat exists), it has been recommended that this species be classified as Vulnerable on the

IUCN Red List The International Union for Conservation of Nature (IUCN) Red List of Threatened Species, also known as the IUCN Red List or Red Data Book, founded in 1964, is the world's most comprehensive inventory of the global conservation status of biol ...

References

{{Taxonbar, from=Q109424155 Octodon Mammals of Patagonia Mammals of Chile Mammals of Argentina Mammals described in 2020