Roig's tuco-tuco is a species of rodent

Rodent

Rodentia is an order of mammals also known as rodents, characterised by two continuously growing incisors in the upper and lower jaws which must be kept short by gnawing....

 in the family Ctenomyidae. It is endemic to a small region near the Paraná River

Paraná River

The Paraná River is a river in south Central South America, running through Brazil, Paraguay and Argentina for some . It is second in length only to the Amazon River among South American rivers. The name Paraná is an abbreviation of the phrase "para rehe onáva", which comes from the Tupi language...

 in Corrientes Province

Corrientes Province

Corrientes is a province in northeast Argentina, in the Mesopotamia region. It is surrounded by : Paraguay, the province of Misiones, Brazil, Uruguay, and the provinces of Entre Rios, Santa Fe and Chaco.-History:...

, northeastern 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 lives on sand dunes, and near rivers. Development is degrading and shrinking this habitat, threatening the rodent's survival. The species is named after Argentine zoologist Virgilio G. Roig. Its karyotype

Karyotype

A karyotype is the number and appearance of chromosomes in the nucleus of an eukaryotic cell. The term is also used for the complete set of chromosomes in a species, or an individual organism.p28...

 has 2n = 48 and FN = 80.