The Rio Negro tuco-tuco (''Ctenomys rionegrensis'') is a species of

rodent Rodents (from Latin , 'to gnaw') are mammals of the Order (biology), order Rodentia ( ), which are characterized by a single pair of continuously growing incisors in each of the upper and Mandible, lower jaws. About 40% of all mammal specie ...

in the family

Ctenomyidae A tuco-tuco is a neotropical rodent in the family Ctenomyidae. Tuco-tucos belong to the only living genus of the family Ctenomyidae, ''Ctenomys'', but they include approximately 60 different species. The common name, "tuco-tuco", comes from the " ...

. It is found in a small fragmented range in

Entre Ríos Province Entre Ríos (, "Between Rivers") is a Center Region, Argentina, central provinces of Argentina, province of Argentina, located in the Mesopotamia, Argentina, Mesopotamia region. It borders the provinces of Buenos Aires Province, Buenos Aires (so ...

in northeastern

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 ...

and in the

Río Negro Department Río Negro Department (, ) is a department of the northwestern region of Uruguay. It has an area of and a population of 57,334. Its capital is Fray Bentos. It borders Paysandú Department to the north, Tacuarembó Department to the east, Durazno ...

of western

Uruguay Uruguay, officially the Oriental Republic of Uruguay, is a country in South America. It shares borders with Argentina to its west and southwest and Brazil to its north and northeast, while bordering the Río de la Plata to the south and the A ...

. It is restricted to sand dunes, and is threatened by the conversion of this habitat to forestry plantations.

References

Mammals of Argentina Mammals of Uruguay Mammals described in 1970 Tuco-tucos {{rodent-stub