Rio Negro tuco-tuco

{{Short description|Species of rodent}}

{{Speciesbox

| name = Rio Negro tuco-tuco

| image =

| status = EN

| status_system = IUCN3.1

| status_ref = {{cite iucn |author=Bidau, C.J. |date=2018 |title=Ctenomys rionegrensis |volume=2018 |page=e.T136635A22193418 |doi=10.2305/IUCN.UK.2018-1.RLTS.T136635A22193418.en |access-date=19 November 2021}}

| genus = Ctenomys

| species = rionegrensis

| authority = Langguth & Abella, 1970

| synonyms =

}}

The Rio Negro tuco-tuco (Ctenomys rionegrensis) is a species of rodent in the family Ctenomyidae.{{MSW3 Hystricognathi|id=13400344|pages = 1187}} It is found in a small fragmented range in Entre Ríos Province in northeastern Argentina and in the Río Negro Department of western Uruguay. It is restricted to sand dunes, and is threatened by the conversion of this habitat to forestry plantations.