Wiktionary
n. Any of the caviomorph rodents of the genus ''Ctenomys'' (the sole extant genus of family Ctenomyidae), which have a large head, small ears, and hairy tail.
Wikipedia
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 "tuc-tuc" sound they make while they dig their burrows.
The relationships among the species are debated by taxonomists. It has been described that they are in a state of "taxonomic chaos," but banded karyotypes have been used to help make progress on their taxonomic study. Their closest relatives are degus and other octodontids. All species of tuco-tucos are found in South America from Peru and central Brazil southward. The tuco-tucos of South America have an ecological role equivalent to that of the pocket gophers of North America.
They occupy an ecological niche previously taken by gondwanatheres such as Patagonia earlier in the Cenozoic.
Usage examples of "tuco-tuco".
In South America, a burrowing rodent, the tuco-tuco, or Ctenomys, is even more subterranean in its habits than the mole.