The Guahiba gracile opossum, Cryptonanus guahybae, is a species of opossum in the family Didelphidae. It is endemic to southern Brazil

Brazil

Brazil , officially the Federative Republic of Brazil , is the largest country in South America. It is the world's fifth largest country, both by geographical area and by population with over 192 million people...

, where it is known only from three islands, Guahiba, São Lourenço, and Taquara, in the state of Rio Grande do Sul

Rio Grande do Sul

Rio Grande do Sul is the southernmost state in Brazil, and the state with the fifth highest Human Development Index in the country. In this state is located the southernmost city in the country, Chuí, on the border with Uruguay. In the region of Bento Gonçalves and Caxias do Sul, the largest wine...

. The poorly studied species is presumed to inhabit subtropical forests, and thus to be threatened by deforestation.