The Species Black List
Cryptonanus guahybae
Guahiba gracile mouse opossum
The Guahiba gracile mouse opossum (Cryptonanus guahybae) is known only from a few localities in southeastern Brazil (Rio Grande do Sul, Santa Catarina and Paraná).
Status Data Deficient on the IUCN Red List Restriction tier 2, restricted, extent unclear Class Mammalia Realm Neotropical Locality not specified in the source As IUCN records it Cryptonanus guahybae (Tate, 1931) This species is one of 3,062 in a list of vertebrates the IUCN Red List records as Data Deficient or has never assessed, ranked by how narrowly restricted the published record says they are. The sentence above is the evidence the tier was read from, quoted from Matthew Richardson, Threatened and Recently Extinct Vertebrates of the World (2023).
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Check this species elsewhere: IUCN Red List · GBIF