This opossum occurs in western Ecuador and nearby parts of northwestern South America. An older, broader classification described coastal populations as dark-coated, and a camera-trap study in one part of Ecuador suggested an association with permanent water.
A 2000 account of the broad species described the melanurus population from coastal Colombia and northern Ecuador as having dark gray to nearly black upperparts and a dark tail that sometimes had a pale tip.
Camera records from the 2023 Cordillera Chongón Colonche survey led the authors to suggest that the species may favor areas with permanent water. This is a local inference from western Ecuador.
An extinction-risk assessment has not been added yet.