This mouse opossum is known only from Mexico's Islas Marías Archipelago. A camera study on María Madre Island recorded it twice, both times during evening or night hours.
It has well-defined black rings around the eyes, light brown limbs, and a uniformly brown tail.
On María Madre Island, two independent camera records were obtained between 20:00 and 23:00. Those times describe the records in that study, not a full daily activity pattern.
An extinction-risk assessment has not been added yet.