The Yapen Island rat occurs on islands in north-western Indonesian New Guinea. A survey also recorded it in the Northern Tamrau Nature Reserve on the Bird’s Head Peninsula.
The three males captured in the survey measured 16.5–22.4 centimetres from head to body and weighed 98–340 grams.
It was caught in traps set on the forest floor. This survey did not establish its diet or activity pattern.
An extinction-risk assessment has not been added yet.