In closely related to Rattus niobe. In 2005 Musser and Carleton provisionally recognized it as a separate species on the grounds that it is larger in size and has slightly darker fur. It is also similar to Rattus arrogans but distinguished by its smaller size and darker fur.[1] They stated that further study need to be done on the relationship to R. niobe.[3]
Distribution
The species is native to the Central Cordillera region of Papua Province, Indonesia and Papua New Guinea. It is found in the mountain tropical forests between 1500 and 2500 m. It is listed on IUCN as least concern as its wide distribution suggests an abundant population. It also has no major threats leading to a decline in numbers.[1]