Rattus villosissimus, the Australian Long-haired Rat, is a species of rodent

Rodent

Rodentia is an order of mammals also known as rodents, characterised by two continuously growing incisors in the upper and lower jaws which must be kept short by gnawing....

 in the family Muridae

Muridae

Muridae is the largest family of mammals. It contains over 600 species found naturally throughout Eurasia, Africa, and Australia. They have been introduced worldwide. The group includes true mice and rats, gerbils, and relatives....

. It is endemic to Australia

Australia

Australia , officially the Commonwealth of Australia, is a country in the Southern Hemisphere comprising the mainland of the Australian continent, the island of Tasmania, and numerous smaller islands in the Indian and Pacific Oceans. It is the world's sixth-largest country by total area...

, where its core range

Range (biology)

In biology, the range or distribution of a species is the geographical area within which that species can be found. Within that range, dispersion is variation in local density.The term is often qualified:...

 is "the Barkly lake system of the Barkly Tableland of the Northern Territory

Northern Territory

The Northern Territory is a federal territory of Australia, occupying much of the centre of the mainland continent, as well as the central northern regions...

 and the Channel Country

Channel Country

The Channel Country is region of outback Australia located mostly in the state of Queensland but also in portions of South Australia, Northern Territory and New South Wales. The name comes from the numerous intertwined rivulets that cross the region, which cover 150,000 km²...

 in Southwest Queensland

Queensland

Queensland is a state of Australia, occupying the north-eastern section of the mainland continent. It is bordered by the Northern Territory, South Australia and New South Wales to the west, south-west and south respectively. To the east, Queensland is bordered by the Coral Sea and Pacific Ocean...

 and north-eastern South Australia

South Australia

South Australia is a state of Australia in the southern central part of the country. It covers some of the most arid parts of the continent; with a total land area of , it is the fourth largest of Australia's six states and two territories.South Australia shares borders with all of the mainland...

". The species occasionally undergoes irruptions outside this core range across large parts of Australia, reaching as far as Alice Springs in 2011.