The Kimberley rock rat (''Zyzomys woodwardi'') is a species of

rodent Rodents (from Latin , 'to gnaw') are mammals of the order Rodentia (), which are characterized by a single pair of continuously growing incisors in each of the upper and lower jaws. About 40% of all mammal species are rodents. They are na ...

in the family

Muridae The Muridae, or murids, are the largest family of rodents and of mammals, containing approximately 1,383 species, including many species of mice, rats, and gerbils found naturally throughout Eurasia, Africa, and Australia. The name Muridae come ...

. It is found only in Australia, specifically in the northern tropical part of the

Northern Territory The Northern Territory (commonly abbreviated as NT; formally the Northern Territory of Australia) is an states and territories of Australia, Australian territory in the central and central northern regions of Australia. The Northern Territory ...

and adjacent Kimberley region of

Western Australia Western Australia (commonly abbreviated as WA) is a state of Australia occupying the western percent of the land area of Australia excluding external territories. It is bounded by the Indian Ocean to the north and west, the Southern Ocean to th ...

, in high-altitude closed forest. Biologists have proposed that ''Zyzomys woodwardi'' speciated from ''

Zyzomys argurus ''Zyzomys'' is a genus of rodents with unusually thick, long tails. Five species of the genus are known in Australia, where they are called rock rats or thick-tailed rats. The genus was classified by Michael Rogers Oldfield Thomas in 1909. Tax ...

'' around 8,000 years ago due to a large flood that increased the wetness of the environment. In response to the wetter environment ''Zyzomys woodwardi'' had a better

Darwinian Darwinism is a theory of biological evolution developed by the English naturalist Charles Darwin (1809–1882) and others, stating that all species of organisms arise and develop through the natural selection of small, inherited variations tha ...

fitness and out-competed ''Zyzomys argurus'' due to new selective pressures and over time the two species were separated by large vine thickets and sandstone barriers. The species is present in the Charnley River–Artesian Range Wildlife Sanctuary in the Kimberley region of WA.

References

* * Zyzomys Mammals of Western Australia Mammals of the Northern Territory Rodents of Australia Mammals described in 1909 Taxa named by Oldfield Thomas Taxonomy articles created by Polbot {{WesternAustralia-stub