Australian scientists will mark the end of 2014 with the discovery of a new species of native marsupial living in the Northern Territory.

For decades, biologists have assumed the Short-eared Rock-wallaby found across northern Australia from the Kimberleys to the Top End was a single species.

An adult male of the newly recognised Wilkins Rock-wallaby photographed in Litchfield National Park, Northern Territory. Credit:Emily Miller

"We've shown it's quite clearly two species," said Mark Eldridge, a principal research scientist at the Australian Museum Research Institute.

The discovery was revealed by genetic tests, and highlights how much there is to learn about well-studied groups such as mammals and birds.