Australian researchers have discovered two new species of rodent native to the country.

In a study published on Thursday, a team from the Australian National University (ANU) and the Commonwealth Scientific and Industrial Research Organization described and named two new species of delicate mouse.

The smallest of Australia's native mice, with a length of up to 7.5 centimeters, the delicate mouse was previously thought to be one species spanning across Australia, but, by using new genetic technology, the researchers found there are three distinct species of rodent.

They have been given names relating to where they are found – the western delicate mouse, eastern delicate mouse and northern delicate mouse.

Emily Roycroft, the lead author of the study from ANU, said that the discovery was significant for conservation and research efforts.

"The two new species haven't had any conservation or research attention, because we didn't know they were there," she said in a media release.

"We don't know, for example, if population declines have gone undetected as a result of all three species being assessed as a single unit."

The study found that delicate mice have excellently adapted to environments ranging from arid deserts to forests.

Roycroft said the delicate mouse is one species of native rodent that has been evolving in Australia for 5 million years but must compete with introduced invasive species such as house mice, black rats and brown rats for resources.