A Queensland University of Technology mammalogist discovered the black-tailed Antechinus in Queensland's Springbrook National Park, the university said Friday.
Its distinctive yellow-orange markings around its eyes and on its rump, and a black tail and feet mark it as a new species, Andrew Baker said.
"Antechinus males and females are highly promiscuous; males mate for long periods of time with many females to promote their own genes," he said. "A single female's brood of young will typically be sired by several fathers.
"But during mating, stress hormone levels rise dramatically, eventually causing the males' bodies to shut down," Baker said. "The males all die before their young are born."
The black-tailed Antechinus likely won't be the last unique creature to be unearthed in Springbrook National Park, said Baker, who is applying for an endangered species listing for the creature.
New mammal discoveries are rare, with only a handful normally found in the world each year.