Australian biologists have described a new species of dasyurid marsupial within the genus Antechinus.

Members of this genus are carnivorous, mouse-like marsupials found in Australia, including Tasmania and some other islands, and New Guinea.

The discovery of the new species, named the Black-tailed Antechinus (Antechinus arktos), brings the total number of species within this genus to 13.

Previously known as a northern outlier of the Dusky Antechinus (Antechinus swainsonii), the Black-tailed Antechinus is a highly sexed marsupial known only from areas of high altitude and high rainfall on the Tweed Volcano caldera of far south-east Queensland and north-east New South Wales, Australia.

Dr Andrew Baker from Queensland University of Technology and his colleagues suspected the rare, black-tailed Antechinus was a separate species when they came across it in May, 2013 because it had distinctive yellow-orange markings around its eyes and on its rump, and a black tail and feet.

“Comparing it to the Dusky Antechinus, which inhabits south-east Australia, we thought it was probably new,” said Dr Baker, who is the first author of a paper published in the journal Zootaxa (abstract in .pdf).

The Dusky Antechinus is more uniformly deep brown-black to grizzled grey-brown from head to rump, with brownish hair on the upper surface of the hindfoot and tail, whereas the Black-tailed Antechinus is “more vibrantly colored, with a marked change from grayish-brown head to orange-brown rump, fuscous black on the upper surface of the hindfoot and dense, short fur on the evenly black tail,” the scientists wrote in the paper.

“Further, the Black-tailed Antechinus has marked orange-brown fur on the upper and lower eyelid, cheek and in front of the ear and very long guard hairs all over the body.”

Antechinus males and females are highly promiscuous. The male can spend up to 12 hours mating to ensure breeding success.

“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. The males all die before their young are born,” Dr Baker said.

The scientists are now applying for an endangered species listing.

“It seems that the species may now be restricted to the highest parts of the Tweed Volcano Caldera, such as the upper parts of Springbrook where we successfully captured the species in May 2013,” they wrote in the paper.

“The most likely explanation for such a contraction is climate change. Given the predictions of future climate in the region this threat will increase. We therefore make a preliminary recommendation that Black-tailed Antechinus be listed as threatened, pending results from our continuing surveys of the region. Although we do not attempt a formal assessment of species status here, it qualifies for an IUCN threat category of endangered or possibly critically endangered, given that it is suspected to be in decline and is known from few locations in a restricted habitat under threat.”

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Baker AM et al. 2014. The Black-tailed Antechinus, Antechinus arktos sp. nov.: a new species of carnivorous marsupial from montane regions of the Tweed Volcano caldera, eastern Australia. Zootaxa 3765 (2): 101-133; doi: 10.11646/zootaxa.3765.2.1