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# One tiny marsupial turned out to be four
- URL: https://www.earthtoseanews.com/planigales/
- Published: 2026-08-18T20:00:00.000Z
- Updated: 2026-08-21T13:06:41.000Z
- Description: The long-tailed planigale, one of the smallest marsupials on earth, has just been sorted into four separate species, and one of them is brand new.
- Author: Nicole McMahon
- Tags: Global Good News, All stories, Rewilding

Australia has gained a mammal without anybody setting a trap.

Researchers went back through museum specimens of the long-tailed planigale, a tiny flat headed marsupial that has been treated as a single species for decades, and found four species inside it. One of the four had never been described at all. It has been named **Planigale petrophila**, the Arnhem Plateau planigale.

Planigales are worth knowing about before we go further. They are among the smallest marsupials on earth, small enough to sit in a tablespoon, and they are carnivores, hunting prey close to their own size, which is roughly the equivalent of you taking on something the size of a labrador for dinner. Most of them live down in the cracks that open in clay soils in the lowlands, which is a large part of why they are so easily missed.

The new one does not do that. It lives up on rocky escarpment country in the Arnhem Plateau, and it is bigger than its closest relatives, with the longest tail ever recorded on a planigale, between eight and nine centimetres, longer than its own body.

"P. petrophila is unique in having a much longer tail than all other planigale species," said **Dr Linette Umbrello** of the Western Australian Museum, who led the work.

The rest of the untangling is just as satisfying. Planigales in the Kimberley that had been filed in with everything else turn out to be their own species, **Planigale subtilissima**. A subspecies was folded back where it belonged. What looked like one animal across a vast stretch of northern Australia was four animals all along, and nobody could see it until somebody put genetics, measurements and old specimens side by side.

The researchers say this themselves: the Arnhem Plateau planigale is known from just three specimens, collected within twelve kilometres of each other, and it has not been recorded in about two decades. It needs proper survey work now. But nothing can be looked for until it has a name, and as of this year it has one.

That is what we love here. Not an expedition, not a helicopter. Drawers in a collection, sitting quietly for years, until somebody looked closely enough. Every museum in the country has drawers like that.

Our short take: Umbrello et al., "Untangling the long-tailed planigale (Dasyuridae: *Planigale ingrami*) species complex: four species revealed using integrative taxonomy", **Zoological Journal of the Linnean Society**, Volume 207, Issue 2, June 2026\. Named on the work: **Dr Linette Umbrello**, Western Australian Museum; **Associate Professor Andrew Baker**, QUT; **Dr Kenny Travouillon**, Western Australian Museum; **Dr Mike Westerman**, La Trobe University; **Dr Mark Blacket**, Department of Energy, Environment and Climate Action; **Dr Skye Cameron** and **Dr Eridani Mulder**, Australian Wildlife Conservancy. Photograph of *Planigale petrophila* from the paper, via Wikimedia Commons under [CC BY 4.0](https://creativecommons.org/licenses/by/4.0/?ref=earthtoseanews.com).