Imagine holding an animal that the world believed vanished before the pyramids were built. Before Stonehenge. Before the wheel.

That is precisely what has happened on the remote Vogelkop Peninsula of West Papua, where two marsupial species — known only from fossilised bones dating back more than 6,000 years — have been confirmed alive and well in the rainforest canopy.

The pygmy long-fingered possum (Dactylonax kambuayai) and the ring-tailed glider (Tous ayamaruensis) are now among the most extraordinary examples of so-called "Lazarus taxa": species that disappeared from the fossil record in the distant past, only to be found — against all conceivable odds — still breathing.

"The chances of finding one mammal species that had been thought gone for millennia was almost zero," says Tim Flannery, the 70-year-old Australian zoologist who led the research. Finding two? "Unprecedented and groundbreaking."

The detective story

The discoveries, published in March 2026 in the journal Records of the Australian Museum, read like a scientific thriller. The pygmy long-fingered possum is a striped creature roughly 14 inches long, nose to tail tip, with one freakishly elongated digit on each hand — twice the length of its other fingers — which it uses to extract wood-boring beetle larvae from rotting timber. Fossil records had placed it in central Queensland some 300,000 years ago and in West Papua around 6,000 years ago. Then, silence.

But in 2007, one researcher suggested the animal might still exist. In 2022, wildlife photographer Carlos Bocos, on an expedition organised by mammalwatching.com, snapped what turned out to be the possum in a tree. Meanwhile, two museum specimens at the University of New Guinea had been sitting there all along — misidentified and used for teaching.

The ring-tailed glider's story is no less remarkable. Related to Australia's greater gliders but possessing unfurred ears and a powerful prehensile tail, it was first described from fossil fragments found during late 20th-century archaeological digs. A subadult was photographed by researcher Arman Muharmansyah by a riverside in 2015, but it took Flannery's team to confirm the animal represents an entirely new genus — the first new genus of New Guinean marsupial described since 1937.

Sacred animals, essential knowledge

Neither species could have been identified without the Indigenous Tambrauw and Maybrat communities of the Vogelkop, who have long known of the animals. The ring-tailed glider is considered sacred by some clans — a manifestation of their ancestors' spirits. The genus name Tous honours the local name for the creature.

"We worked very carefully and collaboratively with Tambrauw Elders," says Rika Korain, a Maybrat woman and research co-author. "Identification would not have been possible without cooperation with Traditional Owners."

Both species inhabit lowland mountain forests in an area under threat from logging. Researchers are keeping the precise locations secret to deter wildlife traffickers.

What extinction really means

The implications ripple far beyond New Guinea. If two mammals can hide in plain sight for six millennia, how confident should we be in any declaration of extinction?

"In a world awash with bad news, and no more so than for the environment, it is always joyous when species once thought extinct turn out not to be," says Euan Ritchie, a wildlife ecologist at Deakin University.

The question resonates closer to home, too. Scotland's own conservation history offers a parallel, if more modest, story of surprise: the pine marten, once driven to the brink in Britain, has staged a remarkable recovery across the Highlands and is now recolonising parts of southern Scotland. Conservationists at the University of Glasgow's Institute of Biodiversity, Animal Health and Comparative Medicine continue to study how remote glens, ancient Caledonian pine forests, and the barely surveyed ecosystems of the Outer Hebrides and St Kilda might yet harbour species — or populations — that science has written off.

If the tangled rainforests of the Vogelkop can conceal mammals for 6,000 years, who is to say what lingers unseen in the deep corries of Knoydart or the sea caves of Mull?

A crowning glory

For Flannery, who has spent a career working in some of the world's least explored landscapes, the discovery carries a deeply personal weight.

"It's sort of a crowning glory in my career as a biologist," he told The Guardian.

The rest of us might settle for a simpler feeling: pure wonder at how much we still don't know.