There are places on the planet that continue to remind us how nature is capable of keeping secrets for millennia. Western New Guinea, with its dense, humid forests that seem to swallow everything, is one such place. Here science has just made an incredible discovery: two marsupials believed extinct for about 6,000 years are still alive.
For years zoologists only knew them through fossil fragments. Some jaws, some teeth, remains found in the Vogelkop peninsula, today part of Indonesian Papua. Silent traces that told the story of animals that belonged to a world far away in time. No one imagined that those same animals could continue to move among the trees of tropical forests.
And yet that’s exactly what happened. Thanks to long and patient work, made up of scientific analyses, photographs taken in the jungle, forgotten specimens in museum collections and knowledge kept by local communities, researchers have managed to reconstruct a story that seemed impossible. Two species considered lost in the past have never truly disappeared.
Marsupials believed to be extinct in New Guinea
In scientific language these cases are called “Lazarus species”. The expression recalls the biblical character who came back to life and indicates those species that reappear after having been considered extinct for a very long time. According to biologist Tim Flannery, one of the authors of the studies published in Records of the Australian Museumthe discovery of just one species of this type already represents an extraordinary event. Discovering two in the same territory is something very rare.
The first is Dactylonax kambuayai, known as the long-fingered pygmy possum. Its identification was possible thanks to a kind of scientific puzzle. Scholars have linked fossil remains dating back to the Holocene, found on the Ayamaru plateau, with two specimens collected in 1992 and preserved in a museum. For years they had been classified as belonging to another species. Subsequent observations and photographs of live animals made it possible to finally recognize the correspondence.
This small marsupial is the tiniest of the striped possums and has a very particular anatomical feature: on each hand it has an extremely elongated finger, a perfect tool for extracting insect larvae from the wood of trees. A behavior that recalls, in some ways, that of the aye-aye of Madagascar.
All confirmed sightings come from the low- and medium-altitude rainforests of the Vogelkop Peninsula, an area that is still little studied from a zoological point of view. According to the researchers, it is a distinct species and probably endemic to this region.
Tous ayamaruensis
The second discovery tells an even more curious story. The marsupial Tous ayamaruensis was only known through very ancient fossil remains, especially mandibles and teeth dating back to the beginning of the Holocene. According to science, the species disappeared about six thousand years ago. Then, in 2015, something unexpected happens. A photograph taken in the South Sorong area shows a small arboreal animal with unusual features: a gliding membrane between its limbs, furless ears and a strongly prehensile tail. Those details didn’t match any known New Guinea possum species.
The researchers compared that image with fossils from Vogelkop and similar remains found in Papua New Guinea. The result was surprising: it was not a variant of already known species, but a completely new genus in the evolutionary tree of marsupials, called Tous.
This identification was also possible thanks to the contribution of the indigenous populations. Elders from the Maybrat and Tambrauw communities immediately recognized the animal in the photographs, distinguishing it from other tree-dwelling possums in the region. According to their descriptions, this marsupial lives in the hollows of large trees in lowland forests, forms monogamous pairs and raises only one young per year.
Forests increasingly vulnerable
The survival of these species, however, is far from guaranteed. The forests of Indonesian Papua and Papua New Guinea are changing rapidly due to logging, agricultural expansion, ranching and oil palm plantations.
The testimonies of the local communities tell an important detail: Tous ayamaruensis it lives right in the tallest trees of the forest, those that are cut down first during logging activities. Scientists hypothesize that the species may also be present in other remote areas such as Misool, the Mamberamo basin or the Torricelli mountains, but these areas still await in-depth studies.
A similar situation also concerns Dactylonax kambuayai, considered one of the mammals with the most limited geographical distribution in the whole of New Guinea. The truth is that these forests still remain largely unexplored. This means the possum may be more widespread than you think. Or it could actually live in a tiny, fragile and easily alterable territory.
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