Two species of marsupials that were thought to have gone extinct at least 6,000 years ago have been found on the island of New Guinea.
The discovery was far from quick, with the first clues to the marsupials appearing in 1999 and requiring ample photographic evidence to confirm. But 27 years later, scientists are now certain that the ringtail glider (Tou’s ayamaruensis) and the pygmy long-toed possum (Dactylonax kambuayai) lives in the remote rainforests of the Vogelkop Peninsula in Papuan Indonesia.
Marsupials are mammals with a distinctive pouch to hold newborns until they are fully developed. The pygmy long-fingered possum and the ring-tailed glider were previously known to scientists only from fossils in Australia dating to last ice age and the first phase of the early Holocene epoch, which is the current period of geologic time.
The pygmy long-fingered possum is a striped marsupial with one digit on each hand that is twice as long as the second longest finger. The ringtail glider is a relative of Australia’s three larger gliders (Petauroides) species, which are named for their ability to soar through forest canopies by means of furry membranes which extends from the elbows to the ankles. The ring-tailed glider is smaller than its Australian cousins and has unfurred ears, as well as a tail adapted for grasping and wrapping around objects such as branches.
Pygmy long-fingered possums and ring-tailed gliders are what scientists call “Lazarus taxa,” meaning they are animals that disappear from the fossil record and appear to be extinct for a long period of time before reappearing as living species. Their recent discovery was made possible thanks to indigenous communities in Papuan Indonesia who helped Flannery and his colleagues track down the animals. Specifically, the researchers collaborated with local elders from the Tambrauw and Maybrat clans.
“The discovery of a Lazarus taxon, although thought to have become extinct recently, is an exceptional discovery,” said Flannery. “But the discovery of two species, thought to have been extinct for thousands of years, is remarkable.”
Some local indigenous groups consider the ring-tailed glider to be sacred and deserving of the highest protection, which may help explain why the species has remained hidden, New Scientist reported.
Ringtail gliders form lifelong pair bonds and raise only one young per year. Like larger gliders, they nest in tree holes, making them extremely vulnerable to logging.
The long-fingered pygmy also faces threats from logging. The ears may be adapted to detect low-frequency sounds, including the noise of wood-dwelling beetle larvae, which possums dig out of rotting wood with their fingers to eat, Flannery told New Scientist.
Much is still unknown about the specific area and ecological needs of each species. The exact locations where they were found are kept secret to prevent wildlife traders from targeting them. What is known so far about the marsupials was published on 6 March in two peer reviewed studies in the journal Records of the Australian Museum.
“The findings underscore the critical importance of conserving these unique bioregions and the value of collaborative research to uncover and protect hidden biodiversity,” Flannery said in the statement.
