A species of egg-laying mammal, named after TV naturalist Sir David Attenborough, is not extinct as was previously thought, say scientists.
On a recent visit to Papua's Cyclops Mountains, researchers uncovered burrows and tracks made by the Attenborough's long-beaked echidna.
The species is only known to biologists through a specimen from 1961, which is housed in a museum in the Netherlands.
The team will return to Papua next year to find and photograph the creature.
The month-long expedition by scientists from the Zoological Society of London (ZSL) involved travelling to parts of the mountain range, covered by thick jungle, which had remained unexplored for more than 45 years.
Jonathan Baillie, ZSL's Evolutionarily Distinct and Globally Endangered (Edge) programme manager, said: "We hope that Sir David Attenborough will be delighted to hear that his namesake species is still surviving in the wilds of the Papaun jungle."
The creature had not been recorded since a Dutch botanist collected the only known specimen in the cloud forest of the Cyclops Mountains in 1961.
As a result, it was widely assumed that the shoe box-sized species (Zaglossus attenboroughi) was extinct.
But while the Edge team were in the area, they spoke to local tribespeople who said that they had seen the creature as recently as 2005.
The scientists also discovered "nose pokes", holes in the ground made by the echidnas as they stuck their long noses into soil to feed.
In the programme's blog, Dr Baillie wrote: "Attenborough's echidna is one of five monotremes (egg-laying mammals) that first inhabited the Earth around the time of the dinosaurs.
Parts of the Cyclops Mountains were unexplored for more than 45 years
"This group includes the duck-billed platypus, which helps demonstrate how different these are from all other mammals."
Very little is known about the animal's ecology. It is thought that it is nocturnal, foraging for earthworms among the forest litter, then spending the day resting in shallow burrows or hollow logs.
When threatened, it is believed the solitary living echidna erects its spine-covered coat to protect it from predators.
The team is planning to return to the Cyclops Mountains next year to carry out further research and to also install camera traps in order to photograph a living Attenborough's long-beaked echidna.