Scientists discover fearless giant rat

The 1.4kg giant rat. Photo / Bruce M Beehler Conservation International

Two species of mammals that may be new to science have been discovered in a remote region of Indonesia which has been labelled a "lost world" because much of much of it remains virtually unexplored and uninhabited.

The pygmy possum and giant rat were found during a scientific expedition earlier this year to the Foja Mountains of western New Guinea - a pristine wilderness which has already revealed a rich array of novel flora and fauna.

The tree-dwelling pygmy possum belongs to the Cercartetus group of marsupials and is one of the world's smallest.

The giant rat is about the size of a cat and has been classified as belonging to the Mallomys genus of woolly rodents.

"The giant rat is about five times the size of a typical city rat," said Kristofer Helgen, a scientist with the Smithsonian Institution in Washington.

"With no fear of humans, it apparently came into the camp several times during the trip."

The Foja wilderness is part of the great Mamberamo Basin and is one of the least disturbed regions in the Asia-Pacific region.

It has the largest area of tropical forest without roads or trails.

Its isolation is helped by its steep mountainous slopes and difficult terrain.

Bruce Beehler, the vice-president of the Conservation International group, which is based in Washington, said that the latest expedition had continued to make the sort of astonishing discoveries that were documented in earlier field trips to the region, which covers an area of about 300,000 hectares.

"It is comforting to know that there is a place on Earth so isolated it remains the absolute realm of wild nature," he added.

"We were pleased to see this little piece of Eden remains as pristine and enchanting as it was when we first visited." Scientists are studying the pygmy possum and the giant rat in more detail to ascertain whether they are genuinely new species and, if so, where they fit in with their closest relatives.

It is rare for scientists to find new species of large mammals, although a dozen or so have been found over the past couple of decades in south-east Asia.

The Foja Mountains rise to about 2,200 metres and are largely uninhabited.