A giant, toothy rat and a tiny possum, thought to be a new species of mammal, have been found by conservationists during an expedition to a mountainous rainforest known as Indonesia's “lost world”. The animals were captured during a night foray into the undergrowth on the Foja mountain range in western New Guinea.

The discoveries add to more than 40 species that have recently been documented in the region, which rises to 2,200 metres (7,218ft) above sea level.

The mountain range's cloud forest environment is home to such a wide variety of species it has been dubbed the Garden of Eden by conservationists.

Last year, the same team reported 20 new frog species, four new butterfly species and five new forest palms during a month-long expedition to the area.

Rare golden-mantled tree kangaroos, previously thought to live only in neighbouring Papua New Guinea, were also spotted in the area.

“When we came back from the first trip we knew we'd only scratched the surface,” said Bruce Beehler of Conservation International. “Once you get up into the cloud forest it's an isolated environment.”
The conservationists returned to the site earlier this year and teamed up with leaders of the indigenous Papasena people to explore the higher reaches of the mountains.

The giant rat, about five times the size of a typical city rat, was spotted one evening wandering towards the team's camp at an altitude of 1,650 metres. Later in the expedition, the leader of the Papasena returned from an evening's search, having shot one of the rats with a bow and arrow.

The animal weighed about 1.4 kg and is thought to have survived on fruit, seeds, and leaves. “It's not the largest rat in the world, but it's an ugly beast. It has huge incisors,” said Beehler.

The pygmy possum, believed to be one of the world's smallest marsupials, belongs to the genus Cercarteus. It was captured at night by hand after it was spotted sitting on a sapling.

Conservationists will extract DNA from the specimens and compare measurements of their skulls and dentition to confirm they are new species.

The Guardian