If you have a tendency to jump shrieking on to a table when you see a mouse, look away now — a species of rat the size of a cat has been discovered.

The outsized rodent, which has been named the Bosavi woolly rat, is almost 3ft long and weighs in at 3.3lb. It was found trapped inside the crater of Mount Bosavi, an extinct volcano on Papua New Guinea, which has been described as a “lost world” in which scientists have found some 40 previously undiscovered species.

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The rat has dense silvery grey fur and the shape of its teeth suggests it is primarily a vegetarian. It is thought to live in subterranean nests.

The animal was found by a BBC Natural History Unit film crew and Dr Kristofer Helgen, of the Smithsonian Institute in Washington DC.

“This is the one of the world's largest rats,” he said. “It is a true rat, related to the same kind you find in the city sewers, but a heck of a lot bigger.”

Initially, the giant rat was first captured on film by an infrared camera trap, which BBC wildlife cameraman Gordon Buchanan set up in the forest on the slopes of the volcano.

The expedition team recorded the rat rummaging around on the forest floor, and were awed by its size.

Immediately, they suspected it could be a species never before recorded by science, but they needed to see a live animal to be sure.

Then trackers accompanying the team managed to trap a live specimen.

“I had a cat and it was about the same size as this rat,” said Buchanan.

The rat’s coat may help it survive the wet and cold conditions that can occur within the high volcano crater. The location where the rat was discovered lies at an elevation of over 1,000m.

Initial investigations suggest that the rat belongs to the genus Mallomys, which also contains |a handful of other out-sized species.

Some of the other new species found include a fanged frog, a fish that grunts, and a gecko. The fish has been called the henamo grunter because of the noises it makes with its swim bladder.

The first episode of Lost Land of the Volcano, a series on Mount Bosavi, will screen at 9pm tomorrow on BBC One.

Source: The Belfast Telegraph