BBC discovers a giant rat that is as big as a cat

If you have a tendency to jump skrieking 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 3 feet long and weighs in at 3.3lbs. 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.

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."

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.