This frog which can puff it's body up to twice it's size is another of the new species discovered by the team.Click to see giant rat and team : http://news.bbc.co.uk/earth/hi/earth_news/newsid_8215000/8215144.stm
"This is one of the world's largest rats. It is a true rat, the same kind you find in the city sewers," says Dr Kristofer Helgen, a mammalogist based at the Smithsonian National Museum of Natural History who accompanied the BBC expedition team. 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 from the BBC Natural History Unit 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," says Buchanan.
The trapped rat measured 82cm in length from its nose to its tail, and weighed approximately 1.5kg. It had a silver-brown coat of thick long fur, which the scientists who examined it believe 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 the rat belongs to the genus Mallomys, which contains a handful of other out-sized species. It has provisionally been called the Bosavi woolly rat, while its scientific name has yet to be agreed upon. Mount Bosavi, where the new rat was found, is an extinct volcano that lies deep in the remote Southern Highlands of Papua New Guinea. The expedition team entered the crater to explore pristine forest, where few humans have set foot.
Even members of the Kasua tribe, who acted as trackers for the expedition, live outside the crater, which is 4km wide and has walls up to 1km high, trapping the creatures that live within. The island which includes Papua New Guinea and New Guinea is famous for the number and diversity of the rats and mice that live there. The giant volcano is so inaccessible, no humans live within it's walls and so it has become a 'Lost World' where an amazing array of exotic fauna has developed and thrived.Steve Greenwood, series producer for Lost Land of the Volcano, said that after scaling the volcano's 2,800m summit, the team was rewarded by finding a wealth of new creatures.
They suspect they may have discovered up to 40 new species, including approximately 16 species of frog, one species of gecko, at least three new species of fish, 20 species of insect and spider and one new species of bat."Highlights include a camouflaged gecko, a fanged frog and a fish called the Henamo Grunter, so named because it makes grunting noises from its swim bladder," Mr Greenwood said.
They also found a Doria's tree kangaroo, which wandered close to camp. Tree kangaroos are notoriously wary of people, but this particular one seemed nonplussed by the team's presence, the BBC reports. As well as large creatures, the team also encountered a variety of odd-looking insects including bizarre spiders. On one trip outside the crater, they found a giant caterpillar surrounded by hundreds of smaller maggots.
With the help of local trackers, the team descended into the crater and spent two weeks documenting the animals they found there. The trip was planned over months, because of the difficulties of reaching the area. The teams goal is to prove the rain forest is worthy of preserving. The forest is cut back about three and a half percent every year.
