By Matt Walker
Editor, Earth News
A close look at the giant Varanus bitatawa
A new species of giant lizard has been discovered in the Philippines.
The 2m-long reptile is a monitor lizard, the group to which the world's longest and largest lizards belong.
The monitor, described as spectacular by the scientists who found it, lives in forests covering the Sierra Madre mountains in the north of the country.
The striking reptile has bright yellow, blue and green skin, and survives on a diet of just fruit, yet until now it has escaped the eyes of biologists.
"It is an incredible animal," says Dr Rafe Brown, one of the scientists who describe the new lizard in the journal Biology Letters.
In the journal, the researchers describe how rare it is to find such a large terrestrial animal new to science.
The discovery of the lizard, they say, is of a similar importance to two other large species of so-called "mega-fauna" discovered in recent years: the kipunji (Rungwecebus kipunji), a new genus of monkey found in Africa, and the saola, a Vietnamese forest bovid (Pseudoryx nghetinhensis).
The giant lizard is actually well known to resident Agta and Ilongot tribespeople living in the forests of northern Luzon Island.
The tribespeople regularly hunt the lizard for its meat, a vital source of protein.
Yet scientists were unaware of its existence.
That was until Dr Brown and an international team of colleagues from the US, Philippines and The Netherlands surveyed a series of lizard specimens preserved in museums both within the US and Philippines.
Within these specimens they identified the new species on the basis of its body size, scales, colouration and DNA.
With a main body length approaching 1m, with an additional 1m-long tail, the lizard has dark skin covered by golden yellow spots and flecks.
The new species is strikingly yellow
Its legs are mainly yellow, and its tail striped black and yellow.
In some pictures, the animal also looks to have green or blue scales.
The new species, which is called Varanus bitatawa, is thought to survive on a diet of fruit, making it one of just three species of fruit-eating monitor lizards in the world.
Monitor lizards include the world's most massive lizard, the Komodo dragon (V. komodoensis), which can reach up to 3m-long and weigh up to 90kg.
While not as massive, other species of monitor, such as the Crocodile monitor or Salvadori's monitor (Varanus salvadorii) of New Guinea, can also reach similar lengths.
Why the new massive lizard has remained undiscovered by scientists until now is a mystery, especially as many biologists work in the northern Philippines.
The researchers say it may be because the lizard is naturally reclusive, being a highly secretive animal that never leaves the forest or crosses open country.
It could also be because few scientific expeditions have characterised the reptiles living in the Sierra Madre forests.
The new species of monitor lives at least 150km away from its nearest relative, another lizard called V. olivaceus, which also lives in trees and eats fruit.