A new giant species of monitor lizard has been discovered in the forests of the Northern Philippines, scientists have said.
The two-metre (6ft 6in) brightly coloured lizard is a secretive, fruit-eating species which was found in the forests of the heavily populated and largely deforested Luzon Island.
The discovery of the monitor lizard was described as an "unprecedented surprise" by scientists documenting the find in the Royal Society Biology Letters journal.
It has become rare to discover previously unknown species of larger animals, they said.
The species (Varanus bitatawa) is restricted to the forests of the central and northern Sierra Madre range, where biologists have conducted relatively few surveys of reptiles and amphibians.
Genetic tests revealed it was a different species from a closely related monitor lizard, from which it is geographically separated by three non-forested river valleys on the island.
The researchers suggested it was a highly secretive species which never left forests to cross open areas.
The scientists said the monitor lizards, which highlighted the "unexplored nature of the Philippines", could become a flagship species for conservation efforts to preserve the remaining forests of the region.