Singapore- Scientists have discovered a frog without lungs that breathes through its skin in a find making evolutionary history, a published report said Thursday.

The aquatic frog was found in August in two mountain rivers in Indonesia's Kalimantan, The Straits Times said. The frog is called "Barbie," short for its scientific name, Barbourula kalimantanensis.

The frog absorbs dissolved oxygen from the water through its skin, said evolutionary biologist David Bickford of the National University of Singapore, who found the frog with eight other researchers.

It is only the fourth vertebrate known to breathe without lungs. The others - also amphibians - are two groups of salamanders and a single species of the earthworm-like caecilians.

Bickford said that he hopes the find will spur more research into South-East Asian wildlife, much of which is threatened by development and other losses of habitat.

"The discovery is not so much a surprise to the scientific community, as much as a surprise that it has taken so long to find it," Bickford was quoted as saying.

A fisherman first took a lungless frog to an Indonesian scientist in 1978. The specimens that the NUS team discovered were more than 50 kilometres from where the first was spotted.

The frogs' original wading grounds had become gold-mining and logging territory.

"Frogs are a clear indication of how degraded our environment is," Bickford told the newspaper. (dpa)