A surprise in science: the "flat-headed frog of Borneo" has lungs after all.
In 2008, a group of researchers dissected 11 specimens of this rare frog and discovered that none of the frogs had a lung system.
After a series of studies, the biologists concluded that the absence of lungs was an adaptation to its habitat, and that this frog breathed through its skin.
Although - as a rule - breathing through the skin doesn't provide amphibians with enough oxygen to do without lungs, so far only one caecilian and a few salamanders were known not to have lungs.
But this frog is different from all the others... especially because it is totally aquatic and lives in cold, fast-flowing streams.
As such, the absence of lungs in this amphibian was not surprising, since this feature would give it advantages, such as making it less buoyant and therefore less susceptible to strong currents.
"Tiny lungs"
On the other hand, it was the discovery that the flat-headed frog from Borneo actually has lungs that really amazed scientists.
This "step backwards" in the biology of this species was revealed this Monday in a study published in Current Biology.
By analyzing two flat-headed frogs from Borneo using a high-resolution micro-CT scanner, it was possible to see a respiratory system supported by small, thin lungs hidden in plain sight.
"Why is there a hole at the bottom of the mouth? It's not supposed to be there," questioned research leader David Blackburn, from the Florida Museum of Natural History (USA), after seeing the slit where the mouth connects to the lungs.
Quoted by New Scientist, the biologist describes the lungs of this rare frog as "very, very tiny", considering their size.
This makes him suspect that this amphibian's lungs may have some kind of even more specific function.
