Lungless Frog

A rare aquatic frog, Barbourula kalimantanensis, from Borneo has been confirmed as the only known (so far) lungless frog. The frog "lives in cold, fast-flowing water, they noted, so loss of lungs might be an adaptation to a combination of factors: a higher oxygen environment, the species’s presumed low metabolic rate, severe flattening of their bodies that increases the surface area of their skin, and selection for negative buoyancy—meaning that the frogs would rather sink than float." (Eurekalert)