A team of Australian scientists has discovered a curious "chocolate frog" tree frog in the lowland rainforests of New Guinea. Tree frogs are known for their green skin - but due to its brown colouring, researchers named it "chocolate frog" - and the name stuck. "The closest known relative of Litoria mira is the Australian green tree frog. The two species look similar except one is usually green, while the new species usually has a lovely chocolate colouring," Paul Oliver of the Centre for Planetary Health and Food Security and Queensland Museum, who described the discovery in a co-authored paper in the journal the Australian Journal of Zoology said in a statement.