Raise your hand if you realized there were frogs so translucent you could see their innards? Ok if you actually raised your hand while reading this, kudos, but put it down now. Glass frogs are tiny green organisms whos organs are visible from their underside given the translucent nature of their bellies. There were 148 species of glass frogs, all of which reside in Central and South America. Well make that 149 species of glass frogs now! Recently a new species of glass frog, Hyalinobatrachium dianae, was discovered in in the forested mountains of eastern Costa Rica.
The frog is nocturnal and stands out from other glass frogs because of its long, thin feet and black-and-white eyes. This new species also boasts a distinct call, which frogs produce to attract females. This frogs call is a long tiny whistle similar to the noise produced by insects, which helps explain why this frog went unidentified for so long.
You can view this study in its entirety at the journal of Zootaxa.