The little guide does oust another New Guinea frog which had only claimed the title in December. The newest frog species is also being said as the world's smallest vertebrate. Although it's the more correctly the smallest free living vertebrate, as 6.2 millimeter meal anglerfish spends its life buried in the body of its mate. Finding the little frog was no smaller achievement. Besides being tiny, the high pitch mating calls researchers followed, sound more insect to amphibian. Tiny vertebrates reveal changes that make many * possible.For instance, some of the digits on the frogs' feet have disappeared, and their skulls developed differently than those of larger critters. So we celebrate the world's smallest frog and free living vertebrate, until the next one is discovered.