Tiniest creature with a backbone found BATON ROUGE, La., Jan. 11 (UPI) -- A tiny frog discovered in New Guinea -- so small it can sit in the center of a U.S. dime -- is the world's tiniest vertebrate, U.S. researchers say. Louisiana State University researcher Chris Austin recently discovered two new species of frogs in New Guinea, one of which, Paedophryne amanuensis, is now the world's tiniest known vertebrate at 7.7 millimeters, less than one-third of an inch long. It beats out the previous record holder Paedocypris progenetica, an Indonesian fish averaging more than 8 millimeters, an LSU release said Wednesday. "It was particularly difficult to locate Paedophryne amauensis due to its diminutive size and the males' high pitched insect-like mating call," Austin said. But it's a great find. New Guinea is a hot spot of biodiversity, and everything new we discover there adds another layer to our overall understanding of how biodiversity is generated and maintained. The size limit of vertebrates, or creatures with backbones, is of considerable interest to biologists because little is understood about the functional constraints that come with extreme body size, whether large or small.