This minute fellow — the one being dwarfed by a US dime — just earned the distinction for not only being the smallest known frog species, but also the smallest known species of vertebrate.
The Paedophryne amauensis is native to Papua New Guinea and measures a scant seven millimeters from nose to tail. It beat out a slightly larger related species, the Brazilian gold frog, which also was awarded the "World's Smallest" title upon its discovery in December of last year.
The frogs live among the tropical forest's heavy leaf litter in low-lying parts of the island and prey on minuscule insects that are often ignored by larger amphibians. In fact, their calls have evolved to be strikingly similar to the chirps of insects.
According to the expedition's leader, Chris Austin from Louisiana State University in Baton Rouge, USA, catching the frogs was easier said than done,
"It was night, these things are incredibly small; so what we did after several frustrating attempts was to grab a whole handful of leaf litter and throw it inside a clear plastic bag. When we did so, we saw these incredibly tiny frogs hopping around."
This evolutionary niche does have its drawbacks, however. Being so tiny, the frogs are often preyed upon by larger insects, like scorpions, that otherwise couldn't take a frog. [BBC News via Neatorama]