The Brazilian flea frog (Brachycephalus pulex) measures only between 7 and 8 millimeters in length, which likely makes it the smallest vertebrate on Earth.
In 2011, Mirco Solé, a researcher at the State University of Santa Cruz in Brazil, discovered the tiny Brazilian flea frog, an amphibian so small that it could comfortably fit on a small coin. The discovery made news headlines in the scientific community, but because of a small available sample, there was simply no way to provide conclusive information regarding the frog’s size. Now, over a decade longer, a team led by the same Mirco Solé has published an extensive study on the elusive frog species that can only be found on two forested hillsides in Bahia, Southern Brazil. It shows that the flea frog is a very likely candidate for the title of ‘world’s smallest vertebrate’.