The flea toad, also known as Brachycephalus pulex, is a tiny amphibian discovered in Brazil. It may be the world’s smallest vertebrate, with adult males being only slightly over 7 millimeters long. This frog was first described by scientists in 2011 and is smaller than the previous record holder for the world’s smallest vertebrate. Despite being small, only a limited number of flea toad specimens have been collected from its habitat on forested hilltops in southern Bahia, Brazil. To verify the species’ maturity and sex, the gonads of the frogs were examined and it was found that only males have vocal slits.
The study also highlighted how small the flea toads can get compared to other mini frogs, with the smallest specimen in the study being only 6.45 millimeters long. At such small scales, frogs tend to develop unusual anatomical quirks, such as losing toes or having underdeveloped ears. The researchers also suggested that there may be even smaller vertebrates yet to be discovered, leading to the possibility of the next record-holder being another small frog or perhaps a parasitic male of a deep-sea anglerfish. The flea toad has been seen perched on a Brazilian real coin which has a diameter of 27 millimeters making it one of the smallest creatures on earth .