According to new research in the journal Zoologica Scripta , the Brachycephalus pulex frog may be the world's smallest frog and smallest vertebrate, IFL Science reported on February 14. The B. pulex frog is smaller than a pea, with males averaging just over 7 mm long and females just over 8 mm long.

This tiny amphibian is endemic to southern Bahia, Brazil, and was first described in 2011. However, few studies have been done and its adult state has not been confirmed.

“Identifying the world’s smallest frog is not easy,” the team said. In the new study, they measured the body lengths of 46 B. pulex frogs and compared them to other small frog species, including the previously confirmed world record holder, Paedophryne amauensis.

The team found that some male B. pulex individuals were smaller than known P. amauensis individuals. However, data on P. amanuensis females were scarce, so they compared the size of female B. pulex frogs to the second-smallest species, P. verrucosa , and continued to find B. pulex to be smaller.

The team also assessed the frogs' maturity by examining their gonads and confirming that they were adults. With all of this data, they concluded that B. pulex could claim the title of the world's smallest frog and vertebrate, closely followed by P. amanuensis from Papua New Guinea.

"This is very clear. These are actually the smallest frogs in the world, which is amazing," said Dr Mark Scherz at the Natural History Museum of Denmark.

Thu Thao (According to IFL Science )