 The actual number of species in each group depends on the taxonomic classification followed . The two most common systems are the classification adopted by the website <unk> , University of California , Berkeley and the classification by herpetologist Darrel Frost and the American Museum of Natural History , available as the online reference database " Amphibian Species of the World " . The numbers of species cited above follows Frost and the total number of known amphibian species is over 7 @,@ 000 , of which nearly 90 % are frogs . 
