a total of three extant genera are placed in the family crocodylidae, including a total of 15 species, including the desert crocodile, which is now accepted as a true species rather than a subspecies of the nile crocodile. recent studies suggest the dwarf crocodile, "osteolaemus tetraspis", is not a single, but two or even three species, and that the slender-snouted crocodile is two species. if so, the species count of extant crocodiles would be 18 or 19, putting the extant crocodylian species to a total of 28 or 29 instead of 25.