Amphibia and reptiles

Australia has four families of native frogs and one introduced toad, the Cane Toad. In a disastrous decision in 1935, the Cane Toad was introduced to Australia in a failed attempt to control pests in sugarcane crops, and has since become a devastating pest. The Myobatrachidae, or southern frogs, are Australia's largest froup of frogs, with 120 species from 21 genera. A notable member of this group is the colourful and endangered Corroboree frog.

The tree frogs, from family Hylidae are common in high rainfall areas on the north and east coasts; there are 77 Australian species from three genera. The 18 species from two genera of the Microhylidae frogs are restricted to the rainforests; the smallest species, the Scanty Frog, is from this family. There is a single species from the world's dominant frog group, family Ranidae—the Australian Wood Frog—which occurs in the Queensland rainforests. As elsewhere, there has been a precipitous decline in Australia's frog populations in recent years; although the full reasons for the decline are uncertain, it can be at least partly attributed to the fatal amphibian fungal disease chytridiomycosis.

Australia has both saltwater and freshwater crocodiles. The Saltwater Crocodile, known colloquially as the 'salty', is the largest living crocodile species; reaching up to 7 m and weighing up to 1,000 kg, they can and do kill humans. They live on the coast and in the freshwater rivers and

wetlands of northern Australia, and they are farmed for their meat and leather. Freshwater Crocodiles are found only in the freshwater waterways of Northern Australia, and are not considered dangerous to humans.

The Australian coast is visited by six species of sea turtle, the Flatback, Green Sea, Hawksbill, Olive Ridley, Loggerhead and the Leatherback Sea Turtles; all are protected in Australian waters. There are 29 species of Australian freshwater turtles, from eight genera of family Chelidae. The Australasian Pig-Nose Turtle is the only Australian member of that family. Australia and Antarctica are the only continents without any living species of land tortoise.

There are more lizards in Australia than anywhere else in the world, with representatives of five families. There are 114 species in 18 genera of gecko, found throughout the Australian continent, but not in Tasmania. The Pygopodidae is a family of limbless snake- or worm-like lizards endemic to the Australian region; of the 34 species from eight genera, only one species does not occur in Australia. The Agamidae or Dragon lizards are represented by 66 species in 13 genera, including the Thorny Devil, Bearded Dragon and Frill-necked Lizard. There are 26 species of monitor lizard, family Varanidae, in Australia, where they are commonly known as goannas. The largest Australian monitor is the Perentie, which can reach up to 2 m in length. There are 389 species of skink from 38 genera, comprising about 50% of the total Australian lizard fauna; this group includes the blue-tongued lizards.

Australian snakes come from seven families. Australia is the only continent where venomous snakes outnumber their non-venomous cousins. The most venomous species include the Fierce Snake, Eastern Brown Snake, Taipan and Eastern Tiger Snake from the family Elapidae. Of the 200 species of elapid, 86 are found only in Australia. Thirty-three sea snakes from family Hydrophiidae inhabit Australia's northern waters; many are extremely venomous. Two species of sea snake from the Acrochordidae also occur in Australian waters. Australia has only 11 species from the world's most significant snake family Colubridae; none is endemic, and they are considered to be a relatively recent arrival from Asia. There are 15 species of boa, and 31 species of insectivorous blind snake.