Cyclorana

Cyclorana is a genus of frogs in the family Hylidae (tree frogs), whose members are found in most of Australia. It was formerly considered a separate genus, but reclassified following a major revision by Frost et al. in 2006. Although classified as tree frogs, this genus is entirely terrestrial and lacks toe pads, which their arboreal relatives use for climbing. They are classified as tree frogs because of their similarity to the other members of the genus Litoria in terms of skeletal structure and physical resemblance of the tadpoles. This genus inhabits some of the most arid zones of Australia. Some species burrow underground and remain dormant for more than 5 years to survive drought conditions. They can store large amounts of water in their bladders, and form a 'cocoon' around themselves to reduce loss of water, so are often called 'water-holding frogs'. They only return to the surface to breed and eat, and normally only after heavy summer rains. Eggs are normally laid in temporary water, and tadpoles develop quickly to metamorphose before the water completely evaporates.