The knife-footed frog (Ranoidea cultripes) is a species of burrowing frog in the family Hylidae. It is endemic to Australia, where it is found over a wide area in the north of the continent. Description The knife-footed frog is of moderate to stout stature and can be grey to grey-brown to olive-brown or green in colouration with irregular patches. A pale thin stripe starts at the tip of its snout and extends lengthways along its spine. Behind the eyes it has a broad pale bar. A streak of colouration that is faint to strong extends from the corner of the eye down to merge with side patterns. The upper lip is brown along its edge with flecks of white. The back of the thighs and groin are light grey-brown in colouration with white mottling. The underside is mostly white. The back of the knife-footed frog is smooth or slightly warty. Both sexes have a coarsely granular belly, but males have a finely granular throat whereas female throats are smooth. Its fingers are unwebbed and about one-third to half of its toes are webbed,. Neither its fingers nor toes have discs. Females (38–43 mm) are slightly larger than males (38–41 mm). The knife-footed frog shares its range with two similar species – the rough frog (Cyclorana verrucosa) and Main's frog (Cyclorana maini). The knife-footed frog can be distinguished from the rough frog by the smoother skin on its back where the rough frog has slightly to extremely warty skin. The knife-footed frog also lacks the dark lateral head stripe of Main's frog. Taxonomy The species was initially described by Parker in 1940 as Cyclorana cultripes. Recent reclassifications of the genus Cyclorana into Dryopsophus and then Ranoidea have not yet been accepted by all taxonomic authorities. Other common names for this species include olive water-holding frog, desert collared-frog, and grassland collared frog. Distribution The knife-footed frog is found from the Kimberley region in Western Australia, through the Northern Territory and western Queensland to north-western New South Wales and north-eastern South Australia. It prefers clay soils and typically inhabits open grassland, sparsely wooded areas, floodplains and cleared agricultural areas. As a burrowing frog, the knife-footed frog emerges to the surface after heavy rain in large numbers to feed and breed in ponds, creeks, pools, roadside drainage ditches and temporary claypans. Ecology Behaviour The knife-footed frog is a predator, opportunistically consuming invertebrates. It has