The gastric-brooding frogs or platypus frogs (Rheobatrachus) were a genus of ground-dwelling frogs native to Queensland in eastern Australia. The genus consisted of only two species, both of which became extinct in the mid-1980s. The genus was unique because it contained the only two known frog species that incubated the prejuvenile stages of their offspring in the stomach of the mother.The combined ranges of the gastric-brooding frogs comprised less than 2,000 square kilometres (770 sq mi).