|Common Name||Platypus Frog|
|Range||Queensland in Eastern Australia.|
|Species|| R. silus|
The Gastric-brooding frog, or platypus frog, (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). Both species were associated with creek systems in rainforests at elevations of between 350 metres (1,150 ft) and 1,400 metres (4,600 ft). The causes of the gastric-brooding frogs' extinction are not clearly understood, but habitat loss and degradation, pollution, and some diseases may have contributed.
The assignment of the genus to a taxonomic family is hotly debated. Some biologists class them within Myobatrachidae under the subfamily Rheobatrachinae, but others place them in their own family, Rheobatrachidae.
Scientists at the University of New South Wales announced in March 2013 that the frog would be the subject of a cloning attempt, referred to as the ”Lazarus Project”, to resurrect the species. Embryos were successfully cloned.
The Gastric-brooding frog was first described in 1973 by David Liem and since has not undergone any scientific classification changes; however the placement of this genus within a family has been controversial. It has been placed in a distinct subfamily of Myobatrachidae, Rheobatrachinae, in a separate family, Rheobatrachidae, placed as the sister taxon of Limnodynastinae and Rheobatrachinae has been synonymized with Limnodynastinae. In 2006, D. R. Frost and colleagues found Rheobatrachus, on the basis of molecular evidence, to be the sister taxon of Mixophyes and placed it within Myobatrachidae.
Both species of gastric-brooding frogs were very different in appearance and behaviour to other Australian frog species. Their large protruding eyes and short, blunt snout along with complete webbing and slimy bodies differentiated them from all other Australian frogs. The largely aquatic behaviour exhibited by both species was only shared (in Australia) with the Dahl's Aquatic Frog and their ability to raise their young in the mother's stomach was unique among all frogs.
The common names, "gastric-brooding frog" and "platypus frog", are used to describe the two species. "Gastric-brooding" described the unique way the female raised the young and "platypus" describes their largely aquatic nature.
Southern Gastric-brooding Frog (Rheobatrachus silus)
Both species are listed as Extinct under both the IUCN Red List and under Australia's Environment Protection and Biodiversity Conservation Act 1999; however, they are still listed as Endangered under Queensland's Nature Conservation Act 1992.
In March 2013, Australian scientists successfully created a living embryo from non-living preserved genetic material. These scientists from the University of New South Wales hope to continue using somatic-cell nuclear transfer methods to produce an embryo that can survive to the tadpole stage. "We do expect to get this guy hopping again," says UNSW researcher Mike Archer.