Male northern gastric-brooding frogs call from the water's edge during summer.

The body shape of the northern gastric-brooding frog was very similar to the southern species.

Despite continued efforts to locate the northern gastric-brooding frog it has not been found.

Southern gastric-brooding frogs have been observed feeding on insects from the land and water.

It is similar to the southern gastric-brooding frog's call although deeper, shorter and repeated less often.

The two species of gastric-brooding frog (genus: Rheobatrachus), are found in this family.

It was thought that the declines of the northern gastric-brooding frog during 1984 and 1985 were possibly normal population fluctuations.

The gastric-brooding frog is presumed to be extinct.

Both species of gastric-brooding frogs were very different in appearance and behaviour to other Australian frog species.

Being a largely aquatic species the southern gastric-brooding frog was never recorded more than 4 m (13 ft) from water.

The northern gastric-brooding frog (Rheobatrachus vitellinus) was discovered and described in 1984.

For example, the female gastric-brooding frog (Rheobatrachus sp.)

The common names, "gastric-brooding frog" and "platypus frog", are used to describe the two species.

Streams that the southern gastric-brooding frog were found in were mostly permanent and only ceased to flow during years of very low rainfall.

Populations of Southern Gastric-brooding Frogs were present in logged catchments between 1972 and 1979.

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 southern gastric-brooding frog lived in areas of rainforest, wet sclerophyll forest and riverine gallery open forest.

Winter surveys of sites where southern gastric-brooding frogs were common only recovered two specimens, and it is assumed that they hibernated during the colder months.

The call of the southern gastric-brooding frog has been described as an "eeeehm...eeeehm" with an upward inflection.

The cause for the gastric-brooding frogs' extinction is unknown but habitat loss/degradation, pollution, pathogens, parasites and over collecting may have contributed.

The female gastric-brooding frog (Rheobatrachus spp.)

Among these species are the gastric-brooding frogs of Australia and the golden toad of Costa Rica.

Southern gastric-brooding frog (R. silus)

The southern gastric-brooding frog was a medium sized species of dull colouration, with large protruding eyes positioned close together and a short, blunt snout.

Northern gastric-brooding frog (R. vitellinus)

The gastric-brooding frogs or platypus frogs (Rheobatrachus) were a genus of ground-dwelling frogs native to Queensland in eastern Australia.

In the frog Rheobatrachus, zygotes developed in the stomach.

The Rheobatrachus female swallows her fertilized eggs, which then gestate in her stomach and are regurgitated as tiny froglets six weeks later.

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.

At the meeting, Michael J. Tyler, an associate professor of zoology at University of Adelaide in Australia who has an enviable record for identifying remarkable species, told of the disappearance of the gastric brooding frog named Rheobatrachus silus.