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A rock art painting at a site rediscovered two years ago in southwest Arnhem Land could be a depiction of Genyornis, an extinct megafauna species similar to the Emu, but three times as tall. The painting's detail of the bird's parrot-like beak - a characteristic feature of the Genyornis that is utterly unlike its Emu ancestor - is a key piece of the evidence. If the painting is indeed a representation of the largest bird that ever lived, it should be about 40,000 years old, when Genyornis was made extinct as Aboriginal peoples progressively cleared land by setting fires. This would make the painting Australia's oldest, as well as the world's oldest painting found outside a cave.
Other Arnhem Land rock art galleries have yielded images of a variety of extinct species, including Palorchestes, a large Tapir-like animal, and Thylacenes, the "Tasmanian Tiger." Images found last year in the Kimberly, in Western Australia, are now accepted by scientists to be depictions of Thylacoleo carnifexin, an extinct marsupial lion.
The relatively unprotected location of the Arnhem Land painting has generated controversy regarding its date and subject matter, however. Gavin Prideaux, a paleontologist at Flinders University, believes that the image probably represents the extinct megafauna species, but Robert Bedarnik of the International Federation of Rock Art Organizations questions the existence of any painting over 10,000 years old located anywhere other than the protected environment of a cave surface.
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Either way, the discovery gives the evolving tradition of Arnhem Land painting a new depth and excitement.