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The Biggest Losers

An artist’s reconstruction of some extinct Australian animals (clockwise from top left): Genyornis newtoni, Diprotodon optatum, Procoptodon goliah, the thylacine (which survived in Tasmania until 1936), Thylacoleo carnifex (the biggest marsupial carnivore) and the giant lizard Megalania prisca. Image courtesy of the artist Peter Trusler and Australia Post

An artist’s reconstruction of some extinct Australian animals (clockwise from top left): Genyornis newtoni, Diprotodon optatum, Procoptodon goliah, the thylacine (which survived in Tasmania until 1936), Thylacoleo carnifex (the biggest marsupial carnivore) and the giant lizard Megalania prisca. Image courtesy of the artist Peter Trusler and Australia Post

By Richard “Bert” Roberts & Barry Brook

New evidence tightens the noose on humans as the decisive factor in the extinction of the last of the megafauna in Australia and North America.

Prof Richard ‘Bert’ Roberts is an Australian Research Council Professorial Fellow in the Centre for Archaeological Science, School of Earth and Environmental Sciences at the University of Wollongong. Prof Barry Brook is the Sir Hubert Wilkins Chair of Climate Change in The Environment Institute at the University of Adelaide.

The full text of this article can be purchased from Informit.

Despite being separated by more than 11,000 km of ocean, the prehistoric heritage of Australia and North America share much in common. Both continents were once home to a diverse range of giant animals – the “megafauna” – that suffered a mass extinction some time in the geologically recent past, and the first humans to colonise both land masses were members of our species (Homo sapiens), an entirely new predator to which the megafauna had to adapt or die.

And die they did. Around 90% of large-bodied animals disappeared from Australia, such as the rhino-sized Diprotodon optatum (a relative of the wombat and the largest marsupial ever to roam this continent) and more than 40 species of kangaroo, including the world’s largest-ever hopping animal, Procoptodon goliah, which stood 2–3 metres tall and weighed 230 kg.

North America followed a similar storyline, losing more than half of its big mammals, including all 10 species weighing over a tonne, with the iconic Ice Age woolly mammoth, sabre-toothed cats and ground sloths among the casualties.

Some obvious questions spring to mind. When did these animals, most of which were herbivores, finally perish? What relegated them to the pages of prehistory? Has a consensus finally been reached on the drivers of their extinction?

Several new studies add further weight to the growing body of evidence...

The full text of this article can be purchased from Informit.