Australia's megafauna roamed the tropics with first humans but then disappeared

Giant wombats, six-metre-long goannas and the world's largest kangaroos are among the enormous megafauna that inhabited Queensland between 40,000 and 60,000 years ago, but where did they go?

Some scientists have argued that hunting by humans was a possible cause of their extinction, but new evidence suggests it was most likely major climatic and environmental change.