Asian News International: A new research has suggested that humans, not climate change, may have caused the mass extinction of Australia’s giant animals, tens of thousands of years ago. Scientists have long argued over what killed off about 50 species of animals weighing more than 45 kilograms, including the gigantic kangaroo, Procoptodon, and the two-tonne wombat-like marsupial Diprotodon, late in the Pleistocene epoch, which stretched from 2.6 million until about 12,000 years ago. Some have proposed …