"New evidence involving the ancient poop of some of the huge and astonishing creatures that once roamed Australia indicates the primary cause of their extinction around 45,000 years ago was likely a result of humans, not climate change ," reports Phys.org. schwit1 quotes their report on new analysis of a prehistoric sediment core from the Indian Ocean off the coast of Australia.The article adds that last year Miller also identified the first direct evidence that humans preyed on Australian megafauna -- burned eggshells from a 400-pound bird.