https://phys.org/news/2017-01-humans-climate-australian-megafauna.html

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.

The Australian collection of megafauna some 50,000 years ago included
1,000-pound kangaroos, 2-ton wombats, 25-foot-long lizards, 400-pound flightless
birds, 300-pound marsupial lions and Volkswagen-sized tortoises. More than 85
percent of Australia's mammals, birds and reptiles weighing over 100 pounds went
extinct shortly after the arrival of the first humans, said Miller.

In 2016 Miller used burned eggshells of the 400-pound bird, Genyornis, as the
first direct evidence that humans actually preyed on the Australian megafauna.