Australian megafauna extinctions
Like the North American megafauna extinctions, Australia's disaster coincided with the arrival of humans. In Australia, that occurred about 45,000-50,000 years ago. Just as it is today, the ancient megafauna of Australia were unlike creatures found anywhere else in the world. They included giant marsupial lions (pictured), hippopotamus-sized marsupials called diprotodons (basically giant wombats), lizards that grew to as long as 7 meters, and huge flightless birds related to waterfowl.