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9 ancient man-made environmental catastrophes

By: Bryan Nelson on Nov. 25, 2009, 8:38 a.m.
Australian Megafauna Extinctions

Photo: Peter Trusler/ Australian Postal Corporation

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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.