SYDNEY – Gigantic animals that once roamed Australia were mostly extinct by the time humans arrived, according to a new study that suggests climate change played the key role in their demise.
For decades, debate has centered on what wiped out megafauna such as the rhinoceros-size, wombatlike Diprotodon, the largest known lizard, and kangaroos so big that scientists are studying whether they could hop.
The study, published Tuesday in the Proceedings of the National Academy of Sciences, said some species were still surviving when people arrived about 45,000 to 50,000 years ago.
But “there is no firm evidence whatsoever that a single human ever killed a single individual megafauna,” the study’s lead author, zoologist Stephen Wroe said. “Not a thing. There is not a single kill site in Australia or (Papua) New Guinea.”