for National Geographic News
Humans, not climate change, were responsible for the extinction of giant "kangaroos" and other massive marsupials in Tasmania more than 40,000 years ago, according to new research.
Hunting on the Australian island exterminated several prehistoric animals, including the kangaroo-like beasts, marsupial "hippopotamuses," and leopard-like cats, a team of scientists announced. (Learn more about the red kangaroos and hippos of today.)
The giant kangaroo-like Protemnon anak, a long-necked leaf browser, survived on Tasmania until at least 41,000 years ago—much later than previously believed and up to 2,000 years after the first human settlers are believed to have arrived—according to new radiocarbon and luminescence dating of fossils, some of which were accidentally found by cavers.
Previous studies had concluded that Tasmania's giant beasts had already disappeared by the time humans crossed a temporary land bridge to the island 43,000 years ago. These studies blamed the extinctions on climate change—including the last ice age—instead.
The new findings appear this week in the journal Proceedings of the National Academy of Sciences.
Six other giant prehistoric Tasmanian species survived the climate change of the time and likely existed until the arrival of humans, although the animals' remains were not specifically dated to the time humans are believed to have been on the island, according to the study.
The other species include "three kangaroos that would have been in the 220-pound (100-kilogram) size range," said team member Tim Flannery of Australia's Macquarie University.
"There was a marsupial leopard, which was probably 100 to 220 pounds [50 to 100 kilograms] in weight," he said.
"There was also what I would call a marsupial ground sloth that weighed several hundred kilograms at least, and perhaps in excess of 1,000 pounds (500 kilogram).
"And then a thing that you might want to call a marsupial hippopotamus, or a marsupial tapir, which would have weighed about 1,000 pounds (500 kilograms)."
Studies have found that Tasmania and present-day Victoria state, on the nearby Australian mainland, shared a similar climate back then, Flannery said
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