email a friend iconprinter friendly iconExtinct Megafauna
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The debate about megafauna pivots to a great degree on the techniques for dating old bones and the sediments in which they are buried. It's all about timing. If scientists can show that the megafauna died out fairly quickly and that this extinction event happened within a few hundred years, or even a couple thousand years, of the arrival of humans, that's a strong case—even if a purely circumstantial one—that the one thing was the direct result of the other. Flannery contends that islands hold another clue to the mystery. Some species of megafauna survived on Tasmania until 40,000 years ago, when falling sea levels allowed humans to finally reach the island, Flannery says. That parallels the situation of mammoths in Siberia and giant sloths in the Americas, which also found island refuges and survived for thousands of years after the broader extinction spasms on the mainland. This line of argument relies on the lack of fossil evidence for a prolonged human-megafauna overlap. If, however, we find evidence that human beings and megafauna lived side by side for many thousands or tens of thousands of years, then the role of humans in the extinctions would become blurry at best. Certainly it would disprove the notion of a rapid-fire, Martin-Flannery-style blitzkrieg.

As it happens, there is one place in the Australian outback where there may be such evidence. But which extinction hypothesis the evidence supports is still in question.

Cuddie Springs is an ephemeral lake in north-central New South Wales. Way back in 1878 a farmer sinking a well turned up megafauna bones at Cuddie. Today the person most vocal about the site, a woman who has spent her career excavating and interpreting its fossils, is Judith Field, an archaeologist at the University of Sydney.

In 1991, working as a graduate student at the site, Field discovered megafauna bones directly adjacent to stone tools—a headline-making find. She says there are two layers showing the association, one about 30,000 years old, the other 35,000 years old. If that dating is accurate, it would mean humans and megafauna coexisted in Australia for something like 20,000 years.

"What Cuddie Springs demonstrates is that you have an extended overlap of humans and megafauna," Field says.

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