New historical revelations about the famed mastodon suggest humans may not have been involved in their local extinction in the Arctic and Subarctic, contrary to popular belief.
Ancient fossils suggest these extinct elephant relatives lived in the Arctic and Subarctic, even though the species tended to prefer forests and wetlands rich in leafy food, the American Museum of Natural History reported. The animal's teeth, which are designed to strip leaves off twigs and crush them, suggest they would have had trouble living in a frozen region.
New radiocarbon dates suggest the region was only a temporary home for mastodons during a time period when the climate was warmer. The findings also suggest mastodons suffered local extinction tens of millennia before the area was colonized by humans.
"Scientists have been trying to piece together information on these extinctions for decades," said Ross MacPhee, a curator in the Department of Mammalogy at the American Museum of Natural History and a co-author on the paper. "Was is the result of over-hunting by early people in North America? Was it the rapid global warming at the end of the ice age? Did all of these big mammals go out in one dramatic die-off, or were they paced over time and due to a complex set of factors?"
To make their findings the researchers used two different types of radiocarbon dating on a collection of 36 fossil teeth and bones of the American mastodon from Alaska and Yukon. The analysis revealed the fossils are older than previously believed, suggesting mastodons lived in the Arctic and Subarctic for a limited time around 125,000 years ago when temperatures in the region were warmer.
These findings suggest humans may not have played as much of a role in the mastodon's local extinction as was previously believed.
"We're not saying that humans were uninvolved in the megafauna's last stand 10,000 years ago. But by that time, whatever the mastodon population was down to, their range had shrunken mostly to the Great Lakes region," MacPhee said. "That's a very different scenario from saying the human depredations caused universal loss of mastodons across their entire range within the space of a few hundred years, which is the conventional view."
The findings were published in a recent edition of the Proceedings of the National Academy of Sciences.
