Fairbanks, AK - American mastodons are much older than scientists previously thought. That’s according to new data recently published in the Proceedings of the National Academy of Sciences.
American mastodons, the extinct and much hairier relatives of today’s elephants that once roamed the Arctic and sub-arctic tundra, are often mistaken for wooly mammoths. “A mammoth and a mastodon can be immediately distinguished on the basis of their teeth, their big cheek teeth," said Pat Druckenmiller. He is the curator of Earth Science at the University of Alaska Museum of the North. “Both of them have really big teeth. The difference is the mammoth has a molar and the top grinding surface looks like a washboard," Druckenmiller explained. "It’s low with little ridges. It’s great for eating grass. Mastodons have these teeth with big giant bumps or cusps that don’t look anything like washboard.”
He held up a gigantic lumpy, gray and brown specimen. It’s larger than a grapefruit, and kind of rectangular shaped with a series of pointy ridges on one end. “I’m not really sure what the best way to describe that is," he laughed. "In side view it looks like a whole bunch of mountains poking up and that tooth type with these big cusps is really ideal for eating things like leaves and twigs.”
The mastodon’s diet is what raised the eyebrows of Druckenmiller’s colleague Grant Zazula at the Yukon Paleontology Program in Canada. At the height of the last ice age - between 75 and 10 thousand years ago - in Alaska and the Yukon - the landscape looked like a grassland steppe: it’s the perfect menu for mammoths. “He resampled all this material and re-dated it using some new techniques because what it turns out is people in the past when they found these teeth and bones, they put glue on them and stuff and that glue can mess up the dates," said Druckenmiller. "In fact, it gives you a date that’s too young. In other words, during a time when we wouldn’t expect them to be here.”
Mastodons didn’t eat grass. Instead, they would have munched on plants from a forest. That’s an ecosystem that existed at a much warmer time in the region, long before the last ice age. “So, they were here prior to 50 thousand, probably more like prior to 75 thousand years when it was a relatively warm period when we know that there were in fact more forested settings in Interior Alaska and actually the North Slope,” he said.
The new dates also mean the mastodon roamed the Arctic long before humans arrived in North America That happened roughly 16 thousand years ago. “All of the ice age mammals – some people say a lot of them began to go extinct at the end of the last ice age because humans effectively were a wave of predators," Druckenmiller explained. "For at the least the story of the Mastodon, we now know for what we call Beringia, Alaska, parts of Yukon and over into northeastern Asia, they al died out before there were humans here humans could not have been part of the story and that’s pretty interesting.”
The study made use of 36 mastodon specimens, many of which are housed at the University of Alaska Museum of the North. They were collected in the Fairbanks area, on the North Slope and in the Yukon. Funding for the project is provided by the Yukon Government.