Science

Mastodon research highlights fascinating lives of mammoths' lesser-known cousins

Mastodons may not make headlines as much as woolly mammoths. But recent research reveals they were every bit as fascinating as their better-known cousins and more important to prehistoric humans in many parts of Canada and the U.S.

'Mammoths and Mastodons: Titans of the Ice Age' exhibit visits Toronto and Victoria this year

A model of an American mastadon is part of the travelling exhibit Mammoths and Mastadons: Titans of the Ice Age, which is currently at the Ontario Science Centre in Toronto. (Emily Chung/CBC)

Many of us imagine a time when prehistoric human hunters stalked herds of woolly mammoths across the Canadian tundra. But in much of Canada, toward the end of the last ice age, mammoths were rare and their cousins, the mastodons, ruled.

While mastodons haven't made headlines as often as mammoths in recent years, research reveals they were every bit as fascinating and perhaps even more important to prehistoric humans throughout Canada and the U.S.

"These animals really were critical for human survival at this time," said Daniel Fisher, a mammoth and mastodon researcher at the University of Michigan and curator of the touring scientific exhibition, Mammoths and Mastodons: Titans of the Ice Age, which is currently at the Ontario Science Centre in Toronto.

Bones and tusks reveal that male mastodons were kicked out of their matriarchal family groups around age 12 and that they fought with other males. (Emily Chung/CBC)

The exhibition, created by the Field Museum in Chicago, features fossils and life-sized reconstructions of mastodons and lesser-known species, like the gargantuan Columbian mammoth, along with interactive displays revealing how these animals lived until their extinction around 10,000 years ago, near the end of the last ice age.

Among them is a miniature scene of prehistoric hunters killing a mammoth and stashing its meat in cold water ponds in what is now Missouri, based on research by paleontologists like Fisher.

"They were the abundant animals at that time," Fisher said. "Humans were able to kill them and humans were able to store them, thereby gaining extended access to those resources for periods of months without having to carry this all around with them, without having to defend those resources from other predators in the landscape."

Ontario was mastodon-land

A map of Ontario posted outside the exhibit shows dozens of sites where mastodon remains have been found in the southern half of the province. There are fewer mammoth remains, mostly farther north.

In this map at the Ontario Science Centre, green circles show where mastodon remains have been found and blue circles show where mammoth remains have been found in Ontario. Mastodon remains are far more common, especially in southern Ontario. (Jefferson Darrell/Ontario Science Centre)

Fisher says that has to do with the nature of the local vegetation.

Mastodon teeth evolved for eating leaves, bark and twigs, perfect for enjoying the type of dining available in the region's forests — "whereas mammoths were more grazers, eating grasses," he said.

The mastodon molar at the front evolved for chewing leaves, twigs and bark. Behind it are the molars of a woolly mammoth, an Asian elephant and an African elephant, better suited for chewing grasses. (Emily Chung/CBC)

Telltale tracks

Like elephants, evidence suggests female mastodons lived in groups with their young; ancient elephant-like tracks were found in Michigan in the 1990s.

"They're footprints that are this big around and sort of a round foot. And come on, what else has those?" Fisher said.

Their stride length gives away the fact that they're mastodons rather than mammoths, he added. "Mastodons are longer in the torso."

Mastodons 'really were critical for human survival' around the end of the ice age, said Daniel Fisher, a mammoth and mastodon researcher at the University of Michigan and curator of the visiting exhibition. (D. Marshke/University of Michigan)

Researchers believe the tracks belonged to one large, solitary male who passed through, followed by a group of smaller females and calves.

More evidence of their family lives comes from their bones, which show that the growth rate of male calves, but not female calves, plummets around age 12, taking two or three years to recover.

"I see the world sort of dropping out from under [them]," Fisher said, adding that it's similar to what he sees in modern elephants when the males reach puberty and are evicted from their family group.

There are other signs that life wasn't easy for mastodon males. Their tusks contain a record of fights they got in with other males.

"There's actually damage on tusks that we can read, like sort of a record of, I don't know, wrecks that a car has been in, by looking at the damage here and the damage there," Fisher said. The growth of the tusks also shows when the damage happened. "So we know quite a bit about their lives and behaviours."

If the animals were so common, so well-studied and such an important part of people's lives, why do we hear so little about them compared to woolly mammoths?

Fisher thinks that the difference in cultural awareness is largely because mammoths dominate the ice age remains of large mammals found in Europe and Asia. At the time that mastodons were common in North America, they were already extinct in Africa, Europe and Asia.

Mammoths and Mastodons: Titans of the Ice Age will be at the Ontario Science Centre until April 24. Its next tour stop is the Royal B.C. Museum in Victoria, where it will be on display from June 3 until Jan. 1, 2017.

A life-sized model of a Columbian mammoth looms over visitors at the Ontario Science Centre. The exhibit will be there until April 24. It will be at the Royal B.C. Museum from June 3, 2016 to Jan. 1, 2017. (Emily Chung/CBC)