The Giant Prehistoric Beavers of the Don Valley Brick Works

Hooooooo boy. Meet the giant beaver. It’s one of the largest rodents to have ever walked the earth: as much as seven feet long and more than 200 pounds. So, like, the size of a black bear. Its teeth were six inches long, but scientists aren’t sure if they were used to chop down trees like beavers do today; giant beavers probably ate aquatic plants, and there’s no evidence they built giant dams either. Their tails were probably quite different from their modern cousins, too: longer and thinner. And they had shaggier hair.

They also used to live in Toronto — about 130,000 years before our modern city was founded.

The first scientist to discover them here was Toronto’s most famous and celebrated geologist: Arthur Philemon Coleman. In the late 1800s, he became the first geologist to realize the importance of the big cliff on the northern end of the Don Valley Brick Works. At the bottom of the cliff was a bedrock of slate from about 450 million years ago — littered with fossils from the days when this part of the world was a tropical sea filled with trilobites. But what really makes the cliff special is what Coleman found above that slate: a remarkably complete geological record of the last 135,000 years.

Layer by layer, the exposed earth shows the last two Ice Ages coming and going, leaving rocks and dirt and boulders behind as enormous glaciers covered this land in ice and then melted away as the climate changed again. It’s the only place in this part of the world where you can see all of that history laid out in front of you. And in between those two Ice Age layers, there are a bunch of other layers: from a time when the planet was warmer. One of them, near the bottom, is a layer of sand and clay from about 130,000 years ago. That’s where A.P. Coleman found the giant tooth of a giant beaver.

Back in our giant beaver days, Toronto was actually a couple of degrees warmer than it is now. Instead of Lake Ontario, there was an even bigger and deeper lake here; they call it Lake Coleman in honour of the moustachioed geologist. Everything that now sits in downtown T.O. was very much underwater back then. The sands and clays at the foot of the cliff in the Brick Works — which is all the way north of Bloor — would have been in the shallow waters near shore, at the mouth of the prehistoric ancestor to the Don River.

A.P. Coleman

Coleman and his team were able to piece together a whole scene thanks to the other fossils they found along with the beaver tooth. The area where the river met the lake was a marshy wetland back then, surrounded by woods and grasslands. Prehistoric stag-moose, bigger even than moose are today, with huge sets of antlers, roamed through a wilderness that would have seemed both familiar and strange to us. There were plenty of trees and other plants that still grow in Toronto today: oaks and pines and maples, willows, cedars and elms. But there were also some species that you can only find further to the south these days — in the United States, where it’s warmer — as well as a few that are long-extinct. There were giant prehistoric bears here, too. Massive, ancient bison. Woodchucks and white-tailed deer. On occasion, a thunderstorm sparked a fire, flames tearing through forests and fields, enormous panicked beasts rushing for the safety of the water.

Scientists figure that giant beavers didn’t spend much of their time on land; even less, it seems, than beavers do today. They stuck to the swamp at the mouth of the river, swimming through the marsh, feeding on the aquatic reeds and long grasses that lined the shore. (And if they did behave like their modern relatives, maybe they were even cutting down trees and building beaver lodges big enough to house a family of rodents the size of a bear.) They’d been living like this, in the wetlands of North America, for two million years. And they had more than another hundred thousand years left to go.

But not in Toronto. As the next Ice Age began, Toronto got colder, eventually getting buried beneath a layer of ice two kilometers thick. The giant beavers would have been forced far to the south. And as the Ice Age ended, around 10,000 B.C. or so, the last members of the species died out. The giant beaver was extinct.

By then, a new species was living in North America: human beings. Back in the days when giant beavers had been swimming around the Don Valley, humans were still a young species, having only recently evolved on the savannas of Africa. But by the time the giant beavers went extinct, indigenous peoples had established cultures and communities all over the Americas — soon to become civilizations. The First Nations and their ancestors have been living in Toronto for thousands and thousands of years. But it was only a few hundred years ago that the first Europeans showed up. And when they did, many of them came looking for the smaller, modern relatives of those prehistoric beavers — so they could turn these new beavers into hats.

Finally, just a little more than 200 years ago, the British founded a new capital on this spot. To build it, they needed bricks. To make bricks, they needed clay. And one of the best sources for clay was discovered in the very same place where that prehistoric river once met that prehistoric lake. The Don Valley Brick Works was born, turning clay into red and yellow bricks of such a high quality that they won gold medals at the Chicago World’s Fair. A lot of Toronto’s old buildings are made of Brick Works bricks. Much of our city was quite literally built from the mud of the swamp where giant beavers once roamed.

Today, the Brick Works is no longer an industrial wasteland. Instead, we’ve tried to return it to its roots: a mixture of wetlands, forests and fields. Native species of plants and animals have been reintroduced and allowed to thrive — some of them are the very same species that would have been here in the days of the giant beaver. In fact, if you get lucky, you might even spot one of the newest residents: a modern, normal-sized beaver, swimming around the wetland where 130,000 years ago its giant beaver cousins did the very same thing.

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A version of this story will appear in The Toronto Book of the Dead Coming September 2017 Pre-order from Amazon, Indigo, or your favourite bookseller

This post was edited from its original version to be more awesome.

Image: Castoroides in New Jersey by Charles R. Knight, 1904 (via Wikimedia Commons).

The ROM has a giant beaver, along with other prehistoric beasts who would have lived in these parts on display, which is raaaaather cool. And a few indigenous nations, like the Mi'kmaq and the Cree, have myths about giant beavers.

You can read more about the north cliff of the Brick Works here, at the oh-my-god-so-good Lost Rivers site.

There's a neat photo of the cliff from it's industrial days here and the wasteland that was the quarry here. 

Oh and Torontoist is currently running a series on our city back in its prehistoric days. They've started with a couple of posts about super-super-super old stuff. You can find them all here.

Here, also, since I made this list and didn't use it but don't want to delete it, a few of the plants A.P. Coleman and his team discovered evidence of from that period 130,000 years ago: sugar maples, ash, cedar, hickory, willows, elm, locust trees, oaks, white pine, sycamore, sedges, which are like rushes, mare's tail, algae, mosses.

And then there's this video about giant beavers from a Discovery Channel series called "Prehistoric New York":

The 11,000 Year-Old Footprints At the Bottom of Our Lake

Footprints on the bottom of Lake Ontario

During the last ice age, a really, really, really, really big glacier covered pretty much all of Canada and the northern United States, including the Toronto area. When the ice age ended, about 12,500 years ago, the ice sheet gradually melted, receding north until it became nothing more than the remnants that are still hanging out around Baffin Island today.

In our neck of the woods, the water that melted off the glacier formed a giant lake called Lake Iroquois. It filled the basin where Lake Ontario is now all the way up to Davenport Road. The big hill running along the north side of the street is the shoreline of the ancient lake.

Now, the reason Lake Iroquois was so big was that for a while the St. Lawrence River was still blocked by the retreating glacier. The water flowing out of the lake had to go south instead, down the Mohawk River, eventually hooking up with the Hudson before flowing out into the ocean. So when the ice dam blocking the St. Lawrence finally broke, much of the water in Lake Iroquois suddenly rushed out, and what was left was a lake that was way smaller than Lake Ontario. Science-y folks call it Lake Admiralty, and its shoreline was five kilometers south of where our waterfront is now.

That meant that about 11,000 years ago the entire Toronto area was a vast plain of tundra and spruce forest. With the glacier gone, animals moved in. There were mammoths and mastodons, ancient caribou, musk ox and bison, bears and wolves. And with them came the Paleoamericans, who are believed to be the very first humans to ever set foot on this land. They were nomadic hunters with stoned-tipped spears and small settlements throughout the region.

At one point, it seems a family of them walked north up from Lake Admiralty toward what’s now downtown Toronto. They were wearing moccasins, and for at least a few steps, they walked through clay, leaving their footprints behind.

Over the next few thousand years, Lake Admiralty gradually grew, filling with water until it became the Lake Ontario we know today. And those 100 footprints, frozen in that clay, were hidden from view. That is, at least, until 1908 when workers installing a waterpipe on the lake bed just east of Hanlan’s Point discovered them.

It was easily one of the most spectacular archeological finds in Toronto’s history, probably the earliest evidence of humans living here. “It looked like a trail,” a city inspector told the Toronto Evening Telegram. “You could follow one man the whole way. Some footprints were on top of the others, partly obliterating them. There were footprints of all sizes, and a single print of a child’s foot…”

But the city was in a rush. They wanted to build a tunnel and they didn’t want to slow down. So they just poured concrete over the prints and kept going.

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I first read about the footprints in HTO: Toronto's Water from Lake Iroquois to lost rivers to low-flow toilets, which is on Google Books, here. And the best article I've found about them is on the Toronto Star's website, here (which is also where the photo's from, though it doesn't seem to show up on the article's page for some reason).

There Are Some Crazyass Fish Living In Our Lake

Lake Sturgeon

This is a lake sturgeon. Sturgeon have apparently been around for about 100 million years, swimming the lakes of North America while there were still dinosaurs walking around on the land. They can live to be more than 100 years old. Some even make it past 150. And they're huge; Wikipedia says they can grow to be more than nine feet long.

So, to recap: there are ancient fish living in our lake that are bigger than you and may have been alive since before the American Civil War.

There used to be tons of them in the Great Lakes, but (surprise!) once the Europeans showed up, overfishing and habitat destruction killed most of them. Now they're protected as a species of "Special Concern" (the same as polar bears) and you can't fish them anymore. (Unless, of course, those same Europeans massacred your ancestors and forcibly occupied all of their land, in which case letting you fish what you want is literally the least we can do.)

Lake sturgeon spend most of their time in the depths, feeding along the bottom, but sometimes they're seen in the shallows, especially during breeding season. And that means next time I'm down by the lake, I'm not going anywhere near the water.

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