June 15 , 2016

by Tom Spears

The dinosaur world looks strange to begin with, but the latest skeletons to arrive at the Canadian Museum of Nature are especially alien. And especially big.

The 16 casts of skeletons are a travelling exhibit called Ultimate Dinosaurs on display on the museum’s fourth floor from June 11 to Sept. 5.

And unlike the dinosaurs we often see in North American museums, these come from the southern hemisphere, which was a completely separate lost world of its own.

The one great continent that once joined all land on Earth split into northern and southern halves 145 million years ago, dividing the dinosaur world forever.

The southern continent, Gondwana, has since split into Africa, Australia, South America and Antarctica. Its dinosaurs followed 80 million years of evolution cut off from those we dig up in Alberta, Montana and China.

They are big. Don’t judge by the first room you see in this exhibit because the biggest guys are farther back. Giganotosaurus in particular, T. Rex’s bigger cousin, is special.

There’s also one dinosaur leg standing alone because that’s all they could fit in. It’s from an enormously long-necked sauropod, like an oversized brontosaurus. For scale, this skeleton is bigger than the blue whale on display two floors below, though in fairness the whale was only a teenager. The whole skeleton is displayed only at the Royal Ontario Museum.

“We do have those long-necked sauropods in North America, but even they didn’t rival these South American forms in overall size. These are called the titanosaurs,” said Jordan Mallon, the museum’s paleontologist.

Other differences: The southern dinosaur group had no horned dinosaurs (like Triceratops.) And the south had a mid-sized meat-eater that makes Mallon imagine a hybrid between big T. Rex and little velociraptor, called austroraptor. Watch for it in the exhibit.

“These ultimate dinosaurs are more than just freak show attractions,” he said. “They document the rise and fall of one of the most successful lineages the world has ever seen. They teach us about the very mechanisms that drive the evolution of biodiversity.”

As Gondwana itself subdivided into today’s continents, “on each of these continents you see evolution go its separate way,” he said.

Understanding how past life adapted to changing landscapes and climates is a lesson we all need to understand today, he believes.

The show “will be a big draw for the busy summer tourist season,” said Mark Graham, a vice-president at the museum.

He called this group “marquee dinosaurs from the Southern Hemisphere.”

Mallon is off to Alberta and Montana for more field work this summer. There’s a fossil skull stuck in the side of a cliff, waiting for him to get it out. He’s going to use a helicopter.