Walking With Dinosaurs Remastered

Ice Giants of Canada

Last Time of Walking with Dinosaurs: We took a journey with the killers of Africa, watching how they lived in the lush swamp forests. Today we will solve the case behind this floating raft of carcasses in an Arctic river.

Chapter 9: Ice Giants of Canada

Time: 75 Million Years Ago, Late Cretaceous

Location: Northern Alberta, Canada

An early spring day on the tundra of Late Cretaceous Canada. Spring time is normally a time of rejoice for the creatures of the Arctic, with the sun signaling the end of the polar night. But this year, the air is ripe with the smell of rot. And the local river is the reason why.

The water is virtually clogged with a putrid blob of rotting carcasses, blood and sludge seep into the water, providing a feast for the fish below. This raft of decaying flesh and bone used to be one of the most spectacular sights in this part of the continent, a massive herd of Centrosaurus, now reduced to a smelly feeding platform for some scavenging pterosaurs. But what force on earth could completely demolish an entire herd of these heavily armed, 3-ton ceratopsids? To answer that, we need to travel to a few weeks before now.

4 Weeks Ago, Montana

This forest is where our story begins, it is the end of winter, and that means that animals that migrated south last year are migrating back north to their summer feeding grounds. And this herd of Centrosaurus are leading the charge northwards, usually, Centrosaurus herds only comprise of 30 or so individuals, but during mass migrations like these, they can join together in massive super herds up to 500 strong, with over 1,500 tons of animal on the move, it is the largest annual migration on Earth.

However, as always in the natural world, wherever there are herbivores, carnivores are never far away. This is a pack of Gorgosaurus, and these guys are relatives of the famous Tyrannosaurus rex.

Tyrannosaurs have their roots in the Jurassic period, as a group of small, raptor like hunters called Tyrannosauroids, throughout the Early Cretaceous, a group known as the Eutyrannosaurs branched off from this group. And from this, another group, the Tyrannosaurids branched off and then split, forming two families. The larger, bulkier Tyrannosaurinae, which includes Tarbosaurus and of course Tyrannosaurus, and the smaller, leaner Albertosaurinae, which is the family that Gorgosaurus belongs to.

For the Gorgosaurus, spring is also a time for migration. For them, Centrosaurus are food, and as the herbivores move out, the carnivores have to follow them, or else risk starvation.

1 Week Later

As the Centrosaurus herd head northward, it doesn't take long for them to be joined by other dinosaurs.

This is a herd of Parasaurolophus, 40 feet long and nearly 7 tons, they are massive animals, dwarfing the Centrosaurus. Parasaurolophus are part of a relatively new family of dinosaurs, the hadrosaurs. Descended from relatives of Iguanodon, these dinosaurs possess a sharp, horny beak that they use to shear leaves off plants, and after that, rows of chewing teeth crush the plants into a pastes that they swallow. This makes them easier to digest and extract energy from, allowing hadrosaurs like Parasaurolophus to spend less time eating and sleeping than other herbivores.

Just like the Centrosaurus, they too are migrating northwards for the spring thaw, where they'll catch the first shoots of grass as they bloom.

Like always though, the carnivores are never far behind. The Gorgosaurus have used their sense of smell to track down the herds. They came for the Centrosaurus, but the Parasaurolophus' lack of armor and horns makes them a more appealing target for the carnivores.