Walking with Monsters

Narrator:
This is Earth, 4.4 billion years ago. A toxic, sterile ball of scorching rubble. Meteorites rain down on its surface. Clouds of lethal acid smother it. The Earth seemed destined to remain devoid of life... but that was about to change. [a nearby planetoid collides with the Earth in a world-shattering explosion, and their remnants merge] Another planet, Theia, smashed into Earth, and the two planets fused, creating a brand-new world: our world. Even today, Theia lies right beneath our feet. A smaller chunk of Theia became our moon...and slowly, our oceans formed, until life on Earth was ready to begin. But who would inherit this blue planet?

Narrator:
[as a Brontoscorpio chases the Cephalaspis] Cephalaspis suddenly changes her path. She's picking up bad vibrations–something Brontoscorpio can't detect. [a huge Eurypterid suddenly emerges from the seabed, seizing the Brontoscorpio and ripping it apart] Pterygotus is the titan of sea scorpions... the largest arthropod to have ever lived. More than three meters long, she's the size of a crocodile. She's turned the tables on Brontoscorpio. He'll make a good meal for her young.

Narrator:
This Mesothelae spider is the size of a human head! She would be hunting cats if she were alive today!

Narrator:
The homeless spider tries her luck further inland, but other Mesothelae fill the forest floor and they don't like to share. Neither does Arthropleura. He's a distant relative of modern Millipedes, but as long as a car. He could rear up tall enough to look you right in the eye. Although he's vegetarian, his strong jaws can still deliver a nasty bite.

Narrator:
Our distant ancestors have come a long way, they've now conquered the land. (Edalphosaurus roars) The worlds first giant reptiles have arrived, but they're not related to dinosaurs, their descendants will be of a very different kind.

Narrator:
[about the Diictodon] Despite the presence of these heavyweights, smaller creatures also eek out a living around the water hole: Diictodon, a hardy little burrower, just half a meter long.

Narrator:
Hunger drives the Gorgonopsid back to the Diictodon, and this time, she tries to dig them out. [The Gorgonopsid digs at the Diictodon's burrow, but to no avail; she eventually gives up and returns to the now dried-up water hole] But the Diictodon's hard work pays off. Their den in the sun-baked earth is deep enough to keep them safe. Instead, the Gorgonopsid's nose leads her back to the dried-up water hole. She senses things are not as lifeless as they seem. [The Gorgonopsid digs up the Rhinesuchus from before] The giant amphibian... Just before the water hole dried up, she must've burrowed into the damp mud, forming a cocoon around herself in a last-ditch attempt to sit out the drought. [The Gorgonopsid begins eating the Rheinosuchus] But in her torpid state, she's helpless, as the Gorgonopsid feasts.

Narrator:
Over the next few million years, the Earth will suffocate under a stagnant blanket of heat, sparking a mass-extinction even greater than the one that will destroy the dinosaurs. The future belongs to a tiny group of survivors, small and adaptable enough to sit it out.

Narrator:
The dawn of the Triassic era and the earth has only just begun to show signs of recovery. The deserts have stopped growing and huge forests of primitive conifer start to recolonize the land. In these new forests, plant-eaters recover first. One in particular, like most of the large reptiles, they may resemble dinosaurs but lystrosaurus are more closely linked to mammals and to us. Astonishingly their vast herds make up more than half of all life on earth. Never again will a single species do so well.

Narrator:
[as the Euparkaria evolves on-screen into an Allosaurus] His descendants will be known as the most notorious monsters of them all: dinosaurs!

Narrator:
[last lines in the series] The unique ability to stand upright, and the agility this allowed, gives the early dinosaurs a competitive edge over our four-legged mammal ancestors. Repressed by these swift killers, our ancestors are reduced to small creatures hiding in the shadows. Their time will come... [The scene cuts ahead to the Jurassic, where the dinosaurs now rule the Earth] But for the next 170 million years, the world belongs to the dinosaurs!