Walking with Dinosaurs

Narrator:
First light across the western hills of Earth's only continent; Pangaea. This world has been ruled by one group of giant reptiles for over fifty million years. But these ancient creatures have had their day.

Narrator:
[about the mammal-like reptiles] One day in the future, this strategy of investing in their young will pay off for their mammalian descendants. But as mammals evolve over the next one hundred sixty million years, they will only survive as a few small species, clinging on at the edge of a world dominated by dinosaurs.

Narrator:
This is the Jurassic period and the giant contient of Pangea that use to stretch from pole to pole is now breaking up. It is much wetter than the earlier Triassic period and where there were once deserts, there are now vast forests of conifer trees.

Narrator:
There are vast open fern prairies and this is were the titian's of the Jurassic roam. (stegosaurus growls) Dinosaurs like Stegosaurus, with its distinctive row of spinal plates. These prairies are kept clear of trees, by the constant grazing of such giant herbivorous. And none have a larger impact on this environment than the biggest dinosaurs of them all, the sauropods. ( a giant herd of diplodicus walk by) There are many different types of these gigantic long-necked creatures, these are Diplodocus, the longest of them all.

Narrator:
[about the Allosaurus] These are the lions of the Jurassic. The top predators of their age!

Narrator:
This is Brachiosaurus, a 13 meter high sauropod that specialises in grazing on the tree tops. His kind can effortlessly harvest cones and fresh leaves no other dinosaur can reach and they have grown enormous on it. These adults weigh 70 tons, making them the largest animals that have ever existed.

Narrator:
Sauropods dominate the late Jurassic, and it will be millions of years before new dinosaur herbivores evolve to replace them. With their passing, life will never again be this large.

Narrator:
Under these azure waters, lies the future continent of Europe. But now in the Late Jurassic period, all that exists here are a few scattered islands.

Narrator:
These rich sunlit waters are on the northern end of the ancient Tethys ocean, the sea that separates the Earth's two continents: one in the north, one in the south.

Narrator:
The newborn pups have just a few seconds to reach the surface and take their first breath. From the moment they are born, the little pups are vulnerable. These waters are full of predators. even adult Ophthalmosaurus will eat the offspring of others to increase chance of survival of their own pups. The only real safety is among the crags of coral.

Narrator:
[about the Liopleurodon] At one hundred and fifty tons, it is the largest and most powerful carnivore ever to live on the planet. This male weighs a colossal 25 meters and is big even for his kind. His size means hes probably over a 100 years old. Liopleurodon has a directional sense of smell, two separate chambers in his nose work in the same way as a pair of ears. pinpointing where a smell is coming from, a sophisticated tracking device. Steering the largest carnivorous jaws ever known.

Narrator:
These islands are regularly ravaged by violent tropical storms from the east, that are strong enough to tear away shallow sea beds, smash corals, and kill thousands of marine animals.

Narrator:
Marine reptiles were one of the glories of this ancient time, even though turtles are the only ones left today. But there was another major group of reptiles that shared the dinosaurs world, the flying pterosaurs. And as we shall see in the next episode, they were just as spectacular.

Narrator:
It is the beginning of a period in Earth's history known as the Cretaceous. And the movement of the continents is not only breaking up the giant northern and southern landmasses, but it continues to push up sea levels. This has opened new seaways and coastlines.

Narrator:
In the far future, the pterosaurs will surrender the skies to the birds!

Narrator:
It is the mid-Cretaceous period, and dinosaurs are now more widespread than ever, reaching every part of the globe. But one place is a special challenge: the South Pole.

Narrator:
Instead of ice caps there are lush forests. But unlike the unchanging tropical climate elsewhere, Antarctica has seasons from hot summers under midnight sun to cold winters of total darkness. (a small dinosaur runs past and hides into the forest)

Narrator:
Leaellynasaura is a dinosaur that is adapted to this extreme climate. Throughout the winter they survive in the warm sheltered heart of the thick forest. But now in spring they emerge to feed on the fresh plant growth. They are just two meters long and their most distinctive feature is their large eyes, which help them find food in the dark winter.

Narrator:
[about the Koolasuchus] This bizarre looking creature is a relic from a time before dinosaurs. In most parts of the world competition from crocodiles has driven these magnificent amphibians to extinction. But here the waters get too cold for crocodiles, and the worlds last Koolasuchus survive still patrolling the waterways, just as their ancestors did 150 million years before them.

Narrator:
The giant carnivore has killed the dominant female. It is a bitter blow; winter is coming, and without a lead female there will be tension in the clan.

Narrator:
Life on the Poles is a remarkable evolutionary achievement for the dinosaurs. But eventually, a slight cooling in the world's climates will spell doom to these lush Antarctic forests. And without them, all these unique dinosaurs will also disappear.

Narrator:
It is the end of the Cretaceous period and the continents are taking on their modern forms. But this ceaseless movement of the Earth's crust has also produced a surge of volcanic activity across the globe. :[A volcano puffs out smoke] Massive eruptions that have lasted for centuries have laid waste to landscapes and have filled the atmosphere with poisonous gases and debris. This desolate world is still ruled by dinosaurs, as it has been for a hundred and sixty million years but they are nearing the end of their reign. Life on Earth is chocking to death.

Narrator:
There are still islands of greenery between the barren lava flows. In the warm moist climate of the late Cretaceous period, the vegetation has transformed.

Narrator:
Millions of years of evolution has also created intimate relationships among different types of dinosaurs. Especially the delicate balance between predator... and prey.

Narrator:
Soon the age of the mammals will dawn, and they will grow to massive sizes. But at ten kilograms this is about as big as Cretaceous mammals can get.

Narrator:
Many dinosaur embryos are not surviving in this volcanic environment. Because acidic pollution is preventing their egg shells from forming properly.

[After the asteroid kills all the dinosaurs of the Cretaceous period, Molten rocks fall out of the sky]

Narrator:
Finally a rain of molten rocks starts to fall out of the darkening sky. This is the end of the age of the dinosaurs. [The scene shows the dark clouds] The comet struck the Gulf of Mexico with the force of 10 billion Hiroshima bombs. In the catastrophic climate changes that followed, 65% of life died out. [The Earth changed everything in fast motion] It took millions of years for Earth to recover, and when it did, the giant dinosaurs were gone, never to return.

[last line of the series]

Narrator:
In their place have emerged other powerful and beautiful creatures. And we now know that one small group of dinosaurs did survive the extinction and they are all around us today: the birds.