Original subtitles

One hundred and twenty-five million years ago,

winter rages across the north.

Entire species have been pushed to the brink.

Even the largest dinosaurs are unable to endure this cold.

Like these sauropods migrating south.

Winter came early this year

and caught them off guard.

With hundreds of kilometers ahead of them,

this time, it will be an especially harsh journey.

But the bitter cold is not the only danger in this frozen land.

There is a much greater threat

here in these woods.

Yutyrannus.

The Snow King.

An early relative of T. rex.

With a thick, insulating coat of feathers,

he's perfectly adapted for life in a world this cold.

But his feathers also serve a more sinister purpose.

Camouflage.

The ultimate weapon for an ambush hunter.

With silent precision,

he picks out the smallest member of the herd.

In a savage, ever-changing world,

some will rise,

and some will fall.

But through it all,

the dinosaurs will expand their empire

and advance relentlessly

to seize Earth's final frontiers.

It's a new age for life on Earth.

An age of extremes.

New worlds are forming

that will give rise to the most famous dinosaurs of all time.

The north is still gripped by cold.

But not for much longer.

Earth's most violent forces are stirring once again.

Volcanoes seethe and fume…

warming the planet.

But some will pay a price for this warmer world.

As global temperatures continue to rise…

the snow and ice all but disappear.

Huge meltwater rivers tear through the land.

This thawing of the north

is expanding the dinosaurs' empire even further.

And in surprising new ways.

In this fresh, fertile landscape, sauropods no longer need to migrate.

But it's also a new world for one of the dinosaurs' oldest rivals.

The pterosaurs.

They are now bigger and badder than ever.

Including Guidraco,

the Ghost Dragon.

But he's an intruder here.

Because these trees are the home of Longipteryx,

a new kind of dinosaur.

Less than 20 centimeters tall,

but highly territorial.

Especially during nesting season.

They're also equipped to take on the pterosaurs.

Now they too can fly.

In a previous era,

flying dinosaurs like Anchiornis could only glide.

Now they're able to flap their wings

and maneuver with precision to strike at their enemies.

They're fast

and fearless.

It only gets worse for the tiring pterosaur.

Because Longipteryx are distant cousins

of Yutyrannus, the Snow King.

They're armed with the teeth and claws of their clan.

After ruling the skies since the Triassic,

pterosaurs are now being matched by the dinosaurs.

But as the dinosaurs fight to expand their empire into the air…

…an even greater revolution lies ahead.

Not in the mountains,

or the skies,

or the oceans.

The biggest twist in Earth's tale is unfolding quietly.

Almost in secret.

Seven million years later,

this new force is slowly rewriting the dinosaur story.

This is one of the first flowers this forest has ever seen.

Just one,

in a vast and diverse new generation of plants.

And they will become a phenomenon

with the help of a close ally.

Beetles.

They carry pollen from one flower to the next.

Nature's most reliable delivery service…

helping these new plants spread far and wide across the globe…

transforming the dinosaurs' empire.

But this new generation of plants has a dark side.

While they need to attract pollinators,

many are also evolved to repel herbivores.

With spines,

thorns,

and poisons.

Nature's defensive weapons.

This green revolution changes everything

for the plant-eating dinosaurs.

Including…

…the great Stegosaurus.

They are herd animals by nature.

But this young stegosaur, barely two years old, is all alone.

She is the last of her herd.

To eat these tougher new plants requires a mouth that can chew food

in a way her primitive jaw cannot.

She's starving.

These once-great herbivores are unable to adapt to this new world.

It's one reason why their 50-million-year existence

will come to an end.

Extinction.

But in the wake of the Stegosaurus' demise,

a new era will emerge.

Over the next 15 million years,

these new plants evolve and diversify,

spreading across the planet

and ever further into the dinosaurs' empire.

The green revolution now covers the globe.

And not just the land,

but the water as well.

Even providing cover

and food

for underwater explorers.

Like Ankylosaurs.

This bathing beauty is a different kind of dinosaur.

He's a plant-eater, like the Stegosaurus.

But a fancier one.

Much fancier.

Because unlike the Stegosaurus,

his advanced jaw can crush food

in a way that makes eating any kind of plant easy.

It's the perfect adaptation for this diverse new world.

He wants to take full advantage of all this great kingdom has to offer.

And he has a plan.

It's a long trek.

But the journey is worth it.

This is the one place where he can truly be himself.

His passion is singing.

He even has special hollows in his snout that amplify his song.

So it can be heard far and wide.

A female has answered his call.

It's time to charm her with his deep, sultry humming.

Then… he shows her his stylish armor.

It's all…

very persuasive.

Their fancy attire does have some drawbacks, mind you.

On the whole, though,

heavy armor and an improved jaw are setting them up for success.

But what no dinosaur could possibly know

is that their empire has been gradually shrinking.

Hidden below the waves,

this world, once ruled by dinosaurs…

is now completely out of their reach.

And there's a reason…

at the very bottom of the ocean.

A slow, imperceptible shift…

reshaping the planet.

The seabed is fracturing

from an endless progression of eruptions.

Earth's tectonic plates are shifting,

breaking apart the ocean floor,

lifting it higher over millions of years.

The water above has nowhere else to go,

but up.

By the middle of the Cretaceous,

sea levels reached their highest point in history.

Over 200 meters higher than they are today.

The rising oceans repaint the map of the world,

erasing entire land masses.

The continent of Europe is reduced to a giant archipelago

that includes the Isle of Hațeg.

Where isolation and evolution have created a kind of

Neverland for the dinosaurs.

A world where normal rules don't apply.

This is the home of Magyarosaurus,

a sauropod.

And, like other sauropods,

he uses his long neck to reach the highest vegetation.

Thing is,

this vegetation is only two meters tall.

Which makes Magyarosaurus about the size of a pony.

On Hațeg,

where there's limited space and food,

sometimes smaller is better.

But unlike Magyarosaurus,

for predators, bigger is still better.

As tall as a giraffe,

one of the largest pterosaurs to ever live.

The nightmare

Hatzegopteryx.

She's flown to this island to feed

on dinosaurs.

The youngest member of the herd gets separated.

But he won't be an easy catch.

Unlike his giant cousins, he's light on his feet.

But being this small, he can't see the others.

They found a safe hiding spot,

perfect for their size.

For tiny dinosaurs trapped on an island,

there's nowhere else to go.

But in a world so divided by the ocean,

evolution takes different turns in different places.

Ninety-six million years ago,

sea levels were close to the highest they've ever been.

Creating a water world that no dinosaur has dared to enter.

But that's about to change.

Lurking in this mangrove swamp

is a carnivore that has specially evolved

to take on the final frontier.

A dinosaur pioneer.

Spinosaurus.

The largest predator to ever walk the Earth.

At 15 meters long,

she's bigger than a school bus.

The forest provides plenty of prey.

But another reason she's gotten this big

is because of where she goes to escape the gloom of the swamp.

Here, the high sea levels have turned the oceans

into a new hunting ground for the dinosaurs.

Where bigger is definitely better.

Spinosaurus is adapted to a planet that is now mostly ocean.

And in this age, some of the largest prey

is here in the water.

Sharks.

In a flat-out chase between a shark and a giant dog-paddling dinosaur,

the shark will always win.

But there's more to Spinosaurus than meets the eye.

Dinosaurs aren't just becoming bigger.

Some are cunning too.

She's going to make the sharks come to her.

Her snout is wired with sensors that can detect the slightest movement.

Now, all she needs to do

is keep completely still.

The best hunters

are the patient ones.

And her patience is starting to pay off.

The blood in the water is drawing the sharks closer.

She doesn't move.

She knows how this game is played.

Brains and brawn.

A killer combination

that is finally letting the dinosaurs get a foothold in the ocean.

Their reach is now global

and extends to the very ends of the Earth…

to what will one day be Antarctica.

While Spinosaurus is stalking the shallow seas in the tropics,

the world's southernmost landmass

is not the frozen wilderness we know today.

It's a green, flourishing Eden.

Where even in the dark, evolution is lighting the way.

And thriving in the darkness

are the dinosaurs.

By this stage in the late Cretaceous,

their empire is so vast

that they now dominate every continent on Earth.

And yet,

while their reign is global,

and their rule almost unchallenged,

their story

will take a dark turn.