Surely, one of the most remarkable animals that has ever existed,
and certainly one of the most famous, is a dinosaur.
Tyrannosaurus rex.
An animal to spark the imagination for all of us.
What kind of an animal was it?
What did it look like? How did it live?
Now, scientific research has answered such questions.
And not just about T. rex,
but the other species that lived alongside it.
And the latest imaging technology enables us to bring them all to life.
[grunting]
[David Attenborough] Planet Earth, 66 million years ago.
[roars]
The skies are filled with flying giants.
In the seas, monstrous reptiles patrol the depths.
And on land, dinosaurs of every kind,
all facing the struggle to survive.
[leaves rustling]
[groaning]
We now know so much about a world that was ruled by the dinosaurs.
[roars]
[shrieks]
This is their story.
[Attenborough] The forests in South America
contain some of the world's tallest trees.
They can grow to a height of over 300 feet.
But there are animal giants here too.
[tree trunk cracking]
[dinosaur bellowing]
Plant-eating dinosaurs.
These are Austroposeidon.
They're 80 feet long.
And they have colossal appetites.
Their teeth are used not to chew,
but simply to cut.
A herd like this one can consume ten tons of vegetation every day.
They prefer the tender, young leaves that grow on the tips of the branches.
But if they find trees that are even taller than they are,
they're not defeated.
[bellows]
They use their great weight and their 8-inch-thick breastbone
to simply push the trees over.
Success.
But life in the forest is always a battle.
Especially when new space is created.
Plants race to claim the light…
and use every kind of method to gain the upper hand.
The gap in the canopy is soon closed.
Over three-quarters of the world's land is covered by plants and trees.
This prehistoric planet is a green planet.
[dinosaur growling]
Many different species of dinosaur live in forests.
Triceratops, one of the biggest in North America.
They can be 26 feet long.
The huge frills on their heads are used for protection when they fight.
But plants have defenses too.
Poisonous toxins.
These are particularly dangerous for youngsters.
This calf weighs only a 50th of the weight of his mother.
[yelps]
And the plant's toxins could make him very sick indeed.
But Triceratops have a way of dealing with such poisons.
They use an antidote.
One source of it lies in a cave to which they pay regular visits.
This youngster, however, has never been in here before.
[huffs]
They have to find their way along a passage
that, over many millennia, has been eroded by an underground river.
They are now beyond the reach of light.
They can't see a thing.
The calf must stick close to his family.
[calf yelps]
But not too close.
[calf yelps]
[wailing]
Now, one wrong turn could be disastrous.
[wailing continues]
At last, the herd reaches the place they need to visit.
This is the antidote: a special clay.
These are known as clay licks, and they're visited time and again.
But someone is missing.
Where is her calf?
[bellows]
[calf yelping]
[parent bellows]
[yelping continues]
[calf grunts]
[bellows]
Luck was on the youngster's side.
Once he's lined his stomach with clay,
he too will be protected from the poisons in the leaves on which he feeds.
Soon they will all head back to the forest and daylight.
In fact, very little of the sun's light
reaches the floor of these dense forests.
In Patagonia,
the thick vegetation stretches unbroken for hundreds of miles.
But occasionally, there are mysterious clearings, like this one.
[dinosaur growling]
It's the work of a two-ton, 12-foot tall Carnotaurus. A male.
Clearing this patch has taken him a long time.
And it needs constant attention if it is to remain tidy.
It's a stage on which he can show off to females.
All is ready, and he announces the fact.
[guttural calling]
His calls are low-pitched
and travel much farther through the dense vegetation
than higher-pitched ones would do.
[calling continues]
At last, a female arrives.
She's bigger than the male and more powerful.
Now, somehow, he must impress her.
And he may only get this one chance.
She watches him carefully.
If he is going to impress her,
he must do so in the most extraordinary way.
He doesn't have huge antlers, nor a spectacular tail.
But he does have a pair of tiny, apparently useless arms.
And each has a ball and socket joint at its base
that enables him to move them independently.
Not today.
How could he have done better? Who knows?
For now, it's back to litter picking.
This is East Asia.
In these mountain forests, autumn arrives early.
This is when many trees produce their fruit.
And amongst the most highly prized are the nuts of the Ginkgo tree.
A bonanza for dinosaurs called Corythoraptors.
Although they have feathers, they're flightless.
These have found a particularly abundant fall of fruit.
But such gatherings can attract unwelcome attention.
Qianzhousaurus, the top predator in these Asiatic forests.
This is a female, over 30 feet long.
If she is to catch a Corythoraptor, she'll have to get close.
There's not much cover here.
But her prey have still not noticed her.
[squawking]
[roars]
She has failed.
But then, most hunts,
throughout the history of life, fail most of the time.
[thunder rumbling]
As the seasonal winds strengthen,
many of the trees in these temperate forests start to lose their leaves.
Winter will be a time of hardship.
Nevertheless, a storm does create a brief opportunity for hunters.
She's trying again.
She's less conspicuous in the gloom, and the gusting wind is distracting.
[leaves rustling]
[grunts]
An 80-pound prize.
All the more valuable, since winter is now closing in.
In the forests of North America,
there is an additional annual hazard for forest dwellers.
[fire crackling]
Fire, started by a strike of lightning.
As it spreads, temperatures rise to over 2,000 degrees Fahrenheit.
The flames rise several hundred feet into the air.
[dinosaur bellowing]
Most animals flee.
But this Edmontosaurus has a family to care for.
[bellowing continues]
She doesn't abandon them.
Now they must keep one step ahead of the blaze until it burns out.
This may look catastrophic.
But remarkably, some plants must be burnt
if they are to complete their life cycle.
The intense heat is needed to open the cones of the pine trees…
and release their seeds.
And only a few hours after the fire has passed,
animals begin to return.
Beetles are among the first.
They start to lay their eggs.
When they hatch, the larvae will be the first to feast
on the near-limitless supply of dead wood.
This Atrociraptor is an opportunist.
Quick to return when there's food on offer.
And there's something else to be gained here.
Smoke is an insecticide…
and it can help an animal to get rid of its parasites.
But you do have to be careful.
[growling]
A two-ton ankylosaur.
It also finds something worth eating after a fire.
Charcoal.
It will bind with many of the plant toxins in its stomach and neutralize them.
[bellows]
The female Edmontosaurus is leaving the forest.
[bellows]
Against the odds, she's led both her babies to safety.
[bellows]
They will have to find new pastures until the forest plants recover.
Even where fires are rare, trees do not live forever.
And after they die, they become food for a very different kind of organism.
[insects chirping]
At night, some of them become eerily conspicuous.
Down on the forest floor…
fungi appear…
and start to glow.
They produce their light by chemical reactions deep within their tissues.
But why they do so is a mystery.
It may be because the light attracts insects,
which then help to spread the spores of the fungus.
Here, in central Asia,
the nighttime forest is filled with strange sounds.
[snoring]
Giant sauropods are asleep.
There are air sacs in their head and neck,
which reduce their weight but also amplify their snores.
But not everyone is asleep.
For smaller creatures, it's safer to be out in the darkness than during the day.
These Therizinosaurus hatched just six months ago.
Barely three feet long, they are only a tenth of their adult size.
Their claws may look like daggers, but they're used more like salad servers…
because these are plant eaters.
This forest, however, has all kinds of food if you know where to look.
Honey.
It's dripping from a bees' nest up in the branches.
Bees usually build their nests beyond the reach of ground dwellers.
[bees buzzing]
But this one is lower than most.
And it's too good to miss.
[grunting]
[bees buzzing]
[grunts]
Unlike most dinosaurs, young Therizinosaurus can climb.
Although they're not exactly experts.
[grunting]
[bees buzzing]
Angry bees produce a Mexican wave to warn intruders to keep away…
or suffer the consequences.
[squawking]
[squawks]
An adult Therizinosaurus.
It's huge, nearly 30 feet tall and weighing five tons.
[bees buzzing]
Nothing the bees can do deters this one.
At last, a little treat.
And a few more stings.
[dinosaur bellowing]
Even by day, it's still dark in the understory of the dense forests,
such as this one in Europe.
Animals of any kind are difficult to distinguish.
Yet, they're everywhere.
Telmatosaurus seldom breaks cover.
And equally inconspicuous…
Zalmoxes.
The last of a very ancient dinosaur lineage.
This forest is one of their few remaining strongholds.
Seven inches tall, baby Zalmoxes are no more than snacks for many predators.
But snacks are nonetheless worth eating…
so they have to be cautious.
[Zalmoxes yelps]
Hatzegopteryx stands 15 feet tall.
It is, in fact, a pterosaur, a reptile with wings,
that here, as it stalks through the trees, it has to keep tightly folded.
This forest, so rich in small creatures, is one of its regular hunting grounds.
It stands on the southernmost edge of Europe.
This is the heaviest animal ever to fly,
and there is nowhere else here where it can open its gigantic wings,
which are over 30 feet across.
Many of the forest's permanent residents regularly come down here…
because the plants are coated with sea spray
and are a welcome source of salt.
Here, sauropods can meet one another, renewing family bonds…
and creating new ones.
But for Hatzegopteryx, the beach is a launching pad.
[squawking]
Now his wings will carry him to yet another forest,
where life proliferates more variously and more abundantly
than anywhere else on our prehistoric planet.
To discover the science behind the stories,
go now to the Prehistoric Planet show page.