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] For millions of years, the lands of planet Earth
have been carved by water.
And the rivers that flow here are still shaping these great canyons.
Such places are the home of flying reptiles.
Pterosaurs.
Their wings of skin stretch from finger to ankle.
And they can fly for hundreds of miles in a day.
[pterosaurs chirping]
[chirping]
Each evening,
they come to this canyon in huge numbers to roost on its narrow ledges.
There is safety in numbers.
And anyway, few land-living hunters venture here.
But one does.
A type of dinosaur. Velociraptor.
Their bodies are kept warm by feathers, but they can't fly.
They are, however, exceptionally agile.
[chirps]
And just as well.
One false step here could bring disaster.
[dinosaur squawks]
The pterosaurs are skittish.
They will take to the air at the first sign of danger.
If the Velociraptors are to get a meal, the element of surprise will be crucial.
Lightweight bodies and feathered arms help them
to control their descent.
And their broad tails assist them in keeping their balance.
[squawking]
Those pterosaurs that are resting on the margins
of the colony will be the easiest targets.
[squawking]
[rocks crashing]
[pterosaurs chirping]
The roar of the waterfall drowns the sound of slipping rocks.
The female goes high.
The two males stay low.
A few pterosaurs are almost within striking distance.
-[rocks crashing] -[pterosaurs shrieking]
She has one, but now the whole colony is alarmed.
[shrieking continues]
In the chaos, her victim slips from the ledge.
The female puts the effectiveness of her feathered tail to the test.
[rocks sliding]
And, in the end, she gets her meal.
The males are left to face the pterosaurs.
The power of fresh water is at work all around the planet.
[thunder rumbles]
Global temperatures are high.
There are violent storms and torrential rains.
[dinosaur groans]
Much of North America is covered by thick, lush forest.
[groaning continues]
[thumping]
Here live some of the most gigantic plant-eaters that have ever existed.
[dinosaur roaring]
And they, in turn, are prey for the most ferocious of hunters.
[flies buzzing]
[dinosaur grunting]
Tyrannosaurus rex.
This old male has just brought down a Triceratops.
[roars]
But in doing so, he's been injured.
[groans]
T. rex are built for hunting large herbivores…
though many of those have evolved heavy defensive weapons.
Decades of battling armored prey has scarred his body.
One battle even cost him the tip of his tail.
These new injuries are more serious.
At his great age, infection is a real risk.
[birds warbling]
River water could help to clean his wounds.
He stands a good chance of living to fight another day.
But that day could come sooner than expected.
[leaves rustling]
Another T. rex.
[roars]
A stranger.
[roars]
But this newcomer has a different smell.
It's a female.
She's younger and smaller.
But nonetheless, she might also be a rival.
[throat vibrating]
He, however, makes it clear that he's not interested in fighting.
[vibrating continues]
He would prefer to mate.
She seems to approve.
The facial area of a tyrannosaur is very sensitive to touch,
and they nuzzle.
His great size and his battle scars are evidence that he is a survivor.
And that perhaps, in her eyes, makes him an attractive partner.
[groaning]
So, they stay together.
And in the coming weeks, they mate frequently.
Eventually, she'll lay up to 15 eggs.
And with them comes the promise of the next generation.
Habitats that depend on fresh water can change rapidly and radically.
In parts of central Asia,
heavy seasonal rains fill the rivers until, eventually,
they overflow their banks.
The surrounding plains are flooded.
And through the water wades one of the most bizarre of all dinosaurs.
[dinosaur grunting]
Deinocheirus.
It's even taller than T. rex.
And its massive duck-bill snout is very effective
in gathering water plants.
This male feeds voraciously,
having eaten very little during the long dry season.
[grunting continues]
Water plants are rich in nutrients.
And his huge, curved claws, eight inches long,
enable him to dredge them up from deep beneath the surface.
[flies buzzing]
He himself is a source of food for smaller creatures.
Bloodsucking flies, which infest his coat.
They're irritating and even painful.
And while his huge claws enable him to have a good scratch…
there are always some spots that are just out of reach.
[grunting continues]
To get to them, he needs assistance.
A dead tree. That could be the answer.
[bird shrieks]
[wood cracking]
That's much better.
[grunts]
And now he can get back to feeding.
[grumbling]
But a diet that consists almost entirely of wet vegetation
does have one inevitable consequence.
[grunts]
[splash]
What was food for one becomes fertilizer for many others.
And a giant as big as Deinocheirus can produce
over 20 tons of dung every year.
[birds chirping]
Southern Africa.
Here, too, the annual rains create floods.
And the land turns into a maze of narrow channels
running between countless small islands.
[insects chirping]
This is now a swamp forest.
And it attracts one of the largest flying animals that has ever lived
on planet Earth.
A giant pterosaur. Quetzalcoatlus.
This is a female.
Her wings are over 30 feet across.
And she's come here for one particular reason.
The small islands created by the rising waters
are just the place for her to lay her eggs.
Quetzalcoatlus are certainly masters of flight.
But they're also, perhaps surprisingly, very competent on the ground.
Each wing is supported by the single greatly elongated bone
of her fourth finger.
By turning her wings upwards,
she can walk very effectively on all fours.
[grumbling]
She's come here to make a nest.
She chooses to do so on damp, swampy soil
that will prevent her soft-shelled eggs from drying out.
These first two are just the start.
For the next three weeks, she will guard the open nest…
and add two more eggs every few days.
Producing eggs takes a lot of effort and energy.
Each one is huge, weighing around a kilo.
Eventually, she produces a clutch of a dozen or so.
She covers them with vegetation to conceal them.
Now, she needs to eat.
There should be enough food on this island to sustain her youngsters when they hatch.
But there's nothing substantial enough here to satisfy her own hunger.
She must leave to hunt for prey elsewhere…
and trust that the isolation of her nest will keep her unhatched young safe
while she's away.
-[leaves rustling] -[birds cawing]
Another, much older Quetzalcoatlus female.
She, too, is looking for a safe place to lay her eggs.
And there may not be enough food here for two sets of giant nestlings.
But there is a way to solve that problem.
And eggs, after all, are very nutritious.
[young female groans]
The owner of the nest is back.
[groaning continues]
[hissing, grunting]
[groans]
The older female is driven off.
But the younger female's nest is wrecked.
Out of the dozen eggs that she laid, only three have survived.
The success of her breeding season now rests on these three fragile eggs.
She will protect them as best she can until they hatch in a few months' time.
But after that, her young will have to fend for themselves.
As river water flows downstream,
it scours out billions of tons of sand and gravel and even shifts great boulders.
The finer sediments may be transported for hundreds of miles,
but as the river broadens, it slows.
And as a consequence, it begins to drop some of its load.
And animals whose ancestors lived in the sea begin to appear.
Crabs.
In some places, there may be dozens per square meter.
This is Masiakasaurus.
A female, six feet long.
And she has a mouthful of needle-sharp teeth.
Just what you need to deal with awkward, multi-legged prey.
[chittering]
Crabs may have hard shells, but they're full of protein.
Too good an opportunity to miss.
And not only for her.
[offspring chittering]
She has three young.
Only four inches tall.
And not quite ready to take on large crabs.
[chittering continues]
They still rely on their mother's leftovers.
But some youngsters develop hunting instincts early.
Very tempting.
The smallest crabs can be swallowed whole.
Unfortunately, what they lack in size, they make up for in speed.
-[offspring chitters] -[squawks]
It's best for the young not to stray too far.
[offspring shrieks]
[shrieking continues, stops]
Beelzebufo, the devil toad.
One of the largest frogs that has ever existed.
[chittering]
He won't need to feed again for a month.
These sandbars may be a rich feeding ground,
but there can be a high price to pay for living here.
[dinosaurs groaning]
The river water is now approaching the sea.
A taste of salt in its waters is already detectable.
[wildlife grunting]
At high tide,
visitors come in from the open sea to explore these channels.
Elasmosaurs.
These are true oceangoing reptiles.
But some come to estuaries to explore the brackish waters.
[dinosaurs groaning]
Now, the millions of tons of sediment carried here
by rivers is finally delivered into the sea.
The river water takes time to mix with the ocean, and, for a while,
the two waters flow side by side.
Nonetheless,
great shoals of fish find plenty on which to feed in these waters.
The clouds of sediment conceal the fish, if they're any distance away.
But the Elasmosaurs don't hesitate to swim into the murkiest of waters
to pursue their prey.
There is no escape for the fish…
even above the water.
These Elasmosaurs collect the last of the river's gifts
before its traces are finally lost in the oceans of the prehistoric planet.
Next on Prehistoric Planet,
the bond between mother and young is tested to the limit
as they struggle to survive.
Ancient foes battle each other and freezing blizzards.
[roars]
And feathered dinosaurs rule the ice worlds.
To discover the science behind the stories,
go now to the Prehistoric Planet show page.