Original subtitles

Dinosaurs ruled the planet for over 150 million years.

They occupied almost every corner of the globe

and came in almost every shape and size imaginable.

Some were truly extraordinary.

We now know that T. rex was a powerful swimmer,

Velociraptors were cunning, feathered hunters,

and that some dinosaurs had the most bizarre behavior.

But new discoveries are being made almost every day

that tell us more about life on this planet 66 million years ago.

This time on Prehistoric Planet,

we reveal new animals…

and new insight into their quest to find a partner,

the challenges faced by raising a family…

and their titanic battles.

Journey to a time when nature put on its greatest show.

This is Prehistoric Planet 2.

This is the largest expanse of lava to flood the earth for 100 million years.

The Deccan in central India,

a hellish place

and certainly not where you would expect to find dinosaurs.

And yet, giants risk their lives traveling here.

Isisaurs.

And all are females.

Lava has been flowing in the Deccan for so long

that in places, it is a mile thick.

Every spring, females leave the safety of their forest home

to make a perilous journey into these badlands.

They can pick a safe route through cooled, hardened lava…

but there are other dangers here.

In addition to the steam, a deadly mixture of carbon dioxide and hydrogen sulfide

spews from volcanic vents.

In the cool pre-dawn air,

these heavy gases sink

to create a barely visible, suffocating blanket.

Just a few lungfuls can kill.

But isisaurs have one crucial advantage.

Their long necks can keep their heads above this blanket of poisonous fumes.

But ahead lies a place where this will be hard to do.

They're entering a low-lying area

where the deadly gases are particularly thick.

And for these females, something is already wrong.

And worse, as the sun rises and warms the air,

the gases swirl even higher.

Long necks can no longer protect the herd.

They must escape to higher ground and quickly.

The climb is steep but should bring fresher air.

Relief at last.

And ahead, their final destination.

A volcanic island in the sky

rising high above these treacherous badlands.

The huge crater, a caldera, provides a safe communal nesting ground.

The surrounding sea of poisonous gases helps to keep predators away…

and the inbuilt geothermal heating makes it an ideal incubator.

Each mother digs a seven-foot trench in the warm sand

to hold over 20 melon-sized eggs.

The eggs are safe in the caldera for now,

but this is just the beginning of their story.

In a few months,

hundreds of tiny babies will hatch to face this desolate world.

If any are to survive,

they'll need a perfectly timed change in conditions.

The badlands of the prehistoric planet

tests even dinosaurs to their limits.

This strange landscape

carved by scouring winds and vast ancient rivers

might appear empty of life.

But here in Asia,

hidden in these narrow canyons…

is a new family of Velociraptors.

The young are just a few weeks old.

It might seem that in such a barren place, they face an uncertain future.

Their survival relies on a strange event, not here, but miles from their home.

Across the baking desert lies a forest trapped in a sea of sand.

A change in the seasons brings rare water to this region.

Huge stands of poplar trees

mark its arrival with a flush of nutritious leaves.

A magnet that draws many hungry animals.

Long necked nemegtosaurs are joined by Mongolian titanosaurs…

and with them, much smaller Prenocephale.

But one thing stands in their way.

This immense plateau.

And the only way to reach the forest is through this maze of canyons.

As they enter, the herd becomes nervous.

It's a good place for an ambush.

The Velociraptors are waiting.

But they can't possibly tackle a titanosaur.

Success will depend instead on other hunters on the prowl.

Tarbosaurs.

Asia's version of Tyrannosaurus rex.

As the predators approach, panic spreads.

Only the Prenocephale can escape to higher ground.

And this is what the Velociraptors have waited for.

Now, the Velociraptors can finally spring their ambush.

At last.

Working together, they have secured a meal for the whole family.

The tarbosaurs have also had success.

For predators, it's actually a time of plenty.

And for the Velociraptors, the perfect time to start a family.

Having clever, caring parents can give youngsters an excellent start.

And here in the badlands of Asia,

there are few more dedicated dinosaur parents than these.

A colony of nesting Corythoraptors.

A few days ago, females laid eggs on these circular mounds.

But the job of brooding them falls to the males.

And that is not easy.

Exposed to the midday sun, the eggs would soon cook.

But the fathers use their broad tail and forearm feathers

to keep the nest shaded.

And pay a heavy price.

Enduring hour after hour in the searing heat.

At last, in the cool of the evening, the males can step away in search of food.

This is when nesting in a colony brings benefits.

Instead of all leaving at once, the Corythoraptors take turns.

So, there's always a neighbor keeping an eye out for danger.

But even this neighborhood watch can't guarantee their safety.

A female Kuru kulla, a relative of Velociraptors.

She is extremely hungry but wary

of the Corythoraptors' powerful beaks and claws.

But she has one key advantage.

Her night vision is better than that of the owners of the nests.

If she's quiet, she can sneak into the colony undetected.

She picks her target carefully.

This is her chance.

But not to attack.

This predator is also a thief.

She will eat as many eggs as fast as she can.

Time's up. She's been discovered.

One last egg to take away.

She now has a chance to enjoy her stolen egg in peace.

But this thief shares her spoils.

With these purring sounds, she calls her young.

Her chicks are not long out of the nest themselves.

They need to learn that this strange new object is food.

And discover how to break into it.

Maybe their beak or perhaps a claw.

Success, perhaps more by luck than skill.

But still a vital lesson for this next generation of egg thieves.

In the badlands, the relief of cooler nights

is all too soon followed by the return of the intense heat of the sun's rays.

The temperature on the surface of the sand can soar to over 160 degrees Fahrenheit.

Any water here soaks away or evaporates in seconds.

This is one of the driest places on earth.

Without water, no animal can survive.

Yet this is home to these young Tarchia.

They are desert-living ankylosaurs.

Heavily armored with huge, clubbed tails.

Dark patches protect the Tarchia's eyes from the glaring sun.

And this is the sound

of Tarchia's very own air conditioning system.

Their large nose cools the air as it leaves the body,

condensing and so conserving valuable water with every breath.

It allows them to survive long periods without drinking

as they search for a meal.

The high temperatures here create scouring winds

which carve the rocks into extraordinary shapes.

But they also strip the ground of soil.

Some plants, however, manage to take root in cracks between the rocks.

Any meager mouthful is worth competing for.

With every minute, the sun climbs higher.

Soon, all shade will be gone.

And even these masters of the desert welcome a drink sometimes.

Like many nomads,

the Tarchia have a mental map of the desert

and can travel across empty landscapes with unerring accuracy.

They remember the rare places where there are natural springs.

Desert oases like this one.

A lifesaver for animals that can find them.

Prenocephale.

Tensions often run high around an oasis…

but a display of strength can prevent a dangerous battle.

In the end, the Prenocephale are little more than annoying.

But an adult Tarchia is another matter.

Especially one almost twice the youngster's weight.

It wields a club weighing almost 50 pounds.

If this comes to a fight, the juvenile can't win.

But reinforcements are on the way.

The pair are reunited.

Now there are twice as many swinging clubs for the adult to deal with.

He decides that perhaps there is enough water here

for everyone to share.

The young Tarchia can finally drink in peace.

But they may not be able to enjoy their rest for long.

In badlands, conditions can change with astonishing speed.

Rising summer temperatures fuel electric storms

hundreds of miles wide.

Here in the Deccan, these seasonal storms cause a shift in the wind direction.

And around the caldera

where the isisaur females laid their eggs months ago,

the poisonous gases have now blown away,

providing a critical window of opportunity.

There are strange sounds coming from beneath the sand.

Baby isisaurs are calling to each other from inside their eggs.

It helps to synchronize their hatching.

The babies are relatively tiny, less than a foot long.

There's nothing to eat except their mothers' dung.

Surprisingly,

it's very nutritious and important to the hatchlings in other ways too.

It introduces healthy bacteria into their guts,

and it also contains pheromones that, like smells,

will enable them to find their mothers' herd.

It will lead them to the safety of the forest.

But the journey isn't easy.

The winds may have changed in their favor,

but many dangers lie ahead for the young isisaurs.

Hot springs and bubbling pools of liquid mud.

A deadly trap.

After two days of trekking,

the babies' reserves are running low…

but their mothers have come to the rescue again.

Small plants have taken root in the cracked lava,

sprouting from seeds dropped in the mothers' dung.

But a new danger is heading their way.

Now the wind has cleared the toxic gases, the door opens for predators.

A rajasaur.

With so many babies out in the open, this could be a feast.

Cracks in the lava are the only possible hiding place.

More rajasaurs arrive.

Despite the dangers, hundreds of babies succeed in reaching the forest.

Here, they will live together hidden in the undergrowth for several years.

Until finally

they are big enough to join their mothers' herds.

With luck, the females among them will return to this crater

in years to come to lay eggs of their own.

Like many animals that live in such inhospitable places,

the risks will be high.

But there are also great opportunities in the badlands of the prehistoric planet.

This is the fossilized egg of a giant dinosaur.

A titanosaur.

When freshly laid,

it would have weighed around a kilo and a half,

and its shell is about two millimeters thick.

While the eggs certainly were tough,

they still needed to be kept safe and warm.

So how did dinosaurs take care of their eggs?

In order to protect their eggs from predators

and to keep their eggs warm, dinosaurs evolved a list of strategies.

One of these strategies was to build a nest

and then to actually sit on top of the nest.

We know for certain dinosaurs did this

because we actually have fossils of dinosaurs sat on top of nests.

Eggs found in these nests contain tiny babies of the same species

as the adults,

providing the first evidence

that some dinosaurs looked after their young.

But although this offered protection and shelter from the elements,

there was a downside to incubating eggs in this way.

Having to sit on an egg and actually look after it means

that you are committed to the care of that egg

for the entire duration of their development

up until the point of hatching.

For some dinosaurs, it was a commitment worth making.

But others, like sauropods, faced a different challenge.

It's likely that some dinosaurs never sat on their eggs.

After all, many of these animals weighed tons and tons

and would have crushed them before they had any chance of hatching.

So, what was their solution?

There are some sauropod egg clutches

where the female excavated a long trench with her back feet.

She then backfilled the trench once she had laid all the eggs.

This behavior can be seen today.

Turtles bury their eggs to protect them from predators,

and the sun-warmed sand keeps them at the ideal temperature.

But some dinosaurs had another trick to keep their eggs warm.

We think some dinosaur groups deliberately collected

and piled up rotting vegetation.

They basically formed a compost heap on top of their egg-filled nests.

Bush turkeys in Australia use this remarkable technique.

As the vegetation breaks down,

it releases enough heat to incubate their eggs

for around seven weeks.

But it was a discovery in 2010

that revealed that some dinosaurs had an even more unusual way

of keeping their eggs warm.

They use heat from the earth itself.

In one particular site in Argentina

that's had lots of sauropod egg discoveries,

it's right next door to some geothermal springs.

We're thinking the sauropods were using that volcanic activity

to help keep its eggs warm.

Another location, the Deccan region of India,

one of the most volcanic areas during the late Cretaceous,

provides more evidence.

There are many, many layers of lava,

then in between the lava flows, we find dinosaur eggs.

Dinosaurs were coming to this location

even when it was highly active volcanically,

using it as a nesting site for literally centuries.

Dinosaurs had many ways to ensure their eggs would hatch…

but we can be certain of one thing.

Their methods worked very effectively,

helping them to rule the world for over 150 million years.