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{\an8}Dinosaurs ruled the planet
for over 150 million years.
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They occupied almost every corner
of the globe
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and came in almost
every shape and size imaginable.
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Some were truly extraordinary.
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[grunts]
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We now know that T. rex was
a powerful swimmer,
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Velociraptors were cunning,
feathered hunters,
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and that some dinosaurs had
the most bizarre behavior.
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But new discoveries
are being made almost every day
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that tell us more about life
on this planet 66 million years ago.
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[bellowing, rumbling]
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[David Attenborough]
This time on Prehistoric Planet,
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- we reveal new animals...
- [roars]
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...and new insight
into their quest to find a partner...
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[chirps]
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...the challenges faced by raising a family...
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[bellows]
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...and their titanic battles.
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[rumbling]
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[bellows]
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[roars]
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- [roars]
- [squawking]
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Journey to a time
when nature put on its greatest show.
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This is Prehistoric Planet 2.
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This is the largest expanse of lava
to flood the earth for 100 million years.
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The Deccan in central India,
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a hellish place
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and certainly not where
you would expect to find dinosaurs.
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And yet,
giants risk their lives traveling here.
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Isisaurs.
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[bellowing]
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And all are females.
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Lava has been flowing in the Deccan
for so long
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that in places, it is a mile thick.
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Every spring, females leave
the safety of their forest home
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to make a perilous journey
into these badlands.
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They can pick a safe route
through cooled, hardened lava...
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but there are other dangers here.
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In addition to the steam, a deadly mixture
of carbon dioxide and hydrogen sulfide
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spews from volcanic vents.
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In the cool pre-dawn air,
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these heavy gases sink
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to create a barely visible,
suffocating blanket.
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Just a few lungfuls can kill.
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But isisaurs have one crucial advantage.
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Their long necks can keep their heads
above this blanket of poisonous fumes.
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But ahead lies a place
where this will be hard to do.
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They're entering a low-lying area
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where the deadly gases
are particularly thick.
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[bellowing]
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And for these females,
something is already wrong.
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And worse,
as the sun rises and warms the air,
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the gases swirl even higher.
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[growling]
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Long necks can no longer protect the herd.
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[breathing heavily]
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They must escape to higher ground
and quickly.
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The climb is steep
but should bring fresher air.
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Relief at last.
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And ahead, their final destination.
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A volcanic island in the sky
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rising high above
these treacherous badlands.
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[bellowing]
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The huge crater, a caldera,
provides a safe communal nesting ground.
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The surrounding sea of poisonous gases
helps to keep predators away...
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[bellowing]
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...and the inbuilt geothermal heating
makes it an ideal incubator.
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Each mother digs a seven-foot trench
in the warm sand
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to hold over 20 melon-sized eggs.
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The eggs are safe in the caldera for now,
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but this is just the beginning
of their story.
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In a few months,
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hundreds of tiny babies
will hatch to face this desolate world.
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If any are to survive,
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they'll need
a perfectly timed change in conditions.
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The badlands of the prehistoric planet
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tests even dinosaurs to their limits.
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This strange landscape
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carved by scouring winds
and vast ancient rivers
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might appear empty of life.
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But here in Asia,
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hidden in these narrow canyons...
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is a new family of Velociraptors.
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[grunting]
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The young are just a few weeks old.
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[yipping, huffing, squawking]
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[chittering, squawking]
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[adult droning]
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It might seem that in such a barren place,
they face an uncertain future.
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Their survival relies on a strange event,
not here, but miles from their home.
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Across the baking desert lies a forest
trapped in a sea of sand.
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A change in the seasons
brings rare water to this region.
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Huge stands of poplar trees
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mark its arrival
with a flush of nutritious leaves.
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A magnet that draws many hungry animals.
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Long necked nemegtosaurs
are joined by Mongolian titanosaurs...
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[droning]
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...and with them, much smaller Prenocephale.
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But one thing stands in their way.
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This immense plateau.
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And the only way to reach the forest
is through this maze of canyons.
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As they enter, the herd becomes nervous.
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It's a good place for an ambush.
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The Velociraptors are waiting.
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But they can't possibly
tackle a titanosaur.
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Success will depend instead
on other hunters on the prowl.
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[predator roars, growling]
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[growling]
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[grunts]
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Tarbosaurs.
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Asia's version of Tyrannosaurus rex.
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[roars]
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As the predators approach, panic spreads.
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[bellowing]
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Only the Prenocephale can escape
to higher ground.
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[chittering]
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And this
is what the Velociraptors have waited for.
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Now, the Velociraptors can finally
spring their ambush.
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- [hissing]
- [squawking]
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At last.
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Working together, they have secured a meal
for the whole family.
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The tarbosaurs have also had success.
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For predators, it's actually a time
of plenty.
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And for the Velociraptors,
the perfect time to start a family.
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[chittering]
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Having clever, caring parents
can give youngsters an excellent start.
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And here in the badlands of Asia,
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there are few more
dedicated dinosaur parents than these.
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A colony of nesting Corythoraptors.
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[grunting, chittering]
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A few days ago, females laid eggs
on these circular mounds.
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But the job of brooding them falls
to the males.
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And that is not easy.
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Exposed to the midday sun,
the eggs would soon cook.
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But the fathers use their broad tail
and forearm feathers
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to keep the nest shaded.
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And pay a heavy price.
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Enduring hour after hour
in the searing heat.
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At last, in the cool of the evening,
the males can step away in search of food.
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This is when nesting
in a colony brings benefits.
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Instead of all leaving at once,
the Corythoraptors take turns.
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So, there's always a neighbor
keeping an eye out for danger.
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But even this neighborhood watch
can't guarantee their safety.
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A female Kuru kulla,
a relative of Velociraptors.
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She is extremely hungry but wary
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of the Corythoraptors' powerful beaks
and claws.
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But she has one key advantage.
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Her night vision is better
than that of the owners of the nests.
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If she's quiet,
she can sneak into the colony undetected.
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She picks her target carefully.
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This is her chance.
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But not to attack.
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This predator is also a thief.
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She will eat as many eggs
as fast as she can.
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[grunts, squawking]
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Time's up. She's been discovered.
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One last egg to take away.
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[squawking]
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She now has a chance
to enjoy her stolen egg in peace.
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But this thief shares her spoils.
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[purring]
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With these purring sounds,
she calls her young.
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[chittering]
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Her chicks are not long
out of the nest themselves.
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They need to learn
that this strange new object is food.
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And discover how to break into it.
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Maybe their beak or perhaps a claw.
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Success, perhaps more by luck than skill.
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But still a vital lesson
for this next generation of egg thieves.
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In the badlands,
the relief of cooler nights
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is all too soon followed by the return
of the intense heat of the sun's rays.
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The temperature on the surface of the sand
can soar to over 160 degrees Fahrenheit.
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Any water here soaks away
or evaporates in seconds.
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This is one of the driest places on earth.
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Without water, no animal can survive.
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Yet this is home to these young Tarchia.
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[grunting]
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They are desert-living ankylosaurs.
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Heavily armored with huge, clubbed tails.
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Dark patches protect the Tarchia's eyes
from the glaring sun.
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[huffing]
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And this is the sound
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of Tarchia's very own
air conditioning system.
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Their large nose cools the air
as it leaves the body,
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condensing and so conserving
valuable water with every breath.
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It allows them to survive long periods
without drinking
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as they search for a meal.
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The high temperatures here
create scouring winds
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which carve the rocks
into extraordinary shapes.
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But they also strip the ground of soil.
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Some plants, however, manage to take root
in cracks between the rocks.
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Any meager mouthful
is worth competing for.
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[grunting]
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With every minute, the sun climbs higher.
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Soon, all shade will be gone.
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And even these masters
of the desert welcome a drink sometimes.
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Like many nomads,
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the Tarchia have a mental map
of the desert
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and can travel across empty landscapes
with unerring accuracy.
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They remember the rare places
where there are natural springs.
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Desert oases like this one.
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[chittering]
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A lifesaver for animals
that can find them.
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Prenocephale.
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- [chittering, squawking]
- [grunts]
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Tensions often run high around an oasis...
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- [hissing]
- [grunting]
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...but a display of strength
can prevent a dangerous battle.
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[squawking]
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In the end, the Prenocephale
are little more than annoying.
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00:27:47,835 --> 00:27:50,879
But an adult Tarchia is another matter.
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[growls]
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Especially one
almost twice the youngster's weight.
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[droning]
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00:28:13,819 --> 00:28:17,698
It wields a club
weighing almost 50 pounds.
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[roars]
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If this comes to a fight,
the juvenile can't win.
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00:28:46,727 --> 00:28:50,397
- But reinforcements are on the way.
- [growls]
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The pair are reunited.
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00:29:02,993 --> 00:29:07,748
Now there are twice as many swinging clubs
for the adult to deal with.
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[roars]
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He decides that perhaps there
is enough water here
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for everyone to share.
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00:29:46,787 --> 00:29:50,332
The young Tarchia can finally drink
in peace.
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But they may not be able
to enjoy their rest for long.
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In badlands, conditions can change
with astonishing speed.
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Rising summer temperatures
fuel electric storms
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hundreds of miles wide.
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[thunder rumbling]
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Here in the Deccan, these seasonal storms
cause a shift in the wind direction.
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And around the caldera
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where the isisaur females
laid their eggs months ago,
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the poisonous gases have now blown away,
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providing a critical window
of opportunity.
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[young isisaurs chittering]
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There are strange sounds coming
from beneath the sand.
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Baby isisaurs are calling to each other
from inside their eggs.
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It helps to synchronize their hatching.
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[hissing, chittering]
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[shrieks]
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The babies are relatively tiny,
less than a foot long.
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[chittering]
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There's nothing to eat
except their mothers' dung.
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Surprisingly,
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it's very nutritious and important
to the hatchlings in other ways too.
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It introduces healthy bacteria
into their guts,
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and it also contains pheromones that,
like smells,
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will enable them
to find their mothers' herd.
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It will lead them
to the safety of the forest.
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00:32:52,723 --> 00:32:54,975
But the journey isn't easy.
251
00:33:00,689 --> 00:33:03,567
The winds may have changed in their favor,
252
00:33:05,027 --> 00:33:09,573
but many dangers lie ahead
for the young isisaurs.
253
00:33:15,204 --> 00:33:19,499
Hot springs and bubbling pools
of liquid mud.
254
00:33:22,002 --> 00:33:23,587
A deadly trap.
255
00:33:25,214 --> 00:33:27,299
[shrieking]
256
00:33:42,523 --> 00:33:44,233
[shrieks]
257
00:33:56,453 --> 00:33:58,956
After two days of trekking,
258
00:33:58,956 --> 00:34:01,792
the babies' reserves are running low...
259
00:34:02,584 --> 00:34:04,378
[shrieks]
260
00:34:04,378 --> 00:34:07,339
...but their mothers have come
to the rescue again.
261
00:34:09,591 --> 00:34:12,886
Small plants have taken root
in the cracked lava,
262
00:34:13,719 --> 00:34:17,516
sprouting from seeds
dropped in the mothers' dung.
263
00:34:25,524 --> 00:34:28,277
But a new danger is heading their way.
264
00:34:31,154 --> 00:34:37,661
Now the wind has cleared the toxic gases,
the door opens for predators.
265
00:34:40,789 --> 00:34:42,123
A rajasaur.
266
00:34:42,123 --> 00:34:44,293
[growling, grunting]
267
00:34:47,880 --> 00:34:52,885
With so many babies out in the open,
this could be a feast.
268
00:34:58,182 --> 00:34:59,683
[snarling]
269
00:35:13,071 --> 00:35:17,201
Cracks in the lava
are the only possible hiding place.
270
00:35:47,773 --> 00:35:49,358
[chittering]
271
00:36:09,336 --> 00:36:11,755
More rajasaurs arrive.
272
00:36:18,262 --> 00:36:19,805
[grunting]
273
00:36:22,391 --> 00:36:24,184
[hissing]
274
00:37:26,747 --> 00:37:31,877
Despite the dangers, hundreds of babies
succeed in reaching the forest.
275
00:37:35,506 --> 00:37:40,385
Here, they will live together hidden
in the undergrowth for several years.
276
00:37:46,183 --> 00:37:47,518
Until finally
277
00:37:47,518 --> 00:37:50,562
they are big enough
to join their mothers' herds.
278
00:38:00,989 --> 00:38:05,577
With luck, the females among them
will return to this crater
279
00:38:05,577 --> 00:38:09,581
in years to come to lay eggs of their own.
280
00:38:12,376 --> 00:38:16,380
Like many animals that live
in such inhospitable places,
281
00:38:16,380 --> 00:38:18,257
the risks will be high.
282
00:38:22,511 --> 00:38:29,518
But there are also great opportunities
in the badlands of the prehistoric planet.
283
00:38:44,825 --> 00:38:48,829
This is the fossilized egg
of a giant dinosaur.
284
00:38:48,829 --> 00:38:50,247
A titanosaur.
285
00:38:50,998 --> 00:38:52,457
When freshly laid,
286
00:38:52,457 --> 00:38:55,752
it would have weighed
around a kilo and a half,
287
00:38:55,752 --> 00:38:59,381
and its shell
is about two millimeters thick.
288
00:39:02,384 --> 00:39:04,845
[Attenborough]
While the eggs certainly were tough,
289
00:39:06,221 --> 00:39:08,682
they still needed
to be kept safe and warm.
290
00:39:12,644 --> 00:39:16,106
So how did dinosaurs take care
of their eggs?
291
00:39:19,276 --> 00:39:21,361
[Naish] In order to protect their eggs
from predators
292
00:39:21,361 --> 00:39:25,782
{\an8}and to keep their eggs warm,
dinosaurs evolved a list of strategies.
293
00:39:25,782 --> 00:39:27,701
{\an8}One of these strategies was
to build a nest
294
00:39:27,701 --> 00:39:30,037
{\an8}and then to actually
sit on top of the nest.
295
00:39:31,663 --> 00:39:33,540
We know for certain dinosaurs did this
296
00:39:33,540 --> 00:39:38,837
because we actually have fossils
of dinosaurs sat on top of nests.
297
00:39:41,048 --> 00:39:45,719
[Attenborough] Eggs found in these nests
contain tiny babies of the same species
298
00:39:45,719 --> 00:39:46,803
as the adults,
299
00:39:48,138 --> 00:39:49,681
providing the first evidence
300
00:39:49,681 --> 00:39:53,268
that some dinosaurs
looked after their young.
301
00:39:56,480 --> 00:40:00,234
But although this offered protection
and shelter from the elements,
302
00:40:00,901 --> 00:40:04,154
there was a downside
to incubating eggs in this way.
303
00:40:06,281 --> 00:40:09,034
[Naish] Having to sit on an egg
and actually look after it means
304
00:40:09,034 --> 00:40:12,871
that you are committed
to the care of that egg
305
00:40:12,871 --> 00:40:14,623
for the entire duration
of their development
306
00:40:14,623 --> 00:40:16,625
up until the point of hatching.
307
00:40:18,377 --> 00:40:21,755
[Attenborough] For some dinosaurs,
it was a commitment worth making.
308
00:40:25,759 --> 00:40:30,138
But others, like sauropods,
faced a different challenge.
309
00:40:32,057 --> 00:40:34,434
[Barrett] It's likely that some dinosaurs
never sat on their eggs.
310
00:40:34,434 --> 00:40:37,187
{\an8}After all, many of these animals
weighed tons and tons
311
00:40:37,187 --> 00:40:40,482
{\an8}and would have crushed them
before they had any chance of hatching.
312
00:40:44,528 --> 00:40:46,405
[Attenborough]
So, what was their solution?
313
00:40:49,199 --> 00:40:51,451
[Naish]
There are some sauropod egg clutches
314
00:40:51,451 --> 00:40:55,873
where the female excavated a long trench
with her back feet.
315
00:40:58,542 --> 00:41:02,671
She then backfilled the trench
once she had laid all the eggs.
316
00:41:04,298 --> 00:41:06,717
[Attenborough]
This behavior can be seen today.
317
00:41:07,885 --> 00:41:11,597
Turtles bury their eggs to protect them
from predators,
318
00:41:12,723 --> 00:41:17,269
and the sun-warmed sand
keeps them at the ideal temperature.
319
00:41:19,396 --> 00:41:23,192
But some dinosaurs had another trick
to keep their eggs warm.
320
00:41:25,068 --> 00:41:28,447
[Naish] We think some dinosaur groups
deliberately collected
321
00:41:28,447 --> 00:41:30,657
and piled up rotting vegetation.
322
00:41:31,700 --> 00:41:36,079
They basically formed a compost heap
on top of their egg-filled nests.
323
00:41:38,415 --> 00:41:42,127
[Attenborough] Bush turkeys in Australia
use this remarkable technique.
324
00:41:43,420 --> 00:41:45,339
As the vegetation breaks down,
325
00:41:45,339 --> 00:41:48,759
it releases enough heat
to incubate their eggs
326
00:41:48,759 --> 00:41:50,677
for around seven weeks.
327
00:41:53,055 --> 00:41:55,724
But it was a discovery in 2010
328
00:41:56,517 --> 00:42:01,522
that revealed that some dinosaurs
had an even more unusual way
329
00:42:01,522 --> 00:42:03,148
of keeping their eggs warm.
330
00:42:04,858 --> 00:42:07,569
They use heat from the earth itself.
331
00:42:09,488 --> 00:42:11,323
[Barrett]
In one particular site in Argentina
332
00:42:11,323 --> 00:42:13,700
that's had lots
of sauropod egg discoveries,
333
00:42:13,700 --> 00:42:16,703
it's right next door
to some geothermal springs.
334
00:42:17,287 --> 00:42:20,624
We're thinking the sauropods
were using that volcanic activity
335
00:42:20,624 --> 00:42:22,292
to help keep its eggs warm.
336
00:42:24,628 --> 00:42:28,215
[Attenborough] Another location,
the Deccan region of India,
337
00:42:28,215 --> 00:42:32,052
one of the most volcanic areas
during the late Cretaceous,
338
00:42:32,052 --> 00:42:33,971
provides more evidence.
339
00:42:35,556 --> 00:42:38,308
[Naish]
There are many, many layers of lava,
340
00:42:38,976 --> 00:42:42,396
then in between the lava flows,
we find dinosaur eggs.
341
00:42:46,441 --> 00:42:48,569
Dinosaurs were coming to this location
342
00:42:48,569 --> 00:42:50,988
even when it was highly active volcanically,
343
00:42:50,988 --> 00:42:55,117
using it as a nesting site
for literally centuries.
344
00:43:01,164 --> 00:43:05,127
[Attenborough] Dinosaurs had many ways
to ensure their eggs would hatch...
345
00:43:07,296 --> 00:43:09,548
but we can be certain of one thing.
346
00:43:09,548 --> 00:43:11,675
[chittering]
347
00:43:11,675 --> 00:43:14,553
Their methods worked very effectively,
348
00:43:15,262 --> 00:43:20,684
helping them to rule the world
for over 150 million years.