Planet Dinosaur (2011): Season 1, Episode 5 - New Giants - full transcript

We're living through the golden
age of dinosaur discoveries.

All over the world,

a whole new generation of dinosaurs
has been revealed.

From the biggest giants

and the deadliest killers

to the weird and the wonderful.

From the Arctic to Africa,

from South America to Asia.

In just the last few years,

we have uncovered
extraordinary fossils,

exquisitely preserved
and tantalisingly intact.



Combined with the latest
imaging technology,

we have been able to probe deeper

and reveal more than ever before.

It gives us our first truly
global view

of these incredible animals.

In this programme
we examine the new giants...

the heavyweights
of the dinosaur world.

It's only in recent years

that we have unearthed the biggest
dinosaurs that ever lived.

Animals on such a huge scale
it is difficult to comprehend.

Just how and why did these titans
grow so massive?

And could any animal attack
such a huge beast?

One of these new giants
has eclipsed all others.

At 35 metres,
it was as long as Diplodocus.



Yet this dinosaur
was seven times as heavy.

The first glimpse of this new giant
was made in the 1990s

during a dig in Argentina.

In Patagonia, a fossil was pulled
from the ground.

It was a single vertebra, but it
was as tall as a human being.

Other bones followed.

They belonged
to the biggest dinosaur

ever known to have walked the Earth.

It lived in South America
95 million years ago.

In a world very different
from our own...

a world that is only now
giving up its secrets.

The start of a new life.

But on these plains,
danger is never far away.

This is a chaoyangopterid pterosaur,

attracted to the easy prey
of a nest site.

Throughout the late 1990s,

extraordinary dinosaurs
were uncovered in Argentina.

At one location, a nest site was
found, so full of dinosaur eggs

that they could barely avoid
crushing them underfoot.

Some eggs even contained exquisitely
preserved dinosaur embryos.

Then, in 1999,
at the same nest site,

a complete adult dinosaur
skeleton was uncovered.

It appeared they'd found the parent.

But first impressions
can be deceptive.

This isn't the parent.

This is a Skorpiovenator...

a predator.

The skeleton found at the nest site
was almost certainly a nest raider,

preying on the hatchlings.

The hatchlings' real parent,

and the owner of the enormous
vertebra is Argentinosaurus.

A plant-eating giant
that dwarfs everything around it.

From the bones that were found,

we've calculated
that Argentinosaurus

was a colossal 35 metres long,

and weighed as much as 75 tonnes.

When born, the hatchlings themselves
weigh a paltry 5kg

and need to fend for themselves
immediately.

From studying the embryos, and
looking at the bones of the adults,

we know that the growth
of these giants was phenomenal.

Over 40 years,

they grow from 5kg
to an astonishing 75,0ookg.

At their peak, it's been calculated
they grow up to 40kg every day.

The dinosaur embryos
are so well preserved

we can see they already
have their teeth,

in preparation for a lifetime
of eating.

But becoming a giant takes more
than simply turning tonnes of food

into muscle.

It's about the success
and survival of a species

over millions of years.

One way to increase
the chances of survival

is by having lots of offspring.

And the best way to do that
is by laying eggs.

Lots of them.

The nest site in Patagonia
stretches for an astonishing 15km

and contains
tens of thousands of eggs.

And the site was used continuously
for hundreds of thousands of years.

For killers like Skorpiovenator,
the nest site provides a feast.

But, with thousands of hatchlings,

they have little impact
on the success of the species.

And pose no threat
to the adults.

But, wherever we find
giant plant-eaters...

there is always a giant killer
lurking nearby.

And, sure enough, another startling
discovery was made in Argentina.

In the same region,
a nearly complete skeleton

of an enormous predator was
unearthed amazingly well preserved.

The skull alone
was over 1.5 metres long.

And when a second, even larger,
specimen was found,

it became clear that this was bigger
than any predator

that had been found before.

Bigger than T Rex.

It was clear that giant predators
roamed South America as well.

And it appeared that Argentinosaurus
may have met its match.

In fact, wherever giant plant eaters
have been discovered,

it appears a giant predator
lived alongside them.

From America, to Europe and Asia,

we see the same relationship
repeated.

But there was one place
on earth that remained a mystery.

For decades, Africa
was the forgotten continent,

a huge gap in our understanding
of planet dinosaur.

Then, in 2000, a cluster of bones
was unearthed in North Africa.

The bones were huge - one single
leg bone was as tall as a human.

It seemed this, too,
was a land of giants.

And that could only mean one thing.

There must also be a giant killer.

95 million years ago, this was a dry
and difficult place to survive.

Food and water were hard to come by
and often only found in one place...

along the banks of a river that has
earned the name River of Giants.

This is Paralititan,
a 45-tonne animal...

and the undisputed heavyweight
here.

For an animal this size,
it's not easy to keep cool,

so being near water is vital.

But rivers are dangerous places.

This is not a good place
for a young animal to get stuck.

And it's not just because of these
crocodiles.

This river holds
much, much bigger threats.

It may look familiar...

but this was no ordinary
crocodile.

With a skull nearly two metres long,

it's more than twice
the size of any modern croc.

This was Sarcosuchus.

Weighing as much as eight tonnes,

it's the undisputed king
of crocodiles.

A cold-blooded killer.

And if it can drag its prey into
the water and drown it, even better.

But, even for a deadly predator
like this,

the River of Giants holds dangers.

Across the world
from Africa to Argentina,

giant sauropods roamed far and wide.

This herd of Argentinosaurus
are now on the move,

travelling across a swamp
covered with volcanic ash.

It's a dangerous place to be
if you're living in the shadows.

These giants are so massive

they've turned the sand beneath
their feet into quicksand,

creating death traps
with every step.

It's a danger that was graphically
revealed in 2010,

when an astonishing set of
footprints were unearthed.

Footprints that contained
a deadly secret.

After months of painstaking
examination,

some of the fossil footprints
were found to contain

bones of other animals.

One exposed the bodies of
two mammals, ten small dinosaurs,

two crocodiles and a turtle.

In total, 18 animals were buried
within a single step.

But becoming this big is not easy.

It requires some serious eating.

Argentinosaurus weighed around
75 tonnes.

A six-tonne African elephant eats
for 18 hours a day to keep going.

Argentinosaurus weighs more
than ten times as much.

So how did they get enough food?

They turned themselves into the
most efficient eating machines

the world has ever known.

Everything about them
is designed to get the most food in

and the most calories out,
with the least effort.

Their long necks give them
access to more food without moving.

But the way they eat
is the crucial bit.

These giants don't waste time
chewing.

They rip and gulp down leaves whole,

which are digested by bacteria
in its massive gut.

Not chewing means it doesn't need
a big, heavy head

with big teeth and muscular jaws,

which also means
its neck can grow so long,

able to reach food
no other animal can reach.

Being so big means you're
off the menu for most predators.

Here, there's a killer
in a completely different league.

Over ten metres long
and weighing around four tonnes,

this is Mapusaurus. A newly
discovered killer on the block.

On its own, even it is not a match
for a fully grown Argentinosaurus.

But this giant killer is not alone.

For years, it was thought that
an adult Argentinosaurus would be

too big for any predator
to tackle.

But in 2006, a new discovery
suddenly made even

the biggest of dinosaurs a lot more
vulnerable. As they dug into

the Argentinean dirt, they didn't
just find one predator buried here.

The skeletons of at least
seven Mapusaurus of different ages

and sizes were found together.
It suggested that this was a group.

A giant killer that appears
to hunt in gangs.

And more than capable of taking on
the very biggest dinosaurs.

Not even a fully grown
Argentinosaurus

is safe from this group.

The best defence
is their sheer size.

Mapusaurus's teeth are perfectly
designed, like blades,

to slice off chunks of flesh.

With prey so large, a single bite
isn't always fatal.

It appears Mapusaurus
could just snack,

feeding from its victim
without actually killing it.

The victim surviving to provide
more food at a later date.

But even in a group,

these giant killers are never far
away from danger.

Attacking an animal more
than ten times your weight

carries grave risks.

Even with the threat of predators
hunting in gangs,

the phenomenal size of these giants
would usually keep them safe.

But a giant needs to grow.

It's the younger, smaller animals
that are in greatest danger from

giant predators like Sarcosuchus.

And here in Africa
there is nowhere to hide.

Things are about to get even worse
for the young Paralititan.

Around the river of giants,
there is another killer.

Carcharodontosaurus. A predator
always looks for the easiest kill,

the weak, injured or young.
The Paralititan is all three.

In such a deadly game of tug of war
there can only be one winner.

But the kill is still not certain.

Carcharodontosaurus can tackle
this youngster,

but a herd of 45-tonne adults
is another matter.

Injured but alive, this youngster
has a lucky escape.

Encounters like this have left
tantalising clues behind.

Amongst the bones of a Paralititan,

we have found a Carcharodontosaurus
tooth suggesting

a predator-prey relationship.

They complete a global picture,

a pattern that is repeated
across the world.

In Asia, we find Mamenchisaurus
and Sinraptor.

In North America, Diplodocus
and Allosaurus and now Africa.

For every giant plant eater
we find a giant predator

living side by side.
And it's in South America

where we have the biggest of all.

Argentinosaurus and Mapusaurus.

Two giants whose fates appear to be
inextricably linked.

This Argentinosaurus
wounded by a gang of mapusaurs

has succumbed to its wounds.

Out on the plain, other keen-eyed
predators are quick to spot

a stricken animal.

It's a prize worth waiting for.

And attracts
carnivores from miles around.

Mapusaurus are not only hunters.

Like virtually every carnivore
today,

scavenged prey plays a huge part
in their diet.

We know enough about the biology
of giant sauropods

to estimate of this 70-tonne
animal, 11 tonnes is bone,

three and a half tonnes blood,
four tonnes is hide and skin,

15 tonnes fat and 39 tonnes is meat.

Enough to feed a whole
ecosystem for days.

Mapusaurus was reliant on the giant
sauropods in life and death.

When the Argentinosaurus disappeared
from South America

93 million years ago,

so did the giant predator
Mapusaurus.

It was the same story in Africa -
when Paralititan vanished,

Caracharodontosaurus followed.

It appears that these
extinctions were linked,

and this story is repeated
time and again.

When the giant sauropods
died out,

the giant predators
lost their main food supply

and they too were doomed.