Original subtitles

Over 66 million years ago...

SCREECHING

..our world...

..was ruled...

..by dinosaurs...

SNARLS

..the largest animals

that have ever walked the Earth.

Today, dinosaur experts across the globe

are uncovering the bones they left behind...

..allowing us to imagine

how these extraordinary creatures may have lived...

..so that we can tell their stories...

..and they...

..can walk again.

ROARS

Amongst the jagged mountain peaks...

..majestic valleys...

..and scattered hill towns of central Portugal...

..an astonishing discovery has been made...

A find so remarkable

it's drawn a team of dinosaur hunters

from across Europe.

Buried here are the remains

of a colossus.

A monumental long-necked Lusotitan.

Known as Old Grande...

..he's one of the largest dinosaurs

ever to have lived.

And using his bones,

we can begin to imagine this giant's story.

In the Late Jurassic,

our planet looks very different.

Amongst its shifting continents,

a small landmass known as the Iberian Meseta,

that one day will include Portugal,

lies surrounded by ocean.

An island cut off from the rest of the world.

CHIRPING

Dense coniferous forest covers much of the land...

..giving way to windswept beaches on the coast.

SQUAWKING

MUNCHING

Here, if you're in luck...

..an easy lunch can be found.

For torvosaurus, the island's top predator,

it's an opportunity

worth fighting for.

SNARLS

LOW GROWLING

THUDDING

But even these four-tonne carnivores...

..are no match

for the enormous Lusotitan -

Old Grande.

LOW GRUNTING

At a staggering 40 tonnes...

..he is the undisputed king of the island.

But as a herbivore,

he isn't on the hunt for food.

He's been drawn to the beach by the allure...

BELLOWS GENTLY

..of a female.

BELLOWS GENTLY

As an ageing male,

this may be his last chance to mate.

But female Lusotitans are only receptive

for a few weeks of the year...

..so he doesn't have long to make an impression.

150 million years later...

..the true scale of Old Grande is emerging

from deep beneath the ground.

As the most complete Lusotitan ever found,

his remains allow the team,

led by Professor Francisco Ortega

and Drs Elisabete Malafaia

and Pedro Mocho...

..to piece together the extraordinary dimensions

of this animal.

They're starting with how tall he was...

..which they can estimate

using the bones from his gigantic front limb.

Their calculations make Old Grande

one of the tallest of his species ever discovered...

..which is certainly one way to impress a mate.

Female Lusotitans may have been most attracted

to the biggest males...

SNORTS

..a sign their offspring will be healthy and strong.

So it should be easy for Old Grande to make his mark.

But it's not all about him.

Before they will mate,

female Lusotitans must first wait for the seasonal rains...

..making sure there is enough fresh vegetation

for their young.

And this year, the rains are late.

Old Grande has no choice but to wait.

He must guard her closely

and hope there is no other suitor close by.

LOWING

But love rarely runs smoothly.

Three miles from where Old Grande was found,

the team has made an important discovery.

The fossilised rib is a similar size to Old Grande's.

But given its distance from the main dig,

it's unlikely to be his.

Unearthing two Lusotitans so close together

is unheard of.

So the team is keen to learn more.

They cover the sections of rib in a layer of plaster...

..so they can be removed safely...

..and examined in one piece,

which is a massive 3m long.

Like elephants and rhinos today,

Lusotitan bulls were likely solitary

and very territorial.

Just like Old Grande,

this rival male would have been searching for a mate,

creating the potential...

..for a dangerous confrontation.

LOW GROWL

Although this contender may be younger than Old Grande...

..he's not afraid to challenge him

for the attentions of the female.

GROWLS

GROWLS

Old Grande is a seasoned fighter

and the largest bull on the island.

A stern warning...

..should be enough to make this upstart back off.

But all is fair in love...

..and war.

BELLOWING

The surprise attack leaves Old Grande seriously hurt...

GRUNTING

..his leg badly injured.

Struggling under his colossal weight...

..he is unable to right himself.

He can only watch...

..as the rival takes his place at the female's side.

For a dinosaur of his size,

a badly damaged leg could mean the end of the road.

So could a Lusotitan survive this kind of injury?

On the coast, a significant piece of evidence might provide the answer.

But reaching it won't be easy...

..because what was once flat ground during the Jurassic

is now a near-vertical cliff face.

So Francisco must descend over 100m.

Etched into the cliff face are footprints

thought to have been made by a large Lusotitan.

And they reveal something surprising.

The discovery of a limping Lusotitan

is important evidence.

It suggests that injuries to their enormous limbs...

..were survivable.

Even so, Old Grande is still weak...

..and won't last long

on a damaged leg.

But he does have a remarkable way...

..to speed up the healing process.

It's known as osteophagia.

Like modern-day giraffes,

he supplements his diet

by breaking apart and swallowing

the skeletons of dead animals.

Like the carcass of this pliosaur,

whose bones are rich in the minerals he needs...

..to repair his own body.

But he's still a long way from recovery...

..and a limp like his...

..may not have gone unnoticed.

Following the path of the Lusotitan footprints...

..something has caught Francisco's eye.

The second set of prints is another 85m

down the sheer cliff face.

Unable to reach the prints by land,

the team decides...

..to take to the air.

Whoa, whoa, whoa.

I think...

Oh...

See?

Yeah.

The second set of prints follows the same path

as the Lusotitan.

But from their distinctive shape,

it's clear they've been made by a different species.

Theropods are a group of dinosaurs that includes T-rex.

But on this island,

the prints are likely to come from a predator...

..Old Grande would be much more familiar with.

The torvosaurus.

10m long and over 3m tall,

this adult female would normally be no match

for a heathy Lusotitan.

But the pain in Old Grande's leg

has become unbearable.

And he must rest until he can recover.

It could mean days without food or water,

leaving him exhausted...

..and vulnerable.

An opportunity this big...

..is rare.

LOW GROWL

But Old Grande is too strong to take on now.

So she's prepared to stay close...

..and wait.

As the days pass...

..Old Grande rests.

LOW GRUNTING

The torvosaurus...

..risks an approach.

SCREECHES

ROARS

A close call.

BELLOWING

Old Grande must recover soon,

because next time

he may not be so lucky.

BELLOWING

At long last...

..Old Grande's leg is finally on the mend...

..and he has unfinished business -

finding the female that left him behind.

But both she and his rival are now miles away...

..and the clock is ticking.

He must move as quickly as he can.

150 million years later...

..the team has made a discovery

that could reveal how fast

a giant like Old Grande travelled.

The new find gives the team an almost-complete profile

of Old Grande's front limb.

Putting these measurements together

with their findings from the cliff-side footprints...

..they can now calculate his speed.

It may sound slow, but like modern elephants,

it's thought Lusotitans could keep up this pace

over huge distances.

This is just what Old Grande needs to do

as he travels miles across the island,

looking for the female.

But he's almost out of time.

THUNDER RUMBLES

A distant storm

heralds the arrival of the seasonal rains.

LOWING

THUNDER CRACKS

The female will finally be ready to mate...

..leaving Old Grande in danger of missing out to his rival.

THUD RESOUNDS

But he's not just relying on his pace alone.

He's using an extraordinary ability to locate the female...

..one he's thought to share with modern-day elephants.

His stomps send powerful seismic waves

through the ground.

SNORTS

QUIET LOWING

Many miles away,

she feels the earth move...

..through specialised nerve endings in her feet...

LOWING

BELLOWS QUIETLY

..and she answers...

..her suitor's call.

THUNDER RUMBLES AND RAIN FALLS

Detecting her response

keeps Grande heading in the right direction.

THUNDER CRACKS

But he must reach her before he misses his chance.

At the dig site, a new section of Old Grande's bones

is emerging from the rock.

..this vertebra. OK.

So perhaps, OK, this is...

..including fossils that belong to his giant tail.

But laying them out from the biggest on the right...

..to the tip on the left,

Pedro has noticed something unusual.

One of the bones doesn't belong in the sequence,

and it's too small to be part of Old Grande.

It's a significant find...

..because a second adult so close to Old Grande

could mean he did find his mate.

After miles of walking...

..he's reached the area

where the female last responded to his call.

BELLOWS QUIETLY

BELLOWING

DISTANT BELLOW

Reunited at last.

DISTANT BELLOW

But the moment...

..is short-lived.

THUDDING

BELLOWING

The rival male has stayed close...

..and he isn't going to give up without a fight.

BELLOWING

THUNDER RUMBLES

Each bull uses his colossal weight...

..as a battering ram.

But these giants are too closely matched.

So, changing tactics...

..they use their teeth

to inflict intense pain.

But neither is backing down.

Taking his chance,

the rival pins Old Grande.

BELLOWING

Rearing up to the height of a four-storey building...

..he bears down with his enormous weight.

But this time...

..Old Grande refuses to go down.

GROANS

A decisive victory.

BELLOWING

But Old Grande still faces one last challenge.

Persuading the female...

..he really is the bull for her.

MACHINERY WHIRS

And it could be that Francisco has discovered the key

to what made Old Grande irresistible.

It's a series of disc-shaped vertebrae

that once formed part of his long neck.

The bones are incredibly fragile...

..so the team covers them in a protective membrane.

But these neck bones are not delicate

simply because of their age.

Each one has a hollow structure,

which may have served a vital purpose.

This dynamic movement would have allowed Old Grande

to walk, fight, and, crucially, display.

It's exactly what he needs to charm the female...

..because he hasn't won her over yet.

LOWING

Like many birds today...

..it's thought he would use his long, lightweight neck

and flexible tail

in an elaborate courtship display...

..with every move he makes

carefully assessed by this most discerning of judges.

And she responds.

Staying in sync with each other's moves...

..will be crucial to proving they're compatible.

But just as everything was going so well...

..Old Grande gets a little overexcited.

GRUNTS

LOWING

Fortunately, he has one last trick up his sleeve.

Just like modern birds such as frigates...

..Old Grande has an inflatable sac to attract attention.

It seems to have worked.

LOWING

And in the hills of central Portugal,

Pedro, Elisabete,

and Francisco have also completed their mission...

..finishing this year's dig

with a treasure trove of fossils.

Even as they pack up, they're already making plans

to return next year.

While they may never know how Old Grande met his end...

..his bones appear to be entwined

with a female Lusotitan.

And so, just maybe,

with her, he was able to secure his legacy.

A batch of giant eggs.

Buried safely beneath the ground...

..this next generation of Lusotitans...

CRACKING

..will soon begin their own story.