All language subtitles for Attenborough and the Giant Sea Monster

DAVID ATTENBOROUGH: I'm on
the south coast of England

in what is known
as the Jurassic Coast.

150 million years ago,

the land was ruled
by dinosaurs...

...but the oceans
were dominated

by a mysterious sea monster.

Its remains are very rare,

but some have
just been discovered

in the cliffs behind me.

And now fossil experts
are working to unearth

this extraordinary find.

No-one's ever done this before,
ever!

Extracting a giant skull
halfway down a cliff face!

This colossal creature

is called a pliosaur.

But little is known
about these prehistoric giants.

What an extraordinary
and terrifying thing!

Together,
with a team of scientists,

we will use new technology

to discover more about
this enormous marine reptile.

I have no doubt that this pliosaur

was the T-rex of the seas.

Comparing it
with animals alive today...

..we can deduce a great deal
about their sheer strength.

This pliosaur has a bite force

that's about twice
the great white shark.

Well, that's unimaginable.

Could this be
the greatest Jurassic predator

that ever lived?

Britain has a wealth

of fossil sites,

but perhaps none
are quite so famous as this,

the Jurassic Coast.

I've been collecting fossils
since I was a boy,

and I haven't yet
got tired of it.

These days, you're supposed
to wear glasses for safety.

And, if you would know a locality,

you would begin to recognise
the sort of block

that might contain a fossil.

And this rock was split earlier

to make it easier to show you.

And if I can...

..hit it quite hard about there...

HE LAUGHS

What about that?

Is anything more beautiful
than that?

Fantastic.

Finding even the smallest fossil

is a thrill, but discovering
something much larger

can be an unforgettable moment.

And that is exactly what happened

to a fossil enthusiast,

who was walking along a beach

near Kimmeridge Bay
in Dorset one morning.

I just found
something quite extraordinary -

it's the jaw of a massive pliosaur.

It's enormous.

It's a massive pliosaur.

It's the best fossil
I've ever found.

It must have just come out
of the cliff up there somewhere.

Renowned fossil expert
Steve Etches was called in,

and he realised immediately

that this find could be
hugely significant.

Look! Look at those teeth.

There's a tooth there - look.

Let's have a look at the front.

You can walk along here
for hundreds of times

and not find anything,

and then, occasionally,
you'll hit the jackpot.

And this certainly is the jackpot.

It's the snout
of an enormous pliosaur skull.

And Steve suspects
that the rest of the head

might still be embedded
in the cliff above.

But he needs to work fast

before the whole thing tumbles
into the sea

and is lost for ever.

So he quickly gathers
a team of experts,

including fellow fossil-hunter
Chris Moore.

It's day one of the dig.

Steve and a team of diggers
are up on the cliffs.

They're putting a net down
to stop any loose rock

rolling down and hitting us,

and then we'll go down
and expose the skull.

DRILL WHIRS

Steve and Chris have worked
together for decades.

But this is the biggest challenge

they have ever faced.

The location of the skull,

high up
on a disintegrating cliff face,

makes it very difficult to reach

and even harder to work on.

These rocks were once mud
on the seafloor...

..in which the remains
of prehistoric marine creatures

were buried.

Over millions of years,
the continents shifted,

the seas receded,

and today, as these cliffs erode,

fossilised skeletons are revealed.

The jaw is there, and the idea

is to actually cut this down
vertically,

and then we form a platform
where the fossil is.

I've known Chris and Steve
for many years,

and I can't wait to join them

and find out how they're getting on.

Here, we've got a live feed
to them actually digging

halfway up the cliff face.

What's happened so far,

the tip of the snout has already
come out and been recovered,

so the rest of it
is going into the cliff.

What exactly are they doing there?

At the moment, they're using tinfoil

to try and protect
the exposed piece of jaw.

In case something falls on it
and breaks it?

Yeah. Yeah, yeah.

And then they're also using
superglue to consolidate

the crumbly teeth and parts

that have been weathered
over millennia.

And they're hanging by ropes there?

Yes, pretty much
in the centre of the cliff.

Dear me!
Pretty dangerous stuff, this.

Yeah, yeah, it really is.

After you've worked there
for a few hours,

it becomes a bit more natural.

And you concentrate
on the actual digging.

You must be pretty sure
that there's something there

to put this amount of effort
into it, really.

Oh, positive
there's something there.

It's beautiful.

It's a beautiful specimen.

Is it?
Yeah. Amazing.

But what can
this spectacular find reveal

about the lives
of these mysterious sea creatures

and the world they inhabited?

In the Late Jurassic,

Europe was an archipelago of islands

much closer to the equator
than it is today.

Its seas were warm, shallow
and teeming with life,

and, in these waters,
underneath my feet,

lurked the ultimate
marine predator...the pliosaur.

Unlike dinosaurs that lived on land,

these colossal marine reptiles

spent their whole lives
in the ocean.

They're thought to have been
around 10m in length...

..that's about the size
of a double-decker bus.

They had long, broad flippers,

short, strong necks...

..huge heads

and enormous jaws.

But there's still a lot
we don't know

about these great sea monsters,

which is why this new discovery

is so important.

Steve believes
that the entire pliosaur

may still be inside the cliff...

..but it's the skull
on which he's concentrating.

A skull can reveal
more about an animal

than any other part of its skeleton.

Finding a complete specimen
is rare,

but it can tell us a great deal

about how the animal lived.

It's quite hot and thirsty work.

Steve and Chris think they will have

about three weeks
to dig the fossil out

before the storms
of late summer come.

This is a learning curve.

I thought, stupidly,

that it wouldn't be
quite as hard as this.

We're probably over a metre in.

There's the skull there,
just behind me.

It's up to us now to get it out
without any damage.

If the skull is
successfully extracted,

it will be taken
to the Etches Collection Museum

in Kimmeridge, which was founded
by Steve in 2016

and now contains
nearly 3,000 fossils

from the Jurassic period.

This was where the pliosaur snout

was brought to be assessed.

And I've come here

to learn what
Steve has found out so far.

What an extraordinary
and terrifying thing!

Huge teeth.
They are. They're massive.

These big, fang-like teeth
that come up.

And they interlock.
Yes, they do.

So how far do these teeth extend?

They come right up here.

Is that characteristic of this?

Yes, typical pliosaur.

It's trihedral teeth,
they're sort of...

They've got two sharp cutting edges

and then a flat face
on the inside.

They must have used that
to rip apart ichthyosaurs.

Ichthyosaurs, plesiosaurs as well -

we've got evidence in the museum.

Because they've got
subtriangular teeth,

when they bite into a bone,

they leave
a very distinctive tooth hole.

Steve's collection contains
a limb bone of a plesiosaur,

another large marine reptile,

which has bite marks on it

that exactly match the size
and shape of pliosaur teeth.

What a godsend it is
that the teeth are triangular,

so that you're able
to then identify prey...

Oh, yeah.
..just as much as you can identify

the one that was the predator.

That's right.
Well, that's pretty unusual

to find teeth in position.
It is.

This is the first pliosaur
I've ever seen

with actually closed jaws.

It is extraordinary.
Mm.

It is quite extraordinary.

And there is another unusual feature

on this snout.

So let me show you the other side.
I'll spin it round.

Oh, gosh.
There's a lot of stuff here.

Oh, yeah. And these...

These holes here.

Well, I think
these are sensory pits,

they're all on the snout.

If you look at them, they go...

See, they strike back in
at an angle. Yes.

They're sensory pits
for picking up its prey,

I'm pretty sure.
Pretty impressive beast.

Astonishing.
Mm.

But exactly how did these sensory
pits help our pliosaur to hunt?

These days, we have equipment

that can help us answer
such a question.

We take the snout
to the University of Southampton,

which has some of the most powerful

CT scanners in the UK.

On that. That's it.
Then we upright it.

Dr Katy Rankin is a specialist

in scientific imaging.

She takes thousands
of X-rays through the fossil

that reveal its internal structure.

But even with such high-tech
equipment, the process

is not straightforward.

The snout was very challenging.

A typical CT scan
can be around an hour.

In this case, because the fossil
was very, very dense,

it actually took very, very long.

So it took about five days.

Five days?!
Yes.

With the scan finally complete,

paleobiologist Dr Neil Gostling

is looking for clues
about the sensory abilities

of our pliosaur.

So what does this scan tell us?

I've taken the CT data,

and we can rack our way
through this stack of images

and we can see
all of those internal structures,

which otherwise
wouldn't have been revealed to us.

And there were some things
which are, I think, quite exciting.

We've got
these little structures in red.

And I had to do these,
each one, slice by slice,

dot by dot, because there's lots of
imperfections and holes in it.

But these are continuous,

and I think these are blood vessels,

little branching blood vessels.

Now, come on.

BOTH CHUCKLE

You're really telling me

this block of stone
can show blood vessels?

Yes, and what I think we've got here

are actually branches
of the trigeminal nerve.

And these are the sensory nerves

in your face that allow you to feel

fingers dancing over your cheeks
and what have you.

But if you're in water
and you've got these sensory pits,

you can detect changes in pressure.

That's going to give you
an advantage

in what might be murky water,

where your eyes
aren't working so well.

So you can always be sure

that you're going to catch
your next meal.

Fantastic.

Knowing how these senses worked,

we can start to build up a picture

of how our pliosaur hunted.

Its prey...

..ichthyosaurs -

reptiles much the same shape
as a modern dolphin

and similarly fast and agile.

The sensory pits found
on our pliosaur's snout...

...may have acted
like miniature pressure pads,

detecting the turbulence
produced by ichthyosaurs

as they swam through deep water.

In effect, our pliosaur
was able to stalk its prey

even in the darkest depths,
just by using its skin.

There are animals today

that have
similar sensory systems.

Crocodiles have
over 9,000 pressure receptors,

which are concentrated
on their snouts,

each one of which is thought
to be ten times more sensitive

than a human fingertip.

Two weeks into the dig,

and the work is proving
to be even harder

than anyone was expecting.

Let me throw this big chunk away.

The last couple or three days
have been...

HE SIGHS
I think it's been sapping everyone.

I think it might be a tooth.
Let's have a look.

But it's got no crown.
Let's have it. Let's have it.

All right! You weren't like this
with David Attenborough.

I bet you didn't give him
a load of lip, did you?

Yeah, but I like him.
Oh. All right, then.

THEY LAUGH

Being 11 metres up a cliff
is one challenge,

digging through incredibly
hard rock with air tools -

every lump is hard won.

But, at last,

there's a breakthrough.

There's something
under there which is huge.

Here, you've got the jaw showing,

and this one's heading back
this way.

It's going to be the underneath
of the skull.

There's a vertebra there.

There's another vertebra there.

Finding these bones confirms
that the entire skull

really is inside the cliff.

It's nice to actually see something.

You feel like
you've been rewarded a bit.

What Alex is doing, he is
chipping out a loose tooth.

Hang on, that's the crown! Yeah.
Oh, that's interesting.

Yeah. Keep going.

LAUGHS GIDDILY

This is part of the root
and there's a pulp cavity there.

That tooth will be probably
about ten inches long.

THUNDER RUMBLES

Oh, the thunder's coming.
Oh, look at that.

Just as the dig is revealing
further exciting finds...

Go on, guys.
Yeah, come on, Chris.

We've got a lot to do.
We've got to get you all up.

..conditions become treacherous,

and the rope safety team decides

that it's too dangerous to continue.

Now it's rained,
this lithified mudstone

is turned like a slippery clay,
it's lethal.

There's certainly no way now,
with us stopping now,

that we're going to get it done
in those days left.

The weather may be against them,

but finding a pliosaur tooth
is a real stroke of luck.

It could also help us
understand more

about the type of prey
our sea monster could eat.

Back in Southampton...

MACHINE WHIRS

..the scan has revealed
something even more intriguing

about the pliosaur snout.

These teeth are extraordinarily
well preserved, aren't they?

Is there new information
that we can get from this?

Well, from the CT scan,

if we take it back again
so we can expose the teeth,

these are large, pointed teeth,

and these are really well adapted

for grasping slippery fish.

But this is on
an order of magnitude larger,

which would have allowed it
to eat all sorts of prey

that are swimming around

in the ancient Kimmeridge Bay
of the time.

Were the teeth permanent,
or were they replaced?

As we move it back through,

we can see
that we've got individual teeth

almost all the way along.

However, in one place,

we've got this little tooth here,

and this is a replacement tooth.

The thing that most animals die of

is that their teeth have worn out,

and they can't feed any more.

And, if you are a large predator

and you are catching large prey,

you might lose teeth
relatively frequently.

Well, this isn't such an issue
if you can replace your teeth

multiple times throughout your life.

Not only were its teeth replaceable,

but they were also shaped
differently -

long and sharp
towards the front of its jaws,

more hook-like at the back.

This deadly combination meant

that pliosaurs could feed

in a variety of ways,

from grabbing large sharks
and squid

to gripping smaller, slippery fish.

But pliosaur teeth
have another special feature,

which scientists are only just
beginning to understand.

These are exact replicas,

cast from the teeth
of our own pliosaur.

As you can see, they're very large

and also trihedral - three-sided.

If we look closer at this one,

we can see it has
very distinct ridges,

known as striations,

that run vertically down the tooth.

A recent study by scientists
in Australia investigated

why pliosaur teeth had these ridges.

And I'm keen to test
some of these theories myself.

The research proposed that,

when the pliosaur plunged
its teeth into its victim,

these tooth ridges could have helped

to not only pierce the flesh

but also prevent a vacuum forming.

So I am going to try and imitate

our sea monster's bite,

using the replica teeth
and a block of ballistic gel,

an artificial equivalent
to animal flesh.

This pliosaur tooth has had
its ridges entirely removed.

Without its striations,

the surfaces are now
completely smooth and flat.

So firstly, if I plunge
this smooth tooth

into the gel...

That did feel difficult
to push the tooth in

and pull it out again.

But now, if I repeat the same
movement with the ridged tooth,

in theory, it should feel easier.

Smoothly in.

And I'll put it out...

..no bother.

Well, that certainly felt
significantly easier.

To get a more scientific opinion,

we test the teeth
at the University of Bristol,

and the results indicate
that the ridged teeth

do require less force
to be pushed into the gel.

While this area is new to science,

it seems that the theories
were on the right track.

The ridges on its teeth
could have enabled the pliosaur

to more easily capture
its prey underwater

by allowing it
to swiftly and repeatedly bite down,

ensuring a quick, successful kill

for this Jurassic sea monster.

METALLIC HAMMERING

Three weeks into the dig,
the weather is holding.

And now the biggest question
for Steve and Chris

is how to lift the skull
off the cliff.

I reckon we take out a big slab.

One piece? Yeah.

Cut it underneath?
What, cut underneath?

Yeah.
All the way through?

Yeah. I can't see
any other way of doing it.

If we do it any other way,

it's going to just crumble up.

What do you think? I think I'm going
home and not coming back!

Luckily, for Steve and Chris,

friend and local farmer
Rob Vearncombe

has been devising a solution.

He's building a crate, which will be
lowered down the cliff,

into which the skull
will be manoeuvred

and then hauled up to the top.

Yeah, I'm actually
a farmer by trade.

Because of all the machinery
and building that's involved,

effectively,
I'm a self-taught engineer.

But it is a massive challenge,

from an engineering point of view.

Rob believes that the crate
will enable them

to get the skull safely
to the top of the cliff.

The theory is that
whatever angle the skids are,

as it comes up the cliff,

the box stays level
to protect the fossil

because we're trying
to keep the fossil

as level as possible.

The big day finally arrives,

and a local army of helpers
is assembled

for this crucial stage
of the operation.

And Steve is feeling the pressure.

With the best will in the world,

it looks like
it's all going to function,

but the risk is immense.
You know, what happens

if it just actually turned
on its side?

There's a lot of things
that could go wrong,

so it's a risky sort of time.

This is one of the largest
and best-preserved

pliosaur skulls ever found.

So the stakes are very high indeed.

When it comes down,
we've got to get that aligned

and we've got to get that jaw,
that skull inside that box.

And we've got to be really careful

that that sled has got a metal bar

and, as it comes down,
it doesn't hit the nose.

No-one's ever done this before,
ever.

Extracting a giant skull
halfway down a cliff face!

The crate must be lowered
into position with great precision

if the skull is not to be damaged.

The position it's coming
down in, it's almost...

It's going to glance
the side of the skull.

Whoa there! Stop!

RADIO: Stop.
Stop.

So somehow,
we've got to manually try

and move the whole sled over.

RADIO: I think
we could afford to do

30cm lower and no more.

After weeks of back-breaking work,

emotions are running high.

Down! Come on.
Quick! Quicker!

This moment's really fraught.

We've got one skid just about
glancing the side of the skull,

and we've got
to try and pull it out now

to get it over the edge.

Very slowly. Six inches.

One clumsy move,

and the skull could be smashed.

Oh, my...
Oh, pull! Pull again.

My hand... That's all right.
Missed it! We've done it!

Stop, stop!

It's all pretty stressful.

Every part of this
is really, really stressful.

After quite a few hours,
we've got it into position.

We haven't knocked the end
of the snout off so far,

and it's all ready to go.

But the next stage
looks even more risky.

Just retreat from the edge,

and we're going up the ropes now!

Al and Steve are going to go
up to the hole

and attach the winch,

and then start the process of slowly
dragging it into the box.

Shifting a fossil that weighs
over half a tonne...

HE GRUNTS

..is really dangerous.

It's moving. It's very nervous
and it's very tense.

So let's see how it goes.

Oh... Go on.

That's good.
That's better.

That's...
Whoa!

Right, I think slide it straight in.

Steve, is it OK?
Has it come off OK?

Well, we're losing a bit of it,
but you can't help it, mate.

Go on. Go on.

Now it's on it. There you go.

Right. Off you go.

That's it. Good, that'll do.

That's well in.

RADIO: It's right in the cage now.

Hey, the fossil's in!

Brilliant, mate.
We're all cheering here.

Well done. Well done.

Well done, everybody.

Right, well done. Brilliant.

We've overcome a lot
of problems to get this far,

and we've done it
by the skin of our teeth.

The skull, at last,
is in the crate...

RADIO: Take up the slack again.

..but shifting it carelessly,
let alone dropping it,

could be disastrous.

Come over a bit.

So there'll be six ropes coming up

to be able to lift it
and hold it steady...hopefully.

With the tide coming in
and the sun setting,

we couldn't cut it any finer.

OK, right. Whoa! Whoa, whoa, whoa.

Finally, the skull is safe.

Brilliant, Rob.

Well done. Well done.

THEY CLAP

Yeah.

It's amazing.

It's a dream come true.
And I'll tell you what,

I don't think anyone would ever
believe we could've done it.

Three weeks ago,
it was buried in a cliff face.

We found the top
food chain predator,

and now we're bringing it
back to life.

And this will be one of the best
that's ever been found.

Hey! Hurray! Good on you.

Oh! None of that.

Go on. Oh, get off,
you little devils!

Oh, dear. Oh, dear.

It's out. The next stage starts.

The skull is transported
to Steve's workshop.

Ready? Go!
One, two, three. Lift.

Right up.

Oh, my God!

The mudstone's cracked and dried.

Of course, what it's done

is just cracked the bone as well.

Jeepers creepers.
You'll be fine!

Oh, yeah. I can see this is
the biggest jigsaw going.

Luckily, you're a young man,
though, aren't you?

Yeah, yeah. Plenty of time.
Yeah, plenty of time.

The painstaking task of removing
the stone from around the skull

so that it can be examined
in detail...

..can at last begin.

After the heavy work of the dig,

this stage requires
a delicate touch.

First, Steve removes the rocks
surrounding the fossil...

DRILL WHIRS

..so that the fragile area
of the skull can be strengthened.

Then, using an air abrasion tool,

he starts work to reveal
the more intricate details

about the anatomy
of this extraordinary animal.

This giant sea monster,

after 150 million years,

finally begins to emerge
from the rock.

And I have the privilege
of coming to see this whole skull

for the first time.

So here it is.

And it's enormous.

I am meeting Dr Judyth Sassoon,

a palaeontologist, who has studied

pliosaur specimens for decades.

Does it still take your breath
away as it takes mine?

It is a most astonishing
specimen, David.

I'm very pleased to be part
of the work on it.

What insights can Judyth give us

into the life
of this ancient monster?

How is it coming along?

What sort of detail
can you get from this,

which you never knew before?

Steve Etches has been working on it
now for several months

and has made some fabulous progress.

We're seeing,
as it's being prepared,

gradually, more and more detail
being revealed.

So far, we have some information

about its senses.

Really?
Was their eyesight good?

There are indications that,
in fact, it could have been.

The eyes themselves
were quite important

for this animal.

One of the reasons
is the position itself.

The eyes are on the side
of the head,

more or less in the middle,

so not too high and not too low.

This important feature
of the skull may suggest

how our pliosaur hunted
in the open ocean.

The position of the eyes
in living animals varies

according to the way
in which they hunt.

Dolphins are pursuit predators.

Their eyes are placed
on the side of their heads,

which gives them
panoramic vision...

..enabling them to attack
their prey with great accuracy.

Ambush predators,
such as crocodiles,

have eyes higher up
on their heads...

..so they can remain
just below the surface

with only their eyes above water

and judge when to attack.

Our pliosaur seems to have had

something in between...

..with an eye position
that not only enabled it

to pursue prey through
the water with accuracy,

but alternatively surprise it
by attacking from below.

And there is
another remarkable feature,

which could tell us more about where
our sea monster may have hunted.

We talked about eyes. There's also
another interesting structure,

which is the parietal eye.

In many reptiles, this still exists.

When it is present
in terrestrial animals,

it has a full eye structure,
like the lateral eyes,

and is light sensitive.

The parietal eye
on the top of the head

is something of a puzzle.

It's known as a third eye

and is still found
in a few living species.

It apparently helps an animal
to regulate its body clock.

The pliosaur's parietal eye
is thought to have had a lens,

a cornea and a retina.

Although its exact function
is unclear,

it may have enabled
our sea monster to gauge

which way was up
when swimming at depth,

and potentially navigate
deeper hunting grounds.

What other questions
would you have wished the skull

to provide answers for?

I've already made some measurements
on this animal,

and the proportions
do seem to be different

from other pliosaurs that we know.

The skull is quite long-snouted,

but the position of the nose
and the eye

and also of the crest

suggest that it is
something else, something new.

A new species of pliosaur?
Of pliosaur, yes.

A new species? Really?
Yes.

I think it could be, yes.

The revelation that our pliosaur
could be a new species

is truly exciting.

There are only eight
recognised species of pliosaur...

..and this skull is certain
to provide new scientific data

on the evolution of these
mysterious marine reptiles.

I have to say,
you take my breath away.

The detail, which you can deduce,

it is mind-blowing, I think.

And that's what
palaeontology is about.

I used to think it was just
a question of finding a fossil

and digging it out
and saying how nice it was.

You've made it sound
rather different.

DAVID CHUCKLES

In recent decades,

huge advances have been made

in our ability
to study prehistoric animals.

And we can now investigate the
predator power of our pliosaur

in more detail than ever before.

Paleobiologist Dr Andre Rowe
is a world-leading expert

in 3D visualisation of fossils.

First thoughts - this thing
is absolutely massive,

and I will also add that the level
of preservation is amazing.

There's this common misconception

that fossilisation is
just this really common thing

and we get these complete skulls

all the time, and that's
certainly not the case.

This is actually a one-in-a-million,

maybe one-in-a-billion-type
specimen here.

Using the latest technology,

Andre is carrying out
the world's first surface scan

of a pliosaur skull.

So, right now, we're capturing

basically hundreds of thousands
of images all at once,

essentially putting together
a big 3D jigsaw puzzle.

The end result is a really
nice-looking 3D model,

which we can use for biomechanics,

studying the anatomy.

I think we'll be able to unlock
a lot of mysteries

about what these sea monsters
were doing,

and I'm really excited
to see where it takes us.

Once the scan has been finalised,

I meet Andre
at the University of Bristol

to discuss his findings.

Has he seen anything
in the skull's structure

that shows our sea monster

had the power
of a truly deadly predator?

There's some massive openings
back here along the jawline.

Yeah.
And that's good for muscles

to attach and bulge out.

There'd be a muscle
running through there.

Yes, we have
the pterygoid muscle group,

which is in
a lot of big dinosaurs,

and it's integral
to having a really strong bite.

And we have hypothesised
that this particular pliosaur

is kind of the apex predator

in the Jurassic ecosystems
it was living in.

In the sea.
Yes.

Now, this, of course,
is not a dinosaur,

but neither is it
a modern reptile.

But it does look a lot
like a crocodile, doesn't it?

Yes. Well, we have this process
called convergent evolution,

where a lot of animals will adapt

this similar-shaped skull
or similar trends

throughout
their evolutionary history,

even if they're not closely related.

That's because having
those similarities

can give you a lot of advantages.

But in terms of this pliosaur,

it's got that kind of
streamlined skull

that's kind of broad in the back,
it's very triangular shaped,

and a lot of marine reptiles
kind of have that skull shape.

I think that it's good for swimming
quickly and ambushing prey.

Does the skull give you
any information

about what animal
its prey might have been?

The animal would have been
so massive

that I think it would have been
able to prey effectively

on anything that was
unfortunate enough

to be in its space.

A popular hypothesis is that

these animals
were actually ripping off

the limbs of other animals
to disable them from swimming away,

and then kind of going in
for a kill.

So this is really a top predator?

Yes. I have very little doubt,

just judging
from how massive that skull is.

I don't see what could have
possibly hurt it.

What size is that, actually?

So the actual skull itself
clocks in

just a little under two metres.

Two metres.
Longer than I am.

Yeah. It's quite a big boy.
And that's just the skull.

The dimensions
of a fossilised skull enable us

to estimate the overall size
of an animal when it was alive.

And based on Andre's measurements,

our pliosaur could have been

up to an astounding 12 metres long.

Just from the sheer size of it,

just from looking at this animal
and how big those pterygoid muscles

would have been
at the back of the jaw,

the animal would have delivered
a devastating bite, no doubt.

A powerful bite is vital
to the success

of any marine predator.

Scientists are able to estimate

how much force an animal can exert

when biting into its prey.

And great white sharks
have one of the strongest bites,

at around 10,000 newtons.

But how do you work out
the bite force of a creature

that became extinct
millions of years ago?

Professor Emily Rayfield is
a world-renowned palaeontologist,

who specialises
in skeletal mechanics.

Using the model created by Andre,

Emily has assessed
the bite force of our pliosaur.

So this is a 3D print, a model.

It's not full size, though.

It's just over a third
of the size of the actual animal.

These large openings
are the spaces in the skull,

which would have been filled
with jaw-closing muscles.

So you can estimate the force
of the bite

from the size of those muscles.
Exactly. Yeah.

We can get an estimate
of that from here.

We know that muscles
of a certain...a certain size,

a certain area,
are capable of generating

a certain amount of force.

Saltwater crocodiles have got

the largest ever bite force
measured,

and they're up to about
16,000 newtons.

And these?
So our pliosaur here,

from the estimations
that we've made,

has a bite force that's about
twice the size of that,

of the largest saltwater crocodile
that's ever been measured.

And it's in the region
of around 32,000 newtons.

So this is
the most powerful biter

in the sea that ever has been,
or that we know of?

That we know of, absolutely.
Yes, definitely.

If you're looking
at kind of statistics

in terms of car-biting metrics,

I'm pretty sure it could
probably bite through a car.

So it's a monster?

Absolutely.

BOTH LAUGH

The evidence gathered
from the skull so far

suggests that this pliosaur

had the jaws, teeth and senses
of a highly successful hunter.

Its long snout, short neck
and streamlined skull

enabled it to move easily
through the water.

But what else helped
our enormous sea monster

to power through
the Jurassic seas

fast enough to catch its prey?

Pliosaurs were unique
in the natural world,

as they had four
almost identical wing-like flippers.

How pliosaurs used their flippers

has been debated
by palaeontologists for decades.

Some believe that they moved
using a sort of rowing stroke,

like oars in a boat,

while others argued
they used a flight stroke

seen in animals,
such as sea turtles.

But, in recent years, scientists
have been able to use

computer modelling
to finally solve this mystery,

and it appears
that these giant sea monsters

swam in a way
that is surprisingly similar

to a very different type
of animal -

one that is alive today.

Woo-oy!

Ha!

Penguins may appear somewhat clumsy

as they waddle around on land,

but once they're underwater,

they move very differently.

These are Humboldt penguins,
and they're excellent swimmers.

Their streamlined body shape
and their oily feathers

enable them to reach
astonishing speeds

of up to 30mph.

But a key factor
behind penguins' speed

are their flippers, which,
underwater, act like propellers,

driving them forward and increasing
their speed dramatically.

In slow motion,

you can see that the penguins
are using

a lift-based
underwater flight movement,

twisting their wings as they flap

and propelling themselves
forward on the upstroke

as well as the downstroke.

As strange as it may seem,

it's thought that pliosaurs
would have moved

in a very similar way.

But, of course,
pliosaurs were enormous,

and most large animals

are relatively slow moving.

So as an apex predator,

how could this huge creature
manoeuvre itself fast enough

to catch its prey?

To find out, I've come
to the Hydrodynamic Laboratory

at Imperial College London,

where Dr Luke Muscutt is studying

the locomotion of pliosaurs,

using a rather unusual
research tool.

How did you first become interested

in the way that pliosaurs swam?

It's the only animal that we know of

that has four large flippers.

So the question is,
how did they use them?

When we're trying to understand
an extinct animal,

the first thing we need to do
is look at the fossils,

so we understand
the shape of the bones,

how the bones fit together...

The fossils of the pliosaur

show that the flippers
were very much like wings.

So what I found was that
the hind flipper

can actually operate
at a much higher thrust

and at a much higher efficiency,

because it's utilising the wake
of the flipper in front of it.

We can see a similar effect

in the flight of migrating birds,
such as geese.

When geese are flying in formation,

each bird benefits
from the uplift created

by the one in front of it,

so that they fly
in a very energy-efficient way.

SQUAWKING

So you can think of the
pliosaur as almost two birds,

one flying behind the other,

and the back one is benefiting
from the one in front.

That's an extraordinary
parallel, yes!

The hind flipper has increases
in thrust and efficiency

of up to 40%.

Ah!

So this would have increased
the swimming speed

that pliosaurs would have been
able to achieve

and increase the number

of different things it could eat.

To take his research
to the next level,

Luke has built a robot

to study the swimming pattern
of pliosaurs

more accurately than ever before.

So what more information
do you think you can get

from this model?

This robot enables me to test
the complete animal.

How fast something can move
is an absolutely critical part

of what that animal is,

and it tells us what animals
it could have eaten,

how far it might have been
able to travel...

All sorts of questions
come back down

to its locomotion ability.

Have you estimated a speed
that this might produce?

Well, I've only finished
building this yesterday.

Oh, really? So, so far, I haven't

actually ran
the experiments yet.

If you'd like to have a go,
you're more than welcome to...

Yes. Oh, show me. So if you just
move this joystick

sort of upwards further.

So this is how
the pliosaur would have swam.

The flippers move primarily
up and down.

It's much more like a bird flies.

Luke and his team set up the robot
for a test swim,

and they entrust me
with its maiden voyage.

If you'd like to take
the control...

There we are. It's off.

Really got
some high acceleration there.

I suppose, actually,
that's only a model,

but if it was full-sized,
it would be going quite fast.

Indeed. You can just imagine it
chasing after a smaller ichthyosaur.

Luke's research is so new,
it's yet to be published,

but it's helping
to provide a new perspective

on these extraordinary animals.

Large marine predators, like orcas,

can swim at great speed
through the ocean.

What speed might our pliosaur,

with its four flippers,

have been capable of?

Estimates suggest
that they could have accelerated

up to 30mph,

making them one of the fastest
animals in the Jurassic seas.

This skull is not only
helping us to understand more

about the lives
of these giant sea monsters,

but also allows scientists,
like Dr Andre Rowe,

to visualise the Jurassic world
as never before.

So often, I've been involved
in looking at fossil skeletons,

and the skull...
Unless the skull is there,

you're really missing
an awful lot of information.

We are lucky to find this
as the first thing.

Yes, I am very biased,

since I study feeding and teeth,

but I think the majority
of information

about an animal you can get
from its skull.

Yeah. The brain, the teeth,
what it was feeding on,

its maximum body size
if you have the whole skull.

It's just a treasure trove
of information.

And we're very fortunate
to have the whole thing.

One of the reasons why I love
the UK is because it's got

such a great collection
of marine reptiles.

Delighted to hear it.

I mean, in America, we've got
our big tyrannosaurs

and our triceratops, but the UK
is great for marine reptiles.

Well, we did discover the dinosaurs.

Yes, the science of palaeontology
did originate here.

How would it compare with T-rex?

I imagine it would be
pretty comparable.

They were kind of both
the respective apex predators

in their ecosystems.

So I have no doubt that this was

sort of like an underwater T-rex,
if you will. OK.

Let me ask you
the million-dollar question.

In a battle
between T-rex and our pliosaur,

who's going to win?

As much as it pains me and brings
a tear to my eye to admit it,

I think my T-rex
is going to lose this fight.

And then,
millions of years later,

an American palaeontologist
will envision this scene

and break down into tears.

DAVID LAUGHS

Bringing an enormous predator
back to life

after 150 million years

is no easy task.

But restoring this giant skull
is a labour of love

for Steve and his team.

Almost a year after the skull
was discovered,

I returned to Kimmeridge
to see how they're getting on.

My goodness.

It is absolutely magnificent.

It's astonishing.

It's bigger than a T-rex.

Is it? Yeah, yeah.
What, the skull? Yeah.

Yeah, bigger than
any T-rex ever found.

David, now what we've done,
since you've come here last,

is we've... I've air penned off
all the mudstone

and then air abraded it.
Now, the air abrasive machine

cleans out all these little voids,

and you see every little detail,

every suture,
where the bone join together,

you can see every detail.
That's what we really wanted.

So the teeth here have been
basically tumbled on the beach,

and the shingle had worn away
all the crowns.

So we're going to do a bit
of dentistry on them.

So we've got this tooth,
which has been scanned,

and then we're going
to increase or decrease it,

and then add all the teeth
back in position

to show people
what it actually looked like.

You must feel, looking at this...

I mean, I know it was a huge amount
of work to get it out.

We never thought we'd get it,
to be honest.

I'll be honest with you.

Well, it's certainly a triumph.

Yeah, quite an emotional moment
for everyone.

I'm sure.
Yeah.

A sensation.

Once the pliosaur's
dagger-like teeth are added...

..the picture is finally complete.

Our journey of discovery has shown

that this sea monster was one
of the greatest predators

the world has ever seen.

And we can now visualise
more accurately than ever

how it may have hunted
in the Jurassic seas.

Ichthyosaurs,

swimming in groups
along the coast...

..concentrating
on hunting their prey...

..unaware that they themselves
are being stalked.

On their trail,

our pliosaur uses
its highly-tuned senses

to launch an attack.

In the chase, its four flippers,

each two metres long,

drive it through the water
at great speed.

Splitting the shoal,
it isolates its target.

Our sea monster's primary weapons

are its 90 razor-sharp teeth...

..with which it slices
through its victim's flesh.

The impact alone
may have been enough to kill.

But with a bite force
twice the strength

of any animal living today,

its prey had little chance
of survival.

From a chance discovery
on a beach one morning

to the painstaking restoration

of such a rare
and impressive specimen,

the story of this fossil
is one of skill, dedication

and of fascinating
scientific discoveries

made along the way.

We've been given a unique insight

into the life of our pliosaur

that swam in the Jurassic seas
150 million years ago,

but we're also reminded

that there is still so much to learn

about these extraordinary
prehistoric animals.

And I, for one, will never tire
of discovering more.