All language subtitles for Attenborough and the Giant Sea Monster 2023 1080p WEBRiP x264.Sdh

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.