Original subtitles

The remains of a dragon have just been discovered

in the cliffs of Dorset on the south-east coast of England...

one that has been hidden in the rocks for 200 million years.

It was an enormous marine reptile that ruled the seas

at the same time as the dinosaurs ruled the land.

Scientifically, it's called an ichthyosaur.

Since Jurassic times,

its fossilized bones have been locked away in these cliffs.

But now we have a chance to reveal it and its story.

Lots and lots of bone in there.

The bones are so well preserved, it may be able to give us

new insights into the lives of these remarkable creatures.

Together with a team of scientists,

we will reconstruct the skeleton and compare it to animals alive today.

We'll try to understand how it looked.

We have actual preservation of the skin of our ichthyosaur.

How extraordinary!

And how it survived in the open ocean.

Could this be a completely new species of ichthyosaur?

Our search for evidence will lead us

into an intriguing forensic investigation into how it died.

I think you're looking at a 200 million year old murder mystery.

Solving that mystery will throw light on the extraordinary world

in the Jurassic seas that once existed just off our shores.

The story of this extraordinary dragon

starts here in Dorset on the south coast of England,

one of the most important geological sites in the world...

the Jurassic Coast.

It stretches for almost 100 miles from Devon to Dorset.

And it was here that the early geologists

first collected evidence that once the world was ruled

by monstrous reptiles, quite unlike anything alive on Earth today.

Evidence of creatures that existed all that time ago

can still be found on these beaches.

Fossil collectors have been coming here for literally centuries

and these rapidly eroding cliffs are providing them

with a continuous supply of exciting things to find.

I started looking for fossils when I was a boy

and I've never lost the feeling of excitement

and anticipation of what one might discover.

The commonest fossils here are coiled shells called ammonites

and you can find them all over the place.

There's one here on this boulder.

You can see the whorls there,

but it's mostly been worn away by the sea.

But sometimes if you're lucky, you can find nodules like this

and if you look at them,

you can see there's the edge there of an ammonite and if I hit it...

If I put on protective glasses and I hit it, it should...

HE LAUGHS

How about that?

Wow!

What a find!

Ammonites, in fact, are quite common on this beach,

but every now and again, something truly rare

and spectacular is found here and quite often by this man...

one of the most skilled fossil hunters I know.

Chris Moore has been collecting fossils here for more than 30 years.

Recently, he came across a boulder

which he thought might contain something unusual.

Back in his workshop,

he exposed a mosaic of small, beautifully preserved bones

which he knew straight away were the front fins,

the paddles, of an ichthyosaur.

But they were unlike any he had ever seen before.

I still collect fossils.

I even have the remains of an ichthyosaur...

a small one of a kind that's relatively common.

This was collected by Chris about ten years ago in Dorset.

I never found anything as beautiful as this.

It's got jaws and it's got teeth and it's got paddles.

And Dorset was the very first place

where they found a really complete skeleton of one of these creatures.

This is a picture of it,

published for the very first time in 1814.

People thought it was some kind of monster, but what was it?

They thought it was a kind of cross between a reptile and a fish

so they called it an ichthyosaur - A fish lizard or sea dragon.

Since that time, many fossil fragments of ichthyosaurs

have been discovered on the Jurassic Coast.

But complete skeletons are very rare.

The particular one that Chris has just found

is significantly different from any that's ever been found here before.

It's not easy to get to the beach where it was discovered.

At high tide, the only way to do so is by boat.

I asked Chris where the rest of the skeleton might still lie.

It's in the very top limestone bed

where the cliffs are at the lowest point.

It's got about two metres on top of clay

and we'll have to clear this material off

till we get to the limestone bed.

It' a lot of hard work.

It's a lot of digging, yeah, and also we have to do it, really,

before the winter turns again and the weather gets bad

because there's a chance that the next landslip

will just push it off onto the beach and destroy it.

In Jurassic times, sea covered all this area.

On its floor, sediments washed down from the land

turned into layers of shales and limestone.

The land rose, the sea retreated

and now in the rocks,

you can find the remains of the creatures

that once lived in those ancient waters.

As well as the remains of ammonites, there are the bones of fish,

such as sharks.

But the top predators at this time were reptiles - ichthyosaurs.

They dominated the seas for more than 150 million years.

After getting permission to dig,

the team clamber down the cliff to the particular layer

where the rest of our ichthyosaur skeleton should be lying.

I'm going to need at least another metre,

cos I need to drop down to the next bit.

It's dangerous work.

These cliffs occasionally collapse without warning.

To make sure that they don't damage any of the fossils,

the team do all the digging by hand.

There's just loads of roots.

Tonnes of clay have to be removed before they even reach

the layer of limestone where they hope

the rest of the bones still lie.

Wayhey!

It was on this very coast

that the first complete skeleton of an ichthyosaur was discovered.

It was found in the 19th century

by a remarkable woman called Mary Anning.

Mary lived in the little town of Lyme Regis,

the daughter of a cabinet maker who collected fossils as a hobby.

When Mary was only 11, her father died

so she and her brother started selling fossils to visitors

to support their widowed mother.

Lyme Regis Museum now devotes a whole gallery to her and her finds.

Mary had an extraordinary talent for finding fossils and in 1811,

she discovered this gigantic creature,

the like of which no-one had ever seen before.

Dinosaurs had not yet been discovered.

No-one had any idea that way back in pre-history,

there were such gigantic creatures,

so this caused a sensation.

It was then that the popular name "sea dragon"

was given to these prehistoric monsters.

Scientists speculated on how they lived

and artists tried to imagine what they must have looked like

and how they behaved.

Back at the cliff face, Chris and his team are hard at it.

But they haven't found any more bones.

This is a massive piece. Tombstone!

Right, ready?

Chris is convinced that the skeleton to which the paddles belonged

must be somewhere here and they check every rock.

Beautiful shale!

- Lovely! - Anything interesting? - Moment of truth...

Nothing.

- Just push it off. - Yeah.

Is there anything showing?

Nothing else here.

Oh, gosh, that's hard work.

I hope there's something here.

I almost don't want to look!

- Ah! - What have you found?

- There's a bone. - Loads of bone going all the way... There's bone there.

- There's something here! - HE LAUGHS

At long last, the team's efforts are rewarded.

We've got some bones here!

- There's loads of bones. - Fantastic!

Ah! What's this?

Is that a vertebrae?

But the bones are not in the position

the team had expected to find them.

Instead of lying across the face of the cliff,

the skeleton seems to be bending back into it.

We're going to have to go down through there.

It means much more work.

And to make matters worse, a storm is brewing.

The rain is just starting,

but I think we've got to make a bit of a run for it.

We won't be working any more in this for the moment. It's torrential.

Beautiful rainbow, though.

A rainbow will be little comfort if the storm persists.

Rough seas and heavy downpours can cause landslips,

which could easily destroy any chance of retrieving the bones.

It was after just such a storm that Chris found the front limbs,

the paddles of our sea dragon.

They convinced him that the fossil was something special.

VOICEOVER: You can see why when you compare them

VOICEOVER: to the paddles of the kind of ichthyosaur

VOICEOVER: that's usually found here.

This is an adult and this is the paddle of this creature

and if you compare it to this one...

- Oh, it's huge. Oh, yeah. - I've never seen anything quite like it.

There are half a dozen rows of digits there and how many there?

I think there's at least nine or ten crossways

and obviously, you know, many more in length.

It's getting on for twice the number of digits.

- And the whole shape of the fin is completely... - Quite different.

And must be new, therefore?

- I think so. I've never seen anything quite like it. - How exciting!

VOICEOVER: It's extremely rare to find

VOICEOVER: a new species of ichthyosaur these days.

Only nine have been discovered here in the last 200 years.

But can these strange paddles tell us something

about how this odd ichthyosaur lived?

To try and find out, we are going to construct a three-dimensional model.

To do that, we first need to have the paddles scanned.

So, Chris is taking them to Southampton University.

Here, the engineering department has one of the largest

high resolution scanners in the country.

It's not every day someone walks in

with a 200-million-year-old sea reptile.

The machine can scan objects of all different shapes and sizes

from ancient coins to the components of spacecraft.

To create a picture, the scanner takes thousands of X-ray images

in cross sections through the fossil as it rotates.

It's not long before the first images appear.

That's amazing. It looks really clear.

You can even see the bones laying underneath the paddle.

At the moment, we're just doing one section.

We're going to do multiple scans down the specimen

and build it all back together into a three-dimensional volume.

The scans of the paddles are sent to Bristol University.

Here, scientists can isolate the image of each bone within the rock

and then assemble them to create a detailed three-dimensional model.

The team is particularly excited by the shape

and structure of these paddles and I've come to find out why.

We've got a complete paddle here taken from the bones itself,

fully reconstructed, rearticulated

so this is as close as we can get to what it would have looked like.

We can actually start using this paddle to try and tell us

what species it might have been.

Because of the size of the paddle

and the way that some of these bones articulate with each other,

it's different to other ichthyosaurus

and so this could be a new species.

- That would be great. - It would be jolly exciting.

VOICEOVER: We won't know for sure until we find the rest of the body,

but can the paddles tell us something

about the way in which this creature swam?

There are a lot of bones in this paddle,

which would have been good for holding steady

and also for allowing it to be manoeuvrable in the water.

- There would have been cartilage round that, wouldn't there? - Yes.

All of the gaps between the bones

would have been filled in with cartilage

and even further around the paddle itself,

giving it a paddle-like shape, giving it a cross section

a bit like an aerofoil

so that it could cut straight through the water.

- Could they fold them in to the side? - Probably not.

Looking at the muscles and where they attach,

it suggests these are moving up and down,

helping it to turn very quickly

or keeping it on the straight and narrow

when it wants to be a little more sedate.

The shape of the paddles and the way they moved

seems very like the way an animal alive today uses its paddles.

That animal usually lives in tropical waters

like these in the Caribbean.

The sea here is warm

with temperatures much like they would have been

in Jurassic times around Britain.

And the animal in question...

is the dolphin.

Dolphins, of course, are mammals, not reptiles like ichthyosaurs.

Nonetheless, the two groups have bodies shaped in very similar ways.

The front fins or paddles of both

would have helped to steady themselves

as they turn and cut through the water.

And both have similar dorsal fins.

So, although they lived 200 million years apart,

dolphins and ichthyosaurs share many physical characteristics

and that's because they evolved in similar ways

as a response to a similar environment.

Like dolphins,

ichthyosaurs evolved from ancestors that had once lived on land.

As they became adapted to life in water,

they lost the ability to walk,

their bodies became more streamlined

and their forelimbs turned into paddles to help them swim.

But ichthyosaurs do differ from dolphins in two striking ways.

Dolphins have tails that are flattened horizontally

and they drive themselves forward by beating their tails up and down.

But we know from their fossils that ichthyosaur tails

were flattened vertically like those of sharks,

so they must have swum in the same sort of way

by sweeping their tails from side to side.

Ichthyosaurs, unlike dolphins, also had back paddles.

They, too, would have helped stabilise them as they swam.

And what's more, the paddles of our ichthyosaur

are particularly large and long,

rather like those of the oceanic whitetip shark.

That shape helps the whitetip to cruise for long distances

with very little expenditure of energy in their search for food.

So, it could be that our ichthyosaur was also a long-distance traveller

and only an infrequent visitor to the Lyme Regis seas,

which could be why no-one has ever found one of these here before.

Back at the dig site, the rain has stopped at last.

But the storm is a reminder that winter is on its way.

The team must try to extract the rest of the dragon's body

before worse weather arrives.

That's how hard the rock is.

It's actually smashed the end off the chisel.

So, you can see what we're dealing with.

At last, they find signs of the rest of the skeleton.

- Lots and lots of bone in there. - Yeah.

Ribs and all sorts of stuff.

And there's another particularly exciting discovery.

- Is there skin? - Yeah, look. - Oh, really?

They've found signs of fossilized skin.

Rare, isn't it?

Yeah, very rare.

The blocks that contain bones and skin

can't be thrown down like the other rocks.

They must be carefully strapped up and gently lowered.

That's the first block down.

A few more to go, but if they go like that, I'll be very pleased.

Two weeks after they started work, I go down again to check on progress.

- How's it going? - Well, quite well so far. - A lot shifted.

- Yeah, about 20 tonnes of it, I think. - Really? - Yes.

How's it doing? Is it caught?

- No, it's OK. - It's OK? Yeah.

What do you reckon's in it?

This block's got vertebrae, the other part of the ribcage

and it's definitely got the back paddles in there.

You can see a cross section through them.

VOICEOVER: While the team continue lowering the huge blocks,

VOICEOVER: Chris shows me what they've already collected.

So, lots over here.

- Ah, well, I can see something there. - Ah!

- That's more obvious, yeah. - Yeah.

Here, you can see, glinting in the sunlight,

sections through the backbone, the vertebral column.

Wow!

And these are the ribs that are still attached to the vertebrae

and these are the neurals

that come off the backbone.

The spines off the top of the back.

- Yeah, but they've actually got skin preserved on them. - No, really? - Yeah.

- Can you see that here? - Well, that's the very black.

You can see it on the impression as well.

VOICEOVER: This is great news, but something puzzles me.

Would the head have been on this side or that side?

Most likely here in this next slab.

- And it's not there? - Not so far.

Oh, boy!

How many more tonnes to go?

HE SIGHS, THEY LAUGH

- Only a few! - THEY LAUGH

OK.

Once the blocks are down on the beach,

the team remove as much excess limestone as possible

to make them lighter.

Even then, they're extremely heavy

so to get them back to Lyme Regis,

they're loaded onto a pontoon and towed back by boat.

So, for the first time in 200 million years,

our strange ichthyosaur once again takes to the water.

The dig may be over,

but the investigation is only just beginning.

WHIRRING

Now, the work becomes more delicate, involving not sledgehammers,

but small vibrating chisels

that chip off the limestone in tiny flakes.

It's detailed work that will take months to complete.

It's like a jigsaw puzzle of things you can't see.

It's almost forensic.

You don't know the story, you don't know what's inside the block

until you reveal it.

I've never seen in all my years an ichthyosaur that looked like this

so every other part of the skeleton that we reveal

is very exciting cos you're never quite sure what's going on,

what it's going to look like and it is, it's very different.

Day after day and week after week,

Chris and his team work patiently to expose more of the skeleton.

And as they do so, the bones reveal something very intriguing.

I've come down to Chris' workshop to take a look.

It's a bit of squeeze past the plesiosaur.

VOICEOVER: It really is an Aladdin's cave.

VOICEOVER; After weeks of work,

VOICEOVER: Chris has exposed the backbones and ribs.

So, this is it so far.

VOICEOVER: And in doing so, he's made a startling discovery.

It looks like it's been attacked.

- Gosh! - There's breakages all through the ribcage.

If you follow one rib, you go along here, down to here,

then this piece corresponds to this, which then goes over to here

so one rib is now broken into three pieces.

How extraordinary! But what's happened here?

Here, the vertebral column's been actually pulled away.

I'm fairly positive it was done in life and the paddles,

the flippers have been ripped off.

Where would they go?

But they're in a very odd position, aren't they?

I mean, they're pointing in the wrong direction.

They should be basically in this position

and facing the other way up

and they've been ripped off and turned over.

Gosh!

Well, where was the head?

The head should be here.

- That's the very last vertebrae. - Back of the neck? - Yeah.

So, the head's been torn off and there's no evidence.

There's no teeth or pieces of bone. It's completely gone.

- So, it's a murder. - Yes! - Really?

Yeah, I think it was killed.

- Did this predator crunch the head, do you think? - Who knows?

It's 200 millions years ago,

so it's a bit of guesswork, really, isn't it?

So, it's a murder story without a complete body yet.

To find out more, we need to reveal the rest of the skeleton.

So it's all hands on deck.

They've even roped me in.

This is more difficult than it looks.

Very good!

Could you start on three days a week?

- Is it all right? - It's good, yeah. - I haven't gone too close to the bone?

- No, no. - Phew, that's a relief!

But what of the missing head?

If it was ripped off,

Chris thinks he might still be able to find it

somewhere on the beach,

so at every opportunity,

he scours the area where the first block was found.

The best time to look is after a storm

when a strong sea has moved sand and shingle

and perhaps revealed the rocks beneath.

To try and deduce just how our ichthyosaur met its fate,

we've sent images of the fossil to someone who specialises

in investigating the cause of death in prehistoric animals.

You sent me some photographs and I had a look at some of these breaks.

Now, first of all, I noticed this, here.

If you look, you can just see this bulbous piece on the rib here.

This is where the rib has healed after a break

and the animal's gone on to live another day.

There's a bite mark here that runs all the way up the paddle bones.

You can see that it's healed as well.

Yeah, it's definitely an old injury.

- This animal's had a little bit of a bad start in life. - Yeah.

But some of the other breaks tell a different story.

If you look down here and especially this one,

this fracture here mirrors that fracture there

and then we can see a whole line of fractures

where there's no new bone growth.

Something has actually crushed this ribcage.

So look here at these neural spines.

These are absolutely perfect

and then from here, they're broken all the way down to here.

This is the last one that's broken and then here,

they're perfect again.

So, there to there is damaged.

On the ribs, there to there is damaged and here, too,

and also on some of these belly ribs

so I think there's a bite which goes right across here.

That probably reflects the width of the skull of the animal that bit it.

Yeah, yeah. So it came in across here, almost.

Somewhere like that, yeah.

There was a massive bite, it caused catastrophic injury

and, remember, the ribcage is protecting lungs.

This was an air-breathing marine animal and as a swimmer,

these lungs are vital not just for breathing, but for its buoyancy.

So, once this ribcage is punctured and the lungs are punctured,

this animal is dead.

It can't breathe

and also it's going to sink straight down to the sea floor as well.

It's quite likely that the animal that killed this animal,

presumably it was looking for food,

it didn't get to eat it.

Oh, no, I think it just killed it.

It didn't eat it, or else it wouldn't be so intact.

So this probably all took place in the surface water,

but as soon as it's done this injury,

this thing just sank like a stone straight down to the sea floor

and then it was lost to the animal that was trying to eat it.

So, it looks as if Chris' attack theory might be right.

But what type of creature could possibly have inflicted

so much damage to our sea dragon?

A rather unusual fossil in Chris' collection might give us a clue.

This is fossilised ichthyosaur droppings called a coprolite

and what makes it particularly interesting

is that within this piece of dung, you can see fish scales.

So, that shows that ichthyosaurs were fish eaters,

but more than that, this one is even more interesting

because in this piece of dung, there are teeth - ichthyosaur teeth.

So, the animal that produced this was almost certainly a cannibal.

It ate other ichthyosaur species.

Could it be that our dragon was killed by one of its own kind?

To find out more,

I've come to the Natural History Museum of Stuttgart in Germany.

Here, they have one of the most impressive

and varied collections of ichthyosaurs in the world.

They came in all shapes and sizes,

but of all the ichthyosaurs that existed 200 million years ago,

there was one which was particularly fearsome.

This is temnodontosaurus,

one of the biggest of the sea dragons so far discovered.

They grew up to 10m long

and individual bones have been discovered which suggest

that they could grow even bigger than that.

The remains of these terrifying sea monsters

were discovered in a quarry just outside Stuttgart.

These are the biggest complete temnodontosaurus fossils ever found.

This huge predator had the largest eye known of any animal,

which would have given it extremely acute eyesight.

Not only that, but the eye was surrounded

by a ring of scutes - bony plates...

to protect it from the water pressure at depth.

So, with eyes the size of footballs,

this monster was able to hunt at all depths of the Jurassic ocean.

It also had rows of sharp teeth

that would have allowed it to rip apart almost anything.

These teeth are shaped like blades, well suited for cutting into flesh.

And here's another specimen of temnodontosaurus

that is proof positive that it really was a hunter.

Here is its stomach and inside its stomach,

you can see these tiny little circular bones,

which are the backbones, the vertebrae, of a baby ichthyosaur.

So we now know that temnodontosaurus

could devour young ichthyosaurs,

but would one have been capable

of eating an adult ichthyosaur like ours?

Fossils of temnodontosaurus have been found in other regions,

including our own Jurassic Coast.

So, this monster could well be our prime suspect.

To build our case further,

we're going to analyse another specimen of the same species

that was found on the Jurassic Coast.

This is the skull of a temnodontosaurus

and as you can see, it's huge.

This specimen was found by Mary Anning

on the Dorset coast in the 19th century

and we are hoping that we may be able to use it

with the latest techniques

to tell us just how powerful these great jaws could be.

So, for the first time ever, our team of scientists

are going to attempt to calculate

the bite strength of a temnodontosaurus.

The first step is to scan the skull.

Not as easy as it sounds.

Very few scanners are big enough,

but there's one here at the Royal Veterinary College,

where they're more accustomed to scanning horses.

The temnodontosaurus skull is 2m long and weighs more than 200kg.

Luckily, it's in two pieces.

Otherwise it couldn't be fitted into even this huge scanner.

OK. One, two, three and up.

These scans will help the team

to not only reconstruct the temnodontosaurus' skull,

but also work out the size of its jaw muscles.

They can then assess the power of this huge predator's bite

and see if it was strong enough to kill our ichthyosaur.

Temnodontosaurs are unusual

in that they had huge, sharp teeth for cutting through flesh,

but how did other ichthyosaurs catch their prey?

To get a clue, I've come to see a modern day predator in action.

That is a gharial crocodile from Indonesia.

Its jaws, as you can see, are not wide and flat

like an African crocodile's,

but long and thin and because of that shape,

there's very little resistance to the water

so they can snatch fish, which they do very effectively.

They're very formidable animals indeed.

Ichthyosaurs must have fed in much the same way as that.

Their jaws were very similar to those of the gharial...

simple studs to grip the prey, no need to chew it

because the jaws at the back were quite big enough

to enable the animal to swallow their prey whole,

just as the gharial does.

Gharials regularly shed their teeth

and here's one I've just picked out of this pool.

You can see that they're very simple teeth, just like ichthyosaur teeth.

But that's all you need if all you have to do is to grab a fish.

So, it's likely that our ichthyosaur had teeth and jaws specially adapted

to catch small, slippery fish and squid,

just like a gharial crocodile.

Back in Lyme Regis, the work on the bones has taken a dramatic turn.

Chris has found that there is fossilized skin

over nearly the whole skeleton.

It seems to be virtually covering the whole thing.

It's rare to find any sign whatever of skin on fossils,

let alone so much of it.

Fiann Smithwick, an expert on fossilized skin,

has come to take a sample back to his lab.

We can look and see if there's any evidence

of the original pigment preserved in the skin.

- Oh, that's a lovely piece. - That's really good. That'll be perfect.

Fiann hopes that this remarkably preserved sample

might tell us what the skin looked like and even what colour it was.

At the University of Bristol,

he places a tiny sample of the fossilized skin in a machine

that coats its surface with minute particles of gold.

They will reflect the rays of a scanning electron microscope.

It's astonishing that you can actually see

the remains of skin on such an ancient fossil.

But this microscope can also magnify its structure

tens of thousands of times.

Here, we have an exceptional level of preservation of the skin

of our ichthyosaur, despite being 200 million years old,

so the structures we're looking at here

are around half a micrometre across

and a micrometre is one millionth of a metre

and you see here these little granules

and these are preserved melanosomes.

Now, melanosomes contain the pigment that you have in mammal hair,

in bird feathers and in reptile skin and the abundance of them

and the distribution of them can tell us

about the overall colour patterns of the animal.

So, having a high abundance means you're likely to be darker

and having a low abundance means you're likely to be lighter.

This area has come from the back.

There's a large abundance of these melanosomes.

There's a lot of pigment here

and when we look at samples

that have come from the bottom of the animal,

we don't see this pigment in this level of abundance

so it most likely had a much darker back than it did a belly

and this conforms to a type of colour pattern

known as countershading in modern animals.

You can see countershading in lots of sea animals today.

Great white sharks, for example.

Both predators and prey are coloured in this way.

It makes them more difficult to see both from above and below.

So, this is the first time that we've actually seen

evidence of a countershaded pattern in an ichthyosaur.

So, that really is a step forward in our knowledge.

It is and it can tell us

a huge amount about the way the animal might have lived.

Just from looking at that picture?

- Just from looking at these melanosomes. - Great!

Today, countershaded animals tend to live in open water

where there's good visibility.

Ichthyosaurs also lived in the open seas

so being camouflaged in this way

would have been very valuable to them.

The latest scientific research suggests that countershading

might also protect against ultraviolet light

and even help to regulate body temperature.

As an air-breathing creature,

our ichthyosaur would have had to spend much time near the surface.

So countershading could have been a benefit for that reason as well.

There are, of course,

many marine reptiles still living in the oceans today, like turtles.

The biggest of them is the leatherback,

whose ancestors, in fact, were around

at the same time as the ichthyosaurs.

Today, they come ashore to nest in many places,

including the Caribbean.

This huge leatherback turtle is laying her eggs.

She's hauled her way up from the sea and dug a hole

and now she's depositing about 100 of them.

She'll then fill in the hole

and then work her way down back to the sea.

It's clearly a very laborious process.

And that's the challenge facing all reptiles that live in the sea...

having to come onto land to lay eggs.

Ichthyosaurs were reptiles and they lived in the sea,

but they were so well adapted to a life at sea,

that they gave birth to live young

and that would have saved the sea dragons

making the dangerous journey onto land.

There is remarkable evidence that ichthyosaurs gave birth

to live young in the Stuttgart museum.

And here is a truly extraordinary, beautiful, almost poignant fossil...

proof positive that ichthyosaurs gave birth to live young.

Here is the baby, just at the moment that it's leaving the birth canal.

It comes out tail first and as soon as it was freed,

it would have risen to the surface to take its first breath.

But something happened before that did

and here is the proof.

Whatever it was, death must have been instant.

So, ichthyosaurs gave birth to live babies,

just as many sharks do today.

After several weeks of research,

the team at Bristol University have managed

to reconstruct the skull of the temnodontosaurus

so that they can analyse the power of its jaws.

How do you assess the strength of this animal's bite?

Well, the first thing that we need to know

is the volume of muscle that could fit into the back of the skull.

So the muscles are attaching round here

and also there's a group of muscles

that are attaching further forward here

and if we know how much muscle volume there is,

we can estimate how much force that muscle can generate.

And what did you discover?

We found out that our upper estimate of bite force

was around 30,000 Newtons and to put that in a modern day context,

that's twice as powerful as the largest saltwater crocodile

- that's been measured. - Twice as powerful? - Yeah.

- So that's enormous, yeah. - Yeah, it's a very powerful bite force.

So, this must have been the animal

with the most powerful bite of its time, mustn't it?

That's absolutely right, yeah.

Of its time, it would have been.

Not only did it have a powerful bite,

its jaw-closing muscles also attach quite close to the jaw joint.

Now, normally in animals where that happens,

they have quite a fast, but less forceful bite,

but the fact that this animal is actually so big

means that it has a fast bite,

but also by virtue of its sheer size,

it also has quite a powerful bite as well, too,

so it basically has the best of both worlds.

- So, this was the king of the Jurassic sea. - Or queen!

Sorry!

- Yeah. - Yeah.

So, it seems fairly likely that temnodontosaurus was strong enough

not only to kill our sea dragon, but to rip its head clean off.

It must have been a terrifying battle.

Our investigations have given us

a pretty good idea of how our sea dragon died.

But can the reconstruction work

carried out at Bristol University tell us more about its life?

All the blocks containing the fossil have now been scanned.

With those scans,

the team were able to separate the individual bones

and then put them back together to create

a 3D image of the ichthyosaur's body before it was attacked.

They've added a head

based on estimates of other ichthyosaur species.

That's magnificent.

This is the whole animal

and we estimate that it may have been up to around 4.5m long.

Is that bigger than most in Lyme?

Yes, this is certainly bigger

than most of the ichthyosaurs that we see at Lyme Regis.

It looks huge. It looks amazing.

Here are the forelimbs right at the front

and we've got hindlimbs here and at the back, we've got a tail bend.

This is supported by the backbone,

which extends along the whole length of the body.

- But that bend is natural, isn't it? That's not a break. - Yes.

That gives strength to the lower element of the tail

for driving it forward.

Much like a shark,

the tail bend is the main propulsive organ of the animal.

So, could this be a new species?

Yes, these pieces of evidence together

suggest that it is going to be a new species and it's jolly exciting.

- They don't come along every day. - Historic! - Yes.

This is wonderful news.

A sighting by Chris on the beach in Lyme Regis

has led to the discovery of a new species of ichthyosaur,

adding to our knowledge of these fascinating creatures.

It's extraordinary how much you can discover from one single fossil.

Digital reconstruction has allowed us

to rebuild this animal to reveal how it looked and how it moved.

We've discovered, for the first time,

that this creature was countershaded.

But that didn't stop it from being attacked.

By analysing its bones,

we've been able to work out that its most likely attacker

was a temnodontosaurus,

the most ferocious predator of the seas at that time.

It's been a fascinating journey of discovery, but, for me,

the real wonder is the bones themselves.

I can't wait to see what they look like when they're finally cleaned.

After many months of painstaking and patient preparation,

Chris and his team have finally completed their work

on the fossil of our ancient sea dragon.

Here it is finished.

Wow!

It's really beautiful, isn't it?

- I mean, it is beautiful, that's for sure. - Thank you.

- It's a great specimen, isn't it? - Lovely.

And how many new species have been discovered in the last 100 years?

Very few, very, very few

and it's thrilling to find something that's just never been seen before.

Well, it was a long time spent

just revealing the body of this creature,

but it's also revealed this extraordinary story

of life and death,

predator-prey fighting it out in the seas

200 million years ago just down there.

Yeah, it's a fantastic story.

Really, really thrilling and romantic.

For Chris, this has been a labour of love

and it's filled in another gap in the palaeontological jigsaw...

a story that all started

with an odd-looking boulder on a Dorset beach.

It's extraordinary to think

that some 200 million years ago exactly here,

the greatest predator of its time was swimming around in the sea

and that's what I really love about fossils and fossil hunting.

It gives you an extraordinarily vivid insight

into what the world was like millions of years before

human beings even appeared on this planet.

Ichthyosaurs died out around 90 million years ago.

No-one knows why,

but standing here and having excavated that spectacular fossil,

it's not difficult to imagine a time

when dragons really did rule the seas.