Original subtitles

STEPHEN FRY: 'Dinosaurs. Prehistoric monsters.

'Huge, terrifying.

'I've always loved them, always been fascinated by them.

'What's mind-boggling is that these extraordinary creatures

'roamed where we walk today.

'But what if I could go back in time millions of years into the past,

'to the magical, dangerous world they lived in?

'I wonder... what would I make of them?

'Face-to-face.'

Oh, you can just pull up here. Thanks.

Imagine being able to explore their world and move with them.

CHUCKLESIt's just a dream, I suppose, but...

Well, I must get on with my life. ROARING

Mind you, you never know.

ROARS

ROARS

For 180 million years, dinosaurs dominated our planet.

In this series, I'm going to be transported back

to the different eras of these awe-inspiring creatures...

..to immerse myself in their amazing, magical world.

DINOSAUR GROWLS Hey! Don't do that.

With the help of experts and the latest scientific discoveries

from our time... DINOSAUR ROARS

..we'll put their power and strength to the test.

Unravel their remarkable story, from humble origins

of the dawn of the dinosaurs,

to see how they evolved a dazzling, bizarre array of forms

to become giants...

DINOSAUR ROARS

..and produce some of the scariest predators

ever to have stalked the Earth.

Until their ultimate demise.

Wiped from the face of the planet

in a single catastrophe of unimaginable power.

Come with me as I travel back in time to encounter the dinosaur.

Reverse back time,

and the Earth we know today looked very different indeed.

The land squashed together into one giant mass called Pangea,

which covered a third of the planet.

And as the Earth changed, so did the conditions.

New and distinct worlds formed,

and each was home to its own class of unique characters.

In this series, I'm going to travel back

to the three eras of the dinosaurs.

The Triassic, Jurassic, and Cretaceous.

But where did it all begin?

Tonight, I'm venturing to the dawn of the dinosaurs, to Pangea itself,

to meet some of the earliest of their kind,

to see how and why they evolved into giants.

I'm in a time when the dinosaurs really came into their own.

Their first golden age, the Jurassic period.

Now, which might put you in mind of a certain movie franchise.

I'm on the western side of Pangea

in an area that will one day become North America.

DISTANT ROARING

There are some familiar sights here, like these ferns

and these towering conifers.

But there are no flowers, they haven't evolved yet.

And no grass, which might disappoint gardeners.

But the dinosaurs are thriving.

And the late Jurassic, around 155 million years ago,

saw the arrival of one of the most iconic dinosaurs.

Indeed, one of the largest animals ever to walk the Earth.

DINOSAUR GROWLS

DINOSAUR ROARS

This is Diplodocus.

Ho-ho!

She's, um, female. Don't ask me how I know.

But she is absolutely massive.

You know, it's only when you're standing next to one

that you get a real sense of just how huge these creatures are.

I'm pretty tall, but she is six metres high,

that's like a two-storey house!

And from tail to nose, 26 metres!

That's like three double-decker buses, only longer.

DIPLODOCUS ROARS

That is seriously bad breath.

Diplodocus was just one of 250 species

that thrived during the Jurassic.

We know about them because their fossilised remains

have been found embedded in rocks across the world.

In prehistoric Germany, there was Archaeopteryx,

a small, feathered meat eater and ancestor of today's birds.

In what would become China, the Guanlong,

which sported a huge, colourful head crest.

While what is today North America

was home to the magnificent armour-plated Stegosaurus.

And right on our very own doorstep, relatives of Diplodocus.

Our Diplodocus here is truly enormous.

But I'm curious,

where did these huge beasts come from in the first place?

Palaeobiologist Paul Barrett

at the Natural History Museum in London has some ideas.

Dinosaurs began their evolutionary journey

as relatively rare, insignificant parts of their ecosystems.

But they wouldn't stay insignificant for long.

The world was about to change

and present them with an opportunity to take over the planet.

So, around the time that the first dinosaur fossils are found,

we see evidence for a major transition in global environments.

For most of the Triassic,

the climate of the Earth is hot and arid.

But for a short interval, this aridity gives way

to a slightly wetter, lusher period with more vegetation,

and it's thought that this may have kick-started the dinosaurs.

At the time, vast volcanic eruptions covered swathes of the Earth in lava

and sent carbon dioxide levels in the atmosphere skyrocketing.

The resultant greenhouse effect caused mega-monsoon rains to pour

and turn the world from arid scrub into a vast wetland.

This new climate produced the first conifers,

vast forests of towering trees,

a food source that the dominant animals were too slow to adapt to,

causing mass extinctions.

But those early dinosaurs survived.

This wetter interval is when we see the first body fossils of dinosaurs

and also of mammals.

And it's suggested that these nicer climatic conditions

may have fostered the conditions for those two groups to have evolved.

And they emerged as the most abundant

and most diverse animals on land for the next 140 million years.

DINOSAURS SCREECH

Well, our Diplodocus seems supremely well adapted

to life in the conifer forests that flourished

after those volcanoes devastated the Earth's climate.

But her sheer size does have its drawbacks.

She's basically 15 tonnes of prime Jurassic steak.

And there are others here who'd love to take a bite -

like this.

This is an Allosaurus, one of the deadliest predators of the Jurassic.

Kind of T-rex of the period.

ALLOSAURUS ROARS

It's longer than a pick-up truck and weighs in at two and a half tonnes.

But unlike our four-footed Diplodocus,

this scary monster goes around on just two hind legs,

leaving its forelegs, its arms, free to grab hold of its prey.

And it looks like he might have found a target

in our Diplodocus over there.

Well, now, this could turn out to be ugly.

I've travelled back in time to a magical and mysterious world.

To an era when dinosaurs were evolving into giants.

This amazing place is what today you'd know better as North America.

We're in the Jurassic period, about 155 million years ago,

and this Allosaurus

has been stalking our rather majestic Diplodocus over there.

But Diplodocus is intimidatingly large,

the size alone is a great defence.

So how can an Allosaurus take on a Diplodocus?

What's it got in its armoury?

Palaeobiologist Stephan Lautenschlager

has been studying its biomechanics

to try to discover how Allosaurus fed.

This is a full-sized replica of the fossilised skeleton

of an actual Allosaurus.

But at just a fifth of the size of a Diplodocus,

is its choice of prey a case of biting off more than it could chew?

Or is there something else going on?

It's certainly well armed, with 34 teeth,

each one a 10cm long, razor-sharp weapon.

The teeth had little serrations along the edges,

similar to a steak knife,

and ideally suited to cut through flesh, through muscle fibre.

But the most recent cutting-edge research

into its massive head reveals a problem.

The simulation here shows stresses during hunting.

Everything in the blue colour is lightly stressed.

Even when biting down, most of the skull experiences little pressure.

In other words, Allosaurus had a very soft bite,

generating a force of just under 800 pounds per square inch,

compared to over 13,000 for the ultimate dino predator, T-rex.

There must be some other feature

to make this dinosaur a successful killer.

And the answer lies in those jaw muscles.

We see here, jaw is extending, and during that extension,

the muscles are being stretched.

However, muscles can only stretch to a certain amount

until they reach a critical limit.

Then the jaw stops extending.

What Stephan's controversial new research reveals

is that those weak jaw muscles

actually acted to the Allosaurus' advantage -

they gave it a huge gape.

It could open its mouth to an incredible 79 degrees...

ALLOSAURUS ROARS

..which gives clues as to how it might have hunted.

Allosaurus would use the skull, the upper row of the teeth,

hatchet-like, and bringing it down onto the prey, animal,

to inflict large wounds or bite larger chunks of meat.

ALLOSAURUS ROARS

So, Allosaurus would open its mouth wide,

and slash down on its prey with its upper jaw like a meat cleaver...

..inflicting a wound and perhaps backing away

and waiting for its victim to weaken or die.

I wonder if I can get close enough to check out that jaw in action.

ALLOSAURUS ROARS

Hah! It really is an enormous gape, isn't it?

It's a bit like a snake when it's about to swallow its prey.

But can it really use the top half of that jaw

to hack away at the much larger Diplodocus?

Engineer Adam Wojcik of University College London

is an expert on all things mechanical.

His team built a set of robo jaws to test how Allosaurus attacked.

Joining him is palaeontologist Joe Bonsor

from London's Natural History Museum.

So, you've got a motor here and a cam action

that interfaces with the arm

that represents the top jaw of the Allosaurus.

The robo jaw is lined with steel teeth,

the exact size, shape and sharpness of fossilised Allosaurus teeth.

So, we can see here on the tooth, we've got these sharp curves,

crown of the tooth.

So, these would act a bit more like a kitchen knife

than a kind of chisel.

And what we've tried to do here is emulate

a mouth opening like this, sort of large gape,

and then applying a kind of swinging action into the target.

And that's kind of how we believe

the animal would've attacked its prey.

Slicing through perhaps the flank of a Diplodocus,

or something like that.

They should be able to cut right into this now, then.

Will the lower jaw swing clear

and allow the upper jaw to deliver a clean bite?

Three, two, one.

Fantastic. Wow.

The serrated metal teeth hack away huge chunks of melon,

leaving the lower jaw totally clear of the prey.

Straight into the top watermelon, and absolutely ripped it to pieces.

A similar wound in the flank of a Diplodocus

may not have proved fatal,

but maybe that was Allosaurus' modus operandi.

Instead of the big crunching bite that a T-rex had

that would have just instantly killed something,

maybe Allosaurus came in with these smaller attacks

that would have gradually worn down

one of these massive sauropod dinosaurs.

Well, I think we might be about to witness Allosaurus

bringing that hatchet-like jaw into action.

ALLOSAURUS ROARS

And I've asked dinosaur expert

and curator of the Natural History Museum in London

Dr Susie Maidment

to help shed light on how the attack might go down.

Well, battle might soon be joined.

But how does a docile dumbo like a Diplodocus...

That's very unfair to call it a dumbo.

..how does it defend itself against this kind of slashing machine?

Well, I think primarily by just being really enormous.

So, this is an animal that's maybe 30 or 40 tonnes...

DIPLODOCUS GROWLING

..whereas our Allosaurus here is maybe more like 15 tonnes.

So it's gonna be really hard

for it to take down an adult Diplodocus like this.

And does it have any other magic gifts?

It's presumably not very fast.

Actually, Diplodocus does have one thing that's quite unique,

and that is a claw on its forelimbs.

It's possible that it could rear up onto its hind limbs,

and then actually use this claw as some sort of defensive structure.

And, of course, the tail is another thing that it might have used

to defend itself against predators.

Yes, I always think that when I get close to a dinosaur -

that one of the things you ought to look out for,

a bit like a horse, is going behind it,

cos this huge tail can thrash around,

and it could kill a human, obviously.

And as far as the Allosaurus goes, this jaw that I've been admiring,

this amazing, gaping jaw... ALLOSAURUS ROARS

..it could presumably...

get... sort of get a lot of flesh off an animal,

even if it doesn't kill it.

We see skeletons that have breaks and traumas that have healed,

so we know that, sometimes, when these animals

were presumably being attacked by predators, they didn't always die.

So, your general feeling is that maybe

this Diplodocus being a full-grown adult

might not be a victim of this Allosaurus.

My money's on the Diplodocus over there.

Ooh, he's off.

ROARING

Ooh!

ROARING

ROARING

Phew.

Well, that was quite something, wasn't it,

to see such a monumental battle up close.

Absolutely terrifying.

But at least it looks as if they'll each live

to fight another day.

So, honours even.

The Diplodocus seemed to be deploying its tail

and just the sheer weight and mass of its body

as it turned and twisted,

which is a pretty sound defence, really, isn't it?

Yeah, absolutely.

I mean, the huge size of this animal alone,

really, I think, is its best defence.

It must have made the Earth tremble to see this.

As well as claws and that huge tail,

the Diplodocus had another neat, strategic trick up its sleeve.

This was more to do with eating than self-defence, however.

And in order to see it properly,

I need to get up high, into those extraordinary trees,

to witness a rather magical trick by the Diplodocus.

I've gone back 155 million years

to the Jurassic period,

an incredible time when ferns and huge conifer trees

dominated the landscape.

Food that one of the largest animals ever to walk the Earth

has become supremely well adapted to.

Our giant friend is happily feeding on ferns down there.

But scientists tell us

that she had an amazing way of expanding her menu options.

Let's see if I can get her to show us.

HE CLICKS TONGUE, WHISTLES

Got a treat! Come on!

Ah, there you are.

Look at that, fresh hay! Fresh hay!

Look at it.

You know you want it. Come on.

No?

HEAVY THUD

Ah. Can't tempt her.

Oh, she's coming up again. Oh.

No? You prefer those, do you? Your conifer needles.

HEAVY THUD

Wow!

That was something, isn't it, the way she used her tail there.

It was like a sort of extra leg, like the leg of a tripod.

And that way, of course, she can really build up her diet.

But there remains the mystery of how she can ever eat enough food

to fuel and build that huge body.

It's common enough for plant-eaters

to be bigger than predators - just look at the gorilla.

But even the largest land animal on Earth today, the elephant,

has to eat 150kg each day to sustain itself.

Well, a Diplodocus is five times the size of an elephant,

so scaling that up,

it would have to eat...

three quarters of a tonne daily just to stay alive.

That seems almost impossible, given how small its head is.

So... what's its secret?

Well, firstly, she didn't really chew her food.

Instead, she had a really long gut

and friendly microbes to break it down for her,

so little energy wasted on digestion.

But her second and biggest energy saver

lies with another ingredient vital for life:

oxygen.

And to see that, we need to look inside our Diplodocus.

Mammals like you and me

breathe air in and out by inflating our lungs.

Not so Diplodocus.

She has a one-way system for air,

thanks to some unique organs beside her lungs.

Air sacs.

When she breathes in, air goes into the sacs at the back of her body.

When she then exhales,

the rear sacs flood her lungs with fresh air.

When she breathes in once more,

spent air from her lungs is passed into the sacs at the front.

When she then exhales,

the front sacs empty stale air from the body.

So fresh air enters her lungs every time she breathes in AND out.

That means she can extract oxygen when inhaling AND exhaling.

That's twice what we can do.

And it's not unique.

Many dinosaurs did this sort of circular breathing.

And birds inherited the system too,

which allows them to fly at high altitude today,

where oxygen is scarce.

Amazing.

So far, the Diplodocus behind me has survived a spectacular attack

and eaten a hell of a lot of food.

So while she's grazing peacefully,

let's try and find out how those small early dinosaurs

evolved into these giant creatures.

Clues lie in the basement vaults of the Natural History Museum

in London, where resident palaeobiologist Paul Barrett

has been studying a trivial-looking fossil

that's languished unseen for the last 90 years.

We often find ourselves going through the drawers

and seeing things we haven't seen before.

So, we've had a large number of surprises here in the basement.

Surprises like this.

Long assumed to be little more than the remains of a reptile,

these unassuming bones

turned out to be something very special indeed.

This rather insignificant-looking specimen

is actually the only evidence that we have

for this enormous great group of animals,

the dinosaurs, first appearing on Earth.

These are the remains

of the earliest dinosaur yet discovered.

But how do we know it WAS a dinosaur?

The biggest clue actually comes from this bone here.

This bone is called a humerus. It's the upper arm bone.

And what makes it a dinosaur

is this huge flap of bone along one of its edges.

Other reptiles that live alongside dinosaurs,

crocodiles and their relatives, lack this feature,

so we are looking, almost certainly, at the earliest dinosaur.

They were found on an expedition to Tanzania 90 years ago,

and they're from an animal called Nyasasaurus,

after the lake it was discovered near.

So, once we'd identified those key features of the skeleton

as dinosaur features,

our idea that this is something to do with the origin of dinosaurs

actually started to come together pretty quickly.

With just an upper arm and six vertebrae to work from,

Nyasasaurus was rebuilt.

And it wasn't the super-sized monster we're accustomed to.

At a mere two metres long, a metre high, and just 60kg,

it was smaller than a man.

But Nyasasaurus did have one advantage

over the reptiles it shared the world with.

It was two-legged.

One of the key things about dinosaurs

that distinguishes them from all other reptile groups

is that they went walking on two legs only

very early in their evolutionary history.

A bit like this animal here, Allosaurus,

one of the meat-eating dinosaurs.

And this really opened up a huge variety of new ways of life

that were previously inaccessible to the other four-legged reptiles.

These included things like being able to support greater weight,

being able to move faster,

and being able to move more efficiently.

And this might be one of the key features

that dinosaurs became so successful.

And with success came a great opportunity for growth.

Because Nyasasaurus may have been small,

but, as they say, from little acorns giant oak trees grow.

So, on the floor in front of me is the thighbone

of a sauropod dinosaur from the Jurassic period.

So one of the much later dinosaurs,

and, we can already see, much, much bigger

than the very early dinosaurs like Nyasasaurus.

And they reached those quite large body sizes

only a few million years

after they started to take over the Earth.

Incredible to think that these two huge beasts,

so different in size and appearance,

both evolved from those small ancestral Nyasasauruses,

way back in the Triassic, 100 million years ago,

before the Jurassic I'm now in,

with our Diplodocus and Allosaurus friends.

And even after defeat in that fierce fight,

Allosaurus seems hungry for round two.

But it looks like the cavalry has arrived.

Will they be able to scare off this deadly predator once and for all?

Oh, he's off into the woods.

No doubt somewhat intimidated by the herd.

Well, maybe our palaeontologist, Susie Maidment,

can tell us whether Diplodocus really lived together

in groups like this.

I think it's extremely unlikely

that these animals could really run away from predators.

We think that these animals probably herded.

There's a lot of evidence from their trackways

that they lived together in groups.

Yeah, I suppose that makes sense.

Lots of plant-eaters today move around en masse.

Safety in numbers.

We can think of a herd of wildebeest

defending itself against the lions or the leopards

that are circling the herd. Yeah, absolutely, yeah.

There is more direct evidence

that these giant beasts really did live in herds,

and it's right on our doorstep, on the Isle of Skye,

off the west coast of Scotland.

During the middle part of the Jurassic,

Skye was totally different from today.

It would have been subtropical.

More like the Canary Islands or Florida.

And it was this paradise.

World-leading expert Steve Brusatte

and dinosaur researcher Paige dePolo

are searching that paradise,

where dinosaurs have left their mark.

Not their fossilised remains, but footprints in rock.

The front foot looks like a circle.

And this toe here helps me understand

that these tracks were most likely made by a Stegosaur.

It's equivalent to our thumb, and the way that Stegosaurs stand

pushes their thumbs into the ground.

And some of the tracks are simply enormous,

left by animals of a similar size to our Diplodocus.

The diameter of this track is about 50-60 cm.

That's about the size of a car tyre.

So imagine that, an animal so big,

every time its hand or foot touched the ground,

it made a hole the size of a car tyre.

And that tells us that this sauropod dinosaur

was roughly the size of about three elephants put together.

Eventually, they would get even bigger,

and some of the descendants of these long-necked dinosaurs

would one day become larger than Boeing 737 aeroplanes.

And what's really remarkable about the footprints on Skye

is that they're not just from individual animals,

but hundreds of dinosaurs.

ROARING

We've discovered a really great diversity of dinosaurs here.

We have the long-necked dinosaurs,

the Stegosaurs with the plates on their backs.

We have meat-eating dinosaurs,

some of which were early cousins of T-rex,

others early cousins of Velociraptor.

Some were the size of jeeps, some were the size of chickens.

And what this is showing us is that dinosaurs were diversifying

by the middle part of the Jurassic period.

They were truly spreading around the world,

diversifying and becoming the dominant animals on land.

And it's so cool to realise

that you're standing in a place where a dinosaur stood,

and that, at one point in time, millions of millions of years ago,

an animal alive passed across the land that you're now walking on.

Well, our herd of Diplodocus seem to be leaving their mark too.

And I suppose there were other times they'd really need to get together.

My word. There's some behaviour going on here.Yeah.

What are they doing exactly? I don't know.

They look quite keen on each other.

Oh, you think they want to be special friends?

The idea of these two enormous creatures

in any way conjoining,

if I can put it delicately, seems extraordinary.

Just the balance and care that would be needed.

Yeah, it certainly does, doesn't it?

We think they might have been able to rear up onto their hind limbs,

because their centre of mass was really far back, over their hips.

So presumably they needed to do that to mate anyway.

Well, they're certainly thrashing and waving their tails around a lot.

Is that some sort of signalling?

We know that there are other animals that use their tails to signal.

For example, peacocks.

And, of course, birds are the direct descendants of dinosaurs,

so it could be that the dinosaurs here

were also using their tails

to actually signal to mates. Right.

And of course, look, we can see here the Diplodocuses' tails are striped,

so maybe they are using them

as some sort of visual signalling device.

There's a theory that those colourful tails

didn't just delight the eye of a potential mate -

they may have been used to impress the ear as well.

In a factory in Seattle,

a dinosaur's tail is being recreated

to test a rather controversial theory

as to how they may have been used.

A passion project of multimillionaire inventor

Nathan Myhrvold.

I read this book that had this one almost throwaway line,

saying he wondered if the tails could have been like a bullwhip.

And I thought, "Hey, we can test that biomechanically."

For a dinosaur tail to act like a whip,

it would have to break the sound barrier.

Which means the tip would have to swing

at over 360 metres per second.

Could that really be possible for an animal so large?

Each vertebrae has several parts.

The typically cylindrical part of the vertebrae

is modelled here by these flat plates.

Coming up from that is something called the neural spine.

That acts as a stiffener for the tail,

because it has tendons and ligaments

that run across the entire top.

After nine months of construction,

it's time to see if the robo-tail can break the sound barrier.

CRACKING

They're using high-speed cameras at over 6,000 frames per second

to capture the action.

SWISHES, CRACKS

As it comes in,

it's going, going, going, and whack. That's the point right there,

when there's that quick little snapping motion,

that it goes faster than the speed of sound.

So this is going greater than 360 metres per second.

And it also makes a very audible cracking noise.

CRACKING

The question is, why would a dinosaur

need a tail that makes such a noise?

Nathan has ideas about that too.

I think it's very possible that they would engage in contests

where they would make this cracking noise to attract a mate.

Well, however they used those giant tails of theirs,

something seems to have worked well for our two lovebirds.

And I assume, given their enormous size,

they don't need to ask the question,

"Did the Earth move for you, darling?"

But if all goes well,

our female will soon be laying some eggs.

Now, scaling up from a chicken,

a Diplodocus egg must be the size of a small car.

This, I must see.

I'm in the conifer forests of the late Jurassic period,

155 million years ago.

A time of giants.

And our Diplodocus friend

has been getting rather intimate with her herd.

Doing her bit to keep the species going, I suppose.

So, how did they have their young?

Dinosaurs, like modern reptiles and birds, lay eggs,

rather than give birth to live young like us mammals.

Well, it looks like our friend here

is ready to produce a clutch of her own.

And given her enormous size, those eggs should be massive.

So I don't want to get too close to the action.

Oh... Oh... Here goes.

I think one's on the way.

DINOSAUR GRUMBLES

Oh.

Is that it?

I thought, given her gargantuan size,

it would be a bit bigger than that.

Erm...

Well...

How can it produce so small an egg?

And how could a creature so big

come from so small an egg?

An answer lies in a surprising place -

on our very own South Coast.

With a set of fossils so rare and valuable

that their exact location has to be kept secret.

Some of the best preserved dinosaur eggs ever discovered.

Looking after them is Dr John Nudds,

the former curator of geology at the Manchester University Museum.

He's dissolved away the hard calcite mineral

that's filled them for millions of years,

to reveal something astonishing.

Something that could tell us

not only how dinosaurs raised their young,

but why their eggs are so small.

This is what the eggs would have looked like,

with no external suggestion whatsoever

that they would have contained

such a beautifully-preserved dinosaur embryo.

There's only a handful across the globe,

so this collection is extremely important.

One egg even contains

a perfectly-preserved baby dinosaur head.

It's really quite remarkable to look down the microscope

and see this little baby dinosaur, 80 million years old,

staring back at you.

This was the orbit, which would have contained the eye.

And in the lower jaw here,

you can see some of the little teeth.

And it's immediately obvious that these are herbivorous teeth.

They have a surface for grinding down the vegetation.

This baby dinosaur would grow into a huge, 5m-tall,

two-legged, plant-eating monster - a Therizinosaur -

that stalked the plains of Mongolia 80 million years ago.

And these preserved embryos help answer

one of the biggest questions in dinosaur biology.

There is this big debate

as to whether dinosaur hatchlings were able to be independent

or whether they required parental care.

Several of the different bones of the skull are fused.

This would mean that the jaws and the skulls

would be able to withstand the mechanical pressures of feeding.

So, the evidence suggests that this dinosaur, at least,

could be independent,

they could fend for themselves pretty much on hatching.

But this embryo isn't a Diplodocus.

To answer whether their babies might have fended for themselves

like Therizinosaurs did, scientists turned to

another clutch of dino eggs found in Argentina.

This time, laid by a Titanosaur,

an enormous sauropod, relative of Diplodocus.

The adults of these were some of the very largest long-necked dinosaurs

that ever existed.

And yet here we have these tiny little skulls,

just a couple of centimetres.

We've been able to show that they had stereoscopic vision,

which would have enabled them to forage for food

immediately on hatching.

Most likely, similar to modern-day turtles,

they would lay huge numbers of eggs and then just leave them.

If you lay sufficient numbers, then a certain number will survive.

So, what about our Diplodocus?

What does our palaeontologist Susie Maidment think?

We don't have any nests from Diplodocus themselves,

but from other sauropods,

we know that they laid quite large nests

with quite a lot of eggs in.

And, of course, the babies had to grow up very quickly

because they had to hatch out of an egg

and grow to something that was 30 or 40 tonnes

in really quite a short period of time.

And I suppose if you're a firm muncher,

a browser and a grazer like a Diplodocus,

you don't need to teach your young anything.

Once they've learnt to eat, that's all they do every day.

Whereas the predator has to learn, really.

Yeah, that's a good point. And we don't actually really know

whether the juveniles lived with the adults

or whether they lived in separate environments

or separate herds at all.

So we don't really have a good idea of that.

So, it could be that, actually, sauropods laid their eggs and left

and did no childcare at all.

So, the evidence suggests Diplodocus would lay lots of eggs

and then abandon them to look after themselves.

But actually, that makes sense.

Think what it would take for her to have to forage

for her offspring as well as for herself.

And burying them also helps hide them from predators, of course.

Maybe best if I leave her to get on with it in peace.

Well, now we need to travel through time

to tell a story of a new era in this dinosaur planet

and to bid farewell to the Jurassic.

In this epic story,

we will move 30 million years into the future.

To a time when a dazzling array of formidable new dinosaurs appears,

including the fearsome raptor.