All language subtitles for BBC.Planet.Dinosaur.Files.PDTV.x264.AAC.MVGroup.org

This is one of the most awesome
dinosaurs ever discovered.

Meet Spinosaurus,

a truly amazing predator that
lived 95 million years ago.

In the dinosaur world,
this is the Terminator,

at a stunning 17 metres in length
and 12 tonnes in weight.

Spinosaurus is one of
the largest predators

to have ever walked the planet.

It lived in North Africa.

Here, it's roaming a swamp,

but this hunter's favourite prey
lived elsewhere.

HISS

Spinosaurus's meal of choice
was fish, not meat.

This is a dinosaur that loved
to hunt in water.

Standing in the river shallows,
Spinosaurus plays a waiting game.

It's on the lookout
for one of these.

Onchopristis, a giant
eight-metre long swordfish.

There's enough fresh sushi there
for a whole Japanese restaurant.

You can find this kind of hunting
going on in the wild today.

This grizzly bear
loves a bit of raw fish too.

He and his mates know that thousands
of juicy salmon are swimming

up river, and they're waiting
for a meal to come their way.

And their super-quick reactions mean
they can catch this fish in mid-air.

But how do we know that Spinosaurus
was as partial to fish

as that grizzly bear?

By looking at the evidence,
that's how.

These are the tooth sockets
in a Spinosaurus's jaw.

It was found
in 2005 in North Africa.

Stuck in one of the sockets
is a tiny piece of backbone

from another creature.

This spino clearly didn't brush
his teeth before he went to bed!

That bone fragment was from a
swordfish, possibly Onchopristis.

These juicy fish were one
of Spinosaurus's favourite foods.

And, a bit like a bored angler,

Spino would spend hours waiting for
these tasty river treats to swim by.

Here was a beast that loved poking
its snout into a fast-flowing river.

And Spinosaurus's way of catching
fish is really clever.

Its secret lies in that snout.

It has lots of small holes in it
that are very similar

to those of a crocodile.

In a crocodile, these snout holes
contain special sensors.

These help the croc to feel
small changes of pressure

caused by other creatures
disturbing the water nearby.

That signal is one of the ways
it zeroes in on prey.

And dinosaur experts believe
that the Spinosaurus had sensors

like the crocodile,
an amazing ability that meant

it could strike at these
onchopristis

without even seeing them.

Take a look at this
amazing creature.

A flying monster,
its name is Hatzegopteryx.

This is a kind of prehistoric
flying reptile called a pterosaur

and it's one of the largest flying
creatures ever known.

This mind-blowingly massive beast

patrolled the skies
65 million years ago.

At that time, Europe was made up
of lots of islands, one of which

was called Hatzeg, which is how
this monster gets its name.

And it really is a monster.

Hatzegopteryx was over
five metres tall

and had an enormous
ten metre wide wingspan.

That's as big as this modern
jet fighter.

Hatzegopteryx was an
incredible flying machine.

But it preferred to
hunt on the ground.

It could gobble up these much
smaller herbivores with ease.

Usually, long-necked sauropods,
like these magyarosaurs,

were the biggest beasts
in the dinosaur world.

Here, though,
they're dwarfed by Hatzegopteryx.

How do we know that a flying reptile
could actually get this big?

By taking a look at the evidence,
that's how.

These are the fossilised
footprints of a pterosaur,

very like Hatzegopteryx.

Discovered in 2002, they measure
a massive 35 centimetres across,

proving that these
creatures could be huge.

Imagine, if the hatzegopteryx
were around today,

it would be three times bigger than
the world's largest flying bird,

the wandering albatross.

And when it landed on the ground,
it would be as tall as a giraffe.

Take a look at this
condor from South America.

This bird glides a bit like Hatze.

A condor's wings take advantage of
warm air currents called thermals.

They help it stay in the air
for hours on end.

Dinosaur experts believe pterosaurs
like Hatzegopteryx

could do the same.

If you thought Tyrannosaurus rex
was an impressive dinosaur,

take a look at this
prehistoric predator.

This is Carcharodontosaurus.

ROAR

Its name means
"shark-toothed lizard".

This monster grew up
to 13 metres long.

An adult weighed a hefty
seven tonnes.

It ruled the roost in North Africa
95 million years ago.

ROAR

Carcharodontosaurus
was a carnivore,

and a whole ton heavier than T-Rex.

How much meat do you think
a killer of this size ate each day?

The amazing answer is that a
full-grown carcharodontosaurus

needed to eat a whopping 60
kilograms of meat every day

just to survive.

That's like having
480 hamburgers every day.

Now, the carcharodontosaurus
liked to hunt

by creeping up slowly on its prey.

But amazingly,
for such a large beast,

we've recently discovered that
it could really move it too.

Watch this.

Over short distances, this hunter's
explosively powerful legs

could get it running
up to 20 miles an hour.

That meant it could catch lighter
prey like this ouranosaurus.

So, where would you have found
one of these ruthless killers?

Most of the 95 million-year-old
carcharodontosaurus bones

have been found in various
sites across North Africa.

Life for these big killers was
a constant battle. For food...

For territory...

For dominance over
other carcharodontosaurs.

ROAR

But how can we tell this kind of
head-to-head battle went on?

By closely looking at
the evidence, that's how.

This is a recently
discovered lower jaw bone.

It came from a meat-eating dinosaur.

It's big, nearly half a metre long,
and the exciting bit?

Two bite marks.

The size and shape of the tooth
marks show that another dinosaur

of the same species had
sunk its teeth into this jaw.

For a carcharodontosaur
to dominate its patch,

it first had to see off rival
carcharodontosaurs.

And that's often the way
it still goes in the wild.

This frilled lizard from Australia
has found a good feeding area

with lots of tasty insects.

So when another male lizard
of the same size enters its patch,

battle commences.

HISSING

And goes on for a long time.

ROAR!

But when two seven-tonne
carcharodontosaurs went at it,

I wonder what kind of destruction
that would cause.

Well, with the help of some power
tools and a chunk of steel,

I'm about to find out.

It's hard to imagine the damage

these carcharodontosauruses
would've caused

if they start throwing
their weight around.

But to get an idea, we've built
a carcharodontosaurus foot.

It's been very specifically shaped
to match the fossilised footprints

that have been found
from the real thing.

It's made of steel,
not flesh and bone,

but hopefully it's going to be
strong enough for the task ahead.

You see, I want to attach this
to something that can provide

the power and weight
that would've been there

with a real carcharodontosaurus.

Rich!

'And this big digger is it.

'A huge hydraulic excavator.

'35 tonnes of steel
on caterpillar tracks.'

Rich the driver assures me
that this enormous excavator

can get my carcharodontosaurus
foot to step down

with the seven tonnes of force

that the real thing would have
applied with every stride.

Want to grab the back end?
This is heavy, to say the least.

Ah! Cheers.

Thing is, first job is to
attach it to this digger.

That's attached.

Now, let's see what kind of impact
a dinosaur like this would have had.

I need something else made of steel

for my carcharodontosaurus foot
to tread on.

So, I've got myself a scrap car.

Now, obviously, they didn't have
those 95 million years ago,

but it's here to represent
the unfortunate dinosaurs

that may have got in the path
of the mighty carcharodontosaurus.

Right, Rich, can you give this
a big, seven-tonne stamp?

Erm...

It didn't really stand a chance.

And I think that's probably
what a lot of dinosaurs

that hung around North Africa
95 million years ago felt.

Because weight
is a massive advantage

in the battle for dominance.

And the carcharodontosaurus
carried a lot of weight.

And this one's angry.

'I'm not sure that that's the kind
of thing covered by car insurance.'

Meet Nothronychus.

A strange-looking dinosaur
with a potbelly.

It lived in swampy jungles
like this 92 million years ago.

Because it walked upright
on two legs,

Nothronychus has the classic look
of a meat-eating dinosaur.

But it's actually a vegetarian.

It's one of a weird group of
dinosaurs called theriznosaurs.

Twice as tall as an adult human,
it had a lengthy neck

and powerful legs.

It used its very long,
curved claws to pull down branches,

to get nice, juicy leaves to eat.

In fact,
its name means "sloth-like claws".

And here's why.

Northro's claws are very like those
of this bizarre-looking creature -

the sloth.

This gentle, tree-dwelling mammal
lives in South America.

It uses its claws to grab

and eat leaves in a very similar way
to how we think Nothronychus did.

Unlike sloths, though, Nothronychus
had to be ready to defend itself

against some dangerous predators.

In these same swamps
is an eight-metre-long tyrannosaur.

A fearsome carnivore
from the same family of dinosaurs

as the famous T-rex.

And this tyrannosaur fancies
some nothronychus for dinner.

And it's at times like this

that those claws become weapons
of self-defence,

making these potbellied beasts
a match for the mighty tyrannosaurs.

Nothronychus is just as powerful

and aggressive as these killers.

And that's because
they're actually close relatives.

So, if they look like a carnivore
and they fight like a carnivore,

how can we be sure
that they were actually herbivores?

By taking a look at the evidence,
that's how.

In 2001, the bones of a dinosaur
very like Nothronychus

were discovered in the USA.

Amongst them were fossil teeth.

Their shape showed they were
designed for eating leaves,

not meat.

Nothronychus,
just like these tyrannosaurs,

started off
as a meat-eating dinosaur.

But over hundreds
of thousands of years,

Nothronychus changed
its eating habits.

It still looked like a carnivore,
with its upright stance,

but now it lived off plants.

'Let's find out more
about the Nothronychus diet

'in the Dinosaur Workshop.'

It doesn't matter whether you're
a bunch of hungry tyrannosaurs,

a nothronychus, or me, a human
being. You've got to eat to survive.

Now, for a human being like me,

every day I'm going to consume
something like this.

Rice, pasta, egg,
fruit and vegetables.

It's got add up to enough energy
for me to do what I need to do.

But what would a one-tonne
dinosaur have to eat?

Now, remember,

Nothronychus is descended
from a long line of big carnivores

and they ate meat. Lots of it.

A typical one-tonne meat-eater
would be getting through

around about ten kilos
of flesh every single day.

So, that's like this lot and,
probably, my leg into the bargain.

Now, that may look like
an awful lot to consume

until you remember
Nothronychus is trying to get

this amount of energy
just by eating plant matter.

And vegetation just
isn't as energy-dense as meat.

You've got to roughly eat five times
as much to get what you need.

So, every day, a nothronychus
would be trying to get through that.

And probably that. And
probably that. And maybe that too.

It is an absolute stack of
vegetation to chomp your way through

every single day.

Which is probably why
Nothronychus was renowned

for its large potbelly.

It had an awful lot to fit in.
But why would it bother?

Well, by eating vegetables,
it didn't have to compete

with all the large carnivores
eating meat.

Easy, tiger.

This is Argentinosaurus.

A massive, plant-eating dinosaur

that lived 95 million years ago
in South America.

They were huge.
But their babies were tiny,

weighing only five kilograms.

That's about the same as
a one-month-old human child.

But fully-grown Argentinosaurs
could weigh as much as 75,000 kilos.

That's heavier
than the combined weight

of all the children
in a typical primary school.

This dinosaur is
the largest creature

known to have walked our planet.

Being so big meant that any other
dinosaur that got too close

to Argentinosaurus
could be in real danger.

It's almost impossible

to comprehend the size
of these enormous creatures.

Maybe this argentinosaurus leg bone
could help you get an idea.

It weighs half a tonne.

It's one of many
found in Argentina in 1993.

Just that single lower leg bone,
which would be the shinbone

for a human, is, incredibly,
taller than an average 13-year-old.

Or, to put it another way,

a fully-grown argentinosaur
weighed as much as ten elephants.

Meet Epidexipteryx.

A very strange-looking,
pigeon-sized creature

that you would have found
in lush forests like this

154 million years ago.

This dinosaur lived in Asia.

It was small, only half a metre long

from its head
to the tip of its tail.

And it had a bird-like skeleton,

covered in feathers.

Epidexipteryxs were dinosaurs
like no others.

Everything about them is weird.

The tongue-twisting name,
the long tail feathers,

sticky-out teeth,

and, especially,
those spindly fingers.

Those fingers, though, are for
more than just climbing trees.

Watch this.

That third finger
on both its clawed hands

is much longer than all the others.

It's a tool Epidex uses
in a very clever way.

For getting at food
hidden inside the tree.

Amazingly,
there is actually an animal today

that uses the very same weird
method for getting its dinner.

This is an aye-aye.

It's a small mammal that lives in
Madagascar off the coast of Africa.

Just like Epidex,
it has a very long third finger.

It taps on the tree and listens.

When it hears something inside,
it scrapes away at the bark,

hoping to get
some juicy insects to eat.

'Time for me to turn myself
into a very strange creature.'

Ha-ha!

Epidexipteryx had probably
the weirdest set of hands

I've ever seen.

It kind of had
these two shorter talons

and then this one
ludicrously long finger.

Its way of life was
to climb trees and eat grubs.

Now, what I want to do
is get an idea

of what that would have been like,

and the strengths and weaknesses
of the features it had evolved.

So, I'm going to set off
as a normal person

to live the life of
an epidexipteryx.

Got myself a jungle, here,

hopefully there's some food
in there somewhere.

I'm going to see if I can find it.

When it comes to climbing,
our hands are actually pretty good.

We've got sort of short, stubby,
strong fingers that can grip

and move our way up through trees
pretty effectively.

But what about foraging for food?

If I wanted to find maybe
a big, fat, tasty grub to eat,

what are my hands like then?

Ha-ha. In here. I see some food.

There's a little grub in this log.

The problem is, our strong, stubby
fingers haven't got the length

to get into little nooks
and crannies to pull grubs out.

What I need is a new set of hands.

On with my epidexipteryx gloves.

Argh.

What I find,
climbing as an epidexipteryx,

I've got to climb
in a different way.

Because I've only got three fingers,
I've got to use my feet more

cos, even with my fingers,

only two of them are any good
for gripping.

This third one feels like a positive
disadvantage on the climbing front.

But I'm getting used to it.

Now, I'm going to get up here,
towards where the food is.

Now, now I can see this big fella
coming into its own.

Cos that little nest of grubs
are now all within reach.

Oh, got it. Come on. Look at that!

Now, I really am beginning
to enjoy life as an epidexipteryx.

There are so many strange things
about Epidexipteryx,

aren't there?

I mean, how can we be sure that
a dinosaur like this really existed?

By taking a look at the evidence,
that's how.

This extraordinary fossil
was discovered recently in China.

It shows a whole epidexipteryx.
Its bird-like appearance is clear.

As are its odd-looking teeth
on its skull.

You can even see
the long tail feathers.

Epidexipteryx was about the size
of a pigeon.

But a pigeon's feathers
help it to fly.

The feathers on this dinosaur
were for display.

In other words, showing off.

This is one of
the strangest dinosaurs

to have walked our planet.

Meet Gigantoraptor.

A breathtaking creature,

with a body like a huge,
overgrown ostrich,

and a head with a fearsome,
parrot-like beak.

It's the largest feathered
animal ever discovered.

Gigantoraptor was
one-and-a-half tonnes in weight

and a massive eight metres long.

It had vicious, dagger-like claws,

and lived 80 million years ago.

Gigantoraptors
were to be found in Asia,

roughly where you'd find
Mongolia today.

They come from a family of dinosaurs
known as oviraptorids.

But Gigantoraptor was
by far and away

the biggest member
of this strange family.

How do we know such
an odd creature ever existed?

By taking a look at the evidence,
that's how.

This is the Gobi Desert
in Mongolia, Asia.

In 2007, the bones of a
gigantoraptor were discovered here.

They were huge. 35 times bigger than
any other of its close relatives.

It's their sheer size
that's incredible.

It looks a bit like an ostrich.

But it would need four ostriches
standing on top each other

to match the height
of a gigantoraptor.

We know that gigantoraptors
had feathers

because they've been found
on the fossils

of other closely-related dinosaurs.

But Gigantoraptor's feathers
weren't for flying -

nor were they for keeping warm.

These were feathers for display -
especially for attracting a mate.

Here, a male and female
gigantoraptor

are doing a kind of dance.

It's a bit like showing off
your best dance moves

at the school disco.

Now, if that sounds
just too far-fetched,

take a look at these grebes.

Just like the gigantoraptors,

they're carrying out what's called
a courtship dance.

They move in time,
display their feathers

and copy each other's movements.

The aim is to find and,
hopefully, attract a mate.

Gigantoraptor's similarity
to birds really stands out

but there's more to this resemblance
than feathers and beaks.

That's because they laid eggs.

This is how all dinosaurs
gave birth.

What's special about Gigantoraptor
is that it stayed with its eggs,

protecting them.

Here, a pair of gigantoraptors
defend their nest

against an attack from
this predator - Alectrosaurus.

Danger over.

The mother gigantoraptor
settles back down on her nest.

'Meanwhile,
in the Dinosaur Workshop,

'I'm hatching a very
egg-citing plan.

'Yeah, er, sorry.'

There is one thing that all
dinosaurs have in common.

They lay eggs.

And, in the case
of the gigantoraptor,

eggs like I have never seen before.

To show you how odd they are, let's
first look at more familiar eggs.

That's a chicken's egg.
We all know what these are like.

They're three centimetres long.
We have them for breakfast.

This is an ostrich egg.

This is the biggest egg that's laid
on the planet in modern times.

It's a pretty good size and it comes
from a pretty good-sized bird.

And this is a genuine dinosaur egg.

Or, at least, a fossil of one.

This would have been laid in muddy
ground about 70 million years ago.

And, over that time,
the mud has turned into rock

and the egg has turned
into a fossil.

And this is our gigantoraptor egg.
I say "ours" because we've made it.

But we've made it very carefully,

to be the right size,
shape and strength

to match fossilised gigantoraptor
eggs that were recently found.

These eggs took
about 80 days to hatch.

Now, that is a long time

for it to be exposed
to potential predators.

So, they would have to have been
made pretty strong. How strong?

Let's find out.

Naturally, my fellow dino engineers,
Andy and Jim,

are filling my gigantoraptor egg
with white and yolk.

This is my egg-strength
testing machine.

Gigantoraptor egg is up there.

Whatever weight gets loaded on here
gets felt by the egg up there.

When this weight here
gets too much for that egg...

First...

These bags weigh 25 kilos.

And the egg doesn't care about that.

Looks like I might have to
get involved, here.

Not in my best T-shirt.

I'm 75 kilos.

100 kilos

on our gigantoraptor egg.

More weight.

That's 125 kilos.

Now, dinosaur experts did
reckon that these eggs

would probably have taken that,

but they weren't sat underneath
the egg at the time. More weight?

'This gigantoraptor egg is living up
to its tough reputation.'

That's 150 kilos.

CRACK

LAUGHTER

Argh!

Argh!

Right. Well,
that's a nice piece of science,

cos that egg pretty much fitted

with what the dinosaur experts
reckoned the Gigantoraptor egg

would have taken.

We're going to look at
the bite strength

of three very powerful dinosaurs.

Allosaurus.

Majungasaurus.

And Daspletosaurus.

All of them are big predators
with terrifying jaws.

Just imagine them clamped
tight round your leg.

How much force do you think it
would take to prise them back open?

'Let's find out in the
Planet Dinosaur Files Workshop.'

Now, obviously,

a dinosaur's jaws are what's
really scary about these beasts.

But I want to know is just
how powerful those jaws are.

To do that,
I've built my own dinosaur jaws.

My first set of experimental jaws
are going to recreate

the bite of an allosaurus,

a muscle-bound, meat-eating dinosaur
that lived 150 million years ago,

roughly where the USA is today.

This is my allosaurus.

And this is what's driving
the bite of the allosaurus.

It works off compressed air,
like this.

I'm using air to force my jaw shut

by squeezing it into
this rubber tube at high pressure.

At the moment, I've got it set
to what dinosaur experts reckon

is the muscle strength
in an allosaurus's jaw.

Now, I figure a good test to see
how powerful a bite these fellas had

is to stuff something in its jaws,

get them to clamp down
with full biting strength

and then see what it takes
to wrestle the jaws back open.

Chris, do want to give that
full allosaurus strength?

Right, it's now clamped down on
my trusty broom. Can I get it back?

No.

It turns out there's no way...

an 11-stone bloke...

..can get the jaws of an allosaurus
open once it's bitten down.

What about two blokes?

Obviously, out in the wild, that
would be a very dangerous manoeuvre.

Right, see if we can get this open.
Oh, my life!

It's not easy.

That is an incredibly powerful bite,

but two full-grown blokes

can just about wrestle open
the jaw of a full-grown allosaurus.

Here's another powerful
prehistoric carnivore.

This is Majungasaurus,

a scavenging predator that
lived 70 million years ago

on the island of Madagascar,
off the east coast of Africa.

Although it was big,
weighing well over a tonne,

Majungasaurus was actually
smaller than Allosaurus.

So, how does it compare
in jaw power?

'Back to the dinosaur workshop.'

Time to test out
the majungasaurus jaws.

Now, I've got the same powerful
artificial muscle as before,

but I've slightly
reduced the head size.

These animals were a little bit
smaller than the allosaurus,

but they had a powerful reputation.

Jaws are set to
majungasaurus strength.

Although ordinarily
a vicious meat-eater,

it's time the majungasaurus
had one of its five a day.

I think it quite likes them!

What will it take to prise open
the mouth of a majungasaurus?

Ready? Yeah.

It's slightly mad
just how hard that bite is.

There's absolutely no way that
both of us are getting that open.

I think this needs something
a bit more than human.

'Where manpower fails,
maybe van power will succeed?'

Are you good?
Start taking that away.

Have you got any more?

Yes, you've got it!

Well, there we go.

The majungasaurus -
too much for a man,

about right for a man and a van.

Time to ratchet up the power factor
with my third and final dinosaur.

Meet Daspletosaurus.

This intimidating beast
lived 75 million years ago

in what today is Canada.

Adult daspletosaurs could be
up to nine metres long

and three tonnes in weight.

That's bigger than Allosaurus
and Majungasaurus put together.

So, how will the jaws
of this hefty hunter

compare with
our other two predators?

This is my daspletosaurus.

Even in dinosaur terms, these
things were veritable monsters.

They were like the granddaddy
of T-rex.

Now, as you can see,

it's a much, much bigger animal

than either the allosaurus
or the majungasaurus.

In order for us to replicate that
bite force with our model,

we had to take the whole rig
right up to maximum.

Chris, do you want to power it up?

That's a concrete brick
wedged in our daspletosaur jaws.

Right. That's down pretty hard.

So, what will it take to force open
the jaws of a daspletosaurus?

Jim, shall we try by hand?
OK, ready?

Right, it's kind of obvious
that this thing

is well beyond
the means of human power.

But the van's not doing
the trick either.

That's pretty shocking,

because we went to great lengths to
build this to accurately reflect

what experts think these
dinosaurs were capable of.

Headline news -

you can't even open the jaw of
a daspletosaurus with a van.

I think we need some
professional help.

What I've got is a daspletosaurus
biting down at full power.

And you're sure
your little dinosaur

is going to be more powerful than
my big dinosaur? I'd imagine so.

What do you normally use those for?

It's a hydraulic spreader,
mainly used for car crashes,

so we can rescue people
stuck in cars.

To get these in here,

I'm going to have to do a bit of
dentistry, aren't I? I'd say so.

Cleanliness is
important in dentistry.

Don't worry, big fella,
this shouldn't hurt at all.

Stay being brave!

Sparky, can you do a job for us?

OK. Fire it up.

So, will these jaws
finally meet their match?

'It's taken that super-powerful
fireman's gadget,

'capable of shifting the weight
of two double-decker buses,

'to get those jaws open.'

I'm seriously impressed.

I don't want to hold you up
from fighting fires.

Thank you ever so much. Cheers.

Looks like we've finally
overcome the daspletosaurus.

It appears as though
normal people can't do it -

if Daspletosaurus
bites down on something,

better call the fire service.

'Down at my local swimming pool,

'we're going to look
at the swimming technique

'of three prehistoric predators.'

Kimmerosaurus.

Sarchosuchus.

And Predator X.

First up is Kimmerosaurus.

This sea beast roamed our oceans
150 million years ago

at a time when the whole continent
of Europe was covered in water.

Kimmerosaurus was a type of
prehistoric sea creature

called a plesiosaur.

It was six metres long -
the length of a killer whale -

and this ocean predator
liked to hunt sharks.

Kimmerosaurus lived
millions of years ago,

but it swam in a way familiar to
creatures in our oceans today.

These sea-lions have four fins,

like Kimmerosaurus.

And, a very similar
swimming technique.

And look at these penguins.

We all know those stubby wings
don't get them airborne,

but once they go underwater,
it's almost like they're flying.

Look how nippy they are.

'Now, let's head to the swimming
pool to find out more about

'how Kimmerosaurus
moved through the water.'

So, how good was a kimmerosaur's
swimming technique?

Well, I'm going to try and
find out in this swimming pool.

I can swim backstroke,
front crawl and things like that,

but I haven't got the equipment
to swim like a kimmerosaurus.

So, we've built this.

It may look a bit big
and bulky, but actually,

it's only about half
the size of the real thing.

And a kimmerosaurus didn't swim
front crawl, like that.

The kimmerosaurus used wings.

What they used to do was sort of
flap these wings in the water

to propel themselves at
great speed underwater.

Jim and I,
the muscles of the kimmerosaurus,

can't spend much time underwater
because of our lungs,

but we can operate these wings.

Ready, Jim? Yeah. Let's go.

We're timing how long it takes
our kimmerosaurus swimming model

to get down this 25-metre pool.

Just how good are
those underwater wings?

That's pretty astonishing.

Just these four flapping fins
have managed to get

well over a quarter of a tonne
of boat and rider

down a swimming pool
in less than 45 seconds.

Obviously, a real kimmerosaur
would be a lot smoother,

because they swam under the water.

They didn't have a big,
bulky boat with them.

I think it is a very effective
swimming technique.

Our next prehistoric swimmer
is this terrifying river beast.

Meet the king of the crocodiles,
Sarchosuchus.

Its name means "flesh crocodile"

and it lived 95 million years ago
in North Africa.

An enormous 12 metres long -

that's the length of a whole
railway carriage.

Heavier than a fully-grown elephant,

weighing an astonishing
eight tonnes.

Twice the size of any
crocodile in the world today.

This is a super crocodile.

Sarchosuchus, like all crocodiles,

was perfectly adapted
to living in water.

True, crocodiles do have to come
to the surface to breathe,

but they've evolved
to be able to spend

staggering lengths of time
underwater.

If they're not moving,
they can spend several hours

beneath the surface without
needing to come up for air.

They also have a special way
of swimming that's different to

sea lions or Kimmerosaurus,
the plesiosaur we've already met.

A crocodile's body and tail
moves in a sideways action,

making a kind of S shape
through the water.

'Let's find out just how effective
that method was in practice.'

OK, now let's see how quick it is
swimming like a sarchosuchus.

First, I need a very long tail.

Next, I want to make myself look as
frightening and sleek as possible.

And finally, to be a top predator,

you need to be able to see
underwater.

That's it. Sarchosuchus.

Sarchosuchus swims in a very
different style to Kimmerosaurus.

How will it compare for speed?

That is astonishingly quick.

That is twice the speed of a
kimmerosaurus and the thing is,

once you get one of these
big crocodile tails on,

you can feel the power in the water.

You can use every muscle in your
body to propel yourself along

and that's why the sarchosuchus
must have been

one of the most feared predators
in prehistoric waters.

Here is our final aquatic contender.

Recently discovered,

it's so fearsome that
even its name is terrifying.

This is Predator X,

a truly enormous monster.

More than 15 metres long
and a massive 45 tonnes.

Nearly five times the weight
of the largest known killer whale.

It had jaws more powerful
than any dinosaur.

Predator X lived
150 million years ago

in the same seas
as Kimmerosaurus

and it's likely that Kimmerosaurus

was top of the menu
for this ocean monster.

Now, often in the water,
smaller can seem faster.

And as Predator X is three times
bigger than Kimmerosaurus,

you might think that Kimmerosaurus

would be able to outswim
this huge hunter.

Let's find out
if that really is the case.

Time to bring a bit of Predator X
to the local swimming pool.

Now, in swimming style, he's pretty
much the same as Kimmerosaurus -

four large fins
flying through the water.

Significant difference -
he's much, much bigger.

There's the little old
Kimmerosaurus one,

here's the big Predator X one.

Whereas Kimmerosaurus was
about the size of a killer whale,

this thing, in real life,

would have been about the size
of this swimming pool.

So, how will our Predator X get on?

'Once we get those massive
fins into a rhythm,

'Predator X eats up the water.'

Just over 30 seconds.
This thing's quick.

It's not quite as quick
as Sarchosuchus,

which was very swift off the mark,

but noticeably faster
than Kimmerosaurus.

The fact is,
the way it felt here,

Jim and I just don't have the
power for water wings this big.

And the difference is,

real-life Predator X
was a veritable monster.

It was like a 45-tonne torpedo
and it had all the strength

it needed to drive its massive
wings through the water,

giving it the ability to devour
just about anything it wanted.

This is the island of Madagascar
off the coast of Africa,

70 million years ago.

A family of scavenging majungasaurs,
a mother and two youngsters,

are feeding off a carcass.

Suddenly, another big meat-eating
dinosaur arrives on the scene.

Another majungasaurus.

It's a male, and he wants
to muscle in on this feast.

Our majungasaur mum has her kids
to think of. They need food.

But this male is greedy.
He wants all that meat for himself.

He won't even let
the youngster have the scraps.

Now, take a look at this fossil.

This is the tail bone
of a majungasaurus,

discovered on Madagascar in 2003.

Take a very close look. There
are some revealing marks on it.

What do you think those marks are,
and how might they have got there?

Here's one possible answer.

They came from the teeth
of another majungasaurus,

caused maybe during a fight
between two of these dinosaurs

that has left
the scars of battle.

But things aren't
always what they seem.

Dinosaur experts discovered
these were bite marks -

another majungasaur's
bite marks.

But this didn't look like a fight
between two angry predators.

This was one majungasaur
eating the other.

So it seems that majungasaurs
could be cannibals.

When the female majungasaur
finally finishes off the male,

it doesn't go back to that carcass.

Instead, it starts eating the
body of the male majungasaur.

If that seems shocking,
maybe unbelievable,

then just take a look
at our world today.

These insects are praying mantises.
A male and a female.

They're mating.

But then the female starts
eating the male's head.

Mantises, just like majungasaurs,
can turn into cannibals

when they're hungry.

Meet Spinosaurus, a huge dinosaur.

17 metres long and
12 tonnes in weight.

This incredible predator lived 95
million years ago in North Africa.

You would typically
find this dinosaur

standing in the shallows of a river.

Here, our spinosaurus has got its
eyes on something in the water.

Now, take a look at this piece
of bone evidence.

These are the tooth sockets
in a spinosaurus's jaw.

It was found in 2005
in North Africa.

Stuck in one of the sockets

is a tiny piece of backbone
from another creature.

How do you think that fragment
of bone got into Spino's jaw,

and what type of creature
might that bone have come from?

Well, here are four possible
prehistoric suspects.

They're all creatures
that lived in water.

There's Kimmerosaurus, Predator X,

Sarcosuchus and Onchopristis.

Which one is it?

Let's look at our suspects.

Well, both Kimmerosaurus
and Predator X

lived 55 million years before
Spinosaurus was around.

They're also sea creatures,

and Spino was a dinosaur that
hunted in rivers, not oceans.

So, that rules them out.

And then there's Sarcosuchus,
a giant prehistoric crocodile.

This reptile lived at
the same time as Spinosaurus

and around the same North African
rivers, but Sarcosuchus

was another massive predator,

too big for even Spinosaurus
to take on.

That leaves just this creature.

Onchopristis,
an eight metre-long sawfish.

It was a prehistoric river fish

that lived at the same time
as Spinosaurus.

Spino, as we know, was a dinosaur
that spent a lot of time by rivers.

Standing in the shallows,
it would play a waiting game.

Usually, it would be on the lookout
for one of these, onchopristis.

Palaeontologists, dinosaur experts,

are convinced this kind of
creature provides our answer.

That mystery bone fragment came
from a sawfish like onchopristis.

These juicy fish were one
of Spinosaurus's favourite foods.

And a bit like a bored angler,
Spino would spend hours

waiting for these tasty
river treats to swim by.

Here was a beast that loved poking
its snout into a fast-flowing river.

When it grabbed an onchopristis
in its jaws,

it's easy to see how a piece

of the sawfish's backbone could
get stuck in Spino's tooth socket.

Subtitles by Red Bee Media Ltd