All language subtitles for Flying.Monsters.with.David.Attenborough.2011.1080p.Bluray.x264.DTS-HDC-Eng

DAVID ATTENBOROUGH: Birds today
are the masters of the skies.

But they were not
the first creatures to fly,

and they are certainly
not the biggest.

The first large animals
to leave the ground

were so extraordinary

they're almost beyond imagination.

They were reptiles.

(PTEROSAURS SQUAWKING)

Pterosaurs.

They evolved into
a huge variety of species.

(GROWLING)

Some, the size of aeroplanes,

were the largest creatures
ever to fly.

They could travel half way
around the world in a single flight.

And the pterosaurs'
extraordinary abilities

enabled them to dominate the skies
of the prehistoric Earth

for a 1 50 million years.

But, why did these magnificent beasts
take to the air in the first place?

How did they fly?

And why, after such success,
did they vanish?

Something very remarkable happened
around 220 million years ago.

The planet then
was a very different place.

It was much drier, for a start,

but, in the tropics
there were rainforests,

and then, as now,

they were the focus of a great deal
of varied wildlife.

In the detail however,
they were very different.

Most notably, there were
no large creatures in the air.

No bats. No birds.

The stage was set
for a remarkable advance

in the history of life.

At that time, the only animals
that could fly were insects.

They were tempting food for reptiles.

But if a reptile were to catch them,

it, too, would have to take to the air.

And a hint, of how
they might first have done so

can be seen in an animal
that is alive today.

This little lizard called Draco,

is found throughout
the forests of Southeast Asia.

And it must certainly have had,
in the far distant past,

lizard ancestors and cousins

that looked very much like it.

Like them, it finds it food, insects,
throughout the forest.

And to do that,
it has to get around.

And it has a very interesting way
of doing that.

Draco is an excellent climber.

Light in weight and with powerful
gripping claws,

it can run along the branches
of the highest trees

in pursuit of its prey.

But Draco faces a problem.

How can it travel
from one tree to the next

without going all the way back down
to the ground and then up again?

The way it has evolved of doing so,
gives us a clue

as to how early reptiles
may first have taken to the air.

It jumps.

But it does more than just leap.

It extends the width of its body

by opening flaps of skin
along its flanks,

and they enable it to glide.

Draco may give us the right idea

as to how gliding, flying,
amongst the reptiles started.

But one thing is certain.

Flapping flight, powered flight,

remained the preserve
of the insects for a very long time.

And then, one group of reptiles
developed even that.

And the evidence of how they did so
is really very intriguing.

This is Dorset,
on England's south coast.

And this is where my journey
into the past begins.

A 90 mile stretch of shoreline here

can tell us a lot
about the evolution of flight.

This is the Jurassic Coast.

Its rocks are full of fossils
of prehistoric creatures,

including evidence of the first
backboned animals ever to fly.

But wasn't until the 1 9th century

that scientist started
putting together those clues

to form a detailed picture

of one of the most dramatic periods

in the whole of the history of life.

And they had an unlikely ally.

A middle aged woman
from the local town,

who used to come out
to scour these cliffs for those clues.

She'd come in all weathers,

but particularly,
after there had been heavy storms,

which might have removed
some section of the cliff,

and so exposed specimens
that no one had ever seen before.

Her name was Mary Anning.

Mary is, for me,
the heroine of this remarkable story.

She had an almost unbelievable
talent for unearthing fossils.

In the early 1 800s,
science was still the preserve of men.

Yet, what she managed
to unearth,

brought academics flocking
to her hometown of Lyme Regis.

So extraordinary
were her achievements

that some called her,
''The Princess of Palaeontology''.

When you consider
Mary Anning's status,

a woman from
a working class background,

with no formal education
to speak of,

it may seem strange that she acquired
such a prestigious reputation,

until, that is, you see what it was
that she discovered.

The Natural History
Museum in London.

It holds one of the most comprehensive
collections of fossils in the world.

And those Mary Anning discovered

are among the very best,
and the most important.

A whole section of the museum
is filled with her finds.

Most of the creatures she collected
were giant aquatic reptiles,

fish eating monsters
that dominated the seas.

But she found other things, too.

One of them in particular
is the key to our story.

In 1 828,

Mary Anning made one of
her most sensational discoveries.

This is it.

It's a small animal,

but its head is missing,

and its spine is missing,

but what remains is fascinating.

Here's its pelvis,

its upper leg, its lower leg,

and there is its foot with its toes.

And here is its arm,

which ends with a hand with fingers.

Except that one of these fingers
is hugely elongated,

it runs all the way along here.

And Mary Anning probably realised
what that meant.

It meant that that long finger
supported a wing.

And as more specimens
were discovered,

it was realised that this was certainly
a reptile with a wing,

so, it was called ''Pterosaur''.

''Winged lizard''.

Mary Anning had found the blueprint

for the first large animals ever to fly.

A creature that set the pattern

for a whole new phase
of aerial evolution.

It lived 200 million years ago,

at a time when the planet
was very different from today.

Much of it was tropical.

(CRICKETS CHIRPING)

(INSECT BUZZING)

(GRUNTING)

The early dinosaurs were rising
to dominance.

And flying high above them
were the pterosaurs

of the kind whose bones
Mary Anning had discovered.

Dimorphodon.

Up here in the trees,

they were safe from those
predatory dinosaurs

down on the ground.

And there were plenty of flying insects
for them to catch and eat.

But these early flying reptiles
were pioneers.

And it maybe that,just occasionally,
they were a little clumsy on the wing.

(SQUAWKING)

(SQUAWKING)

Sometimes, as their bodies lay
on the sea floor,

they were slowly covered with mud,

that over millenia,
eventually turned to stone.

Fossils of pterosaurs
have been discovered

in many parts of the world.

In Africa, Asia and South America.

But the very first were found here,
at Solnhofen, in Southern Germany.

This limestone has been quarried
for building purposes,

since Roman times.

But those who work here

sometimes find something
far more valuable

than just roof tiles.

The discoveries made here

make this one of the most important
places in all over the world

for anybody who's interested
in pterosaurs.

And the perfection
of their preservation

has enabled us to unlock
many of the secrets

about how these
wonderful animals flew.

The Solnhofen limestone
formed on the floor

of a shallow tropical lagoon,

protected from the currents
of the open sea by a reef.

So, its waters were still,
and they were few currents

to disturb the rotting bodies.

(GRUNTING)

The rock here is really extraordinary.

When it's fresh, it's very solid,
hard building stone.

Excellent.

But when the frost gets at it,
it begins to split.

And when it's really weathered,

you can open blocks of it
like leaves of a book.

Like that, for example.

And sometimes there's something
written on these leaves,

but mostly

nothing.

And maybe for...

(CHUCKLING)

I was going to say,
''Maybe there's nothing.''

But, on this one,
there's a perfect little ammonite,

a shellfish.

This quarry has produced so many fossils

that the town's castle has been
turned into a museum to house them.

The majority are sea creatures,

but sometimes, there are animals
that fell into the water

from the skies above.

Pterosaurs.

Here is one that did.

It's a kind called Rhamphorhynchus.

Not only are its bones still connected,
as they were in life,

you can even see something
of its soft parts.

This one of the most perfect
pterosaur fossils ever found.

And it's a miracle, bearing in mind
it's a 1 50 million years old,

and yet it's complete
in all the tiny details.

It had a long bony tail,

long toes on its feet.

Its spine and its ribs still connected.

Its jaws have long teeth

which would've enabled it to snatch fish
from the surface of the lagoon.

But the most fascinating parts
of its anatomy are its wings.

They are supported as in all pterosaurs
by a hugely elongated finger.

This is the wing membrane,

which, in life, would have been
less than a millimetre thick,

and yet, it's so perfectly preserved
you can see within it

all the tiny details of
little structures

that would have given
that membrane strength.

There are rows of tiny fibres
called actinofibrils,

which may have given it
precise muscular control

right across the wing surface.

You can also see from this fossil

how pterosaurs managed their wings
when they weren't flying.

Here, at the base of this long finger,

is the miracle joint,

which enabled the pterosaurs
to move their fingers in any direction.

And that was a huge advantage

because it allowed them
to fold up their wings when they landed.

(SQUAWKING)

The pterosaurs had evolved
a brilliant first solution

to the problems of travelling
through the air.

But they were about to become
even better aeronauts.

About 50 million years
after the first winged pterosaur

came something much more advanced.

It lived in a region of the planet
that is now China.

Its skeleton was unearthed

by one of the world's leading
experts on pterosaurs,

Dr David Unwin.

So, here's one of the pterosaurs
that we found last year in China.

ATTENBOROUGH:
He named it after Charles Darwin.

Darwinopterus.

ATTENBOROUGH:
Gosh, it's very beautiful.

It's almost complete, isn't it?

UNWIN: It's absolutely complete.

We can tell that from things
like this long tail,

that we're dealing with a rather
primitive kind of pterosaur.

These are classic features
of that group.

But revelation came
when we looked at the neck,

and in particular at the skull,
because that's quite astonishing.

ATTENBOROUGH: Why, it's huge, isn't it?

I mean, that's...

longer than the body.

UNWIN: The jaws themselves
are really very powerful

and it's got some
big pointed teeth as well.

This is a skull which looks like that
of a really advanced pterosaur.

But, the rest of the body
looks really quite primitive.

So we've got this weird mix
of characters, primitive and advanced.

This is a little bit
like Frankenstein's monster.

(ROARING)

ATTENBOROUGH: The big head and
pointed teeth of Darwinopterus

makes it clear
that this was a predator.

So it must have been
very agile in the air.

But, this pterosaur
wasn't just eating insects.

Pterosaur wings were clearly
very efficient in the air.

But they evolved at a cost.

(PTEROSAUR SHRIEKING)

Using wireframe computer simulations
of pterosaur movement,

David Unwin has investigated
how they moved on the ground.

UNWIN: What I've done is feed to
the vital statistics of this pterosaur

into the computer,

and build this model
that you can see on the screen.

ATTENBOROUGH: It's easy to see that
walking on flat surfaces

would have been quite difficult for it.

Did they always move around like that?

Well, we can try and get him to stand

just on the hind limbs alone,
like a bird,

but when you do that,

the thing you can see
is not very well balanced at all.

Looks quite unstable, and worst still,

the tail is actually
catching on the ground.

(PTEROSAUR CALLING SOFTLY)

So, now we can see him standing,
in this four-legged pose.

The winged membranes,
which are attached to the hind limbs,

get in the way somewhat.

It doesn't look
all that comfortable on the ground.

And in fact, when we look at the claws
on the hands and the toes,

we find that they're
really not well suited

to life on the ground at all.

Where's he off to now?

(ATTENBOROUGH EXCLAIMS)

(LAUGHING)

And now we see,
it looks a lot more happy,

just hanging up there,

just as they would have done
on trees and cliffs...

-Yeah.
-...back in the Jurassic.

(EXCLAIMS)

(CHUCKLES)

ATTENBOROUGH: So, early pterosaurs,
with their long tails,

probably spent most of their time
hanging from vertical surfaces

like cliffs and the trunks of trees.

But, if they were to spread
beyond those environments,

they would have to change
the shape of their bodies.

This fossil is 1 40 million years old.

It has the enlarged head
of an advanced pterosaur,

but its tail is different.

It's become much shorter.

And this short-tail species
wasn't alone.

It was clearly
a very successful modification.

There were many like it,
with these new style short-tails

and reduced hind flight membranes.

Here, in France, at Crayssac,
in the valley of the Lot,

discoveries have been made
that give us a unique insight

into the lives of these
new style pterosaurs.

The short-tail creatures that appeared,
are called ''pterodactyls''.

This is one of them.

The loss of the tail

had given them greater mobility
in the air,

but at the cost of
a certain amount of stability.

But also, the membrane
between the two legs, have split.

And that too,
probably helped them in steering.

But flying
was only part of their lives.

The sea in which these
limestones formed,

was here quite shallow.

And not far away, there was a beach.

And there, pterosaurs left particularly
vivid evidence of their presence.

Fossils, not of the animals themselves,

but traces that only
revealed themselves after dark.

The best way to look for fossils here,
is at night.

Because then, you can control the light,

and makes sure that it shines
almost horizontally

across the surface of the rock.

And so, expose every tiny
little mark and ripple.

The muddy sand here
was once soft, but firm.

And in consequence, it retained the
tracks of animals that moved over it.

In fact, there are so many of them here,

that it seems that this particular beach
was a kind of pterosaur runway.

Here is a track

that extends for 1 1 feet,
between three and four metres.

The most distinct tracks
are made by the feet.

There's one, there's another,

there's another.

But, outside these footprints,

there are other,
rather more indistinct prints,

which are made
by the knuckles of the hand,

without the little finger,
which, of course,

is enormously extended,
and it supports the wing membrane,

and is cocked up in the air.

There's one, there's another,

there's another,
and there's another.

And when you examine
the footprints,

you can see that they have
four toes.

Not five, four.

That's a sign that these were made
by short-tailed pterosaurs.

And the distance
between the feet varies.

Sometimes it's relatively short,
sometimes it's longer.

And that's because
these animals moved at different speeds.

When they were moving at speed,
they took bigger strides.

So, these show,
this marvellous deposit shows that

short-tails, on the ground,
were really very nimble indeed.

And that's probably because
the membrane between the legs,

in the short-tails,
has been divided.

So the legs have more freedom.

(SQUAWKING)

So, the short-tail species were able to
get about on the ground pretty well.

And that was important,

because this enabled them
to exploit new sources of food.

Indeed, it might be the case
that the future of the pterosaurs

was assured, for some time at least,

not by their ability to fly,
but their ability to walk.

This ability to walk

had a profound effect
on pterosaur evolution.

There's evidence
that from this time on,

all kinds of new species
began to emerge

that fed on a wide range
of different food.

The short-tails proceeded to diversify
into a great number of different forms,

finding food
in a great variety of places.

And you can tell what they ate
by their skulls.

This one for example,

has, what look like
a pair of tweezers on the front,

and very rounded teeth.

It is thought to have been able
to dig out,

cockles and mussels from the sand
and crush them.

So, this was walking on the ground.

This one, on the other hand,
found its food while it was on the wing.

And that it dipped down
and seized big fish,

which it stabbed
with these teeth.

And then, carried off in its jaws
to rip apart, perhaps on the ground.

Others had dense rows of teeth
that were so thin

they were scarcely more than bristles.

That enabled these animals
to use their jaws like sieves

to filter out small crustaceans
such as shrimps and other small morsels.

And some
lost their heavy teeth altogether

and evolved beaks.

Adaptations like these
were probably influenced,

not only by
the different ways of eating,

but by the universal need
of all flying animals,

to keep their weight down
to a minimum.

So, by about 80 million years ago,

the short-tailed pterosaurs
dominated the skies.

Not only were they catching
flying insects in mid-air,

they were snatching food
from the surface of the seas

and filtering it from the shallows.

This was the pterosaur's heyday.

One species in particular
symbolises their success.

It's called Pteranodon.

It was the most common pterosaur
of its time,

and it was also very big.

It measured about 1 8 feet
from wingtip to wingtip.

But how did such large animals
manage to stay airborne?

You can see the answer
in this fossilized bone.

It's hollow.

It's been treated with acid,
so that you can see inside it.

And inside, it's got a network of struts
to support the bone.

So, it was very, very lightweight.

The full extent of these cavities,
is revealed by x-rays.

And a cross-section shows that they had
another and very valuable function.

This is the upper arm bone
of a pterosaur.

And at the top, it has a hole.

And that's a clue,
as to how they generated power.

Because it was connected
by a tube to the lungs,

and internally, to these cavities.

So, it was in there,

that the pterosaur was able to store air
and the oxygen that it contained.

And from that, it could get the power
when it really needed it.

With all these ingenious
adaptations for flight,

the pterosaurs now
had the freedom of the skies.

But, a new kind of flying reptile
had been evolving away from the coast,

in the forests farther inland.

And its arrival would have enormous
consequences for the pterosaurs.

In that remarkable quarry in Germany,

another amazing discovery was made.

Among all those
shellfish, shrimps and fish,

something utterly new
had appeared.

There can be no doubt about what it is.

It's a feather.

And a few months after its discovery,

a quarryman found
the fossil of the animal

to which it must have belonged.

Its outstretched wings
made it quite clear to anyone

that this was an animal that could fly.

They called it Archaeopteryx.

And this is what it
may have looked like in life.

The feathers on its wings
are strong and rigid.

So, they don't need to be attached
to the legs, as membranes do,

and it leaves the legs free,
so that they could run.

The head doesn't have
a lightweight beak,

like modern birds.

But it's still very much
the head of a reptile

with bony jaws and teeth in it.

And, the tail, too,

has a line of bones
running down its legs,

just like a lizard's tail.

So, this is half reptile, half bird.

We now know,
that Archaeopteryx was not alone.

There were several different kinds
of feathered reptiles

living about this time.

Their skeletons are very rare,
perhaps because they lived inland,

where conditions for fossilization
were not as good as they were

in the coastal seas.

But it's clear that the pterosaurs
now had rivals in the sky.

And, perhaps, in response,

they began to evolve
in some quite extraordinary ways.

In Texas, aeronautical engineers
are trying to understand the pterosaur,

that is surely one of
the oddest creatures that ever flew.

It had a simply enormous
head crest.

It's called Tapejara.

This reconstruction of it
is the result of seven years of study

by evolutionary biologist
Dr Sankar Chatterjee.

He used data from fossils
discovered in Brazil,

and he has advanced some
revolutionary theories

as to how this animal used
its amazing body.

This huge crest

was developed in some kind,
like a motion sensor,

so they could pick up if there's
a disturbance in the wind,

and they could relay it
to the inner ear,

which is a very large ear,

and which is like a gyroscope.

So, nerves in this
go down into the brain?

Brain.

So, any factor working on this
is going to be relayed to the brain.

Relayed to the...

It's almost like autopilot device.

You know, it's a sensor,
also, it is a beautiful steering device.

This is much more extreme
than any other.

Extreme. Right.

So, what could this do
that the others couldn't do?

One of things, as I said,
they could turn very quickly.

So it's like steering,
it's like a rudder in front.

So, this enabled them in fact,
to be more aerobatic?

Aerobatic, yes.

ATTENBOROUGH: Some specimens
of Tapejara show that it had fur.

And that suggests
that it was warm-blooded.

Warm blood enables an animal
to generate the abundant energy

that's needed for aerobatics.

(SQUAWKING)

But, Dr Chatterjee has another

imaginative and
controversial interpretation

of Tapejara's bizarre anatomy.

What we have found special
in this model, we did some simulations.

That is, when they simply
raise their wing,

they could also sail.

You think that it could not only
fly in the air,

but it went down to sail on the sea,
is that right?

There's a very good chance

when they land on water
during their foraging,

because they are probably hot-blooded,
they need lots of food, lots of fish.

And during the foraging,
maybe the whole daytime,

you know, they will just
eat and eat and eat.

So, how to move?
How to cover the large area?

And it looks like that it was
a beautiful sailing animal.

Just like a sail boat.

Did the head crest have a function
when it was on the water?

I think so.

Basically, when they're sailing,
the head crest would be

just like a jib, you know,
the very front sail of a sailing boat.

And these two would be the main sail.

And simply by, you know,
arranging these three sails,

they could really sail very fast.

(SQUAWKING)

ATTENBOROUGH: Swans and geese
today sometimes lift their wings,

to catch gusts of air.

A behaviour called
'goose-winging''.

So perhaps, Tapejara did indeed
do something similar.

But big head crests had
a much more likely function.

(SQUAWKING)

There are clues of what that might be
in animals alive today.

Like this colony of gannets
on Bass Rock,

off the coast of Scotland.

Pterosaurs doubtless

would have lived in great groups
around the ancient coastlines.

And living in tightly packed
communities,

then, as now,

must have led to all kinds
of dramas.

Just as it does in communities
like this one.

(SQUAWKING)

Gannets nesting close to one another

squabble with their neighbours
over food and territory.

(SQUAWKING)

Pterosaurs doubtless also
competed with one another,

for the attentions of the opposite sex.

(CHITTERING)

(SQUAWKING)

So, perhaps Tapejara

used its huge head crest
in displays to its mate

during the breeding season.

And indulged in the same sort of
strutting performances

that so many birds do today.

(BIRDS SQUAWKING)

After their courtship, pterosaurs,
just like birds, laid eggs.

This fossilized egg,

which is about the same size
as one of these gannet eggs,

is actually the egg
of a pterosaur.

And although it's squashed flat,
it's marvellously preserved,

so you can see details
of the bone inside.

The head,
as you'd expect with a bird head,

is quite well formed.

It's amongst these massive bones here.

But whereas a bird's wings
will hardly be formed at this stage,

here, the pterosaur wings

have got these
well formed bones in them.

And that leads us to one
extraordinary conclusion.

A pterosaur chick, when it hatched,

was almost immediately able to fly.

The bones of the pterosaur embryo
reveal another extraordinary fact.

They develop in a way
quite different from birds.

And what is more,
they continue to do so,

even after the young have hatched.

This led to some species
becoming gigantic.

Here, in the south western
United States,

close to the Mexican border,

evidence was found
of the largest animal ever to fly.

A pterosaur so gigantic,

that for years,
some scientists refused to believe

that it could have existed.

Seventy million years ago,

the area was a hot, lush floodplain.

I've come here to meet
fossil hunter, Doug Lawson.

And here, Doug made one of the most
remarkable discoveries

in the history of pterosaur research.

On the side of the sandstone hill
was this one isolated ball.

And you might have thought,
''Well, it's just another dinosaur,''

except the material of this animal

was very thin, very light individual.

And, uh, it was difficult because,

actually, if you thought
it was pterosaur,

then the bone that you were
gonna be comparing it to

was usually the size
of a grain of rice.

And this bone was bigger
than a grapefruit.

And it was covered with sandstone,

so it was very difficult
to see what it was.

But I finally figured out that
it was the wrist of the animal.

And pterosaur wrists are unique.

So, given that,
when we had these other

pieces of bone
that we discovered in the location,

you'd come to understand
how big that was.

This is just the upper arm bone
of the specimen.

-This...
-Yeah, yeah.

And looking at this you realise,

''Wow, we have something
that's dinosaur sized.

''But it's a pterosaur.''

Now, you could not have prevented
yourself from saying,

''How big is this?''

Oh, yeah, right.
Then you'd say, ''Wow...''

Okay, we've...

So, based on what we have,
the estimate was about 50 feet.

-Wingspan?
-Yeah.

Yeah, 50 foot wingspan.

-I mean that... That is gigantic.
-Oh, yeah, definitely.

ATTENBOROUGH: Mind blowing.

Did people believe it?

LAWSON: Well, there was some question.

No other pterosaur was even
half the size of this one.

And the fact that something so large
that could fly,

there was almost an aerodynamic question
of whether this could even be.

ATTENBOROUGH:
It was a truly astounding discovery.

His creature had wings
that were so large,

they could easily have spanned
the width of this building.

It lived 70 million years ago,
during the Cretaceous period.

(LOW GROWL)

It stood 20 feet high.

So tall it could look a giraffe
in the eye.

This was Quetzalcoatlus.

Named after
the Serpent God of the Aztecs.

It was probably a scavenger.

Using its long neck to probe
deep into the carcasses

of dead dinosaurs.

Any small animal
foolish enough to get in its way

was likely to meet a grizzly end.

(LIZARD SQUEALING)

But how did the giant Quetzalcoatlus
get off the ground?

The answer may be found inside
the pterosaur arm bones.

There are two things
you have to get right,

if an animal the size of a giraffe,
like Quetzalcoatlus,

is to get into the air.

Weight and power.

And a close examination of the bones,

show how the pterosaurs did that.

A scan of the arm bone
of Quetzalcoatlus

shows that just like those
of other pterosaurs,

it was hollow.

This animal was very lightweight.

It may have been the size
of a giraffe,

but it was no heavier than
two human beings.

But at the very top of the arm,
the bone is very different.

All these supporting struts line up
in one direction.

And that gives us a clue as to how
the animal got airborne.

The upper arms were reinforced

so that they could withstand
the sudden burst of great power

without breaking.

The animal used all four
of its limbs

as a giant catapult.

To launch its body skyward
at 35 miles an hour.

It used a quadrupedal launch.

But how did it actually fly?

There is a practical way
of finding out.

A modern glider is about the same size
as that giant pterosaur.

It too, has long slender wings.

And it too, is extremely light.

This flying machine is so lightweight,

it doesn't even need an engine.

All it requires is a tow
to get it into the air.

This is the nearest I will ever get
to experiencing the magic

of Quetzalcoatlus in flight.

(CALLING)

With its giant wingspan,

this was the largest animal
ever to fly.

Quetzalcoatlus kept its wing beats
to a minimum.

It was a living glider.

And it had much more detailed control

that even the most advanced
and sophisticated of modern aircraft.

(OVER RADIO)
We are controlling our flight,

using at least in part, our tail.

However,

whereas powered aeroplanes have tails
and birds have tails,

advanced pterosaurs like Quetzalcoatlus

didn't have a tail.

So, steering must have been
much more difficult,

and would have required
very considerable brain power.

But there was,
people think, a payoff to that.

Because without a tail,

Quetzalcoatlus was even more
manoeuvrable,

than we are in this.

Quetzalcoatlus doubtless used
many of the techniques

employed by human glider pilots.

(SCREECHES)

To maintain our height,
we need to find a thermal.

That's those columns of warm air
that rise from patches of the landscape,

that heat well in the sun,
like patches of rock.

You can tell where they are,

because white fluffy clouds
form at the top of them.

And there's one over there,
and we're going to have to get to it

if we're going to maintain our height.

It's been estimated
that by exploiting thermals,

Quetzalcoatlus could travel some
1 0,000 miles in a single flight.

And that is almost half
the circumference of the entire planet.

It might even be that
like some eagles today,

these flying giants undertook
long migratory journeys every year.

And so, a 1 50 million years after
they had first appeared,

the pterosaurs were at
their most spectacular.

(SCREECHING)

And then, suddenly, they vanished.

A meteor that crashed into Earth
65 million years ago

is often blamed for the extinction
of the dinosaurs and the pterosaurs.

But the truth is that
their fate was already sealed

millions of years before that moment,

by the early birds
that had been evolving in their shadow.

It was the birds that rose
from the ashes of that meteor.

They occupy all the niches that
the pterosaurs once did.

So, why did birds survive
and the pterosaurs die?

Birds had one great advantage
over the pterosaurs.

Their rigid flight feathers

meant that their wings had no need
to be anchored to either

their flanks or their legs.

So, birds could run,

and walk, and pounce,

whatever they needed to do,

to collect their food in almost any
of the land's environments.

No pterosaurs,
encumbered by their skinny wings,

could wade like flamingos.

Birds today

have evolved into thousands
of different species,

flying with many
different techniques.

But it was the pterosaurs

that were first into the air.

It was they that solved
the fundamental problems of flight.

And in their prime,

they reached a grandeur,

that the birds still can't match.

(SQUAWKING)

The dynasty of the pterosaurs
lasted over a 1 50 million years.

We human beings have only
been around for about two.

But only now, are we beginning
to appreciate to the full

the wonders and the splendours
of those pioneers of flight,

the pterosaurs.