All language subtitles for Dinosaur Apocalypse 022

# (music)

Dinosaurs.

Perhaps some of the most
dramatic animals

ever to have walked the earth.

They dominated the world for
over 150 million years,

until a huge asteroid struck the
planet.

But how exactly did they die?

Palaeoltologists have been
searching for the answer for decades.

And now, new evidence is
coming to light.

We're out looking for clues.

Each fossil is a clue and
that tells us something about

what the world was like at
that time.

Since 2012, a team of
palaeontologists has been

investigating a remarkable site
deep in the badlands of North Dakota.

The team's leader, Robert De Palma,

hopes it holds evidence of what
happened the very last day

of the dinosaurs...

(thunder rolls)

Could it even contain the remains
of an animal that bore witness

to that terrible event?

We've got all these bones
in the ground right now.

But the one thing
that we would just dream

of finding is that one dinosaur

that died on the day of the impact.

The idea that there is a dinosaur
fossil potentially who was

a direct victim of that,
that's very exciting.

Oh, that's skin right there.

That's actually scaly skin.
Oh, my God.

Can they find a dinosaur that died
on the day the asteroid hit?

For 10 years, Robert De Palma and
his team,

have bene digging in a small corner
of the Hell Creek formation.

An area famous for more thna a
Century, of major dinosaur discovery.

They've already found a wealth
of fossilised creatures in

a patch of land they call Tanis.

What appears to be a piece of
fossilised skin from a Triceratops.

The unhatched egg and what looks like
pterosaur embryo.

Jawbones of a mammal called
a Pediomyid.

And teeth and footprints of
carnivorous dinosaurs

like T-rex.

There is no other dinosaur
that has teeth like this.

Many of these fossils were found
in a thick layer of crumbly rock.

The rock here is really not
quite rocky.

It just falls apart in your hands.

Right above the rock, is the KPG
boundary,

a layer of iradium-rich debris
from the asteroid impact

that hit the earth 66 million
years ago.

It marks the end of the age
of dinosaurs.

If you look below this layer,
you see fossils of dinosaurs.

If you look above this layer,
no dinosaurs.

The methaplastic layer of rock at
Tanis is full of ejector spherules.

Beautiful. Look at that.

Tiny glass droplets
created in a major asteroid impact.

Robert thinks that this is
compelling evidence that

everything in the layer was buried
while the spherules fell.

If he's right and the spherules can
be matched to the asteroid impact,

this dig site could provide a
snapshot of what happened

on the very last day of
the dinosaurs.

It opens up that whole debate about
how do we link catastrophic events

to fossil and geologic deposits?

If we can both match spherules
to the impact site geochemically and

in terms of radiometric ages,
that's pretty accurate.

The asteroid hit in what is now
the Yukutan Peninsula in Mexico.

It's called the Chicxulub Asteroid
after the town nearest to

the centre of its crater.

To find out if the spherules
the found in North Dakota

can be linked to Chicxulub,
Robert has come to the Diamond Light

Synchotron in the UK.

Joining him is Professor Phil Manning
of the University of Manchester.

THey've already run initial
tests on the spherules in America.

Every piece of ejector from every
impact that's ever occurred on earth

has a unique chemical signature.

The Chicxulub impact event is no
exception.

When you look at material from
different sites, it has a very

diagnostic chemical fingerprint.

That's precisely what the team
have been looking for.

By comparing their spherule with
spherules from other known

Chicxulub dig sites, the
team can see if it's a match.

What the team has done is look
at ejector from other sites

and produced an elemental map.

A chemical fingerprint from
each site.

Whether they be in Haiti, Mexico
or other localities in North Dakota.

You can see they all follow
similar concentrations,

and sort of map on top
of each other here.

When you look at the material
from the Tanis site,

again they perfectly map on top of
this chemical fingerprint.

It was unequivocal that Tanis
was tied in to the KPG extinction
event or the impact event,

that makes this an astoundingly
important site.

A site that really brings you down
to the last day of the dinosaurs.

This is very important because it
immediately gives a time stamp

for the locality itself.

The Tanis site is like a window
into a snapshot of time.

With ejector spherules found
throughout the deposit,

Robert and his team seem to be able
to link their site to a single day.

And the synchotron here in the UK
reveals something even more
remarkable.

This particular spherule is probably
one of the most significant ones

I've ever seen in my life.

This irregular piece of debris
which is inside this swirling glass,

is actually a piece of unmelted
rock.

That was initially an absolute
red flag to us.

Why is there a piece of angular
rock inside the spherule?

Then when we look at that chemical
map, that's when we really started
jumping for joy.

Because we start seeing
iron and chromium and nickel

in ratios that we would expect for
something that could've been not
from earth.

The thought that crosses our mind is
this could be a piece of the
asteroid.

I've never seen anything like this.

That was immediately of incredible
interest to us.

Robert's team may have found a
fragment of the asteroid itself,

in North Dakota.

Physical evidence linking
this site to the Chicxulub impact.

Tanis is around 3,000 kilometres away
from where the asteroid hit.

So exactly how did the asteroid
cause the death of the animals here?

To answer that question,
Robert is searching in something

he calls the mass death assemblage.

Right here we got this
intertangled mass of fish.

There's one fish here.
Another goes this way.

Underneath the body of a paddlefish
there's another sturgeon that goes
this way.

His head hit that log and has
deflected downward at a 90 degree
angle.

Robert has a theory that the
creatures he found surrounded by

spherfules in a logjam,
were swept to their death in some

kind of turbulent surge or water
and quickly entombed in sediment,

which is why they're so well
preserved.

But what could've caused the wave?

One hypothesis is a tsunami.

The asteroid hit at sea.

We talkt about a tsunami of a
completely different scale.

Much higher, much larger than we've
ever seen before in mondern tsunami.

So if you had 2km of water,
at least half of that would've

left as the rim wave.

So at last a kilometre high
at a mimimum.

The tsunami raced towards land.

When they reached the coastlines,
they were still very high waves

of up to hundreds of metres.

That's a very impressive wave.

Imagine a wave that's the size of a
building approaching the coastline.

In the LAte Crutaceous, North America
was divided by a narrow sea

that's been called the Western
Interior Seaway.

The tsunamin could have theoretically
travelled up this towards Hell Creek.

Tsunamis generally travel
at the speed of a jet plane.

It's not something you could
say run away from.

It had plenty of energy
to get over the coastline.

It could easily still have
been tens of metres high

by the time it reached
well into the Seaway.

Could the rapid deposition at Tanis
have been caused by a tsunami?

To test the idea, the team
needs to look at the timing.

Which fish is that?
That's a new one.

If a tsunami buried he fish,
it would have to have hit while

the ejector spherules were falling.

Because spherules were found
everywhere,

including in the fish's gills.

So much depends on determining when
these spherfules were falling at the
site.

Modelling the ejecta always
has error bars on it.

In that we're not there to measure
it, we've had no equivalent impact
like this

on earth since then.

We can look at the computational
models that we do and say alright,

this material is coming
from this point.

It's now moving away this fast
with about this much mass.

Then we can tell with the sorts of
equations that we might

use to calculate the trajectory of a
canon ball, where it would go.

We can observe from these
simulations how long it takes

these ejecta to reach
their final destination.

Down to the order of
a few minutes.

What the calculation shows
is surprising.

Robert and his team have found that
these spherules landed at Tanis

between 13 minutes and 2 hours
after the impact.

So if a wave buried the fish, it must
also have reached the site within
2 hours.

Data from recent tsunamis
show even a powerful one would take

much longer than that to
travel around the 3,000 km

from the impact site to Tanis.

So if wasn't the tsunami, what
could've cause the surge of water
at Tanis?

Professor Bondevich is an expert
in tsunamis.

The fjords here in Norway
are very special.

We have tall mountains surrounding
bodies of weater.

So the water is usually very calm.

In 2011, something very strange
happened.

The water in the fjord
began to move violently.

The height of the water increased
by 1.4 metres.

Like a maelstrom with turbulent
water.

Someone said that the fjord was
boiling.

News started to roll in,
there had been an earthquake

8,000 kilometres away in Japan.

A journalist from the local
newspaper called me and

said that people were observing
waves here in the fjords.

I got a video clip of
the waves.

I saw immediately that they
looked like a tsunami wave.

Here you can see that he fjord
is perfectly calm.

But at the beach here, you can see
the water sloshing back and forth.

And no-one had every seen
anything like it.

Some people got
very upset and afraid.

A magnitude 9 earthquake had
devastated the northeast of Japan.

But how that affect a fjord
so far away?

So no-one in Norway
could feel the earthquake.

But I could see that the times
matched the arrival of the waves

here in the fjord.

Eventaully Stein and his team
realised that this might have

something to do with seizmic waves,
shock waves that pass quickly

through teh earth during
an earthquake.

So it took only 12 minutes
before the first signal

of the earthquake in Japan reached
all the way here to Western Norway.

So it was the seismic waves
that caused the normally calm water

in the fjord, to slosh turbulently
back and forth.

Just thinking of that...

Scientifically, it's fantastic.

Could something similar have
happened in Tanis?

Trying to find out is geophysicist,
Professor Mark Richards,

who's been studying the site
at Tanis for several years.

He's working with Robert to discover
what could've caused a surge of water
here.

A tsunami can't get here
in less than 12 hours.

But seismic waves travelling
from teh Yukatan impact site to

North Dakota, can arrive
here fairly quickly.

In the late Crutaceous, the Western
Interior Seaway that bisected North
America,

could have been connected to Tanis
through the extensive river system

that once flowed here.

If you have a very large body of
water,

like the Western Interior Seaway,

and you can shake it back and forth,
you can generate a large water wave

coming up this river
at Tanis.

So this is bigger than any
techtonic generated earthquake.

You would have shaking literally
everywhere on the planet.

So seismic waves from the impact
could have caused surges of water

in the Hell Creek river system.

Seismic waves get here quickly
enough to cause this wall of water

coming up the Tanis river,
inundating this area,

arriving at the same time these
spherules are still falling.

If they're right, those surges could
have carried mud and marine creatures

from the Western Interior Seaway.

And dumped on the Tanis sand bank,

burying everything all at the same
time, as spherules fell.

Debris and fine iridium dust
from the asteroid,

would have gradually covered the
deposit, forming the KPG boundary.

Over millions of years the surge of
mud would become the deep layer of
rock.

That's the beauty of Tanis.

What you're seeing is the deposit
that is literally recording

the last say, 45 minutes to 90
minutes of the Crutaceous.

If the extinction of the dinosaurs
was a crime,

the detectives solving it
would have plenty of evidence.

They would see that the asteroid was
in the right place at the right time.

They would see that no dinosaurs
survived after the hit.

They would have a piece of
the murder weapon,

a fragment of the asteroid,

but they would be missing
one very important thing.

A body.

A lot of the bones that exist from
those last Crutaceous days

were basically destroyed.

As far as we know, we've never
actually found a fossil

of a dinosaur individual.

A signel skeleton, let's say,

that we can unequivocally say was
there the day the asteroid hit.

But before the site was time stamped
to the Chicxulub impact,

Robert's team did find part of a
triceratops in the crumbly layer at
Tanis.

So could that be the body?
A dinosaur that died on that day?

Something that would help them
would be establishig the cause of
death.

Which can be difficult when
you only have a piece of skin and
horn to go on.

This is the horn after they've
cleanead it up.

This triceratops horn is probably
the most beat up one I've ever seen.

I'm noticing a very big crack
right here.

There's another very large one
right here.

We have fractures, breakage of
the bone that occurred

during the lifetime of the dinosaur.

Triceratops is such a massive
animal and a really strong animal.

So it must've taken a tremendous
force to cause these cracks

that go all the way through
the horn.

Possibly fighting between
two triceratopses or

fighting with a predatory dinosaur
could've caused this.

A big question that comes into
my mind when I see a crack like
that is when did it happen?

When I look closely inside
that crack,

I see healing bone.

This animal must've survived for
some time after the injuries.

So is survived whatever
caused it and it started to reheal.

Part of putting the story together
of this triceratops

is how it died and
when it died.

Was it involved in the impact
in some way?

Or was it already dead at that time?

Luckily enough, the animal
can tell me its own story.

So I'm looking at the skin
here and I see a lot of areas

that have kind of sagged
in places.

Where it had already started
to rot from the inside.

So before the thing was buried,
a lot of decay had already occurred.

So this animal was probably dead and
partially devayed shortly before
impact.

Given the size of partial decay,

it's likely this triceratops wouldn't
have lived to see the last day of the
dinosaurs.

However, the triceratops fossil
does show that dinosaurs were alive

shortly before the asteroid hit.

Perhaps even within weeks of the
impact.

This is an extraordinary
discovery and one that

has never been found before.

But if it's true that dinosaurs were
here until the final weeks before

the impact, there could be even
more still to find in this deposit.

We've got all these bones in
the ground right now.

But the thong that we could just
dream of finding is that one

dinosaur that died on
the day of the impact.

And the weather isn't helping
his search.

That print is toasted.

It was in a low corner.

It's full of mud and water.

The problem is it's wet.

If we're not careful,
we're gonna lose the print.

That's the biggest print we've got.

I see some areas that could
use glue right now too.

The team is racing to excavate
the footprints, along with dozens of
fish fossils

tangled together in a logjam,
before storms wash them away.

We're up against the clock here.

This stuff that could be exposed
right now is gonna get ruined by
the rain.

But then Robert comes across
something that looks very unusual.

What is going on right there?

Are we sure this isn't
crocidilian?

That's not crocodilian.

I'll go in from the top and then
twist. It separates on that line.

That's skin right there.
That's actually scaly skin.

Look, look, look.

Look at that pattern right ther.

Have you ever seen elongated
scales like that before, Dave?

Just careful.

It's changing again.

We're seeing it for the first
time in 66 million years.

I think we got ourselves
a dinosaur.

A dinosaur fossil.

And unlike the triceratops, this is
located in the logjam,

the mass death layer,

surrounded by the fish with
spherules in their gills.

This is the most incredible thing
we could possibly imagine.

The best case scenario.

We're excavating this mass death
layer of fish from the surge sent up

by the impact, and we've got
dinosaur remains.

The one thinkg that we would
always want to find.

And here we've got it.

This is unreal. I cannot
process this in my brain.

I am absolutely blown away
by this.

My heart is literally pumping
out of my chest wondering

what is behind there. Just a couple
centimetres back in the outcrop.

What is waiting for us back there?

The team keeps digging.

This could be laying against
ribs that are curved.

There's something here.

That's hard. That's bone right
next to the skin.

This is either a hip or
a shoulder element.

After hours
of painstaking work...

And we can go
from the thigh of the animal.

There's the knee.

And then you've got
the little calf muscles

of the dinosaur,
they're bulging out,

and you go down
to the anklebones,

and these are the toes
of the feet.

We have got nails
at the tips of the toes.

It's a beautifully preserved leg,

all articulated, covered with skin.

The complete leg of a dinosaur.

In my wildest dreams,

I never expected to find
a dinosaur leg in this deposit.

Yeah. I mean, and then
it's got skin and tissue.

It does look
just like a drumstick.

It looks like
a Thanksgiving turkey,

just laid out in the ground.

Robert thinks he has found
the body in question -

a dinosaur that might itself
have witnessed

the cataclysmic impact.

Dinosaur fossils are not known

from the last years
of the Cretaceous.

And it was unclear whether
they were already extinct

or in decline
or what was going on.

So they were just sort of absent.

And this answers that question.

Were dinosaurs still there then?

Well, yes - this one likely
died in that surge.

For such big claims,
Robert needs verification.

He's brought the dinosaur leg
to London

to get a second opinion...

...from Professor Paul Barrett,

an expert
in ornithischian dinosaurs

from the Natural History Museum.

We thought this was a herbivore
similar to a theselosuarus but

not quite certain so hoping
to get your opinion.

There are some obvious things
we can rule out.

It's clearly not a meat-eating
dinosaur.

These are the claws of a small
running animal, that's not using

the claws to pin things down.

It's not a heavy, stocky animal.
Not a duckbill or a horn dinosaur.

This looks like a more agile
runner than one of those.

It limits those possibilities down
ot a small bipedal plant-eater.

A thescelosaur sounds like a great
way to go with this.

Thescelosaurs lived next to rivers

where there was plenty
of rich vegetation to feed on.

They had leaf-shaped teeth,

common amongst herbivores,

and claws
on their short front limbs -

excellent for digging.

They probably dug for food.

But how did
Robert's thescelosaur die?

I'm trying to think of how
this animal might've died.

Could it have been killed
by another dinosaur?

It's possibile.

This is one of the more agile
dinosaurs.

Its primary defence against the
predators is gonna be to run away.

Hopefully giving the advantage
over a slower predator.

Whenever we're excavating a dinosaur,
we're always keen to know

is how did the animal die.

It's not always easy to do that.

Maybe we can find evidence
for things like broken bones

that didn't heal back up.

We can even see things like
bone tumours and gout.

There are some wonderful fossils
where you can find bite marks.

You can even find a predator tooth
buried within the bones.

CT scans allow a closer look at what
the animal might've gone through.

I can't see any evidence
of predation on this animal.

There are no puncture marks causedby
teeth.

There's no obvious scraping
or gnawing of the bones.

Then what else could've brought
this down?

One thing that does leave marks on
bones are some forms of disease.

I can't see any obvious evidence
of those kinds of features here.

Could this leg be from a dinosaur
that died in the surge?

I think it's certainly compatible
with that idea.

Something could've been moved around
in a very physical way.

This is actually a shoulder blade,

and this bone in a living animal

would actually be way over my
shoulder.

When you have got those big lumps of
wood in a rapid flow like

an overflowing river, that would do
a lot of damage to anything caught
between them.

That's phenomenal. We could be
looking at a casualty of the impact.

This could be one of those dinosaurs
that saw the fireball coming down.

And was just there on the last day
of the Cretaceous, when all the
lights went out.

It's unbelievable to think this
animal might've witnessed that
event.

Paleaontologists do depend
a lot on tragedy.

Every little disaster is the
material we need to develop our
subject.

Tragic for the individual concerned,
but we're just really happy that it
happened.

After years of investigation,

Robert has found out a great deal

about the creatures
which lived at Tanis,

and he knows that many of them were
alive on that fateful day

when the asteroid
devastated our planet.

But how exactly did they die?

Robert's finds now allow us
to tell the story of that day

and finally answer that question.

One of the most important days
in Earth's history

probably started much like any
other late spring morning.

We know the season because Robert
found fossils of young fish that

died at the size they reach
at that time of year.

This agrees
with evidence already found

by other scientists.

Perhaps this day, that would end
with so much death,

began with something different.

A new life.

SQUEAKING

SQUAWKS

No-one can be certain
of the exact timings of the day

when the asteroid collided
with our planet.

But it's estimated that within
just 40 minutes of the impact,

the consequences
for the creatures of Tanis

would have been profound.

Based on Robert's finds

and the latest evidence
from other scientists,

this is how the catastrophe
might have unfolded.

The asteroid is around
seven miles across,

bigger than Mount Everest...

...and travelling at close
over 70,000km an hour.

The impact causes an explosion

over a billion times the power
of the first atomic bomb.

It comes in so fast that it wouldn't
even have been visible

passing through the atmosphere.

It would have come and hit
in a moment.

At Tanis,
almost 2,000 miles away...

...it's completely silent.

But at the impact site...

...the asteroid vaporises.

More than three trillion
tonnes of rock

are ejected into space

in a blast
of super-heated violence.

Winds of almost 1,000kph.

A colossal earthquake, followed
by a ring of massive tsunamis.

RUMBLING

ANIMAL CALLS

All the while,
the creatures at Tanis

go about their business...

CACOPHONY OF
ANIMAL NOISES

...just like any other day.

COOING

CLICKING

WARBLES

SNEEZES

THUNDER RUMBLES

SQUAWKS

The evidence suggests
that baby pterosaurs

emerge from the egg
ready to fend for themselves.

And that includes...

...flying?

Well, almost.

Elsewhere, as the devastation
spreads out across North America

towards Tanis...

...dinosaurs and creatures
of all shapes and sizes

are obliterated by the blast.

If I were a dinosaur standing
on the coast of North America,

I would just see a flash and a
fireball coming at me

and I would be fried.

All you'd feel is an awfully sharp
stabbing pain in your ears,

then you explode.

At Tanis, for a few more
precious minutes,

life carries on as usual.

But the clock is ticking.

GRUNTING

DEEP BELLOWING

The blast from the impact
never reaches Tanis,

but seismic shock waves do.

RUMBLING

They are far more powerful

than any earthquake
ever recorded.

That magnitude 12 earthquake would've
been strong enough to actually

jam your femurs up into your
body cavity.

While the earthquake that reached
Tanis was likely less destructive,

the effects would've been felt
by all that lived there.

Seismic waves are now shaking
the whole region,

causing water to slosh and churn.

At Tanis,
strange currents in the river

give a hint
of what is still to come.

THUNDER CRACKS

Next, it begins to rain.

PATTERING

Ejecta spherules
are falling back to Earth.

As the spherules
begin their fall...

...friction heats them
until they're red hot.

Then the heat transfers
to the air.

Temperatures rise with every second.

As the heat builds,
the creatures of Tanis

are fighting for their lives.

ROARS

And then, as seismic waves

continue to slowly rock
the whole region...

...a violent surge wave
ten metres high

rushes up the Tanis river.

Surviving the turbulence
of the surge

is a challenge
even for the best swimmers.

Then, the powerful rocking
of the river system

slowly begins to draw the water
back the way it came.

A large, robust animal
like a T-rex

might have survived the surge.

As might a hard-shelled reptile.

But there is much more to come.

As billions of tonnes of superheated
spherules continue to fall,

the atmosphere gets even hotter...

...igniting dead leaves
and sparking wildfires.

Earthquakes,

fire...

...devastation.

Little would survive for long,

on land...

ROARS

...or in the air.

SHRIEKS

The air around the planet was
effectively set to boil.

This was something that you
couldn't escape on the surface.

Those that live
deep underground

may have a better chance.

As the slow sloshing of
the river system continues...

...another powerful surge hits.

There is no escaping
the destruction.

For many of the creatures
of Tanis,

their stories end underwater.

In less than two hours,
the world has changed forever.

The mud the surge waves leave behind

will gradually turn into the thick
layer of crumbly rock

entombing the creatures
which died here...

...until 66 million years later,

when they're finally unearthed.

We have a general idea of what
horrors were unleashed on the
landscape by the asteroid.

I think these sites may give us the
ability to put them in sequence

and understand what these
organisms went through.

Even though there's a lot of debate,

every new thing that we find,
every new hypothesis,

gets us a little bit closer
to doing that mental time travel

and imagining ourselves back
in the Cretacious world.

Robert's finds have helped us
understand in remarkable detail

what happened at Tanis

in the minutes
after the asteroid impact.

But what about
the rest of the world?

Fires raged, destroying many
of the world's forests.

As that horrific day
drew to a close,

many of the world's dinosaurs
were already dead.

Research shows that the angle
at which the asteroid hit

and the sulphur-rich rocks
at the impact site

amplified the devastation.

Without light, most plants died,
and food became scarce.

As the weeks and months passed,

any dinosaur left alive
would've died of hunger.

In the oceans, it was the same.

Nearly all of the world's
plankton disappeared,

leading to the starvation
of most marine creatures.

It's thought that the nuclear
winter that followed

caused a global temperature drop

of at least
25 degrees centigrade.

The fossil record tells us that this
huge change in climate

marked the disappearance of three
quarters of all species,

including the dinosaurs.

The location of the Chicxulub
impact really was a worst case
scenario.

If the asteroid had come in 30
seconds earlier,

30 seconds later, it would've hit
the Atlanic Ocean or Pacific

and not the sediment-rich,
sulphur-rich Yukutan Peninsula.

Forests collapse. The planteaters
didn't ahve any food to eat.

They died. The meat-eaters didn't
have any plant-eaters to eat.
They died.

This unintentional accident
was set in motion

long before dinosaurs even existed.

And it just happened to be
the one case of bad luck.

The one worst day in the history
of the planet.

The planet was in semi-darkness
for around a decade,

as dust and soot
slowly fell to Earth.

But then came something wonderful.

A new beginning.

Once the dust cleared
from the atmosphere

and the sunlight returned...

...plant life was gradually restored,

led by ferns,

the spores of which had lain
dormant deep underground,

and the world began
to turn green once more.

But what about the animals?

One of the reasons some mammals
survived the great extinction, were
burrows.

During the nuclear winter,

a burrow would've provided warmth,

protection,
and a place to store food.

Mammals that survived
were resourceful omnivores,

and insects would've been
a plentiful source of food.

Their size woud have been
another advantage.

When catastrophe strikes
and food is scarce,

the largest tend to die out,

whilst the smallest
often survive.

And they weren't alone.

Robert's fossil turtle
may have been unlucky,

but many others survived.

As did crocodiles,

snakes,

and many fish species.

Life has found a way and life
is now thriving again.

It it those ecosystems
that are the foundations of our
ecosystems today.

it's kind of amazing that we can put
our finger on this line in the rock

and as much as we miss the dinosaurs
if this hasn't happened,

we wouldn't be here.

And as for the dinosaurs,

did the impact
really kill them all?

Well, this beautiful
fossilised feather

isn't from a bird,

but from a predatory dinosaur.

So we have to be careful

when we say
that dinosaurs are extinct,

because what we call birds
originally evolved

from the smallest
feathered dinosaurs.

So to be correct, we should say

all non-avian dinosaurs
are extinct.

Robert's finds have given us

a better idea
than ever before...

...about what happened on the day
that led to the extinction...

...of the largest beasts
ever to walk the Earth.

Dinosaurs were perhaps

some of nature's
most extraordinary creatures,

dominating the planet
for over 150 million years

before they became extinct.

But extinction
comes in different forms,

and many of the amazing creatures

and plants alive today
are also threatened.

It's possible that humanity
is having

as big an impact on the world

as the asteroid that ended
the age of the dinosaurs.

As human beings,
we are unique in our ability

to learn from the distant past.

The question is will we use that
ability wisely and do our very best

to protect the millions of species

for whom, alongside us,
this planet is home?

# (music)