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66 million years ago,

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Planet Earth was very different
from today.

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Back then, one of our closest
ancestors might have looked

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something like
this little furry creature.

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RUMBLING GROWL

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The rulers of the land
were giant reptiles.

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Dinosaurs.

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That's one of the most infamous,

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a carnivorous T-rex.

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And just behind are
the bison of their time,

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a common plant-eater,
Edmontosaurus.

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But what happened to them all?

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66 million years ago,

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an asteroid hit the Earth,

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and scientists think
that it was this collision

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that wiped out the dinosaurs.

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But no-one has ever found
direct evidence of that.

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In fact, no-one has ever found
the fossil of a dinosaur

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that died within
a thousand years of the impact.

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However, a remarkable dig site
promises to change that.

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It's in the Hell Creek formation

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in the American Midwest.

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These badlands are rich
in prehistoric remains...

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ROARS
..from triceratops...

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SQUAWKS
..to pterosaurs.

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And here, one patch of land

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about the size of a football pitch

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is yielding a collection
of astonishing fossils.

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The precise location is
a closely guarded secret,

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because this place
may hold evidence...

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..of one of the most dramatic events

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in all the four-and-a-half-
billion-year history

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of our planet.

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Right, let me get down here
between you.

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For ten years,
a palaeontologist and his team

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have been trying to find out
exactly what happened here.

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You're at the edge
of your seat every moment,

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trying to dig this stuff up.

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It's like trying to defuse
a nuclear weapon

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while you're in a rainstorm.

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He's named the site Tanis,

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and believes it could be
a mass graveyard

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of creatures that were killed

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in the catastrophic asteroid strike.

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A site that could reveal not only
how the last dinosaurs lived,

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but how they died.

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If the dig team is right,
Tanis could be a place

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where the remains
of a long-lost world

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are frozen in time.

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A place that gives us,
for the first time,

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an unprecedented window...

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SHRIEKS

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..into the lives
of the very last dinosaurs...

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..and a minute-by-minute
picture of what happened

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on the day the asteroid hit.

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This landscape is full of fossils

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dating from the Late Cretaceous,

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the period which began
around 100 million years ago

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and ended 66 million years ago,

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when the dinosaurs vanished.

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Palaeontologist Robert DePalma
wants to find out more.

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I think anybody
who's ever liked dinosaurs

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in the past, or still does,

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has thought at one point
or another,

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"Well, what happened to them?

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"Why are they not here
any more?"

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So many different theories
are out there,

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and nobody has a tight answer
to that question.

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Judging from fossil evidence,

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this is what Hell Creek looked
like in the Late Cretaceous.

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There were low-lying,
marshy flood plains,

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intercut by river channels
and covered with horsetails,

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ferns and trees.

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Back then, it was warm
and wet here all year round.

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Tanis lies
in the north-eastern corner

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of the Hell Creek formation.

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Instead of today's
dusty prairies,

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there were sandy river banks.

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Instead of rocky cliffs,
there were forests.

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And instead
of the life we know today...

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DEEP RUMBLING CALLS

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TRILLING

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..well, Robert is hoping
to find out more

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about what that was like.

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COOING

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A sandbank lying between
a river and a forest

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would one day become
what Robert now calls Tanis.

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He and his team have been
digging here since 2012.

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So somewhere from between there

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and down here
is where that came from.

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It's come from up above.
Hey, look at this.

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What? Look.

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Oh, yeah, yeah, yeah. OK.

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And what they found is unexpected.

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Here we've got
this freshwater environment

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of the Hell Creek formation,

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and these shocking
red, green colours

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coming from the shells of ammonites,
a marine organism,

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kind of like a coiled snail
in appearance.

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So we've got this marine organism
that's been thrown up

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into this freshwater environment,

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and they do not belong here.

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How they got here is a mystery.

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OK...

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And there's more.

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I'm just going to go ahead and
plane down some of this rock.

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Sitting just above the ammonites

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is something that
many dinosaur hunters

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are desperate to find.

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So this orange layer right here
is composed 100%

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of impact-related debris
that is enriched in iridium.

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Iridium is an element that's rare
in the Earth's crust,

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but it's common in asteroids.

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The layer it's in is called
the K-Pg boundary.

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Dear Momma...

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Oh, dear. Really?
Yeah.

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It's made up of dust and debris
from a huge asteroid impact.

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Look at that. That's amazing.

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Yeah, yeah, yeah, yeah, yeah.
That's what we want.

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OK. So it's coming
from this area here.

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So somewhere within that region is
where these pieces are coming from.

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The boundary separates
the age of the dinosaurs

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from the age of mammals,

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so the rocks here
come from about the time

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that the dinosaurs became extinct.

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No rattlesnakes.

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What makes the site even
more exciting

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is the rock layer
right beneath the boundary

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where Robert found the ammonites.

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The rock here
is really not quite rocky,

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as you would expect dinosaur bones
and things to be encased -

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you expect really, really hard
rocks and jackhammers

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and things like this,
but it's very, very crumbly

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and it just falls apart
in your hands.

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As well as being crumbly
throughout,

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this layer of rock is also
around a metre thick,

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which, along with
other unusual features, makes

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Robert think that something very
strange must have happened here.

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Maybe a flood or a mud flow,

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burying anything within it
in an instant.

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Oh, there's a beautiful...
Look at that one - beautiful.

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This could mean that anything
he finds in this layer

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would have been quickly entombed,

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like the bodies in
the volcanic ash of Pompeii.

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Robert knows from the geology

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that anything he finds at Tanis
will be tantalisingly close

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to the end
of the age of the dinosaurs

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and could be so well preserved

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that it could reveal new evidence

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that will bring this time period
to life

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in a way
no-one has ever done before.

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Robert digs at Tanis each summer,

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the only time the weather
allows him to do so.

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Come on down,
check out this lens over here.

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In order to understand how the
impact affected life on Earth,

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you really need to get
a very clear picture

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of what the world was like
right before.

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That is a critical part
of the story.

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Palaeontologists Dr David Burnham

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and Loren Gurche have been
digging with Robert for years.

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Oh, wow!

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See...see the brown? Yep.

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That might be a tubercle
right there.

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And it seems today is their
lucky day.

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Oh, my God! Look at that!
Look at that.

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Look, the scales are preserved!

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Holy crap! Like doing
a freaking dissection.

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Oh, my God. Biology of Tanis.

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Oh, the scale...

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Look, look - the wrinkles
continue down that way.

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Mine's all nice and wet so far.

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The scales are getting smaller
in that direction.

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How big are they there?

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I got a...I got one with
the projection over here.

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What? Oh!

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Yeah. Oh.

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Yeah, there's the protuberance
right there.

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I've only seen that on one other
specimen, in life. Yep.

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This is the closest thing
to getting to touch

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a living, breathing dinosaur.

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It is.

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They found something extraordinary.

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It is so exceedingly rare -

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a piece of triceratops skin
in the Hell Creek formation.

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It may look like
an impression in the rock,

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but this is skin
that has been fossilised

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and, over millions of years,
has turned to stone.

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Triceratops bones are relatively
common finds in Hell Creek,

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but skin in such condition as this
is very rare indeed.

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The size and the patterning
of the scales,

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together with the age
and location of the rocks

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where it was found,
strongly suggests

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that this is
from a triceratops.

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The brown colour contains
traces of organic material.

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So it might even be possible
from this

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to work out
which pigments were in it.

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Finding and studying

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such well-preserved fossils
as this

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helps palaeontologists build

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a much more detailed picture
of how these creatures lived.

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Combining this information

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with insights from scientists
around the world

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makes it possible to speculate

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about what life
in the Late Cretaceous

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might have been like.

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We know from bones

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that adult triceratops could
reach nine metres in length

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and three metres in height.

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RUMBLING

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Marks on the fossil also show us

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that this one was badly scarred.

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RUMBLING GROWL

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Triceratops were plant-eaters.

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Other fossils tell us
that they had sharp beaks

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and hundreds of teeth that enabled
them to shred tough plants

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such as these cycads.

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DISTANT TRUMPETING

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Almost all adult
triceratops fossils,

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including Robert's,
have been found on their own.

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So it's possible
that the adults were solitary,

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like modern-day male rhinos.

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So they were
probably territorial,

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chasing rivals away.

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And perhaps
marking their territories.

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If you weigh more
than an African elephant,

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there's not much
that can bother you...

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SQUEAKING

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..except perhaps a little mammal.

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GROWLS

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Robert found these jawbones

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in the fossilised burrow at Tanis.

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The shape of this tiny bone
and tooth

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means it's most likely come
from what's known

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as a pediomyid, an early mammal

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and a type of marsupial.

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Robert also discovered
fossilised nuts and seeds

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in the burrow.

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So we have an idea about
what it might have eaten.

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DISTANT TRUMPETING

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Robert's finds are adding

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to our knowledge
of the complex world

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at the very end
of the Late Cretaceous.

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And it's not just
the fossilised creatures.

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If you walk on damp sand,

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you'll leave a trace behind.

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A footprint.

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The same was true
66 million years ago.

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And very, very occasionally,
such traces were preserved.

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And that's exactly
what happened here at Tanis.

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You know, we won't foil a backside.

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Right, we'll just put...
Put plaster right on.

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That way you've got...

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Robert has discovered
a number of footprints.

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Yeah. Let's see.

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Looks like a good print. Yeah.

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Their shape gives him a clue

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00:15:53,040 --> 00:15:55,520
as to what might have made them.

258
00:16:00,600 --> 00:16:01,920
If he's right,

259
00:16:01,920 --> 00:16:04,400
they were made by a winged creature,

260
00:16:04,400 --> 00:16:07,360
that might well have liked
a small mammal...

261
00:16:10,200 --> 00:16:11,320
..for lunch.

262
00:16:18,440 --> 00:16:20,880
The footprints are long and narrow

263
00:16:20,880 --> 00:16:22,480
with four toe prints.

264
00:16:23,920 --> 00:16:27,200
Two are slightly longer
than the others,

265
00:16:27,200 --> 00:16:30,000
and that suggests
they were made by...

266
00:16:32,640 --> 00:16:34,080
..a pterosaur.

267
00:16:34,080 --> 00:16:35,600
SQUAWKS

268
00:16:43,440 --> 00:16:47,520
Pterosaurs are not dinosaurs,
but flying reptiles

269
00:16:47,520 --> 00:16:50,480
on a different branch
of the evolutionary tree.

270
00:16:57,840 --> 00:16:59,480
SCREECHING

271
00:17:04,960 --> 00:17:07,480
Male pterosaurs
usually had crests,

272
00:17:07,480 --> 00:17:09,400
while females didn't.

273
00:17:09,400 --> 00:17:12,880
So crests may have been
used in courtship displays.

274
00:17:19,200 --> 00:17:20,640
SHRIEKS

275
00:17:22,520 --> 00:17:26,600
And we have an indication of
where females laid their eggs,

276
00:17:26,600 --> 00:17:30,560
because evidence suggests
one pterosaur laid hers

277
00:17:30,560 --> 00:17:34,080
in the soft, sandy banks
of the river at Tanis.

278
00:17:49,320 --> 00:17:52,400
And this is a fossilised egg

279
00:17:52,400 --> 00:17:55,280
of a pterosaur
that Robert found there.

280
00:17:56,760 --> 00:18:00,080
The only one ever discovered
in North America.

281
00:18:00,080 --> 00:18:02,480
If you look at it
with the naked eye,

282
00:18:02,480 --> 00:18:06,520
all you see
is a jumble of lines.

283
00:18:06,520 --> 00:18:09,560
But if you examine it
with the latest technology,

284
00:18:09,560 --> 00:18:13,600
you can find out
a wealth of information,

285
00:18:13,600 --> 00:18:15,840
from the chemistry of the bones

286
00:18:15,840 --> 00:18:17,800
to the composition of the shell.

287
00:18:17,800 --> 00:18:20,720
And that, in turn,
can tell us a lot about

288
00:18:20,720 --> 00:18:23,480
how these incredible creatures
lived.

289
00:18:29,440 --> 00:18:31,480
Robert has been given access

290
00:18:31,480 --> 00:18:35,480
to the Diamond Light Source
synchrotron in Oxfordshire.

291
00:18:37,160 --> 00:18:39,360
It's a very powerful research tool

292
00:18:39,360 --> 00:18:41,440
that acts like a giant microscope.

293
00:18:44,680 --> 00:18:48,360
By accelerating electrons
in this huge ring,

294
00:18:48,360 --> 00:18:50,320
the synchrotron creates
beams of light

295
00:18:50,320 --> 00:18:52,840
many times brighter than the sun.

296
00:18:59,560 --> 00:19:03,800
Robert and paleobiologist
Dr Victoria Egerton

297
00:19:03,800 --> 00:19:06,840
now want to turn that beam
onto the egg fossil

298
00:19:06,840 --> 00:19:10,280
to discover more
about its chemical make-up.

299
00:19:10,280 --> 00:19:12,920
We're pretty much lined up
on the skeleton,

300
00:19:12,920 --> 00:19:14,720
but we might have to move
the stage a little bit

301
00:19:14,720 --> 00:19:17,640
to get to the right part. Sure.

302
00:19:17,640 --> 00:19:22,640
Meanwhile, Robert can reveal
the creature inside.

303
00:19:22,640 --> 00:19:24,880
And this?

304
00:19:24,880 --> 00:19:28,160
Who made this wonderful thing?

305
00:19:28,160 --> 00:19:31,360
I got replicas of the bones
from inside that egg

306
00:19:31,360 --> 00:19:33,840
and I restored the remainder

307
00:19:33,840 --> 00:19:34,920
and put together

308
00:19:34,920 --> 00:19:37,320
what the skeleton would've
looked like when it hatched.

309
00:19:37,320 --> 00:19:39,280
That's how big the creature
would've been

310
00:19:39,280 --> 00:19:40,760
outside the egg, if it had hatched.

311
00:19:40,760 --> 00:19:45,760
So this is the baby.
How big was it going to grow?

312
00:19:45,760 --> 00:19:48,520
These very long neck vertebrae
here

313
00:19:48,520 --> 00:19:51,680
are what really gave part
of the story away to us,

314
00:19:51,680 --> 00:19:54,120
because those long bones
match very, very closely

315
00:19:54,120 --> 00:19:55,800
with the azhdarchid pterosaurs.

316
00:19:55,800 --> 00:19:57,440
That is the giant pterosaurs.

317
00:19:57,440 --> 00:19:59,520
Oh, they were the whoppers,
weren't they?

318
00:19:59,520 --> 00:20:02,640
I mean, what, 25 feet?

319
00:20:02,640 --> 00:20:04,280
Wingspan? Some of them.

320
00:20:04,280 --> 00:20:08,600
This probably had a wingspan,
maybe 15 feet, five metres.

321
00:20:08,600 --> 00:20:11,320
Well, it looks as though
it could take off, really.

322
00:20:11,320 --> 00:20:13,400
It's easy to picture
something like that

323
00:20:13,400 --> 00:20:15,480
just hatching out of the egg
and fluttering out,

324
00:20:15,480 --> 00:20:17,320
almost like a little bat.

325
00:20:22,200 --> 00:20:26,680
They've scanned the egg,
here and in America.

326
00:20:28,480 --> 00:20:30,880
Victoria has the results.

327
00:20:32,760 --> 00:20:36,000
So what have you learned
from the synchrotron image?

328
00:20:36,000 --> 00:20:38,440
What we have here is a chemical map

329
00:20:38,440 --> 00:20:42,320
of calcium directly within
the bones of this animal.

330
00:20:42,320 --> 00:20:46,400
That tells us that these bones
were already hardened.

331
00:20:46,400 --> 00:20:50,240
So it might be ready to fly
not long after it hatches.

332
00:20:50,240 --> 00:20:52,760
OK. Can you see any sign
of the shell,

333
00:20:52,760 --> 00:20:54,120
and what sort of shell was it?

334
00:20:54,120 --> 00:20:57,440
We can. What I can show you...

335
00:20:57,440 --> 00:20:58,840
Ah!

336
00:20:58,840 --> 00:21:02,040
..is we can see the rim
of the egg in sulphur.

337
00:21:02,040 --> 00:21:06,880
Does that tell you whether it was
a hard shell or a soft shell?

338
00:21:06,880 --> 00:21:08,520
We have been looking at this.

339
00:21:08,520 --> 00:21:13,600
We can see folding occurring,
and this unusual undulation.

340
00:21:13,600 --> 00:21:15,480
If it were a hard egg,

341
00:21:15,480 --> 00:21:18,400
we would expect splintered bits
and broken bits,

342
00:21:18,400 --> 00:21:20,520
just like a chicken egg.

343
00:21:20,520 --> 00:21:22,320
This helped to tell us
that it was soft.

344
00:21:22,320 --> 00:21:24,520
So it was perhaps like a turtle?

345
00:21:24,520 --> 00:21:25,840
Absolutely.

346
00:21:25,840 --> 00:21:28,400
That's not the case, is it,
with dinosaurs?

347
00:21:28,400 --> 00:21:31,480
Many dinosaurs laid
hard-shelled eggs. Yes.

348
00:21:31,480 --> 00:21:34,720
So this is a new discovery
about azhdarchid pterosaurs?

349
00:21:34,720 --> 00:21:37,160
Absolutely. This is something

350
00:21:37,160 --> 00:21:39,360
that we are confirming
for the first time.

351
00:21:39,360 --> 00:21:40,680
Huh!

352
00:21:40,680 --> 00:21:43,920
That flying pterosaurs
had eggs like turtles.

353
00:21:43,920 --> 00:21:45,080
Yes.

354
00:21:45,080 --> 00:21:47,720
Much more reptilianlike
than birdlike.

355
00:21:47,720 --> 00:21:50,080
And that can potentially
tell us more

356
00:21:50,080 --> 00:21:53,400
about the environment
in which these eggs were laid.

357
00:21:53,400 --> 00:21:55,200
How interesting. Yeah.

358
00:22:03,560 --> 00:22:07,520
Creatures that lay soft eggs
tend to bury them

359
00:22:07,520 --> 00:22:09,000
in order to protect them.

360
00:22:10,880 --> 00:22:12,720
SQUAWKS

361
00:22:14,840 --> 00:22:17,360
So female pterosaurs
probably looked for

362
00:22:17,360 --> 00:22:20,560
places like Tanis
to lay their eggs...

363
00:22:23,280 --> 00:22:27,280
..because the sandy soil here
is just soft enough

364
00:22:27,280 --> 00:22:30,440
for the hatchling to dig itself out.

365
00:22:30,440 --> 00:22:32,240
SNIFFING

366
00:22:32,240 --> 00:22:35,800
Now the pterosaur
just has to make sure

367
00:22:35,800 --> 00:22:37,240
that the hole...

368
00:22:38,880 --> 00:22:40,280
..is perfect.

369
00:22:44,840 --> 00:22:46,200
SQUAWKS

370
00:22:50,520 --> 00:22:52,600
WARBLING

371
00:22:56,960 --> 00:22:58,560
Success!

372
00:23:00,000 --> 00:23:02,360
But it's not over yet.

373
00:23:02,360 --> 00:23:05,840
Pterosaurs had two ovaries,

374
00:23:05,840 --> 00:23:08,560
and they laid their eggs in pairs.

375
00:23:18,280 --> 00:23:20,360
Here on the sandbank,

376
00:23:20,360 --> 00:23:24,600
sandwiched between the river
and these glorious trees,

377
00:23:24,600 --> 00:23:27,520
life at Tanis
seemed to be thriving.

378
00:23:27,520 --> 00:23:29,480
GASPS
Whoops!

379
00:23:29,480 --> 00:23:31,480
Never a dull moment.

380
00:23:31,480 --> 00:23:34,560
But all that was about to change.

381
00:23:41,880 --> 00:23:45,240
The chain of events that led to the
extinction of the dinosaurs

382
00:23:45,240 --> 00:23:50,160
began in the distant past,
deep in space.

383
00:23:54,720 --> 00:23:58,840
Most scientists think it all started
in a ring of dust,

384
00:23:58,840 --> 00:24:02,560
rocks, and debris
known as the asteroid belt.

385
00:24:05,840 --> 00:24:08,240
It's usually an uneventful place.

386
00:24:12,280 --> 00:24:15,400
But it's thought that many,
many millions of years ago,

387
00:24:15,400 --> 00:24:18,600
a rock was bumped
into a new orbit...

388
00:24:23,120 --> 00:24:27,000
..and diverted onto a collision
course with Planet Earth.

389
00:24:39,680 --> 00:24:42,600
Robert is building a vivid picture

390
00:24:42,600 --> 00:24:44,760
of Late Cretaceous life
at Tanis.

391
00:24:47,480 --> 00:24:51,120
And the team have found some more
well-preserved footprints.

392
00:24:52,560 --> 00:24:55,800
So these are animals that were
actually walking in the water?

393
00:24:55,800 --> 00:24:57,800
These guys would've been
essentially on

394
00:24:57,800 --> 00:24:59,320
a mushy river bank going down

395
00:24:59,320 --> 00:25:01,080
to drink at some point.

396
00:25:01,080 --> 00:25:04,240
You know, animals tend to
congregate around the rivers.

397
00:25:04,240 --> 00:25:06,960
This print is 30 centimetres long.

398
00:25:08,200 --> 00:25:10,480
So I think this is from
a type of dinosaur

399
00:25:10,480 --> 00:25:12,480
that we call a duck-billed dinosaur.

400
00:25:12,480 --> 00:25:16,080
And they would've been
very common in the Cretaceous.

401
00:25:16,080 --> 00:25:18,400
They ate the plants in the area

402
00:25:18,400 --> 00:25:21,000
and they got very large -
30 feet long.

403
00:25:22,600 --> 00:25:24,240
And there are more.

404
00:25:24,240 --> 00:25:27,960
This track, you see all the toes
are very well preserved.

405
00:25:27,960 --> 00:25:31,040
You even see a nail print
at the tips of the toes.

406
00:25:31,040 --> 00:25:33,320
So the little toenails
dug into the mud.

407
00:25:33,320 --> 00:25:34,560
I love this one.

408
00:25:39,240 --> 00:25:42,320
This is Robert's prized footprint.

409
00:25:42,320 --> 00:25:45,320
It has three toes,

410
00:25:45,320 --> 00:25:48,920
and it's longer than it is wide.

411
00:25:48,920 --> 00:25:53,520
So it's very likely to be
a carnivorous dinosaur.

412
00:25:53,520 --> 00:25:55,960
It's so well preserved
that you can see

413
00:25:55,960 --> 00:25:59,560
the mark left by
its sharp claw there.

414
00:26:00,800 --> 00:26:02,400
Hell Creek is well known

415
00:26:02,400 --> 00:26:06,240
for one carnivore in particular -
T-rex.

416
00:26:07,320 --> 00:26:11,800
This footprint is too small
for an adult T-rex,

417
00:26:11,800 --> 00:26:15,760
but it's possible that it was made
by a young one.

418
00:26:29,680 --> 00:26:32,080
the crown of a tooth.

419
00:26:32,080 --> 00:26:36,160
Its shape and its serrated edge

420
00:26:36,160 --> 00:26:38,440
are indications that it comes

421
00:26:38,440 --> 00:26:40,200
from an adult T-rex.

422
00:26:44,680 --> 00:26:46,720
RUMBLING GROWL

423
00:26:53,600 --> 00:26:58,640
DEEP RUMBLING GROWL

424
00:27:01,960 --> 00:27:04,080
GROWLS

425
00:27:05,600 --> 00:27:08,240
Bite marks found on T-rex bones

426
00:27:08,240 --> 00:27:11,240
show that they ate other T-rexes.

427
00:27:12,920 --> 00:27:15,520
And a youngster
would make an easy catch.

428
00:27:15,520 --> 00:27:17,640
SNEEZES

429
00:27:21,160 --> 00:27:23,080
But not this time.

430
00:27:32,440 --> 00:27:35,640
Very few footprints
are preserved as fossils

431
00:27:35,640 --> 00:27:37,480
in Hell Creek.

432
00:27:37,480 --> 00:27:39,720
So if you find several
in one place,

433
00:27:39,720 --> 00:27:41,400
as Robert has done,

434
00:27:41,400 --> 00:27:43,080
it's a reasonable assumption

435
00:27:43,080 --> 00:27:46,440
that there would've been
many more nearby.

436
00:27:49,720 --> 00:27:52,520
And that supports the idea

437
00:27:52,520 --> 00:27:57,160
that dinosaurs and pterosaurs
were thriving at Tanis

438
00:27:57,160 --> 00:27:59,200
shortly before the impact.

439
00:27:59,200 --> 00:28:01,640
GROWLING

440
00:28:06,720 --> 00:28:08,360
And if they were thriving...

441
00:28:08,360 --> 00:28:09,560
SQUAWKING

442
00:28:10,960 --> 00:28:14,680
..they must have been reproducing.

443
00:28:21,400 --> 00:28:24,440
Fossils from dinosaurs
similar to T-rex

444
00:28:24,440 --> 00:28:27,560
show they may have laid
around 20 eggs

445
00:28:27,560 --> 00:28:29,480
in a circular nest.

446
00:28:35,200 --> 00:28:37,640
It's possible that, like crocodiles,

447
00:28:37,640 --> 00:28:41,000
they partly covered their eggs
to keep them warm.

448
00:28:42,440 --> 00:28:43,960
SNEEZES

449
00:28:56,480 --> 00:28:59,560
For one T-rex, a misfortune.

450
00:29:06,680 --> 00:29:09,400
But for all dinosaurs...

451
00:29:09,400 --> 00:29:10,520
ROARS

452
00:29:10,520 --> 00:29:13,560
..a disaster was looming.

453
00:29:26,720 --> 00:29:31,000
Deep in space,
the asteroid was approaching.

454
00:29:35,760 --> 00:29:37,760
Its journey would take it through
the orbit

455
00:29:37,760 --> 00:29:40,560
of our neighbouring planet, Mars.

456
00:29:46,120 --> 00:29:48,080
Had the two collided,

457
00:29:48,080 --> 00:29:51,120
a catastrophe on Earth
would've been avoided.

458
00:29:59,920 --> 00:30:01,840
But it was not to be...

459
00:30:03,360 --> 00:30:06,080
..and Earth's fate was sealed.

460
00:30:19,760 --> 00:30:21,840
As Robert's dig continues,

461
00:30:21,840 --> 00:30:24,000
his vision of what happened at Tanis

462
00:30:24,000 --> 00:30:26,800
is finally starting to come
together.

463
00:30:28,800 --> 00:30:31,560
It seems the sandbank was full
of life.

464
00:30:31,560 --> 00:30:34,200
T-rex, triceratops,

465
00:30:34,200 --> 00:30:35,440
little mammals,

466
00:30:35,440 --> 00:30:39,280
alongside the footprints of
other dinosaurs and pterosaurs,

467
00:30:39,280 --> 00:30:41,320
all in a very small area.

468
00:30:43,160 --> 00:30:45,080
BLOWS
You see the scales?

469
00:30:45,080 --> 00:30:47,160
I do. Oh, my God.

470
00:30:47,160 --> 00:30:49,320
That excites me just looking at it!

471
00:30:51,280 --> 00:30:54,840
Then Robert finds
something truly remarkable.

472
00:30:58,200 --> 00:31:01,000
See the cracks already forming?
Look at that.

473
00:31:01,000 --> 00:31:03,880
So we're going to have to really
monitor that before we glue it.

474
00:31:03,880 --> 00:31:06,120
Cos this is getting vulnerable
now.

475
00:31:06,120 --> 00:31:08,640
An almost complete creature.

476
00:31:11,800 --> 00:31:14,000
To get this block out,
we're freezing it.

477
00:31:20,760 --> 00:31:23,600
Robert is about to attempt
something tricky.

478
00:31:25,560 --> 00:31:28,000
Steady... Let's go.

479
00:31:30,000 --> 00:31:32,920
To get the fossil out
in one piece, they're trying

480
00:31:32,920 --> 00:31:35,360
to freeze it using liquid nitrogen

481
00:31:35,360 --> 00:31:38,600
at almost 200 degrees below zero.

482
00:31:44,400 --> 00:31:45,720
Watch your footing.

483
00:31:47,160 --> 00:31:49,200
Loren, I'm worried
about brittleness here.

484
00:31:49,200 --> 00:31:52,400
Get that hammer. Give this a couple
whacks with the hammer.

485
00:31:54,200 --> 00:31:57,040
OK. Move over five centimetres.
Good.

486
00:32:00,360 --> 00:32:03,960
It's cracked loose. Yep.
OK. It's loose.

487
00:32:03,960 --> 00:32:06,400
So we have to get this out
in one piece.

488
00:32:06,400 --> 00:32:09,440
One, two, three.

489
00:32:11,080 --> 00:32:12,760
Yeehaw!

490
00:32:13,960 --> 00:32:15,960
Total success. Total success.

491
00:32:17,440 --> 00:32:20,040
This is a technique
used in archaeology

492
00:32:20,040 --> 00:32:22,600
for digging up human remains.

493
00:32:22,600 --> 00:32:24,720
We've got enough time
to work with the fossil

494
00:32:24,720 --> 00:32:26,400
and not damage it.

495
00:32:26,400 --> 00:32:28,880
And I couldn't be happier.

496
00:32:31,600 --> 00:32:33,960
And the creature Robert found?

497
00:32:35,360 --> 00:32:36,800
A turtle.

498
00:32:38,880 --> 00:32:42,720
This is the fossil
now it's been cleaned up.

499
00:32:42,720 --> 00:32:45,440
It's lying on its side.

500
00:32:45,440 --> 00:32:48,280
Here's the outline of its shell.

501
00:32:49,680 --> 00:32:53,320
The shape of the shell
and the scalloped edges here

502
00:32:53,320 --> 00:32:55,960
tell us that this was
a baenid turtle.

503
00:32:59,600 --> 00:33:02,760
Robert's baenid turtle
looks very similar

504
00:33:02,760 --> 00:33:04,640
to modern cooter turtles

505
00:33:04,640 --> 00:33:08,040
and lived in the same sort
of freshwater environment.

506
00:33:15,080 --> 00:33:18,200
For a turtle,
Tanis would've been ideal.

507
00:33:22,120 --> 00:33:24,840
Warm, shallow water.

508
00:33:27,040 --> 00:33:28,400
Plenty to eat.

509
00:33:33,160 --> 00:33:36,000
And lots of safe places
in which to warm up

510
00:33:36,000 --> 00:33:38,240
in the Late Cretaceous sunshine.

511
00:33:43,120 --> 00:33:46,560
The turtle fossil Robert found
is almost complete.

512
00:33:46,560 --> 00:33:49,560
This is the underside,

513
00:33:49,560 --> 00:33:54,680
and this brown material up here
is fossilised wood.

514
00:33:54,680 --> 00:33:58,280
It's the end of a stick that passes
right through its body

515
00:33:58,280 --> 00:34:01,480
and comes out just here.

516
00:34:01,480 --> 00:34:03,320
So the evidence points towards

517
00:34:03,320 --> 00:34:05,640
this turtle having been impaled.

518
00:34:08,320 --> 00:34:11,440
A violent end to one of
the many creatures found

519
00:34:11,440 --> 00:34:14,600
in the crumbly rock layer at Tanis.

520
00:34:15,720 --> 00:34:17,440
When I look at the animals

521
00:34:17,440 --> 00:34:20,040
and plants preserved
in the sediments of Tanis

522
00:34:20,040 --> 00:34:21,760
and the footprints beneath it,

523
00:34:21,760 --> 00:34:24,360
I see a picture of
a vibrant ecosystem,

524
00:34:24,360 --> 00:34:28,560
many different dinosaurs,
and a thriving, thriving place.

525
00:34:31,840 --> 00:34:33,840
After ten years of digging,

526
00:34:33,840 --> 00:34:36,960
there is now enough evidence
to piece together

527
00:34:36,960 --> 00:34:38,760
much of the story of Tanis

528
00:34:38,760 --> 00:34:41,400
and the creatures which lived here.

529
00:34:45,000 --> 00:34:48,520
Robert has found so many fossils,
it looks as if,

530
00:34:48,520 --> 00:34:50,880
even at the very end
of the Late Cretaceous,

531
00:34:50,880 --> 00:34:52,960
Tanis was bursting with life.

532
00:34:52,960 --> 00:34:54,880
VARIOUS ANIMAL CALLS

533
00:34:54,880 --> 00:34:58,760
Full of the giant reptiles
that had dominated the planet

534
00:34:58,760 --> 00:35:01,840
for more than 150 million years.

535
00:35:06,640 --> 00:35:07,800
BARKING

536
00:35:07,800 --> 00:35:10,920
It's impossible to know
how much longer

537
00:35:10,920 --> 00:35:12,520
their reign would've continued...

538
00:35:14,640 --> 00:35:16,040
SQUAWKS

539
00:35:16,040 --> 00:35:20,600
..because all this was about to end.

540
00:35:41,760 --> 00:35:43,680
The asteroid hit...

541
00:35:47,440 --> 00:35:51,520
..in what is now the Yucatan
peninsula in Mexico.

542
00:35:54,360 --> 00:35:57,160
It's called the Chicxulub asteroid

543
00:35:57,160 --> 00:36:00,000
after the town nearest
to the centre of its crater.

544
00:36:03,080 --> 00:36:04,760
ROARING

545
00:36:11,200 --> 00:36:13,040
ROARS

546
00:36:18,320 --> 00:36:22,400
Any living thing within 900 miles
of the impact...

547
00:36:24,640 --> 00:36:27,440
..was destroyed by the blast.

548
00:36:32,360 --> 00:36:35,120
But what effect
did the impact have on Tanis,

549
00:36:35,120 --> 00:36:37,640
nearly 2,000 miles away?

550
00:36:47,360 --> 00:36:49,000
To find out,

551
00:36:49,000 --> 00:36:53,040
Robert is looking for clues
that might link Tanis

552
00:36:53,040 --> 00:36:56,280
to the actual day the asteroid hit.

553
00:36:57,280 --> 00:36:58,720
BLOWS

554
00:37:02,160 --> 00:37:03,600
We've got some wood,

555
00:37:03,600 --> 00:37:06,640
and pressed up against this
and all intertangled,

556
00:37:06,640 --> 00:37:08,480
we've got the carcasses of fish.

557
00:37:08,480 --> 00:37:09,840
OK.

558
00:37:11,120 --> 00:37:13,040
That's a beautifully preserved
tail,

559
00:37:13,040 --> 00:37:16,000
so that fish is going to be
absolutely gorgeous.

560
00:37:16,000 --> 00:37:18,520
So part of the detail work
that we're doing right now

561
00:37:18,520 --> 00:37:20,200
is going in and checking out

562
00:37:20,200 --> 00:37:23,920
all the individual elements
in this mass death layer.

563
00:37:23,920 --> 00:37:27,200
Some of the evidence
he's found so far

564
00:37:27,200 --> 00:37:30,680
has been hidden inside
the fish themselves.

565
00:37:33,840 --> 00:37:36,960
In more ways than one, it literally
is an operation of a Cretaceous

566
00:37:36,960 --> 00:37:40,000
fish, so we're performing surgery
on this thing.

567
00:37:40,000 --> 00:37:43,000
Robert needs to open this
fish's skull.

568
00:37:44,800 --> 00:37:48,080
And very carefully,
we want to separate this

569
00:37:48,080 --> 00:37:49,520
from the rest of the fish.

570
00:37:50,720 --> 00:37:52,040
OK.

571
00:37:55,600 --> 00:37:57,880
Here we go.

572
00:37:57,880 --> 00:38:00,240
Opening up the fish.

573
00:38:00,240 --> 00:38:02,400
Got a nice ant
that made a home in there.

574
00:38:03,520 --> 00:38:05,160
And beautiful, look at that.

575
00:38:05,160 --> 00:38:08,240
OK, here we have
the gill bars of the fish.

576
00:38:08,240 --> 00:38:10,840
Those are the bars that hold
the filaments of the gills.

577
00:38:12,040 --> 00:38:13,840
And between the gill bars,

578
00:38:13,840 --> 00:38:15,920
all of these clusters
of round objects,

579
00:38:15,920 --> 00:38:17,640
those are the ejecta spherules.

580
00:38:18,720 --> 00:38:23,240
Ejecta spherules are tiny balls
that were once molten rock.

581
00:38:23,240 --> 00:38:25,760
They could be evidence
of what Robert suspects -

582
00:38:25,760 --> 00:38:27,360
that creatures here died

583
00:38:27,360 --> 00:38:30,080
on the day
of the asteroid strike.

584
00:38:31,360 --> 00:38:34,200
Those ejecta spherules
last saw the light of day

585
00:38:34,200 --> 00:38:37,120
when they were flying through
the air 66 billion years ago.

586
00:38:47,680 --> 00:38:51,280
After a large asteroid impact,

587
00:38:51,280 --> 00:38:54,080
a mix of vaporised and molten rock

588
00:38:54,080 --> 00:38:56,200
is propelled into space.

589
00:38:59,160 --> 00:39:00,720
There, it cools,

590
00:39:00,720 --> 00:39:03,880
solidifying
into tiny glass droplets.

591
00:39:05,480 --> 00:39:08,600
Some carry on deeper into space.

592
00:39:10,800 --> 00:39:14,000
But most are pulled back
to Earth by gravity.

593
00:39:21,520 --> 00:39:24,520
After a major asteroid hit,

594
00:39:24,520 --> 00:39:29,040
trillions of ejecta spherules
would fall from the sky.

595
00:39:29,040 --> 00:39:31,320
Then, over millions of years,

596
00:39:31,320 --> 00:39:34,320
pressure and chemical reactions
in the ground

597
00:39:34,320 --> 00:39:37,520
would turn most of them to clay.

598
00:39:37,520 --> 00:39:40,000
They'd look something like this.

599
00:39:41,280 --> 00:39:45,240
So finding spherules
in the gills of a fish,

600
00:39:45,240 --> 00:39:47,560
as Robert has done at Tanis,

601
00:39:47,560 --> 00:39:50,000
suggests the fish sucked them in

602
00:39:50,000 --> 00:39:52,800
while the spherules
were still falling.

603
00:39:52,800 --> 00:39:54,560
So these creatures could have died

604
00:39:54,560 --> 00:39:57,480
at the time of an asteroid impact.

605
00:40:02,960 --> 00:40:06,200
Once Robert begins to look
for ejecta spherules,

606
00:40:06,200 --> 00:40:08,080
he finds more and more,

607
00:40:08,080 --> 00:40:12,320
and realises the thick,
crumbly layer of rock at Tanis

608
00:40:12,320 --> 00:40:13,720
is full of them.

609
00:40:17,160 --> 00:40:19,320
I mean, this stuff is go...
Oh, my God, look at that one.

610
00:40:19,320 --> 00:40:21,280
These things are just gorgeous.

611
00:40:22,640 --> 00:40:24,120
Ejecta spherules like this

612
00:40:24,120 --> 00:40:26,720
give us a fingerprint
of where they came from.

613
00:40:28,360 --> 00:40:30,400
If these spherules were connected

614
00:40:30,400 --> 00:40:32,240
to the Chicxulub impact,

615
00:40:32,240 --> 00:40:35,280
then the whole crumbly layer
could be full of evidence

616
00:40:35,280 --> 00:40:38,920
of what happened on the day
the asteroid hit.

617
00:40:38,920 --> 00:40:40,280
That's a good one.

618
00:40:40,280 --> 00:40:42,680
Oh, is that a droplet right there?

619
00:40:42,680 --> 00:40:44,640
To see if that's the case,

620
00:40:44,640 --> 00:40:48,280
Robert needs to find a spherule
that hasn't turned to clay.

621
00:40:48,280 --> 00:40:52,120
Oh, my God,
that's a beautiful droplet.

622
00:40:52,120 --> 00:40:53,920
OK.

623
00:40:53,920 --> 00:40:57,080
The small pieces of orange material

624
00:40:57,080 --> 00:40:58,960
that Robert and Loren are digging up

625
00:40:58,960 --> 00:41:01,080
may be able to help.

626
00:41:01,080 --> 00:41:04,120
They're amber.

627
00:41:04,120 --> 00:41:06,640
If there was anything flying
through the air at that time,

628
00:41:06,640 --> 00:41:08,360
this is where it's going to get
caught.

629
00:41:10,840 --> 00:41:14,120
The amber they're collecting
was once sticky resin

630
00:41:14,120 --> 00:41:17,280
oozing out of
a Late Cretaceous tree trunk.

631
00:41:19,000 --> 00:41:21,360
It's a way for the tree
to protect itself,

632
00:41:21,360 --> 00:41:24,200
like a scab forming on a cut.

633
00:41:32,520 --> 00:41:35,200
Anything covered by the resin
would be frozen

634
00:41:35,200 --> 00:41:37,280
in an amber time capsule.

635
00:41:43,760 --> 00:41:46,160
If they find a spherule
preserved in amber,

636
00:41:46,160 --> 00:41:48,720
it could be analysed

637
00:41:48,720 --> 00:41:51,840
to see if it comes from
the Chicxulub asteroid impact.

638
00:41:54,920 --> 00:41:56,480
So during this batch,

639
00:41:56,480 --> 00:41:59,960
we were incredibly lucky
that we came across

640
00:41:59,960 --> 00:42:02,400
two completely unaltered spherules.

641
00:42:03,960 --> 00:42:07,320
This spherule could be
something amazing.

642
00:42:07,320 --> 00:42:11,880
Evidence preserved well enough
to analyse for chemical clues.

643
00:42:14,760 --> 00:42:16,240
If so,

644
00:42:16,240 --> 00:42:20,680
it could link Tanis directly
with the Chicxulub impact

645
00:42:20,680 --> 00:42:23,200
and the last day of the dinosaurs.

646
00:42:30,840 --> 00:42:33,480
To investigate, Robert is joined

647
00:42:33,480 --> 00:42:35,600
at the Diamond Light Source

648
00:42:35,600 --> 00:42:38,400
by Professor of Natural History
Phil Manning,

649
00:42:38,400 --> 00:42:40,760
of the University of Manchester.

650
00:42:40,760 --> 00:42:43,200
They've already run initial tests

651
00:42:43,200 --> 00:42:45,160
on the spherules in America.

652
00:42:45,160 --> 00:42:47,120
What have you found out so far?

653
00:42:47,120 --> 00:42:50,920
These little glass spherules,
these globs

654
00:42:50,920 --> 00:42:52,920
of molten material
from the impact site

655
00:42:52,920 --> 00:42:56,240
have a chemical signal that ties it
with where they came from.

656
00:42:56,240 --> 00:42:57,840
Cos when an asteroid hits,

657
00:42:57,840 --> 00:43:00,040
it melts the ground that it hits,

658
00:43:00,040 --> 00:43:02,280
but also that glass has

659
00:43:02,280 --> 00:43:04,840
a little bit of contamination
from the asteroid itself.

660
00:43:04,840 --> 00:43:08,200
And that gives you a unique
geochemical fingerprint.

661
00:43:08,200 --> 00:43:09,760
We can see once we've scanned it,

662
00:43:09,760 --> 00:43:12,600
and looking at spherules from
other sites in North Dakota,

663
00:43:12,600 --> 00:43:14,320
we can get a baseline

664
00:43:14,320 --> 00:43:18,520
for what the ejecta should look
like when it's related to

665
00:43:18,520 --> 00:43:20,160
the Chicxulub crater.

666
00:43:20,160 --> 00:43:21,720
And you can see each element here

667
00:43:21,720 --> 00:43:23,880
and the ratios of those elements.

668
00:43:23,880 --> 00:43:26,960
And when we look at Tanis,
it's a match.

669
00:43:26,960 --> 00:43:29,760
I mean, it perfectly overlays.

670
00:43:29,760 --> 00:43:32,800
So I think
this is powerful evidence

671
00:43:32,800 --> 00:43:36,360
supporting that Tanis
and Chicxulub are linked.

672
00:43:36,360 --> 00:43:38,480
And what do these findings mean

673
00:43:38,480 --> 00:43:41,360
for the rest of the fossils
that you're finding in Tanis?

674
00:43:41,360 --> 00:43:44,400
This data is key for the
entire site,

675
00:43:44,400 --> 00:43:46,680
because once you have that link

676
00:43:46,680 --> 00:43:49,480
and you know
what impact affected Tanis,

677
00:43:49,480 --> 00:43:53,120
then you essentially know
that every object in that site,

678
00:43:53,120 --> 00:43:55,920
all the animals and the plants
and everything buried

679
00:43:55,920 --> 00:43:57,400
in those sediments,

680
00:43:57,400 --> 00:43:59,920
are linked to the last day
of the Cretaceous.

681
00:44:01,840 --> 00:44:04,880
And the synchrotron here in the UK

682
00:44:04,880 --> 00:44:07,360
reveals something even more
remarkable.

683
00:44:09,800 --> 00:44:14,280
So this is showing
a beautiful synchrotron scan

684
00:44:14,280 --> 00:44:16,680
of the half of one spherule.

685
00:44:16,680 --> 00:44:19,480
The glass is
a good geochemical fingerprint,

686
00:44:19,480 --> 00:44:23,160
and we've got calcium, some iron,

687
00:44:23,160 --> 00:44:25,320
we've got strontium,

688
00:44:25,320 --> 00:44:27,040
but when we look at the
entire thing,

689
00:44:27,040 --> 00:44:30,000
we see something quite unexpected.

690
00:44:30,000 --> 00:44:32,120
That's your entire spherule.

691
00:44:32,120 --> 00:44:33,560
What's this?

692
00:44:33,560 --> 00:44:36,600
In this, we've got
a little bit of a nugget.

693
00:44:36,600 --> 00:44:38,800
There was a little particle
right there.

694
00:44:38,800 --> 00:44:40,120
So we scan it.

695
00:44:40,120 --> 00:44:42,680
And that's a lot of iron
in there.

696
00:44:42,680 --> 00:44:45,400
Over here, we've got chromium,
a big peak in chromium.

697
00:44:45,400 --> 00:44:48,600
Over here, we've got
a big peak in nickel.

698
00:44:48,600 --> 00:44:51,280
And the abundances
of iron, nickel and chromium,

699
00:44:51,280 --> 00:44:52,680
all together,

700
00:44:52,680 --> 00:44:55,480
that matches what you expect
to see in a meteoric body.

701
00:44:55,480 --> 00:44:58,520
That does not match what you
would normally have down here.

702
00:44:58,520 --> 00:45:02,000
So this is
extraterrestrial material?

703
00:45:02,000 --> 00:45:04,320
If you were to sort of grind up

704
00:45:04,320 --> 00:45:09,720
and stuff into a spherule
a piece of meteorite,

705
00:45:09,720 --> 00:45:11,520
that's what it's going to look
like.

706
00:45:11,520 --> 00:45:14,960
This could be a piece of
the Chicxulub asteroid.

707
00:45:14,960 --> 00:45:17,040
A piece of the bullet
that killed the dinosaurs.

708
00:45:17,040 --> 00:45:18,400
No!

709
00:45:25,040 --> 00:45:26,600
Robert could have found

710
00:45:26,600 --> 00:45:30,040
a fragment of the asteroid itself
in Tanis,

711
00:45:30,040 --> 00:45:35,720
physical evidence linking this site
to the Chicxulub impact.

712
00:45:35,720 --> 00:45:38,920
But Tanis is almost 2,000 miles away

713
00:45:38,920 --> 00:45:41,000
from where the asteroid hit.

714
00:45:41,000 --> 00:45:44,640
So exactly how did it cause
the creatures' deaths?

715
00:45:48,280 --> 00:45:50,560
To answer that question,

716
00:45:50,560 --> 00:45:54,160
Robert is searching
in the mass death layer.

717
00:45:56,840 --> 00:46:00,640
Right here, we've got
this intertangled mass of fish.

718
00:46:00,640 --> 00:46:03,120
There's one fish here,
another sturgeon goes this way,

719
00:46:03,120 --> 00:46:05,160
underneath the body of a paddlefish.

720
00:46:05,160 --> 00:46:07,000
There's another sturgeon
that goes this way,

721
00:46:07,000 --> 00:46:10,480
underneath this log, and continues
out the other side.

722
00:46:10,480 --> 00:46:12,680
And his head hit that log

723
00:46:12,680 --> 00:46:16,040
and has deflected downward
at a 90-degree angle.

724
00:46:18,160 --> 00:46:23,160
Robert uncovered a tangled mass of
fossilised creatures and logs

725
00:46:23,160 --> 00:46:25,320
surrounded by spherules

726
00:46:25,320 --> 00:46:29,760
and crushed together
in what's known as a logjam.

727
00:46:29,760 --> 00:46:32,600
He has a theory that
the creatures were swept

728
00:46:32,600 --> 00:46:36,000
to their death in some kind
of turbulent surge of water

729
00:46:36,000 --> 00:46:38,480
and quickly entombed in sediment,

730
00:46:38,480 --> 00:46:41,200
which is why
they're so well preserved.

731
00:46:41,200 --> 00:46:44,000
But what could have caused the wave?

732
00:46:47,800 --> 00:46:50,440
One theory is a tsunami.

733
00:46:54,680 --> 00:46:57,160
The asteroid hit at sea.

734
00:46:57,160 --> 00:46:58,800
Recent studies show

735
00:46:58,800 --> 00:47:02,840
it may have caused a wave
almost a mile high.

736
00:47:15,800 --> 00:47:18,600
The height of the wave
would've gradually reduced

737
00:47:18,600 --> 00:47:20,760
as it spread across the oceans.

738
00:47:22,320 --> 00:47:23,800
In the Late Cretaceous,

739
00:47:23,800 --> 00:47:26,960
North America was divided
by a narrow sea

740
00:47:26,960 --> 00:47:30,200
that's been called
the Western Interior Seaway.

741
00:47:30,200 --> 00:47:32,920
The tsunami could have
travelled up this,

742
00:47:32,920 --> 00:47:34,520
towards Tanis.

743
00:47:38,000 --> 00:47:40,720
But there's a big question
about the tsunami idea.

744
00:47:42,360 --> 00:47:44,280
The timing.

745
00:47:44,280 --> 00:47:47,320
Oh, which fish is that?

746
00:47:47,320 --> 00:47:50,320
That's a new...
It's a new contact. New one. Yeah.

747
00:47:50,320 --> 00:47:53,200
If a tsunami killed the fish,

748
00:47:53,200 --> 00:47:55,240
it would have to have hit

749
00:47:55,240 --> 00:47:57,080
while ejecta spherules
were falling...

750
00:47:58,520 --> 00:48:02,400
..because spherules were found
in the fish's gills.

751
00:48:04,200 --> 00:48:09,520
So how long after impact did
the spherules arrive at Tanis?

752
00:48:09,520 --> 00:48:12,080
Pretend this ball of foil
is a piece of ejecta

753
00:48:12,080 --> 00:48:15,160
coming out of the crater. It would
then go on an arc path,

754
00:48:15,160 --> 00:48:17,200
ballistic trajectory,
out of the crater

755
00:48:17,200 --> 00:48:19,680
and to wherever it lands -
in this case, Tanis.

756
00:48:21,880 --> 00:48:24,320
If we know the distance
between myself

757
00:48:24,320 --> 00:48:27,720
and the landing site, and if we know
the size of that ball,

758
00:48:27,720 --> 00:48:30,880
we can accurately calculate how long
it would take to get there.

759
00:48:34,840 --> 00:48:36,840
The result is surprising.

760
00:48:36,840 --> 00:48:39,320
Robert and his team calculated

761
00:48:39,320 --> 00:48:42,600
that these ejecta spherules
landed at Tanis

762
00:48:42,600 --> 00:48:47,000
between 13 minutes
and two hours after the impact.

763
00:48:49,560 --> 00:48:51,720
If a wave killed the fish,

764
00:48:51,720 --> 00:48:54,920
it must also have reached Tanis
within two hours.

765
00:48:59,000 --> 00:49:01,440
Data from recent tsunamis show

766
00:49:01,440 --> 00:49:04,720
even a powerful one would take much
longer than that

767
00:49:04,720 --> 00:49:08,560
to travel almost 2,000 miles
from the impact site

768
00:49:08,560 --> 00:49:09,960
to Tanis.

769
00:49:10,960 --> 00:49:13,640
So if it wasn't a tsunami,

770
00:49:13,640 --> 00:49:16,360
what could have caused
a surge of water at Tanis?

771
00:49:25,680 --> 00:49:29,600
Professor Stein Bondevik
is an expert in tsunamis.

772
00:49:35,200 --> 00:49:38,040
The fjords in Norway
are very special.

773
00:49:39,440 --> 00:49:43,360
We have tall mountains
surrounding bodies of water.

774
00:49:43,360 --> 00:49:46,800
So the water is usually very calm.

775
00:49:46,800 --> 00:49:51,480
In 2011, something very strange
happened.

776
00:49:51,480 --> 00:49:55,800
The water in the fjord
began to move violently.

777
00:49:55,800 --> 00:50:00,400
The height of the water increased
by one and a half metre,

778
00:50:00,400 --> 00:50:04,440
like a maelstrom
with the turbulent water.

779
00:50:04,440 --> 00:50:07,080
Someone said
that the fjord was boiling.

780
00:50:07,080 --> 00:50:08,680
THUNDER RUMBLES

781
00:50:08,680 --> 00:50:10,560
News started to roll in -

782
00:50:10,560 --> 00:50:14,800
there'd been an earthquake
5,000 miles away in Japan.

783
00:50:17,760 --> 00:50:20,640
A journalist from
the local newspaper called me,

784
00:50:20,640 --> 00:50:23,480
and he said that
people were observing waves

785
00:50:23,480 --> 00:50:24,840
here, in the fjords.

786
00:50:26,960 --> 00:50:29,440
I got a video clip of the waves.

787
00:50:29,440 --> 00:50:32,880
I saw immediately that they looked
like a tsunami wave.

788
00:50:32,880 --> 00:50:34,720
So later in the afternoon,

789
00:50:34,720 --> 00:50:37,920
you can see that the fjord is
perfectly calm.

790
00:50:39,520 --> 00:50:40,840
But at the beach here,

791
00:50:40,840 --> 00:50:44,000
you could see that the water
is sloshing back and forth,

792
00:50:44,000 --> 00:50:46,880
and no-one had ever seen
anything like it.

793
00:50:48,240 --> 00:50:51,400
And some people
got very upset and afraid.

794
00:50:54,720 --> 00:50:59,880
A magnitude nine earthquake had
devastated the northeast of Japan,

795
00:50:59,880 --> 00:51:01,880
around Fukushima.

796
00:51:04,800 --> 00:51:08,600
But how did that affect a fjord
so far away?

797
00:51:11,280 --> 00:51:14,160
So no-one in Norway
could feel the earthquake,

798
00:51:14,160 --> 00:51:17,760
but I could see that
the times matched

799
00:51:17,760 --> 00:51:20,400
the arrival of the waves here,
in the fjord.

800
00:51:24,280 --> 00:51:27,520
Eventually,
Stein and his team realised

801
00:51:27,520 --> 00:51:32,400
that this might have something
to do with seismic waves -

802
00:51:32,400 --> 00:51:35,400
shock waves that pass quickly
through the Earth

803
00:51:35,400 --> 00:51:36,960
during an earthquake.

804
00:51:38,480 --> 00:51:41,920
So it took only 12 minutes
before the first signal

805
00:51:41,920 --> 00:51:44,520
of the earthquake in Japan
reached all the way here,

806
00:51:44,520 --> 00:51:45,840
to western Norway.

807
00:51:48,400 --> 00:51:50,280
So it was the seismic waves

808
00:51:50,280 --> 00:51:53,080
that caused the normally calm
water in the fjord

809
00:51:53,080 --> 00:51:55,920
to slosh turbulently
back and forth.

810
00:51:57,800 --> 00:52:02,680
Just thinking of that,
scientifically, it's fantastic.

811
00:52:08,960 --> 00:52:12,600
Could something similar
have happened in Tanis?

812
00:52:12,600 --> 00:52:15,920
A large weather front's
coming through the northwest...

813
00:52:17,480 --> 00:52:19,320
Trying to find out

814
00:52:19,320 --> 00:52:22,600
is geophysicist professor
Mark Richards,

815
00:52:22,600 --> 00:52:26,040
who's been studying the site at
Tanis for several years.

816
00:52:27,240 --> 00:52:29,680
He's working with Robert
to discover

817
00:52:29,680 --> 00:52:32,360
what could have caused
a surge of water here.

818
00:52:39,640 --> 00:52:42,880
A tsunami can't get here
in less than minimum 12 hours.

819
00:52:44,760 --> 00:52:48,560
But seismic waves travelling
from the Yucatan impact site

820
00:52:48,560 --> 00:52:51,360
to North Dakota
can arrive here fairly quickly.

821
00:52:53,760 --> 00:52:57,680
In the Late Cretaceous,
the Western Interior Seaway

822
00:52:57,680 --> 00:53:01,760
that divided North America could
have been connected to Tanis

823
00:53:01,760 --> 00:53:03,560
through a system of rivers.

824
00:53:09,000 --> 00:53:11,320
If you have
a very large body of water,

825
00:53:11,320 --> 00:53:14,360
like the Western Interior Seaway,

826
00:53:14,360 --> 00:53:16,760
and you can shake it back and forth,

827
00:53:16,760 --> 00:53:19,880
you can generate
a large water wave

828
00:53:19,880 --> 00:53:22,440
coming up this river at Tanis.

829
00:53:27,000 --> 00:53:30,720
So seismic waves from the impact
could have caused

830
00:53:30,720 --> 00:53:33,600
surges of water
in the Tanis river system.

831
00:53:34,680 --> 00:53:37,880
The seismic waves
get here quickly enough,

832
00:53:37,880 --> 00:53:40,240
coming up the Tanis river,

833
00:53:40,240 --> 00:53:42,600
inundating this area,
arriving at the same time

834
00:53:42,600 --> 00:53:45,280
these spherules are
still falling out of the air.

835
00:53:48,080 --> 00:53:49,720
The mystery of the wave

836
00:53:49,720 --> 00:53:54,120
and the thick layer of crumbly rock
has been solved.

837
00:53:54,120 --> 00:53:56,640
Seismic waves travelling
through the Earth

838
00:53:56,640 --> 00:54:00,400
could have caused powerful surges of
water at Tanis...

839
00:54:03,120 --> 00:54:05,560
..possibly carrying mud
and marine creatures,

840
00:54:05,560 --> 00:54:09,600
like ammonites, from the Western
Interior Seaway...

841
00:54:12,480 --> 00:54:16,960
..dumping them on the Tanis sandbank
and burying everything

842
00:54:16,960 --> 00:54:19,880
at the same time as spherules fell.

843
00:54:28,280 --> 00:54:29,560
Over millions of years,

844
00:54:29,560 --> 00:54:33,760
the mud would turn into
the layer of crumbly rock.

845
00:54:35,480 --> 00:54:37,520
And that's the beauty of Tanis.

846
00:54:37,520 --> 00:54:40,720
What you're seeing is a deposit

847
00:54:40,720 --> 00:54:45,160
that is literally recording
the last, say,

848
00:54:45,160 --> 00:54:48,960
45 minutes to an hour and a half
of the Cretaceous.

849
00:54:59,160 --> 00:55:02,240
If the extinction
of the dinosaurs was a crime,

850
00:55:02,240 --> 00:55:06,560
the detective solving it
would have plenty of evidence.

851
00:55:06,560 --> 00:55:08,520
They would see
that the asteroid was

852
00:55:08,520 --> 00:55:11,120
in the right place
at the right time.

853
00:55:11,120 --> 00:55:13,680
They would see
that no dinosaurs survived

854
00:55:13,680 --> 00:55:15,120
after the hit.

855
00:55:16,160 --> 00:55:18,440
They would have a piece
of the murder weapon -

856
00:55:18,440 --> 00:55:20,520
a fragment of the asteroid.

857
00:55:20,520 --> 00:55:24,400
But they would be missing
one very important thing -

858
00:55:24,400 --> 00:55:25,960
a body.

859
00:55:30,680 --> 00:55:34,320
No-one has ever found
the fossil of a dinosaur

860
00:55:34,320 --> 00:55:38,640
that was killed by the effects
of the asteroid impact.

861
00:55:38,640 --> 00:55:42,200
But Robert did find
part of a triceratops

862
00:55:42,200 --> 00:55:44,520
in the crumbly layer at Tanis.

863
00:55:44,520 --> 00:55:46,920
So could that be the remains

864
00:55:46,920 --> 00:55:49,640
of a dinosaur
that died on that day?

865
00:55:49,640 --> 00:55:51,200
I'm still dubious about the horn.

866
00:55:51,200 --> 00:55:53,200
I kind of want to keep
the horn in the jacket.

867
00:55:53,200 --> 00:55:54,440
I think if you took it off,

868
00:55:54,440 --> 00:55:56,000
at least take this section off,

869
00:55:56,000 --> 00:55:57,640
to see what's going on under here.

870
00:55:57,640 --> 00:55:58,920
Yeah?

871
00:55:58,920 --> 00:56:03,720
To find out, the team needs to
establish cause of death,

872
00:56:03,720 --> 00:56:07,000
which can be difficult when you only
have a piece of skin

873
00:56:07,000 --> 00:56:09,240
and a horn to go on.

874
00:56:11,320 --> 00:56:15,520
This is the horn
after they've cleaned it up.

875
00:56:15,520 --> 00:56:19,800
The team is particularly
interested in these lines here.

876
00:56:19,800 --> 00:56:22,440
And they found that the fractures go

877
00:56:22,440 --> 00:56:25,120
right through the horn.

878
00:56:25,120 --> 00:56:28,360
So rather than dying
as a result of the impact,

879
00:56:28,360 --> 00:56:31,760
they wondered whether
it had been killed in a fight.

880
00:56:37,480 --> 00:56:39,920
But when they looked at
the fractures in more detail,

881
00:56:39,920 --> 00:56:42,760
they found signs
of new bone growth here.

882
00:56:43,800 --> 00:56:47,240
An indication that
the bone had started to heal.

883
00:56:47,240 --> 00:56:49,800
So it looked as though
the triceratops survived

884
00:56:49,800 --> 00:56:52,160
the event that broke its horn.

885
00:56:56,920 --> 00:56:59,600
Could this triceratops
have survived

886
00:56:59,600 --> 00:57:02,320
until the day of the impact?

887
00:57:02,320 --> 00:57:05,920
The team found evidence,
including sagging in the skin,

888
00:57:05,920 --> 00:57:09,800
which suggested that
there was decay underneath.

889
00:57:09,800 --> 00:57:12,160
That means its body had started
to rot

890
00:57:12,160 --> 00:57:16,080
before it was entombed
and preserved by the surge.

891
00:57:16,080 --> 00:57:21,040
So it seems that this dinosaur
didn't die as a result

892
00:57:21,040 --> 00:57:23,000
of the asteroid impact.

893
00:57:24,720 --> 00:57:27,880
Perhaps, in the months
before the impact,

894
00:57:27,880 --> 00:57:29,920
the broken horn put the triceratops

895
00:57:29,920 --> 00:57:32,280
at a disadvantage over its rivals.

896
00:57:34,160 --> 00:57:35,760
GRUNTS

897
00:57:48,160 --> 00:57:50,800
And that might have led
to starvation.

898
00:58:02,160 --> 00:58:04,600
THUNDER CRACKS

899
00:58:09,120 --> 00:58:10,720
WIND WHOOSHES

900
00:58:12,960 --> 00:58:16,240
Robert has still not found
direct evidence

901
00:58:16,240 --> 00:58:19,080
of a dinosaur that was killed
by the asteroid.

902
00:58:20,360 --> 00:58:22,520
We've got all these bones
in the ground right now.

903
00:58:22,520 --> 00:58:25,120
But the one thing
that we would just dream

904
00:58:25,120 --> 00:58:27,160
of finding is that one dinosaur

905
00:58:27,160 --> 00:58:29,800
that died on the day of the impact.

906
00:58:33,720 --> 00:58:36,840
And the weather
isn't helping his search.

907
00:58:43,200 --> 00:58:45,040
GROANS

908
00:58:54,680 --> 00:58:56,920
That therapod print is toasted.

909
00:58:56,920 --> 00:58:59,080
Yeah, it was in a low corner.

910
00:58:59,080 --> 00:59:02,120
Look, it's full mud.
It's full of mud and water.

911
00:59:02,120 --> 00:59:04,360
The problem is it's wet, look.

912
00:59:04,360 --> 00:59:07,000
See... If we're not careful,
we're going to lose the print.

913
00:59:08,440 --> 00:59:10,440
And that's the biggest
theropod print we've got.

914
00:59:11,600 --> 00:59:14,080
I see some areas that could use
glue right now, too.

915
00:59:16,640 --> 00:59:19,920
The team is racing
to excavate the footprints,

916
00:59:19,920 --> 00:59:22,440
along with dozens of fish fossils

917
00:59:22,440 --> 00:59:27,120
tangled together in a logjam,
before storms wash them away.

918
00:59:27,120 --> 00:59:28,480
THUNDER RUMBLES

919
00:59:28,480 --> 00:59:30,120
We're up against the clock here.

920
00:59:30,120 --> 00:59:31,880
This stuff that could be
exposed right now

921
00:59:31,880 --> 00:59:33,760
is going to get ruined by the rain.

922
00:59:36,360 --> 00:59:38,880
But then,
Robert comes across something

923
00:59:38,880 --> 00:59:40,600
that looks very unusual.

924
00:59:40,600 --> 00:59:42,320
That's going there.

925
00:59:43,960 --> 00:59:45,680
What is going on right there?

926
00:59:45,680 --> 00:59:47,960
Are we sure
this isn't crocodilian?

927
00:59:47,960 --> 00:59:50,080
That's not crocodilian. No.

928
00:59:50,080 --> 00:59:52,600
Right, let me try
this piece right here.

929
00:59:52,600 --> 00:59:55,120
I'll go in from the top
and then twist up,

930
00:59:55,120 --> 00:59:56,840
and it separates right on that line.

931
00:59:56,840 --> 00:59:59,440
Oh, that's skin right there.

932
00:59:59,440 --> 01:00:01,840
That's actually scaly skin.
Oh, my God.

933
01:00:01,840 --> 01:00:03,680
No, no, no, no, no.
Look, look, look.

934
01:00:03,680 --> 01:00:05,680
Look at that pattern
right there.

935
01:00:05,680 --> 01:00:08,440
Have you ever seen elongated
scales like that before, Dave?

936
01:00:08,440 --> 01:00:10,600
That's insane.
Scuttelates - in birds.

937
01:00:10,600 --> 01:00:12,400
Just careful.

938
01:00:12,400 --> 01:00:14,800
Oh, my God.
It's changing again.

939
01:00:14,800 --> 01:00:16,240
It's changing again.
Oh, my God.

940
01:00:17,520 --> 01:00:21,120
We're seeing it for the first time
in 66 million years.

941
01:00:21,120 --> 01:00:22,960
I think we've got ourselves
a dinosaur.

942
01:00:27,640 --> 01:00:29,240
A dinosaur fossil!

943
01:00:29,240 --> 01:00:32,440
And, unlike the triceratops,

944
01:00:32,440 --> 01:00:36,720
this is located in the logjam,
the mass death layer,

945
01:00:36,720 --> 01:00:40,960
surrounded by the fish
with spherules in their gills.

946
01:00:43,880 --> 01:00:46,720
This is the most incredible thing
that we could possibly imagine here.

947
01:00:46,720 --> 01:00:48,400
The best-case scenario.

948
01:00:48,400 --> 01:00:51,480
We're excavating
this mass death layer of fish

949
01:00:51,480 --> 01:00:54,280
from the surge
sent up by the impact,

950
01:00:54,280 --> 01:00:56,520
and we've got dinosaur remains.

951
01:00:56,520 --> 01:00:59,720
The one thing that we would always
want to find at this site,

952
01:00:59,720 --> 01:01:02,160
and here we've got it.

953
01:01:02,160 --> 01:01:05,840
This is unreal. I-I-I cannot
process this in my brain.

954
01:01:05,840 --> 01:01:08,440
No, I am absolutely blown away
by this.

955
01:01:08,440 --> 01:01:10,760
Just my heart is literally
pumping out of my chest

956
01:01:10,760 --> 01:01:12,320
wondering what is behind there,

957
01:01:12,320 --> 01:01:14,320
just a couple of centimetres
back in the outcrop.

958
01:01:14,320 --> 01:01:16,000
What is waiting for us back there?

959
01:01:17,800 --> 01:01:19,600
Get it out...

960
01:01:19,600 --> 01:01:21,240
This is...

961
01:01:21,240 --> 01:01:22,640
The team keeps digging.

962
01:01:22,640 --> 01:01:24,520
The scales get big again
over on this side.

963
01:01:24,520 --> 01:01:26,080
So this could be a ribcage,

964
01:01:26,080 --> 01:01:28,120
it could be laying against ribs
that are curved.

965
01:01:28,120 --> 01:01:29,800
There's something here.

966
01:01:29,800 --> 01:01:31,320
That's hard. A bit more bone.

967
01:01:31,320 --> 01:01:33,280
That's bone right next
to the skin.

968
01:01:33,280 --> 01:01:35,320
Yeah, that's an articular
surface right there,

969
01:01:35,320 --> 01:01:37,680
so this is either a hip
or a shoulder element.

970
01:01:41,760 --> 01:01:44,800
After hours
of painstaking work...

971
01:01:48,080 --> 01:01:50,480
And we can go
from the thigh of the animal.

972
01:01:50,480 --> 01:01:52,160
There's the knee.

973
01:01:52,160 --> 01:01:54,800
And then you've got
the little calf muscles

974
01:01:54,800 --> 01:01:56,760
of the dinosaur,
they're bulging out,

975
01:01:56,760 --> 01:01:59,680
and you go down
to the anklebones,

976
01:01:59,680 --> 01:02:02,520
and these are the toes
of the feet.

977
01:02:02,520 --> 01:02:04,480
We have got nails
at the tips of the toes.

978
01:02:04,480 --> 01:02:06,320
It's a beautifully preserved leg,

979
01:02:06,320 --> 01:02:08,200
all articulated, covered with skin.

980
01:02:09,280 --> 01:02:13,160
The complete leg of a dinosaur.

981
01:02:13,160 --> 01:02:15,240
In my wildest dreams,

982
01:02:15,240 --> 01:02:17,480
I never expected to find
a dinosaur leg in this deposit.

983
01:02:17,480 --> 01:02:20,760
Yeah. I mean, and then
it's got skin and tissue.

984
01:02:20,760 --> 01:02:23,240
It does look
just like a drumstick.

985
01:02:23,240 --> 01:02:25,120
It looks like
a Thanksgiving turkey,

986
01:02:25,120 --> 01:02:27,000
just laid out in the ground.

987
01:02:27,000 --> 01:02:30,800
And this weird scale pattern
on the thigh of the animal,

988
01:02:30,800 --> 01:02:33,560
which we've never seen
in a dinosaur before.

989
01:02:33,560 --> 01:02:36,440
Well, thescelosaurs don't have
any form of defence,

990
01:02:36,440 --> 01:02:38,440
so they have to have camouflage
or something.

991
01:02:38,440 --> 01:02:40,000
That's a good point.

992
01:02:40,000 --> 01:02:43,520
So this could have been some
sort of a camouflage marking. Yeah.

993
01:02:43,520 --> 01:02:47,360
Robert thinks he has found
the body in question -

994
01:02:47,360 --> 01:02:51,520
a dinosaur that might itself
have witnessed

995
01:02:51,520 --> 01:02:53,360
the cataclysmic impact.

996
01:02:56,480 --> 01:02:58,960
Dinosaur fossils are not known

997
01:02:58,960 --> 01:03:01,800
from the last years
of the Cretaceous.

998
01:03:01,800 --> 01:03:04,320
And it was unclear whether
they were already extinct

999
01:03:04,320 --> 01:03:06,240
or in decline
or what was going on.

1000
01:03:06,240 --> 01:03:08,080
So they were just sort of absent.

1001
01:03:11,560 --> 01:03:13,080
And this answers that question.

1002
01:03:13,080 --> 01:03:15,720
Were dinosaurs still there then?

1003
01:03:15,720 --> 01:03:19,800
Well, yes - this one likely
died in that surge.

1004
01:03:23,720 --> 01:03:28,200
For such big claims,
Robert needs verification.

1005
01:03:30,640 --> 01:03:32,760
He's brought the dinosaur leg
to London

1006
01:03:32,760 --> 01:03:35,520
to get a second opinion...

1007
01:03:35,520 --> 01:03:38,160
And then here are the pads
of the toes.

1008
01:03:38,160 --> 01:03:40,720
We see all those
beautiful scales lined up.

1009
01:03:40,720 --> 01:03:43,040
..from Professor Paul Barrett,

1010
01:03:43,040 --> 01:03:46,280
an expert
in ornithischian dinosaurs

1011
01:03:46,280 --> 01:03:49,160
from the Natural History Museum.

1012
01:03:49,160 --> 01:03:51,440
So what do you think
this might be?

1013
01:03:51,440 --> 01:03:54,440
When we look at the leg,
it has claws,

1014
01:03:54,440 --> 01:03:58,840
like the claws we see in small,
agile, bipedal, running dinosaurs

1015
01:03:58,840 --> 01:04:01,320
that are plant-eaters.

1016
01:04:01,320 --> 01:04:03,360
We can rule out things
like triceratops,

1017
01:04:03,360 --> 01:04:05,800
partly just because
it's not big and stocky.

1018
01:04:05,800 --> 01:04:09,000
And the proportions of those legs
are also different

1019
01:04:09,000 --> 01:04:11,240
from some of
the other plant-eaters we see,

1020
01:04:11,240 --> 01:04:13,120
in that they have
this rather long ankle

1021
01:04:13,120 --> 01:04:16,520
and shin, compared with its
thighbone.

1022
01:04:16,520 --> 01:04:18,480
So as we narrow
those possibilities down,

1023
01:04:18,480 --> 01:04:20,000
what we're left with, probably,

1024
01:04:20,000 --> 01:04:21,800
is an animal called a thescelosaur.

1025
01:04:21,800 --> 01:04:23,240
SQUEAKS

1026
01:04:30,760 --> 01:04:33,440
Thescelosaurs lived next to rivers

1027
01:04:33,440 --> 01:04:36,440
where there was plenty
of rich vegetation to feed on.

1028
01:04:38,960 --> 01:04:41,240
They had leaf-shaped teeth,

1029
01:04:41,240 --> 01:04:43,400
common amongst herbivores,

1030
01:04:43,400 --> 01:04:45,400
and claws
on their short front limbs -

1031
01:04:45,400 --> 01:04:47,480
excellent for digging.

1032
01:04:57,880 --> 01:04:59,160
SQUEAKS

1033
01:05:01,280 --> 01:05:03,160
CRUNCHING

1034
01:05:05,000 --> 01:05:08,160
But how did
Robert's thescelosaur die?

1035
01:05:09,800 --> 01:05:12,640
Could it have been killed
by another dinosaur?

1036
01:05:12,640 --> 01:05:14,440
It's a possibility.

1037
01:05:14,440 --> 01:05:16,560
This is a relatively agile animal.

1038
01:05:16,560 --> 01:05:18,720
And that turn of speed
would've been

1039
01:05:18,720 --> 01:05:22,640
its primary defence against the
large predators living alongside it.

1040
01:05:28,040 --> 01:05:31,960
So, to escape a hungry T-rex,

1041
01:05:31,960 --> 01:05:34,320
a thescelosaur's first line
of defence...

1042
01:05:34,320 --> 01:05:35,600
BARKS

1043
01:05:35,600 --> 01:05:37,160
..would've been to run.

1044
01:05:39,880 --> 01:05:44,120
But it may have had
another defensive trick.

1045
01:05:47,840 --> 01:05:49,720
ROARS

1046
01:05:52,600 --> 01:05:54,200
Living next to rivers,

1047
01:05:54,200 --> 01:05:57,920
it's possible thescelosaurs
were able to swim.

1048
01:06:11,360 --> 01:06:13,760
It doesn't seem to me
like there is any evidence

1049
01:06:13,760 --> 01:06:15,440
that this animal was predated -

1050
01:06:15,440 --> 01:06:18,240
none of the obvious tooth marks

1051
01:06:18,240 --> 01:06:20,240
or leftover bits
of carnivore teeth

1052
01:06:20,240 --> 01:06:22,360
to suggest it's been eaten.

1053
01:06:22,360 --> 01:06:24,960
So how do you think it died?

1054
01:06:24,960 --> 01:06:27,920
It didn't have any particularly
nasty diseases when it died,

1055
01:06:27,920 --> 01:06:30,640
as we can see
that the bones look OK.

1056
01:06:30,640 --> 01:06:32,640
So this is an animal
that was probably living

1057
01:06:32,640 --> 01:06:35,840
and healthy at the time
that this happened to it.

1058
01:06:35,840 --> 01:06:40,880
Could this be a victim
of the meteor strike?

1059
01:06:40,880 --> 01:06:42,280
I think it's entirely possible.

1060
01:06:42,280 --> 01:06:44,520
This is actually a shoulder bone,

1061
01:06:44,520 --> 01:06:46,440
and this bone in a living animal

1062
01:06:46,440 --> 01:06:48,480
would actually be way over here.

1063
01:06:48,480 --> 01:06:50,360
And similarly, this little bone here

1064
01:06:50,360 --> 01:06:53,160
would've been from about
maybe a third of the way

1065
01:06:53,160 --> 01:06:55,040
along the tail, maybe halfway down.

1066
01:06:55,040 --> 01:06:59,680
So somehow these two bones
have been telescoped together.

1067
01:06:59,680 --> 01:07:02,120
So maybe this animal's
been tumbled around.

1068
01:07:02,120 --> 01:07:04,720
We've ruled out
a lot of other possible

1069
01:07:04,720 --> 01:07:06,760
causes of death for this animal.

1070
01:07:06,760 --> 01:07:09,600
So it could well be
that this is an animal

1071
01:07:09,600 --> 01:07:11,400
that was there, being tumbled around

1072
01:07:11,400 --> 01:07:13,040
in its death throes, in that river,

1073
01:07:13,040 --> 01:07:14,840
as a result of the asteroid impact.

1074
01:07:16,080 --> 01:07:18,760
Well, it is exactly analogous

1075
01:07:18,760 --> 01:07:21,920
to those human bodies
found in Pompeii.

1076
01:07:21,920 --> 01:07:25,040
It's very similar in terms of
you get that quick entombment.

1077
01:07:25,040 --> 01:07:27,120
Yes. And it's almost as evocative.

1078
01:07:27,120 --> 01:07:29,560
That's absolutely true.

1079
01:07:29,560 --> 01:07:31,720
You've got literally
the blink of an eye

1080
01:07:31,720 --> 01:07:33,680
at the end of the Cretaceous,

1081
01:07:33,680 --> 01:07:35,840
snapped up into history,
and there it is,

1082
01:07:35,840 --> 01:07:39,240
ready to be dug up. Wow.
LAUGHS

1083
01:07:50,640 --> 01:07:52,840
After years of investigation,

1084
01:07:52,840 --> 01:07:55,240
Robert has found out a great deal

1085
01:07:55,240 --> 01:07:57,360
about the creatures
which lived at Tanis,

1086
01:07:57,360 --> 01:08:01,920
and he knows that many of them were
alive on that fateful day

1087
01:08:01,920 --> 01:08:04,920
when the asteroid
devastated our planet.

1088
01:08:06,120 --> 01:08:08,320
But how exactly did they die?

1089
01:08:09,360 --> 01:08:13,160
Robert's finds now allow us
to tell the story of that day

1090
01:08:13,160 --> 01:08:15,640
and finally answer that question.

1091
01:08:19,960 --> 01:08:22,960
One of the most important days
in Earth's history

1092
01:08:22,960 --> 01:08:26,800
probably started much like any
other late spring morning.

1093
01:08:31,960 --> 01:08:36,880
We know the season because Robert
found fossils of young fish that

1094
01:08:36,880 --> 01:08:39,640
died at the size they reach
at that time of year.

1095
01:08:39,640 --> 01:08:42,080
This agrees
with evidence already found

1096
01:08:42,080 --> 01:08:44,200
by other scientists.

1097
01:08:46,720 --> 01:08:50,160
Perhaps this day, that would end
with so much death,

1098
01:08:50,160 --> 01:08:52,800
began with something different.

1099
01:08:54,640 --> 01:08:56,240
A new life.

1100
01:08:58,280 --> 01:09:00,720
SQUEAKING

1101
01:09:06,520 --> 01:09:08,360
SQUAWKS

1102
01:09:19,840 --> 01:09:23,080
No-one can be certain
of the exact timings of the day

1103
01:09:23,080 --> 01:09:26,240
when the asteroid collided
with our planet.

1104
01:09:26,240 --> 01:09:30,600
But it's estimated that within
just 40 minutes of the impact,

1105
01:09:30,600 --> 01:09:33,120
the consequences
for the creatures of Tanis

1106
01:09:33,120 --> 01:09:34,640
would have been profound.

1107
01:09:38,680 --> 01:09:40,200
Based on Robert's finds

1108
01:09:40,200 --> 01:09:43,000
and the latest evidence
from other scientists,

1109
01:09:43,000 --> 01:09:46,400
this is how the catastrophe
might have unfolded.

1110
01:09:49,200 --> 01:09:52,600
The asteroid is around
seven miles across,

1111
01:09:52,600 --> 01:09:54,520
bigger than Mount Everest...

1112
01:09:56,160 --> 01:10:00,640
..and travelling at close
to 45,000mph.

1113
01:10:04,280 --> 01:10:06,640
The impact causes an explosion

1114
01:10:06,640 --> 01:10:10,680
bigger than a billion
Hiroshima atomic bombs.

1115
01:10:18,080 --> 01:10:20,880
At Tanis,
almost 2,000 miles away...

1116
01:10:22,440 --> 01:10:24,640
..it's completely silent.

1117
01:10:28,680 --> 01:10:30,520
But at the impact site...

1118
01:10:32,800 --> 01:10:34,760
..the asteroid vaporises.

1119
01:10:36,680 --> 01:10:39,160
More than three trillion
tonnes of rock

1120
01:10:39,160 --> 01:10:41,080
are ejected into space

1121
01:10:41,080 --> 01:10:43,720
in a blast
of super-heated violence.

1122
01:10:48,600 --> 01:10:51,440
Winds higher than 600mph.

1123
01:10:53,000 --> 01:10:57,520
A colossal earthquake, followed
by a ring of massive tsunamis.

1124
01:11:03,360 --> 01:11:05,680
RUMBLING

1125
01:11:05,680 --> 01:11:08,120
ANIMAL CALLS

1126
01:11:08,120 --> 01:11:10,120
All the while,
the creatures at Tanis

1127
01:11:10,120 --> 01:11:12,120
go about their business...

1128
01:11:12,120 --> 01:11:14,120
CACOPHONY OF
ANIMAL NOISES

1129
01:11:16,000 --> 01:11:18,400
..just like any other day.

1130
01:11:18,400 --> 01:11:21,480
COOING

1131
01:11:21,480 --> 01:11:23,360
CLICKING

1132
01:11:23,360 --> 01:11:24,720
WARBLES

1133
01:11:29,920 --> 01:11:32,400
SNEEZES

1134
01:11:32,400 --> 01:11:33,840
THUNDER RUMBLES

1135
01:11:35,360 --> 01:11:36,560
SQUAWKS

1136
01:11:36,560 --> 01:11:39,160
The evidence suggests
that baby pterosaurs

1137
01:11:39,160 --> 01:11:42,640
emerge from the egg
ready to fend for themselves.

1138
01:11:45,280 --> 01:11:47,200
And that includes...

1139
01:11:49,720 --> 01:11:51,160
..flying?

1140
01:11:52,640 --> 01:11:54,200
Well, almost.

1141
01:12:02,960 --> 01:12:07,120
Elsewhere, as the devastation
spreads out across North America

1142
01:12:07,120 --> 01:12:08,440
towards Tanis...

1143
01:12:10,120 --> 01:12:13,160
..dinosaurs and creatures
of all shapes and sizes

1144
01:12:13,160 --> 01:12:15,680
are obliterated by the blast.

1145
01:12:27,160 --> 01:12:30,560
At Tanis, for a few more
precious minutes,

1146
01:12:30,560 --> 01:12:32,320
life carries on as usual.

1147
01:12:34,400 --> 01:12:36,640
But the clock is ticking.

1148
01:12:43,760 --> 01:12:44,960
GRUNTING

1149
01:12:46,040 --> 01:12:48,840
DEEP BELLOWING

1150
01:12:50,160 --> 01:12:53,920
The blast from the impact
never reaches Tanis,

1151
01:12:53,920 --> 01:12:56,400
but seismic shock waves do.

1152
01:13:01,120 --> 01:13:03,000
RUMBLING

1153
01:13:04,480 --> 01:13:06,600
CHIRPS

1154
01:13:09,480 --> 01:13:11,520
They are far more powerful

1155
01:13:11,520 --> 01:13:13,880
than any earthquake
ever recorded.

1156
01:13:16,880 --> 01:13:20,960
DEEP BELLOWING

1157
01:13:20,960 --> 01:13:22,560
SHRIEKING

1158
01:13:22,560 --> 01:13:25,960
The thescelosaur might head
for a place of safety...

1159
01:13:30,840 --> 01:13:33,160
..but seismic waves
are now slowly shaking

1160
01:13:33,160 --> 01:13:37,480
the whole region, causing water
to slosh and churn.

1161
01:13:42,880 --> 01:13:45,960
At Tanis,
strange currents in the river

1162
01:13:45,960 --> 01:13:48,560
give a hint
of what is still to come.

1163
01:13:54,440 --> 01:13:56,040
THUNDER CRACKS

1164
01:13:57,520 --> 01:14:00,360
Next, it begins to rain.

1165
01:14:00,360 --> 01:14:02,600
PATTERING

1166
01:14:02,600 --> 01:14:05,760
Ejecta spherules
are falling back to Earth.

1167
01:14:13,760 --> 01:14:16,600
As the spherules
begin their fall...

1168
01:14:17,840 --> 01:14:21,000
..friction heats them
until they're red hot.

1169
01:14:27,600 --> 01:14:30,840
Then the heat transfers
to the air.

1170
01:14:32,360 --> 01:14:34,640
Temperatures rise with every second.

1171
01:14:43,040 --> 01:14:46,320
the creatures of Tanis

1172
01:14:46,320 --> 01:14:48,000
are fighting for their lives.

1173
01:14:49,720 --> 01:14:51,520
ROARS

1174
01:14:53,120 --> 01:14:55,680
And then, as seismic waves

1175
01:14:55,680 --> 01:14:58,440
continue to slowly rock
the whole region...

1176
01:15:01,920 --> 01:15:05,320
..a violent surge wave
ten metres high

1177
01:15:05,320 --> 01:15:07,560
rushes up the Tanis river.

1178
01:15:26,480 --> 01:15:29,040
Surviving the turbulence
of the surge

1179
01:15:29,040 --> 01:15:32,160
is a challenge
even for the best swimmers.

1180
01:15:44,120 --> 01:15:48,000
Then, the powerful rocking
of the river system

1181
01:15:48,000 --> 01:15:51,600
slowly begins to draw the water
back the way it came.

1182
01:16:01,200 --> 01:16:02,920
Swimming may have saved

1183
01:16:02,920 --> 01:16:05,680
the thescelosaur in the past,

1184
01:16:05,680 --> 01:16:07,400
but not this time.

1185
01:16:13,000 --> 01:16:15,640
A large, robust animal
like a T-rex

1186
01:16:15,640 --> 01:16:17,680
might have survived the surge.

1187
01:16:23,160 --> 01:16:25,600
As might a hard-shelled reptile.

1188
01:16:27,200 --> 01:16:30,120
But there is much more to come.

1189
01:16:30,120 --> 01:16:35,120
As billions of tonnes of superheated
spherules continue to fall,

1190
01:16:35,120 --> 01:16:37,520
the atmosphere gets even hotter...

1191
01:16:40,040 --> 01:16:44,040
..igniting dead leaves
and sparking wildfires.

1192
01:16:50,320 --> 01:16:51,960
Earthquakes,

1193
01:16:51,960 --> 01:16:53,960
fire...

1194
01:16:56,040 --> 01:16:57,560
..devastation.

1195
01:17:00,120 --> 01:17:02,120
Little would survive for long,

1196
01:17:02,120 --> 01:17:03,920
on land..

1197
01:17:03,920 --> 01:17:06,200
ROARS

1198
01:17:08,520 --> 01:17:10,320
..or in the air.

1199
01:17:13,280 --> 01:17:15,680
SHRIEKS

1200
01:17:16,760 --> 01:17:18,600
GRUNTS

1201
01:17:30,800 --> 01:17:34,560
As the air reaches the temperature
of an industrial oven...

1202
01:17:37,600 --> 01:17:39,600
..those that live
deep underground

1203
01:17:39,600 --> 01:17:41,160
may have a better chance.

1204
01:17:49,200 --> 01:17:52,640
As the slow sloshing of
the river system continues...

1205
01:17:55,560 --> 01:17:57,920
..another powerful surge hits.

1206
01:18:18,760 --> 01:18:21,360
There is no escaping
the destruction.

1207
01:18:24,600 --> 01:18:27,600
For many of the creatures
of Tanis,

1208
01:18:27,600 --> 01:18:30,000
their stories end underwater.

1209
01:18:45,640 --> 01:18:49,800
In less than two hours,
the world has changed forever.

1210
01:18:56,520 --> 01:18:59,280
The mud the surge waves leave behind

1211
01:18:59,280 --> 01:19:03,400
will gradually turn into the thick
layer of crumbly rock

1212
01:19:03,400 --> 01:19:06,160
entombing the creatures
which died here...

1213
01:19:09,120 --> 01:19:12,160
..until 66 million years later,

1214
01:19:12,160 --> 01:19:14,520
when they're finally unearthed.

1215
01:19:23,960 --> 01:19:28,160
Robert's finds have helped us
understand in remarkable detail

1216
01:19:28,160 --> 01:19:29,960
what happened at Tanis

1217
01:19:29,960 --> 01:19:33,480
in the minutes
after the asteroid impact.

1218
01:19:33,480 --> 01:19:35,480
But what about
the rest of the world?

1219
01:19:38,760 --> 01:19:41,600
The impact triggered catastrophic
events

1220
01:19:41,600 --> 01:19:44,440
such as earthquakes all over
the planet.

1221
01:19:46,080 --> 01:19:48,480
And as spherules
continued to fall...

1222
01:19:51,640 --> 01:19:54,800
..wildfires may have sprung up
around the globe.

1223
01:19:57,640 --> 01:20:00,920
As that horrific day
drew to a close,

1224
01:20:00,920 --> 01:20:04,760
many of the world's dinosaurs
were already dead.

1225
01:20:10,240 --> 01:20:14,720
Research shows that the angle
at which the asteroid hit

1226
01:20:14,720 --> 01:20:17,720
and the sulphur-rich rocks
at the impact site

1227
01:20:17,720 --> 01:20:19,960
amplified the devastation.

1228
01:20:19,960 --> 01:20:22,040
Billions of tonnes of sulphur

1229
01:20:22,040 --> 01:20:24,240
were ejected into the atmosphere,

1230
01:20:24,240 --> 01:20:26,120
blocking the sunlight.

1231
01:20:28,320 --> 01:20:33,120
Without light, most plants died,
and food became scarce.

1232
01:20:34,880 --> 01:20:37,680
As the weeks and months passed,

1233
01:20:37,680 --> 01:20:40,880
any dinosaur left alive
would've died of hunger.

1234
01:20:43,760 --> 01:20:46,640
In the oceans, it was the same.

1235
01:20:46,640 --> 01:20:49,880
Nearly all of the world's
plankton disappeared,

1236
01:20:49,880 --> 01:20:53,880
leading to the starvation
of most marine creatures.

1237
01:20:55,560 --> 01:20:58,960
It's thought that the nuclear
winter that followed

1238
01:20:58,960 --> 01:21:01,760
caused a global temperature drop

1239
01:21:01,760 --> 01:21:04,680
of at least
25 degrees centigrade.

1240
01:21:04,680 --> 01:21:08,720
The fossil record tells us that this
huge change in climate

1241
01:21:08,720 --> 01:21:12,400
marked the disappearance of three
quarters of all species,

1242
01:21:12,400 --> 01:21:14,280
including the dinosaurs.

1243
01:21:16,880 --> 01:21:21,480
The planet was in semi-darkness
for around a decade,

1244
01:21:21,480 --> 01:21:24,600
as dust and soot
slowly fell to Earth.

1245
01:21:26,400 --> 01:21:28,680
But then came something wonderful.

1246
01:21:30,640 --> 01:21:32,320
A new beginning.

1247
01:21:36,800 --> 01:21:39,400
Once the dust cleared
from the atmosphere

1248
01:21:39,400 --> 01:21:41,160
and the sunlight returned...

1249
01:21:42,640 --> 01:21:46,320
..plant life was gradually restored,

1250
01:21:46,320 --> 01:21:48,360
led by ferns,

1251
01:21:48,360 --> 01:21:52,440
the spores of which had lain
dormant deep underground,

1252
01:21:52,440 --> 01:21:56,480
and the world began
to turn green once more.

1253
01:21:58,680 --> 01:22:00,720
But what about the animals?

1254
01:22:03,480 --> 01:22:06,880
Back at Tanis,
Robert has unearthed something

1255
01:22:06,880 --> 01:22:09,600
that could have helped save
some of the creatures

1256
01:22:09,600 --> 01:22:12,320
from the devastating fires.

1257
01:22:12,320 --> 01:22:13,880
We saw a little thing
poking out,

1258
01:22:13,880 --> 01:22:15,840
so we kind of followed it back.

1259
01:22:15,840 --> 01:22:17,960
And I'm so glad that we did,

1260
01:22:17,960 --> 01:22:20,200
because what we have here
is a fossil burrow

1261
01:22:20,200 --> 01:22:23,000
from an animal 66 million years ago.

1262
01:22:24,640 --> 01:22:27,080
The only animals that
would've been around back then

1263
01:22:27,080 --> 01:22:29,400
that would likely build
a burrow like this

1264
01:22:29,400 --> 01:22:32,200
would be the small mammals,
roughly ferret-sized,

1265
01:22:32,200 --> 01:22:34,840
and also some reptiles.

1266
01:22:34,840 --> 01:22:38,960
If it is from a mammal,
this is sort of a window

1267
01:22:38,960 --> 01:22:41,840
into the lifestyle of some of
our oldest ancestors out here.

1268
01:22:43,000 --> 01:22:45,000
This guy would've burrowed
sideways,

1269
01:22:45,000 --> 01:22:46,440
right into the river bank.

1270
01:22:47,760 --> 01:22:49,800
We actually have
some scratch marks on there

1271
01:22:49,800 --> 01:22:52,040
from the interior
when they were digging it,

1272
01:22:52,040 --> 01:22:54,840
going back,
and he would've lived back here

1273
01:22:54,840 --> 01:22:56,720
and sought shelter
from the dinosaurs

1274
01:22:56,720 --> 01:22:58,920
cos they just did not
want to get eaten.

1275
01:23:05,360 --> 01:23:07,600
Burrows are part of the reason

1276
01:23:07,600 --> 01:23:10,640
that mammals survived
the great extinction.

1277
01:23:12,240 --> 01:23:14,160
During the nuclear winter,

1278
01:23:14,160 --> 01:23:16,440
a burrow would've provided warmth,

1279
01:23:16,440 --> 01:23:19,560
protection,
and a place to store food.

1280
01:23:26,880 --> 01:23:30,240
Mammals that survived
were resourceful omnivores,

1281
01:23:30,240 --> 01:23:33,960
and insects would've been
a plentiful source of food.

1282
01:23:39,680 --> 01:23:43,360
And they had another advantage -
their size.

1283
01:23:45,760 --> 01:23:49,640
If conditions are right,
many animal species get larger

1284
01:23:49,640 --> 01:23:52,480
as they evolve
over millions of years.

1285
01:23:52,480 --> 01:23:55,880
Take T-rex as an example.

1286
01:23:55,880 --> 01:23:59,280
This is a cast of the lower jaw

1287
01:23:59,280 --> 01:24:02,040
of a predecessor, called
gorgosaurus,

1288
01:24:02,040 --> 01:24:04,680
which lived
72 million years ago.

1289
01:24:04,680 --> 01:24:10,640
Whereas this is the cast
of the lower jaw of a T-rex,

1290
01:24:10,640 --> 01:24:13,200
which lived
five million years later.

1291
01:24:13,200 --> 01:24:17,120
Look at the difference in size.

1292
01:24:17,120 --> 01:24:18,520
But the bigger the creature,

1293
01:24:18,520 --> 01:24:21,120
the more energy they need
to stay alive.

1294
01:24:21,120 --> 01:24:24,840
So when catastrophe strikes
and food is scarce,

1295
01:24:24,840 --> 01:24:27,320
the largest tend to die out,

1296
01:24:27,320 --> 01:24:30,200
whilst the smallest
often survive.

1297
01:24:33,280 --> 01:24:35,280
That's one of the reasons

1298
01:24:35,280 --> 01:24:37,680
why many of the smaller mammals

1299
01:24:37,680 --> 01:24:40,440
lived through the great darkness.

1300
01:24:40,440 --> 01:24:42,520
And they weren't alone.

1301
01:24:45,080 --> 01:24:48,320
Robert's fossil turtle
may have been unlucky,

1302
01:24:48,320 --> 01:24:49,960
but many others survived.

1303
01:24:53,720 --> 01:24:56,240
As did crocodiles,

1304
01:24:56,240 --> 01:24:58,080
snakes,

1305
01:24:58,080 --> 01:25:01,040
and many fish species.

1306
01:25:01,040 --> 01:25:03,800
And as for the dinosaurs,

1307
01:25:03,800 --> 01:25:06,320
did the impact
really kill them all?

1308
01:25:06,320 --> 01:25:09,840
Well, this beautiful
fossilised feather

1309
01:25:09,840 --> 01:25:11,960
isn't from a bird,

1310
01:25:11,960 --> 01:25:14,080
but from a predatory dinosaur.

1311
01:25:14,080 --> 01:25:15,920
So we have to be careful

1312
01:25:15,920 --> 01:25:19,200
when we say
that dinosaurs are extinct,

1313
01:25:19,200 --> 01:25:23,200
because what we call birds
originally evolved

1314
01:25:23,200 --> 01:25:26,240
from the smallest
feathered dinosaurs.

1315
01:25:26,240 --> 01:25:28,560
So to be correct, we should say

1316
01:25:28,560 --> 01:25:32,400
all non-avian dinosaurs
are extinct.

1317
01:25:35,200 --> 01:25:37,400
Robert's finds have given us

1318
01:25:37,400 --> 01:25:39,680
a better idea
than ever before...

1319
01:25:41,360 --> 01:25:45,080
..about what happened on the day
that led to the extinction...

1320
01:25:47,160 --> 01:25:50,640
..of the largest beasts
ever to walk the Earth.

1321
01:25:54,000 --> 01:25:56,320
Dinosaurs were perhaps

1322
01:25:56,320 --> 01:25:59,840
some of nature's
most extraordinary creatures,

1323
01:25:59,840 --> 01:26:03,760
dominating the planet
for over 150 million years

1324
01:26:03,760 --> 01:26:05,760
before they became extinct.

1325
01:26:08,560 --> 01:26:11,360
But extinction
comes in different forms,

1326
01:26:11,360 --> 01:26:13,640
and many of the amazing creatures

1327
01:26:13,640 --> 01:26:17,120
and plants alive today
are also threatened.

1328
01:26:17,120 --> 01:26:20,000
It's possible that humanity
is having

1329
01:26:20,000 --> 01:26:22,520
as big an impact on the world

1330
01:26:22,520 --> 01:26:27,240
as the asteroid that ended
the age of the dinosaurs.

1331
01:26:27,240 --> 01:26:30,720
As human beings,
we are unique in our ability

1332
01:26:30,720 --> 01:26:33,960
to learn from the distant past.

1333
01:26:33,960 --> 01:26:38,920
Now we must use that ability
wisely and do our very best

1334
01:26:38,920 --> 01:26:41,400
to protect the millions of species

1335
01:26:41,400 --> 01:26:45,800
for whom, alongside us,
this planet is home.