66 million years ago,
Planet Earth was very different from today.
Back then, one of our closest ancestors might have looked
something like this little furry creature.
RUMBLING GROWL
The rulers of the land were giant reptiles.
Dinosaurs.
That's one of the most infamous,
a carnivorous T-rex.
And just behind are the bison of their time,
a common plant-eater, Edmontosaurus.
But what happened to them all?
66 million years ago,
an asteroid hit the Earth,
and scientists think that it was this collision
that wiped out the dinosaurs.
But no-one has ever found direct evidence of that.
In fact, no-one has ever found the fossil of a dinosaur
that died within a thousand years of the impact.
However, a remarkable dig site promises to change that.
It's in the Hell Creek formation
in the American Midwest.
These badlands are rich in prehistoric remains...
ROARS
..from triceratops...
SQUAWKS
..to pterosaurs.
And here, one patch of land
about the size of a football pitch
is yielding a collection of astonishing fossils.
The precise location is a closely guarded secret,
because this place may hold evidence...
..of one of the most dramatic events
in all the four-and-a-half- billion-year history
of our planet.
- Right, let me get down here between you.
- For ten years, a palaeontologist and his team
have been trying to find out exactly what happened here.
- You're at the edge of your seat every moment,
trying to dig this stuff up.
It's like trying to defuse a nuclear weapon
while you're in a rainstorm.
- He's named the site Tanis,
and believes it could be a mass graveyard
of creatures that were killed
in the catastrophic asteroid strike.
A site that could reveal not only how the last dinosaurs lived,
but how they died.
If the dig team is right, Tanis could be a place
where the remains of a long-lost world
are frozen in time.
A place that gives us, for the first time,
an unprecedented window...
SHRIEKS
..into the lives of the very last dinosaurs...
..and a minute-by-minute picture of what happened
on the day the asteroid hit.
This landscape is full of fossils
dating from the Late Cretaceous,
the period which began around 100 million years ago
and ended 66 million years ago,
when the dinosaurs vanished.
Palaeontologist Robert DePalma wants to find out more.
- I think anybody who's ever liked dinosaurs
in the past, or still does,
has thought at one point or another,
"Well, what happened to them?
"Why are they not here any more?"
So many different theories are out there,
and nobody has a tight answer to that question.
- Judging from fossil evidence,
this is what Hell Creek looked like in the Late Cretaceous.
There were low-lying, marshy flood plains,
intercut by river channels and covered with horsetails,
ferns and trees.
Back then, it was warm and wet here all year round.
Tanis lies in the north-eastern corner
of the Hell Creek formation.
Instead of today's dusty prairies,
there were sandy river banks.
Instead of rocky cliffs, there were forests.
And instead of the life we know today...
DEEP RUMBLING CALLS
TRILLING
..well, Robert is hoping to find out more
about what that was like.
COOING
A sandbank lying between a river and a forest
would one day become what Robert now calls Tanis.
He and his team have been digging here since 2012.
- So somewhere from between there
and down here is where that came from.
It's come from up above. - Hey, look at this.
- What? - Look.
- Oh, yeah, yeah, yeah. OK.
- And what they found is unexpected.
- Here we've got this freshwater environment
of the Hell Creek formation,
and these shocking red, green colours
coming from the shells of ammonites, a marine organism,
kind of like a coiled snail in appearance.
So we've got this marine organism that's been thrown up
into this freshwater environment,
and they do not belong here.
- How they got here is a mystery.
- OK...
- And there's more.
- I'm just going to go ahead and plane down some of this rock.
- Sitting just above the ammonites
is something that many dinosaur hunters
are desperate to find.
- So this orange layer right here is composed 100%
of impact-related debris that is enriched in iridium.
- Iridium is an element that's rare in the Earth's crust,
but it's common in asteroids.
The layer it's in is called the K-Pg boundary.
- Dear Momma...
Oh, dear. Really? - Yeah.
- It's made up of dust and debris from a huge asteroid impact.
- Look at that. - That's amazing.
- Yeah, yeah, yeah, yeah, yeah. That's what we want.
OK. So it's coming from this area here.
So somewhere within that region is where these pieces are coming from.
- The boundary separates the age of the dinosaurs
from the age of mammals,
so the rocks here come from about the time
that the dinosaurs became extinct.
- No rattlesnakes.
- What makes the site even more exciting
is the rock layer right beneath the boundary
where Robert found the ammonites.
- The rock here is really not quite rocky,
as you would expect dinosaur bones and things to be encased -
you expect really, really hard rocks and jackhammers
and things like this, but it's very, very crumbly
and it just falls apart in your hands.
- As well as being crumbly throughout,
this layer of rock is also around a metre thick,
which, along with other unusual features, makes
Robert think that something very strange must have happened here.
Maybe a flood or a mud flow,
burying anything within it in an instant.
- Oh, there's a beautiful... Look at that one - beautiful.
- This could mean that anything he finds in this layer
would have been quickly entombed,
like the bodies in the volcanic ash of Pompeii.
Robert knows from the geology
that anything he finds at Tanis will be tantalisingly close
to the end of the age of the dinosaurs
and could be so well preserved
that it could reveal new evidence
that will bring this time period to life
in a way no-one has ever done before.
Robert digs at Tanis each summer,
the only time the weather allows him to do so.
- Come on down, check out this lens over here.
In order to understand how the impact affected life on Earth,
you really need to get a very clear picture
of what the world was like right before.
That is a critical part of the story.
- Palaeontologists Dr David Burnham
and Loren Gurche have been digging with Robert for years.
- Oh, wow!
See...see the brown? - Yep.
- That might be a tubercle right there.
- And it seems today is their lucky day.
- Oh, my God! Look at that! - Look at that.
- Look, the scales are preserved!
- Holy crap! Like doing a freaking dissection.
Oh, my God. - Biology of Tanis.
- Oh, the scale...
Look, look - the wrinkles continue down that way.
- Mine's all nice and wet so far.
- The scales are getting smaller in that direction.
How big are they there?
- I got a...I got one with the projection over here.
- What? - Oh!
- Yeah. - Oh.
- Yeah, there's the protuberance right there.
- I've only seen that on one other specimen, in life. - Yep.
- This is the closest thing to getting to touch
a living, breathing dinosaur.
- It is.
- They found something extraordinary.
- It is so exceedingly rare -
a piece of triceratops skin in the Hell Creek formation.
- It may look like an impression in the rock,
but this is skin that has been fossilised
and, over millions of years, has turned to stone.
Triceratops bones are relatively common finds in Hell Creek,
but skin in such condition as this is very rare indeed.
The size and the patterning of the scales,
together with the age and location of the rocks
where it was found, strongly suggests
that this is from a triceratops.
The brown colour contains traces of organic material.
So it might even be possible from this
to work out which pigments were in it.
Finding and studying
such well-preserved fossils as this
helps palaeontologists build
a much more detailed picture of how these creatures lived.
Combining this information
with insights from scientists around the world
makes it possible to speculate
about what life in the Late Cretaceous
might have been like.
We know from bones
that adult triceratops could reach nine metres in length
and three metres in height.
RUMBLING
Marks on the fossil also show us
that this one was badly scarred.
RUMBLING GROWL
Triceratops were plant-eaters.
Other fossils tell us that they had sharp beaks
and hundreds of teeth that enabled them to shred tough plants
such as these cycads.
DISTANT TRUMPETING
Almost all adult triceratops fossils,
including Robert's, have been found on their own.
So it's possible that the adults were solitary,
like modern-day male rhinos.
So they were probably territorial,
chasing rivals away.
And perhaps marking their territories.
If you weigh more than an African elephant,
there's not much that can bother you...
SQUEAKING
..except perhaps a little mammal.
GROWLS
Robert found these jawbones
in the fossilised burrow at Tanis.
The shape of this tiny bone and tooth
means it's most likely come from what's known
as a pediomyid, an early mammal
and a type of marsupial.
Robert also discovered fossilised nuts and seeds
in the burrow.
So we have an idea about what it might have eaten.
DISTANT TRUMPETING
Robert's finds are adding
to our knowledge of the complex world
at the very end of the Late Cretaceous.
And it's not just the fossilised creatures.
If you walk on damp sand,
you'll leave a trace behind.
A footprint.
The same was true 66 million years ago.
And very, very occasionally, such traces were preserved.
And that's exactly what happened here at Tanis.
- You know, we won't foil a backside.
- Right, we'll just put... - Put plaster right on.
That way you've got...
- Robert has discovered a number of footprints.
- Yeah. Let's see.
- Looks like a good print. - Yeah.
- Their shape gives him a clue
as to what might have made them.
If he's right,
they were made by a winged creature,
that might well have liked a small mammal...
..for lunch.
The footprints are long and narrow
with four toe prints.
Two are slightly longer than the others,
and that suggests they were made by...
..a pterosaur.
SQUAWKS
Pterosaurs are not dinosaurs, but flying reptiles
on a different branch of the evolutionary tree.
SCREECHING
Male pterosaurs usually had crests,
while females didn't.
So crests may have been used in courtship displays.
SHRIEKS
And we have an indication of where females laid their eggs,
because evidence suggests one pterosaur laid hers
in the soft, sandy banks of the river at Tanis.
And this is a fossilised egg
of a pterosaur that Robert found there.
The only one ever discovered in North America.
If you look at it with the naked eye,
all you see is a jumble of lines.
But if you examine it with the latest technology,
you can find out a wealth of information,
from the chemistry of the bones
to the composition of the shell.
And that, in turn, can tell us a lot about
how these incredible creatures lived.
Robert has been given access
to the Diamond Light Source synchrotron in Oxfordshire.
It's a very powerful research tool
that acts like a giant microscope.
By accelerating electrons in this huge ring,
the synchrotron creates beams of light
many times brighter than the sun.
Robert and paleobiologist Dr Victoria Egerton
now want to turn that beam onto the egg fossil
to discover more about its chemical make-up.
- We're pretty much lined up on the skeleton,
but we might have to move the stage a little bit
to get to the right part. - Sure.
- Meanwhile, Robert can reveal the creature inside.
And this?
Who made this wonderful thing?
- I got replicas of the bones from inside that egg
and I restored the remainder
and put together
what the skeleton would've looked like when it hatched.
That's how big the creature would've been
outside the egg, if it had hatched.
- So this is the baby. How big was it going to grow?
- These very long neck vertebrae here
are what really gave part of the story away to us,
because those long bones match very, very closely
with the azhdarchid pterosaurs.
That is the giant pterosaurs.
- Oh, they were the whoppers, weren't they?
I mean, what, 25 feet?
Wingspan? - Some of them.
This probably had a wingspan, maybe 15 feet, five metres.
- Well, it looks as though it could take off, really.
- It's easy to picture something like that
just hatching out of the egg and fluttering out,
almost like a little bat.
- They've scanned the egg, here and in America.
Victoria has the results.
So what have you learned from the synchrotron image?
- What we have here is a chemical map
of calcium directly within the bones of this animal.
That tells us that these bones were already hardened.
So it might be ready to fly not long after it hatches.
- OK. Can you see any sign of the shell,
and what sort of shell was it?
- We can. What I can show you...
- Ah!
- ..is we can see the rim of the egg in sulphur.
- Does that tell you whether it was a hard shell or a soft shell?
- We have been looking at this.
We can see folding occurring, and this unusual undulation.
If it were a hard egg,
we would expect splintered bits and broken bits,
just like a chicken egg.
This helped to tell us that it was soft.
- So it was perhaps like a turtle?
- Absolutely.
- That's not the case, is it, with dinosaurs?
Many dinosaurs laid hard-shelled eggs. - Yes.
- So this is a new discovery about azhdarchid pterosaurs?
- Absolutely. This is something
that we are confirming for the first time.
- Huh!
That flying pterosaurs had eggs like turtles.
- Yes.
Much more reptilianlike than birdlike.
And that can potentially tell us more
about the environment in which these eggs were laid.
- How interesting. Yeah.
Creatures that lay soft eggs tend to bury them
in order to protect them.
SQUAWKS
So female pterosaurs probably looked for
places like Tanis to lay their eggs...
..because the sandy soil here is just soft enough
for the hatchling to dig itself out.
SNIFFING
Now the pterosaur just has to make sure
that the hole...
..is perfect.
SQUAWKS
WARBLING
Success!
But it's not over yet.
Pterosaurs had two ovaries,
and they laid their eggs in pairs.
Here on the sandbank,
sandwiched between the river and these glorious trees,
life at Tanis seemed to be thriving.
GASPS
Whoops!
Never a dull moment.
But all that was about to change.
The chain of events that led to the extinction of the dinosaurs
began in the distant past, deep in space.
Most scientists think it all started in a ring of dust,
rocks, and debris known as the asteroid belt.
It's usually an uneventful place.
But it's thought that many, many millions of years ago,
a rock was bumped into a new orbit...
..and diverted onto a collision course with Planet Earth.
Robert is building a vivid picture
of Late Cretaceous life at Tanis.
And the team have found some more well-preserved footprints.
- So these are animals that were actually walking in the water?
- These guys would've been essentially on
a mushy river bank going down
to drink at some point.
You know, animals tend to congregate around the rivers.
- This print is 30 centimetres long.
- So I think this is from a type of dinosaur
that we call a duck-billed dinosaur.
And they would've been very common in the Cretaceous.
They ate the plants in the area
and they got very large - 30 feet long.
- And there are more.
- This track, you see all the toes are very well preserved.
You even see a nail print at the tips of the toes.
So the little toenails dug into the mud.
I love this one.
- This is Robert's prized footprint.
It has three toes,
and it's longer than it is wide.
So it's very likely to be a carnivorous dinosaur.
It's so well preserved that you can see
the mark left by its sharp claw there.
Hell Creek is well known
for one carnivore in particular - T-rex.
This footprint is too small for an adult T-rex,
but it's possible that it was made by a young one.
Robert also found this at Tanis -
the crown of a tooth.
Its shape and its serrated edge
are indications that it comes
from an adult T-rex.
RUMBLING GROWL
DEEP RUMBLING GROWL
GROWLS
Bite marks found on T-rex bones
show that they ate other T-rexes.
And a youngster would make an easy catch.
SNEEZES
But not this time.
Very few footprints are preserved as fossils
in Hell Creek.
So if you find several in one place,
as Robert has done,
it's a reasonable assumption
that there would've been many more nearby.
And that supports the idea
that dinosaurs and pterosaurs were thriving at Tanis
shortly before the impact.
GROWLING
And if they were thriving...
SQUAWKING
..they must have been reproducing.
Fossils from dinosaurs similar to T-rex
show they may have laid around 20 eggs
in a circular nest.
It's possible that, like crocodiles,
they partly covered their eggs to keep them warm.
SNEEZES
For one T-rex, a misfortune.
But for all dinosaurs...
ROARS
..a disaster was looming.
Deep in space, the asteroid was approaching.
Its journey would take it through the orbit
of our neighbouring planet, Mars.
Had the two collided,
a catastrophe on Earth would've been avoided.
But it was not to be...
..and Earth's fate was sealed.
As Robert's dig continues,
his vision of what happened at Tanis
is finally starting to come together.
It seems the sandbank was full of life.
T-rex, triceratops,
little mammals,
alongside the footprints of other dinosaurs and pterosaurs,
all in a very small area.
BLOWS
- You see the scales?
- I do. Oh, my God.
- That excites me just looking at it!
- Then Robert finds something truly remarkable.
- See the cracks already forming? Look at that.
So we're going to have to really monitor that before we glue it.
Cos this is getting vulnerable now.
- An almost complete creature.
- To get this block out, we're freezing it.
- Robert is about to attempt something tricky.
- Steady... Let's go.
- To get the fossil out in one piece, they're trying
to freeze it using liquid nitrogen
at almost 200 degrees below zero.
- Watch your footing.
Loren, I'm worried about brittleness here.
Get that hammer. Give this a couple whacks with the hammer.
OK. Move over five centimetres. Good.
It's cracked loose. Yep. - OK. It's loose.
- So we have to get this out in one piece.
One, two, three.
Yeehaw!
Total success. - Total success.
- This is a technique used in archaeology
for digging up human remains.
We've got enough time to work with the fossil
and not damage it.
And I couldn't be happier.
- And the creature Robert found?
A turtle.
This is the fossil now it's been cleaned up.
It's lying on its side.
Here's the outline of its shell.
The shape of the shell and the scalloped edges here
tell us that this was a baenid turtle.
Robert's baenid turtle looks very similar
to modern cooter turtles
and lived in the same sort of freshwater environment.
For a turtle, Tanis would've been ideal.
Warm, shallow water.
Plenty to eat.
And lots of safe places in which to warm up
in the Late Cretaceous sunshine.
The turtle fossil Robert found is almost complete.
This is the underside,
and this brown material up here is fossilised wood.
It's the end of a stick that passes right through its body
and comes out just here.
So the evidence points towards
this turtle having been impaled.
A violent end to one of the many creatures found
in the crumbly rock layer at Tanis.
- When I look at the animals
and plants preserved in the sediments of Tanis
and the footprints beneath it,
I see a picture of a vibrant ecosystem,
many different dinosaurs, and a thriving, thriving place.
- After ten years of digging,
there is now enough evidence to piece together
much of the story of Tanis
and the creatures which lived here.
Robert has found so many fossils, it looks as if,
even at the very end of the Late Cretaceous,
Tanis was bursting with life.
VARIOUS ANIMAL CALLS
Full of the giant reptiles that had dominated the planet
for more than 150 million years.
BARKING
It's impossible to know how much longer
their reign would've continued...
SQUAWKS
..because all this was about to end.
The asteroid hit...
..in what is now the Yucatan peninsula in Mexico.
It's called the Chicxulub asteroid
after the town nearest to the centre of its crater.
ROARING
ROARS
Any living thing within 900 miles of the impact...
..was destroyed by the blast.
But what effect did the impact have on Tanis,
nearly 2,000 miles away?
To find out,
Robert is looking for clues that might link Tanis
to the actual day the asteroid hit.
BLOWS
- We've got some wood,
and pressed up against this and all intertangled,
we've got the carcasses of fish.
- OK.
That's a beautifully preserved tail,
so that fish is going to be absolutely gorgeous.
- So part of the detail work that we're doing right now
is going in and checking out
all the individual elements in this mass death layer.
- Some of the evidence he's found so far
has been hidden inside the fish themselves.
- In more ways than one, it literally is an operation of a Cretaceous
fish, so we're performing surgery on this thing.
- Robert needs to open this fish's skull.
- And very carefully, we want to separate this
from the rest of the fish.
OK.
Here we go.
Opening up the fish.
Got a nice ant that made a home in there.
And beautiful, look at that.
OK, here we have the gill bars of the fish.
Those are the bars that hold the filaments of the gills.
And between the gill bars,
all of these clusters of round objects,
those are the ejecta spherules.
- Ejecta spherules are tiny balls that were once molten rock.
They could be evidence of what Robert suspects -
that creatures here died
on the day of the asteroid strike.
- Those ejecta spherules last saw the light of day
when they were flying through the air 66 billion years ago.
- After a large asteroid impact,
a mix of vaporised and molten rock
is propelled into space.
There, it cools,
solidifying into tiny glass droplets.
Some carry on deeper into space.
But most are pulled back to Earth by gravity.
After a major asteroid hit,
trillions of ejecta spherules would fall from the sky.
Then, over millions of years,
pressure and chemical reactions in the ground
would turn most of them to clay.
They'd look something like this.
So finding spherules in the gills of a fish,
as Robert has done at Tanis,
suggests the fish sucked them in
while the spherules were still falling.
So these creatures could have died
at the time of an asteroid impact.
Once Robert begins to look for ejecta spherules,
he finds more and more,
and realises the thick, crumbly layer of rock at Tanis
is full of them.
- I mean, this stuff is go... Oh, my God, look at that one.
These things are just gorgeous.
Ejecta spherules like this
give us a fingerprint of where they came from.
- If these spherules were connected
to the Chicxulub impact,
then the whole crumbly layer could be full of evidence
of what happened on the day the asteroid hit.
- That's a good one.
- Oh, is that a droplet right there?
- To see if that's the case,
Robert needs to find a spherule that hasn't turned to clay.
- Oh, my God, that's a beautiful droplet.
- OK.
- The small pieces of orange material
that Robert and Loren are digging up
may be able to help.
They're amber.
- If there was anything flying through the air at that time,
this is where it's going to get caught.
- The amber they're collecting was once sticky resin
oozing out of a Late Cretaceous tree trunk.
It's a way for the tree to protect itself,
like a scab forming on a cut.
Anything covered by the resin would be frozen
in an amber time capsule.
If they find a spherule preserved in amber,
it could be analysed
to see if it comes from the Chicxulub asteroid impact.
- So during this batch,
we were incredibly lucky that we came across
two completely unaltered spherules.
- This spherule could be something amazing.
Evidence preserved well enough to analyse for chemical clues.
If so,
it could link Tanis directly with the Chicxulub impact
and the last day of the dinosaurs.
To investigate, Robert is joined
at the Diamond Light Source
by Professor of Natural History Phil Manning,
of the University of Manchester.
They've already run initial tests
on the spherules in America.
What have you found out so far?
- These little glass spherules, these globs
of molten material from the impact site
have a chemical signal that ties it with where they came from.
Cos when an asteroid hits,
it melts the ground that it hits,
but also that glass has
a little bit of contamination from the asteroid itself.
And that gives you a unique geochemical fingerprint.
- We can see once we've scanned it,
and looking at spherules from other sites in North Dakota,
we can get a baseline
for what the ejecta should look like when it's related to
the Chicxulub crater.
And you can see each element here
and the ratios of those elements.
And when we look at Tanis, it's a match.
I mean, it perfectly overlays.
So I think this is powerful evidence
supporting that Tanis and Chicxulub are linked.
- And what do these findings mean
for the rest of the fossils that you're finding in Tanis?
- This data is key for the entire site,
because once you have that link
and you know what impact affected Tanis,
then you essentially know that every object in that site,
all the animals and the plants and everything buried
in those sediments,
are linked to the last day of the Cretaceous.
- And the synchrotron here in the UK
reveals something even more remarkable.
- So this is showing a beautiful synchrotron scan
of the half of one spherule.
The glass is a good geochemical fingerprint,
and we've got calcium, some iron,
we've got strontium,
but when we look at the entire thing,
we see something quite unexpected.
That's your entire spherule.
- What's this?
- In this, we've got a little bit of a nugget.
There was a little particle right there.
So we scan it.
And that's a lot of iron in there.
Over here, we've got chromium, a big peak in chromium.
Over here, we've got a big peak in nickel.
And the abundances of iron, nickel and chromium,
all together,
that matches what you expect to see in a meteoric body.
That does not match what you would normally have down here.
- So this is extraterrestrial material?
- If you were to sort of grind up
and stuff into a spherule a piece of meteorite,
that's what it's going to look like.
- This could be a piece of the Chicxulub asteroid.
- A piece of the bullet that killed the dinosaurs.
- No!
Robert could have found
a fragment of the asteroid itself in Tanis,
physical evidence linking this site to the Chicxulub impact.
But Tanis is almost 2,000 miles away
from where the asteroid hit.
So exactly how did it cause the creatures' deaths?
To answer that question,
Robert is searching in the mass death layer.
- Right here, we've got this intertangled mass of fish.
There's one fish here, another sturgeon goes this way,
underneath the body of a paddlefish.
There's another sturgeon that goes this way,
underneath this log, and continues out the other side.
And his head hit that log
and has deflected downward at a 90-degree angle.
- Robert uncovered a tangled mass of fossilised creatures and logs
surrounded by spherules
and crushed together in what's known as a logjam.
He has a theory that the creatures were swept
to their death in some kind of turbulent surge of water
and quickly entombed in sediment,
which is why they're so well preserved.
But what could have caused the wave?
One theory is a tsunami.
The asteroid hit at sea.
Recent studies show
it may have caused a wave almost a mile high.
The height of the wave would've gradually reduced
as it spread across the oceans.
In the Late Cretaceous,
North America was divided by a narrow sea
that's been called the Western Interior Seaway.
The tsunami could have travelled up this,
towards Tanis.
But there's a big question about the tsunami idea.
The timing.
- Oh, which fish is that?
That's a new... It's a new contact. - New one. Yeah.
- If a tsunami killed the fish,
it would have to have hit
while ejecta spherules were falling...
..because spherules were found in the fish's gills.
So how long after impact did the spherules arrive at Tanis?
- Pretend this ball of foil is a piece of ejecta
coming out of the crater. It would then go on an arc path,
ballistic trajectory, out of the crater
and to wherever it lands - in this case, Tanis.
If we know the distance between myself
and the landing site, and if we know the size of that ball,
we can accurately calculate how long it would take to get there.
- The result is surprising.
Robert and his team calculated
that these ejecta spherules landed at Tanis
between 13 minutes and two hours after the impact.
If a wave killed the fish,
it must also have reached Tanis within two hours.
Data from recent tsunamis show
even a powerful one would take much longer than that
to travel almost 2,000 miles from the impact site
to Tanis.
So if it wasn't a tsunami,
what could have caused a surge of water at Tanis?
Professor Stein Bondevik is an expert in tsunamis.
- The fjords in Norway are very special.
We have tall mountains surrounding bodies of water.
So the water is usually very calm.
- In 2011, something very strange happened.
The water in the fjord began to move violently.
- The height of the water increased by one and a half metre,
like a maelstrom with the turbulent water.
Someone said that the fjord was boiling.
- THUNDER RUMBLES
News started to roll in -
there'd been an earthquake 5,000 miles away in Japan.
- A journalist from the local newspaper called me,
and he said that people were observing waves
here, in the fjords.
I got a video clip of the waves.
I saw immediately that they looked like a tsunami wave.
So later in the afternoon,
you can see that the fjord is perfectly calm.
But at the beach here,
you could see that the water is sloshing back and forth,
and no-one had ever seen anything like it.
And some people got very upset and afraid.
- A magnitude nine earthquake had devastated the northeast of Japan,
around Fukushima.
But how did that affect a fjord so far away?
- So no-one in Norway could feel the earthquake,
but I could see that the times matched
the arrival of the waves here, in the fjord.
- Eventually, Stein and his team realised
that this might have something to do with seismic waves -
shock waves that pass quickly through the Earth
during an earthquake.
- So it took only 12 minutes before the first signal
of the earthquake in Japan reached all the way here,
to western Norway.
- So it was the seismic waves
that caused the normally calm water in the fjord
to slosh turbulently back and forth.
- Just thinking of that, scientifically, it's fantastic.
- Could something similar have happened in Tanis?
- A large weather front's coming through the northwest...
- Trying to find out
is geophysicist professor Mark Richards,
who's been studying the site at Tanis for several years.
He's working with Robert to discover
what could have caused a surge of water here.
- A tsunami can't get here in less than minimum 12 hours.
But seismic waves travelling from the Yucatan impact site
to North Dakota can arrive here fairly quickly.
- In the Late Cretaceous, the Western Interior Seaway
that divided North America could have been connected to Tanis
through a system of rivers.
- If you have a very large body of water,
like the Western Interior Seaway,
and you can shake it back and forth,
you can generate a large water wave
coming up this river at Tanis.
- So seismic waves from the impact could have caused
surges of water in the Tanis river system.
- The seismic waves get here quickly enough,
coming up the Tanis river,
inundating this area, arriving at the same time
these spherules are still falling out of the air.
- The mystery of the wave
and the thick layer of crumbly rock has been solved.
Seismic waves travelling through the Earth
could have caused powerful surges of water at Tanis...
..possibly carrying mud and marine creatures,
like ammonites, from the Western Interior Seaway...
..dumping them on the Tanis sandbank and burying everything
at the same time as spherules fell.
Over millions of years,
the mud would turn into the layer of crumbly rock.
- And that's the beauty of Tanis.
What you're seeing is a deposit
that is literally recording the last, say,
45 minutes to an hour and a half of the Cretaceous.
- If the extinction of the dinosaurs was a crime,
the detective solving it would have plenty of evidence.
They would see that the asteroid was
in the right place at the right time.
They would see that no dinosaurs survived
after the hit.
They would have a piece of the murder weapon -
a fragment of the asteroid.
But they would be missing one very important thing -
a body.
No-one has ever found the fossil of a dinosaur
that was killed by the effects of the asteroid impact.
But Robert did find part of a triceratops
in the crumbly layer at Tanis.
So could that be the remains
of a dinosaur that died on that day?
- I'm still dubious about the horn.
I kind of want to keep the horn in the jacket.
- I think if you took it off,
at least take this section off,
to see what's going on under here.
- Yeah?
- To find out, the team needs to establish cause of death,
which can be difficult when you only have a piece of skin
and a horn to go on.
This is the horn after they've cleaned it up.
The team is particularly interested in these lines here.
And they found that the fractures go
right through the horn.
So rather than dying as a result of the impact,
they wondered whether it had been killed in a fight.
But when they looked at the fractures in more detail,
they found signs of new bone growth here.
An indication that the bone had started to heal.
So it looked as though the triceratops survived
the event that broke its horn.
Could this triceratops have survived
until the day of the impact?
The team found evidence, including sagging in the skin,
which suggested that there was decay underneath.
That means its body had started to rot
before it was entombed and preserved by the surge.
So it seems that this dinosaur didn't die as a result
of the asteroid impact.
Perhaps, in the months before the impact,
the broken horn put the triceratops
at a disadvantage over its rivals.
GRUNTS
And that might have led to starvation.
THUNDER CRACKS
WIND WHOOSHES
Robert has still not found direct evidence
of a dinosaur that was killed by the asteroid.
- We've got all these bones in the ground right now.
But the one thing that we would just dream
of finding is that one dinosaur
that died on the day of the impact.
- And the weather isn't helping his search.
GROANS
- That therapod print is toasted.
- Yeah, it was in a low corner.
Look, it's full mud. - It's full of mud and water.
The problem is it's wet, look.
See... If we're not careful, we're going to lose the print.
And that's the biggest theropod print we've got.
I see some areas that could use glue right now, too.
- The team is racing to excavate the footprints,
along with dozens of fish fossils
tangled together in a logjam, before storms wash them away.
THUNDER RUMBLES
- We're up against the clock here.
This stuff that could be exposed right now
is going to get ruined by the rain.
- But then, Robert comes across something
that looks very unusual.
- That's going there.
What is going on right there?
- Are we sure this isn't crocodilian?
- That's not crocodilian. - No.
- Right, let me try this piece right here.
I'll go in from the top and then twist up,
and it separates right on that line.
- Oh, that's skin right there.
That's actually scaly skin. - Oh, my God.
- No, no, no, no, no. Look, look, look.
Look at that pattern right there.
Have you ever seen elongated scales like that before, Dave?
- That's insane. - Scuttelates - in birds.
- Just careful.
- Oh, my God. - It's changing again.
- It's changing again. - Oh, my God.
We're seeing it for the first time in 66 million years.
I think we've got ourselves a dinosaur.
- A dinosaur fossil!
And, unlike the triceratops,
this is located in the logjam, the mass death layer,
surrounded by the fish with spherules in their gills.
- This is the most incredible thing that we could possibly imagine here.
The best-case scenario.
We're excavating this mass death layer of fish
from the surge sent up by the impact,
and we've got dinosaur remains.
The one thing that we would always want to find at this site,
and here we've got it.
This is unreal. I-I-I cannot process this in my brain.
No, I am absolutely blown away by this.
Just my heart is literally pumping out of my chest
wondering what is behind there,
just a couple of centimetres back in the outcrop.
What is waiting for us back there?
Get it out...
This is...
- The team keeps digging.
- The scales get big again over on this side.
- So this could be a ribcage,
it could be laying against ribs that are curved.
- There's something here.
That's hard. - A bit more bone.
- That's bone right next to the skin.
Yeah, that's an articular surface right there,
so this is either a hip or a shoulder element.
- After hours of painstaking work...
- And we can go from the thigh of the animal.
There's the knee.
And then you've got the little calf muscles
of the dinosaur, they're bulging out,
and you go down to the anklebones,
and these are the toes of the feet.
We have got nails at the tips of the toes.
It's a beautifully preserved leg,
all articulated, covered with skin.
- The complete leg of a dinosaur.
- In my wildest dreams,
I never expected to find a dinosaur leg in this deposit.
- Yeah. I mean, and then it's got skin and tissue.
It does look just like a drumstick.
- It looks like a Thanksgiving turkey,
just laid out in the ground.
And this weird scale pattern on the thigh of the animal,
which we've never seen in a dinosaur before.
- Well, thescelosaurs don't have any form of defence,
so they have to have camouflage or something.
- That's a good point.
So this could have been some sort of a camouflage marking. - Yeah.
- Robert thinks he has found the body in question -
a dinosaur that might itself have witnessed
the cataclysmic impact.
- Dinosaur fossils are not known
from the last years of the Cretaceous.
And it was unclear whether they were already extinct
or in decline or what was going on.
So they were just sort of absent.
And this answers that question.
Were dinosaurs still there then?
Well, yes - this one likely died in that surge.
- For such big claims, Robert needs verification.
He's brought the dinosaur leg to London
to get a second opinion...
- And then here are the pads of the toes.
We see all those beautiful scales lined up.
- ..from Professor Paul Barrett,
an expert in ornithischian dinosaurs
from the Natural History Museum.
So what do you think this might be?
- When we look at the leg, it has claws,
like the claws we see in small, agile, bipedal, running dinosaurs
that are plant-eaters.
We can rule out things like triceratops,
partly just because it's not big and stocky.
And the proportions of those legs are also different
from some of the other plant-eaters we see,
in that they have this rather long ankle
and shin, compared with its thighbone.
So as we narrow those possibilities down,
what we're left with, probably,
is an animal called a thescelosaur.
- SQUEAKS
Thescelosaurs lived next to rivers
where there was plenty of rich vegetation to feed on.
They had leaf-shaped teeth,
common amongst herbivores,
and claws on their short front limbs -
excellent for digging.
SQUEAKS
CRUNCHING
But how did Robert's thescelosaur die?
Could it have been killed by another dinosaur?
- It's a possibility.
This is a relatively agile animal.
And that turn of speed would've been
its primary defence against the large predators living alongside it.
- So, to escape a hungry T-rex,
a thescelosaur's first line of defence...
BARKS
..would've been to run.
But it may have had another defensive trick.
ROARS
Living next to rivers,
it's possible thescelosaurs were able to swim.
- It doesn't seem to me like there is any evidence
that this animal was predated -
none of the obvious tooth marks
or leftover bits of carnivore teeth
to suggest it's been eaten.
- So how do you think it died?
- It didn't have any particularly nasty diseases when it died,
as we can see that the bones look OK.
So this is an animal that was probably living
and healthy at the time that this happened to it.
- Could this be a victim of the meteor strike?
- I think it's entirely possible.
This is actually a shoulder bone,
and this bone in a living animal
would actually be way over here.
And similarly, this little bone here
would've been from about maybe a third of the way
along the tail, maybe halfway down.
So somehow these two bones have been telescoped together.
So maybe this animal's been tumbled around.
We've ruled out a lot of other possible
causes of death for this animal.
So it could well be that this is an animal
that was there, being tumbled around
in its death throes, in that river,
as a result of the asteroid impact.
- Well, it is exactly analogous
to those human bodies found in Pompeii.
- It's very similar in terms of you get that quick entombment.
- Yes. And it's almost as evocative.
- That's absolutely true.
You've got literally the blink of an eye
at the end of the Cretaceous,
snapped up into history, and there it is,
ready to be dug up. - Wow.
LAUGHS
After years of investigation,
Robert has found out a great deal
about the creatures which lived at Tanis,
and he knows that many of them were alive on that fateful day
when the asteroid devastated our planet.
But how exactly did they die?
Robert's finds now allow us to tell the story of that day
and finally answer that question.
One of the most important days in Earth's history
probably started much like any other late spring morning.
We know the season because Robert found fossils of young fish that
died at the size they reach at that time of year.
This agrees with evidence already found
by other scientists.
Perhaps this day, that would end with so much death,
began with something different.
A new life.
SQUEAKING
SQUAWKS
No-one can be certain of the exact timings of the day
when the asteroid collided with our planet.
But it's estimated that within just 40 minutes of the impact,
the consequences for the creatures of Tanis
would have been profound.
Based on Robert's finds
and the latest evidence from other scientists,
this is how the catastrophe might have unfolded.
The asteroid is around seven miles across,
bigger than Mount Everest...
..and travelling at close to 45,000mph.
The impact causes an explosion
bigger than a billion Hiroshima atomic bombs.
At Tanis, almost 2,000 miles away...
..it's completely silent.
But at the impact site...
..the asteroid vaporises.
More than three trillion tonnes of rock
are ejected into space
in a blast of super-heated violence.
Winds higher than 600mph.
A colossal earthquake, followed by a ring of massive tsunamis.
RUMBLING
ANIMAL CALLS
All the while, the creatures at Tanis
go about their business...
CACOPHONY OF ANIMAL NOISES
..just like any other day.
COOING
CLICKING
WARBLES
SNEEZES
THUNDER RUMBLES
SQUAWKS
The evidence suggests that baby pterosaurs
emerge from the egg ready to fend for themselves.
And that includes...
..flying?
Well, almost.
Elsewhere, as the devastation spreads out across North America
towards Tanis...
..dinosaurs and creatures of all shapes and sizes
are obliterated by the blast.
At Tanis, for a few more precious minutes,
life carries on as usual.
But the clock is ticking.
GRUNTING
DEEP BELLOWING
The blast from the impact never reaches Tanis,
but seismic shock waves do.
RUMBLING
CHIRPS
They are far more powerful
than any earthquake ever recorded.
DEEP BELLOWING
SHRIEKING
The thescelosaur might head for a place of safety...
..but seismic waves are now slowly shaking
the whole region, causing water to slosh and churn.
At Tanis, strange currents in the river
give a hint of what is still to come.
THUNDER CRACKS
Next, it begins to rain.
PATTERING
Ejecta spherules are falling back to Earth.
As the spherules begin their fall...
..friction heats them until they're red hot.
Then the heat transfers to the air.
Temperatures rise with every second.
As the heat builds, the creatures of Tanis
are fighting for their lives.
ROARS
And then, as seismic waves
continue to slowly rock the whole region...
..a violent surge wave ten metres high
rushes up the Tanis river.
Surviving the turbulence of the surge
is a challenge even for the best swimmers.
Then, the powerful rocking of the river system
slowly begins to draw the water back the way it came.
Swimming may have saved
the thescelosaur in the past,
but not this time.
A large, robust animal like a T-rex
might have survived the surge.
As might a hard-shelled reptile.
But there is much more to come.
As billions of tonnes of superheated spherules continue to fall,
the atmosphere gets even hotter...
..igniting dead leaves and sparking wildfires.
Earthquakes,
fire...
..devastation.
Little would survive for long,
on land..
ROARS
..or in the air.
SHRIEKS
GRUNTS
As the air reaches the temperature of an industrial oven...
..those that live deep underground
may have a better chance.
As the slow sloshing of the river system continues...
..another powerful surge hits.
There is no escaping the destruction.
For many of the creatures of Tanis,
their stories end underwater.
In less than two hours, the world has changed forever.
The mud the surge waves leave behind
will gradually turn into the thick layer of crumbly rock
entombing the creatures which died here...
..until 66 million years later,
when they're finally unearthed.
Robert's finds have helped us understand in remarkable detail
what happened at Tanis
in the minutes after the asteroid impact.
But what about the rest of the world?
The impact triggered catastrophic events
such as earthquakes all over the planet.
And as spherules continued to fall...
..wildfires may have sprung up around the globe.
As that horrific day drew to a close,
many of the world's dinosaurs were already dead.
Research shows that the angle at which the asteroid hit
and the sulphur-rich rocks at the impact site
amplified the devastation.
Billions of tonnes of sulphur
were ejected into the atmosphere,
blocking the sunlight.
Without light, most plants died, and food became scarce.
As the weeks and months passed,
any dinosaur left alive would've died of hunger.
In the oceans, it was the same.
Nearly all of the world's plankton disappeared,
leading to the starvation of most marine creatures.
It's thought that the nuclear winter that followed
caused a global temperature drop
of at least 25 degrees centigrade.
The fossil record tells us that this huge change in climate
marked the disappearance of three quarters of all species,
including the dinosaurs.
The planet was in semi-darkness for around a decade,
as dust and soot slowly fell to Earth.
But then came something wonderful.
A new beginning.
Once the dust cleared from the atmosphere
and the sunlight returned...
..plant life was gradually restored,
led by ferns,
the spores of which had lain dormant deep underground,
and the world began to turn green once more.
But what about the animals?
Back at Tanis, Robert has unearthed something
that could have helped save some of the creatures
from the devastating fires.
- We saw a little thing poking out,
so we kind of followed it back.
And I'm so glad that we did,
because what we have here is a fossil burrow
from an animal 66 million years ago.
The only animals that would've been around back then
that would likely build a burrow like this
would be the small mammals, roughly ferret-sized,
and also some reptiles.
If it is from a mammal, this is sort of a window
into the lifestyle of some of our oldest ancestors out here.
This guy would've burrowed sideways,
right into the river bank.
We actually have some scratch marks on there
from the interior when they were digging it,
going back, and he would've lived back here
and sought shelter from the dinosaurs
cos they just did not want to get eaten.
- Burrows are part of the reason
that mammals survived the great extinction.
During the nuclear winter,
a burrow would've provided warmth,
protection, and a place to store food.
Mammals that survived were resourceful omnivores,
and insects would've been a plentiful source of food.
And they had another advantage - their size.
If conditions are right, many animal species get larger
as they evolve over millions of years.
Take T-rex as an example.
This is a cast of the lower jaw
of a predecessor, called gorgosaurus,
which lived 72 million years ago.
Whereas this is the cast of the lower jaw of a T-rex,
which lived five million years later.
Look at the difference in size.
But the bigger the creature,
the more energy they need to stay alive.
So when catastrophe strikes and food is scarce,
the largest tend to die out,
whilst the smallest often survive.
That's one of the reasons
why many of the smaller mammals
lived through the great darkness.
And they weren't alone.
Robert's fossil turtle may have been unlucky,
but many others survived.
As did crocodiles,
snakes,
and many fish species.
And as for the dinosaurs,
did the impact really kill them all?
Well, this beautiful fossilised feather
isn't from a bird,
but from a predatory dinosaur.
So we have to be careful
when we say that dinosaurs are extinct,
because what we call birds originally evolved
from the smallest feathered dinosaurs.
So to be correct, we should say
all non-avian dinosaurs are extinct.
Robert's finds have given us
a better idea than ever before...
..about what happened on the day that led to the extinction...
..of the largest beasts ever to walk the Earth.
Dinosaurs were perhaps
some of nature's most extraordinary creatures,
dominating the planet for over 150 million years
before they became extinct.
But extinction comes in different forms,
and many of the amazing creatures
and plants alive today are also threatened.
It's possible that humanity is having
as big an impact on the world
as the asteroid that ended the age of the dinosaurs.
As human beings, we are unique in our ability
to learn from the distant past.
Now we must use that ability wisely and do our very best
to protect the millions of species
for whom, alongside us, this planet is home.
6600万年前、
地球与今天非常不同。
那时候，我们最亲近的一个祖先可能看起来是
像这样的毛茸茸的小动物。
咆哮的咆哮
这片土地的统治者是巨大的爬行动物。
恐龙。
这是最臭名昭著的一个、
一个食肉的T-REX。
而紧随其后的是他们那个时代的野牛、
一种常见的植物食客，埃德蒙顿龙。
但他们都发生了什么？
6600万年前、
一颗小行星撞击地球、
而科学家们认为，正是这种碰撞
消灭了恐龙。
但没有人找到过这方面的直接证据。
事实上，从来没有人发现过恐龙的化石
在撞击后一千年内死亡的人。
然而，一个引人注目的挖掘网站有望改变这种状况。
这是在地狱溪地层中
在美国中西部。
这些坏境有丰富的史前遗迹...
咆哮
...来自三角龙...
鱿鱼
...到翼龙。
而这里，有一片土地
大约一个足球场的大小
正在产生一批令人惊讶的化石。
准确的位置是一个严密的秘密、
因为这个地方可能有证据...
...最戏剧性的事件之一
在所有四百五十亿年的历史中
我们的星球的。
- 对了，让我在你们之间下来。
- 十年来，一位古生物学家和他的团队
一直在试图找出这里到底发生了什么。
- 你每时每刻都处在座位的边缘、
试图把这些东西挖出来。
这就像试图拆除一个核武器一样
当你在暴雨中时。
- 他将该网站命名为Tanis、
并认为这可能是一个集体墓地
被杀的生物的数量
在灾难性的小行星撞击中。
一个不仅可以揭示最后的恐龙是如何生活的网站、
但他们是怎么死的。
如果挖掘队是正确的，塔尼斯可能是一个地方
在那里，一个久违的世界的遗迹
被冻结在时间中。
一个第一次给我们的地方、
一个前所未有的窗口...
震撼
...进入最后一批恐龙的生活...
......以及所发生的每一分钟的画面
在小行星撞击的那一天。
这种景观充满了化石
可追溯至晚白垩世、
约1亿年前的时期
并在6600万年前结束、
当恐龙消失的时候。
古生物学家罗伯特-德帕尔马想了解更多。
- 我认为任何曾经喜欢过恐龙的人
在过去，或仍然如此、
在某一时刻，人们都有这样的想法、
"嗯，他们怎么了？
"为什么他们不在这里了？"
有这么多不同的理论、
而且没有人对这个问题有一个严密的答案。
- 从化石证据来看、
这就是地狱溪在晚白垩世的样子。
这里有低洼、沼泽的洪泛平原、
被河道穿插，并覆盖着马尾巴、
蕨类植物和树木。
那时，这里一年四季都是温暖湿润的。
塔尼斯位于东北角
的地狱溪地层。
而不是今天的尘土飞扬的大草原、
这里有沙质的河岸。
这里没有岩石峭壁，而是有森林。
而不是我们今天所知的生活...
深沉的轰鸣声
特里林
......好吧，罗伯特希望能找到更多的线索
关于那是什么样子的。
运作
位于河流和森林之间的沙岸
有一天会成为罗伯特现在所说的坦尼斯。
他和他的团队自2012年以来一直在这里挖矿。
- 因此，在这之间的某个地方
而这下面就是这句话的出处。
它是从上面来的。- 嘿，看看这个。
- 什么？
- 哦，对，对，对。好的。
- 而他们的发现是出乎意料的。
- 在这里，我们已经有了这个淡水环境
的地狱溪地层、
和这些令人震惊的红、绿颜色
来自于海洋生物--阿莫尼特的外壳、
外观上有点像卷曲的蜗牛。
因此，我们已经有了这个被抛出的海洋有机体
进入这个淡水环境、
而他们不属于这里。
- 他们如何来到这里是一个谜。
- 好吧...
- 而且还有更多。
- 我只是要去把这块石头刨下来一些。
- 坐落在氨化石的上方
是许多恐龙猎人的事
是急于找到的。
- 因此，这个橙色层在这里是由100%的
与撞击有关的碎片中富含铱元素。
- 铱是一种在地壳中罕见的元素、
但它在小行星中很常见。
它所在的层被称为K-Pg边界。
- 亲爱的妈妈...
哦，亲爱的。真的吗？- 是的。
- 它是由巨大的小行星撞击产生的灰尘和碎片组成的。
- 看看这个。- 这真令人吃惊。
- 是的，是的，是的，是的，是的。这就是我们想要的。
好的。所以它是从这个区域来的。
因此，在这个区域内的某个地方就是这些作品的来源地。
- 恐龙时代的分界线
从哺乳动物的时代开始、
因此，这里的岩石来自于大约的时间
恐龙已经灭绝了。
- 没有响尾蛇。
- 是什么让该网站变得更加令人激动
是边界下面的岩石层
罗伯特在这里发现了氨化石。
- 这里的岩石确实不太像岩石、
正如你所期望的那样，恐龙的骨头和东西都被包裹着------。
你期待着非常、非常坚硬的岩石和手锤的出现
诸如此类的东西，但它非常、非常容易碎裂
而它在你的手中就这样散架了。
- 由于整个过程中都是碎的，所以也是碎的、
这层岩石的厚度也在一米左右、
这与其他不寻常的特征一起，使得
罗伯特认为，这里一定发生了非常奇怪的事情。
也许是洪水或泥石流、
瞬间将任何东西埋在里面。
- 哦，有一个美丽的...看那一个--美丽。
- 这可能意味着，他在这一层发现的任何东西
就会很快被埋葬、
就像庞贝的火山灰中的尸体。
罗伯特从地质学上知道
他在坦尼斯发现的任何东西都将是诱人的。
到恐龙时代的结束
并能如此完好地保存下来
它可以揭示新的证据
这将使这一时期的生活更加生动
以一种从未有人做过的方式。
罗伯特每年夏天都会在坦尼斯挖掘、
只有在天气允许的情况下，他才会这样做。
- 下来吧，看看这里的这个镜头。
为了了解这种影响如何影响地球上的生命、
你真的需要得到一个非常清晰的画面
的世界是什么样子的，就在之前。
这是故事的一个关键部分。
- 古生物学家David Burnham博士
和Loren Gurche已经和罗伯特一起挖掘了多年。
- 哦，哇哦!
看到......看到棕色了吗？- 是的。
- 这可能是一个小瘤，就在那里。
- 而今天似乎是他们的幸运日。
- 哦，我的上帝！看看这个！- 看看这个。
- 看，鳞片被保留下来了!
- 我的妈呀!就像在做一个该死的解剖。
哦，我的天哪。- 坦尼斯的生物学。
- 哦，规模...
看，看--皱纹继续往那边走。
- 到目前为止，我的都很好，很湿。
- 天平在这个方向上越来越小。
他们在那里有多大？
- 我有一个......我有一个投影在这里。
- 什么？
- 是的 哦。
- 是的，那里是突起的地方。
- 我只在另外一个标本上看到过这种情况，在生活中。- 是的。
- 这是最接近于接触的东西
一个活生生的恐龙。
- 它是。
- 他们发现了一些非同寻常的东西。
- 它是如此极其罕见 --
地狱溪地层中的一块三角龙皮肤。
- 它可能看起来像岩石上的一个印记、
但这是已被化石化的皮肤
并在数百万年的时间里，变成了石头。
三角龙的骨头是在地狱溪比较常见的发现、
但像这样的皮肤状况确实非常罕见。
鳞片的大小和图案、
以及岩石的年龄和位置
发现它的地方，强烈表明
这是一个三角龙的作品。
棕色含有微量的有机物质。
因此，甚至有可能从这个
以找出其中的颜料。
寻找和研究
像这样保存完好的化石
帮助古生物学家建立
一个关于这些生物如何生活的更详细的图片。
结合这些信息
伴随着世界各地科学家的洞察力
使得推测成为可能
关于晚白垩世的生命是什么？
可能是这样的。
我们从骨头上知道
成年三角龙的身长可以达到9米
和三米的高度。
嗡嗡声
化石上的印记还向我们展示了
这个人身上有严重的伤痕。
咆哮的咆哮
三角龙是吃植物的。
其他化石告诉我们，他们有尖锐的喙
和数以百计的牙齿，使它们能够撕碎坚硬的植物
如这些苏铁植物。
遥远的喇叭声
几乎所有成年三角龙的化石、
包括罗伯特的，都是自己发现的。
因此，有可能成年人是孤独的、
像现代的雄性犀牛。
因此，他们可能是有领地的、
驱赶对手。
也许还可以标记他们的领土。
如果你的体重超过了非洲大象、
没有什么可以困扰你的...
咳嗽
...也许除了一个小哺乳动物。
增长
罗伯特发现了这些颚骨
在塔尼斯的洞穴化石中。
这个小小的骨头和牙齿的形状
意味着它很可能来自于已知的
作为一个早期哺乳动物的小肠动物
和一种有袋动物。
罗伯特还发现了坚果和种子的化石
在洞穴里。
因此，我们对它可能吃过的东西有了一个概念。
遥远的喇叭声
罗伯特的发现正在增加
为我们对复杂世界的认识
在晚白垩世的最末端。
而且这不仅仅是生物化石。
如果你走在潮湿的沙地上、
你会留下痕迹的。
一个脚印。
6600万年前的情况也是如此。
而且非常、非常偶然地，这种痕迹被保留了下来。
而这正是在Tanis发生的事情。
- 你知道，我们不会衬托出一个背影。
- 对，我们就把......--把石膏贴上。
这样一来，你就有...
- 罗伯特发现了一些脚印。
- 是的。让我们来看看。
- 看起来是个不错的印刷品。- 是的。
- 它们的形状给了他一个线索
至于是什么原因造成了它们。
如果他是对的、
它们是由一个有翅膀的生物制造的、
这很可能是喜欢一个小的哺乳动物...
...吃午饭。
脚印又长又窄
有四个脚趾印。
有两个比其他的略长、
这表明它们是由......制成的。
...一只翼龙。
鱿鱼
翼龙不是恐龙，而是飞行的爬行动物
在进化树的一个不同分支上。
尖叫声
雄性翼龙通常有脊柱、
而女性则没有。
因此，徽章可能被用于求偶展示。
震撼
而且我们有迹象表明，雌性在哪里产卵、
因为有证据表明，有一只翼龙为她生下了孩子。
在塔尼斯河柔软的沙岸上。
这是蛋的化石
罗伯特在那里发现的一只翼龙的照片。
这是迄今为止在北美发现的唯一一个。
如果你用肉眼看它、
你看到的只是杂乱无章的线条。
但是，如果你用最新的技术来检查它、
你可以找到大量的信息、
从骨子里的化学成分
对外壳的组成。
而这反过来又可以告诉我们很多关于
这些不可思议的生物是如何生活的。
罗伯特已被允许进入
到牛津郡的钻石光源同步加速器。
这是一个非常强大的研究工具
这就像一个巨大的显微镜。
通过在这个巨大的环中加速电子、
同步加速器产生的光束
比太阳还要亮很多倍。
Robert和古生物学家Victoria Egerton博士
现在想把这束光转到鸡蛋化石上
以发现更多关于其化学构成的信息。
- 我们基本在骨架上排好了队、
但我们可能要把舞台移开一点儿。
以获得正确的部分。- 当然。
- 同时，罗伯特可以揭开里面的生物。
那这个呢？
谁制造了这个美妙的东西？
- 我从那个蛋里得到了骨头的复制品
而我恢复了剩余的部分
并将其放在一起
骨架在孵化的时候会是什么样子。
这就是该生物的大小。
在蛋的外面，如果它已经孵化。
- 所以这就是宝宝。它要长到多大？
- 这些非常长的颈椎在这里
是真正把故事的一部分给了我们、
因为这些长骨非常、非常地吻合
与Azhdarchid翼龙的关系。
这就是巨型翼龙。
- 哦，他们是大人物，不是吗？
我的意思是，什么，25英尺？
翼展？- 有的。
这可能有一个翼展，也许是15英尺，5米。
- 嗯，它看起来好像可以起飞了，真的。
- 很容易想象这样的事情
刚从蛋里孵化出来，就飞快地跑了出去、
几乎像一只小蝙蝠。
- 他们已经扫描了鸡蛋，在这里和在美国。
维多利亚有了结果。
那么，你从同步辐射图像中了解到了什么？
- 我们在这里得到的是一张化学地图
在这种动物的骨骼中直接含有钙质。
这告诉我们，这些骨头已经变硬了。
因此，它可能在孵化后不久就可以飞了。
- 好的。你能看到任何贝壳的迹象吗、
它是什么样的外壳？
- 我们可以。我可以给你看的是...
- 啊!
- ...是我们可以在硫磺中看到鸡蛋的边缘。
- 这是否说明它是一个硬壳或软壳？
- 我们一直在关注这个问题。
我们可以看到折叠的发生，以及这种不寻常的起伏。
如果它是一个硬蛋、
我们将期待分裂的碎片和破碎的碎片、
就像一个鸡蛋。
这有助于告诉我们，它是软的。
- 所以它也许像一只乌龟？
- 绝对的。
- 恐龙就不是这样了，是吗？
许多恐龙产硬壳蛋。- 是的。
- 所以这是一个关于阿兹达奇翼龙的新发现？
- 绝对的。这是一件
这是我们首次确认的。
- 哼!
飞行翼龙有像乌龟一样的蛋。
- 是的。
比起鸟类，更像爬虫类。
而这有可能告诉我们更多
关于这些鸡蛋所处的环境。
- 多么有趣。是的。
产软蛋的生物往往会把它们埋起来
以保护他们。
鱿鱼
所以雌性翼龙可能会寻找
像坦尼斯这样的地方产卵......。
...因为这里的沙质土壤足够柔软
孵化出的雏鸟要自己挖出来。
嗅觉
现在，翼龙只是要确保
那个洞...
...是完美的。
鱿鱼
莺歌燕舞
成功了!
但这还没有结束。
翼龙有两个卵巢、
他们成双成对地产卵。
在这里的沙岸上、
夹在河流和这些光荣的树木之间、
塔尼斯的生活似乎正在蓬勃发展。
喘息
呜呼!
从来没有一个沉闷的时刻。
但这一切即将改变。
导致恐龙灭绝的一系列事件
开始于遥远的过去，在太空深处。
大多数科学家认为这一切都开始于一个尘埃环、
岩石和碎片被称为小行星带。
这通常是一个不平静的地方。
但人们认为，在许多、许多百万年前、
一块石头被撞到了新的轨道上......
...并转入与地球相撞的轨道。
罗伯特正在构建一个生动的画面
在塔尼斯的晚白垩世生活。
而研究小组又发现了一些保存完好的脚印。
- 所以这些是真正在水中行走的动物？
- 这些人基本上都会在
泥沙俱下的河岸
在某些时候喝酒。
你知道，动物往往聚集在河流周围。
- 这个印刷品长30厘米。
- 所以我想这是来自一种恐龙。
我们称之为鸭嘴龙的恐龙。
而且它们在白垩纪会非常普遍。
他们吃了该地区的植物
而且它们变得非常大--30英尺长。
- 而且还有更多。
- 这个轨道，你看所有的脚趾都保存得非常好。
你甚至可以在脚趾尖上看到一个指甲印。
于是，小脚趾甲钻进了泥土。
我喜欢这个人。
- 这是罗伯特珍贵的脚印。
它有三个脚趾、
而且它比它的宽度要长。
所以它很有可能是一种肉食性恐龙。
它保存得非常好，你可以看到
它尖锐的爪子在那里留下的痕迹。
地狱溪是众所周知的
特别是对于一种食肉动物--T-rex。
这个脚印对于一个成年的T-rex来说太小了、
但有可能是由一个年轻的人做的。
罗伯特还在塔尼斯发现了这个--
牙齿的牙冠。
它的形状和锯齿状的边缘
有迹象表明，它来自
来自一只成年的T-REX。
咆哮的咆哮
深沉的隆隆声
增长
在T-rex的骨头上发现咬痕
显示他们吃了其他的T-rexes。
而一个年轻人会很容易接住。
嗅觉
但这次不是。
很少有脚印被作为化石保存下来
在地狱溪。
因此，如果你在一个地方找到几个、
正如罗伯特所做的那样、
这是一个合理的假设
附近会有更多的人。
而这也支持了这一观点
恐龙和翼龙在Tanis兴旺发达
撞击前不久。
咆哮
而如果他们正在茁壮成长...
颤抖吧
......他们一定是在繁衍后代。
与T-REX相似的恐龙化石
显示它们可能已产下约20个蛋
在一个圆形的巢穴中。
有可能，像鳄鱼一样、
他们将鸡蛋部分覆盖以保持温暖。
嗅觉
对于一只T-rex来说，是一种不幸。
但对于所有的恐龙来说...
咆哮
...一场灾难正在逼近。
在太空深处，这颗小行星正在接近。
它的旅程将带着它穿越轨道
我们的邻星，火星的。
如果这两者相撞了、
地球上的灾难就可以避免了。
但这是不可能的...
......地球的命运也就注定了。
随着罗伯特的挖掘继续进行、
他对在坦尼斯发生的事情的看法
终于开始了。
看来沙岸上充满了生命力。
T-rex, triceratops、
小哺乳动物、
与其他恐龙和翼龙的脚印并列、
都在一个非常小的区域内。
爆炸
- 你看到天平了吗？
- 我愿意。哦，我的上帝。
- 光是看着它，我就觉得很兴奋!
- 然后，罗伯特发现了一些真正了不起的东西。
- 看到已经形成的裂缝了吗？看看这个。
因此，我们必须在胶合之前真正监测这一点。
因为这现在变得很脆弱。
- 一个几乎完整的生物。
- 为了把这个区块弄出来，我们要把它冷冻起来。
- 罗伯特正准备尝试一些棘手的事情。
- 稳住...我们走吧。
- 为了将化石完整地取出来，他们正在尝试
用液氮冷冻它
在零下近200度。
- 注意你的脚步。
洛伦，我担心这里会变脆。
拿起那把锤子。用锤子敲打一下这个。
好的。移动超过五厘米。好的。
它的裂缝松动了。好的，松动了。
- 所以我们必须把这个东西完整地取出来。
一、二、三。
Yeehaw!
完全成功。- 完全成功。
- 这是在考古学中使用的一种技术
用于挖掘人类遗骸。
我们有足够的时间来与化石合作
而不是损坏它。
而我不能再高兴了。
- 罗伯特发现的那个生物呢？
一只乌龟。
这就是现在已经被清理过的化石。
它是侧躺着的。
这是它外壳的轮廓。
这里的壳的形状和扇形的边缘
告诉我们，这是一只巴尼德龟。
罗伯特的巴尼德龟看起来非常相似
到现代库特龟
并生活在同一种淡水环境中。
对于乌龟来说，坦尼斯本来是最理想的。
温暖的浅水。
有很多吃的。
还有很多安全的地方可以取暖
在晚白垩世的阳光下。
罗伯特发现的海龟化石几乎是完整的。
这是底面、
这上面的棕色物质是木头化石。
它是一根棍子的末端，直接穿过它的身体
并在这里出来。
因此，证据指向了
这只乌龟已经被刺穿。
众多生物中的一个暴力终结者
在Tanis的碎屑岩层中。
- 当我看着这些动物
以及保存在塔尼斯沉积物中的植物
和它下面的脚印、
我看到的是一幅充满活力的生态系统的画面、
许多不同的恐龙，以及一个繁荣昌盛的地方。
- 经过十年的挖掘、
现在有足够的证据来拼凑
塔尼斯的大部分故事
和生活在这里的生物。
罗伯特发现了这么多化石，看起来好像是、
甚至在晚白垩世的最末端、
坦尼斯的生命力迸发了。
各种动物叫声
充满了曾主宰地球的巨型爬行动物
超过1.5亿年的时间。
吠叫
不可能知道还有多长时间
他们的统治会继续下去...
鱿鱼
...因为这一切即将结束。
小行星击中...
...在现在墨西哥的尤卡坦半岛上。
它被称为Chicxulub小行星
在离其火山口中心最近的城镇之后。
咆哮声
咆哮
撞击范围内900英里的任何生物...
...被爆炸摧毁。
但这种影响对坦尼斯产生了什么影响、
近2,000英里之外？
要找出答案、
罗伯特正在寻找可能与坦尼斯有关的线索
到小行星撞击的实际日期。
爆炸
- 我们有一些木材、
并压在这个上面，所有的东西都交织在一起、
我们已经得到了鱼的尸体。
- 好的。
那是一个保存完好的尾巴、
因此，那条鱼将是绝对华丽的。
- 因此，我们现在正在做的部分细节工作是
是进入和检查出
这个大规模死亡层中的所有单个元素。
- 迄今为止，他所发现的一些证据
已被隐藏在鱼本身的内部。
- 在更多方面，它实际上是一个白垩纪的行动。
鱼，所以我们要对这个东西进行手术。
- 罗伯特需要打开这条鱼的头骨。
- 而且非常小心，我们要把这个分开
从其余的鱼中。
好的。
在这里，我们走了。
打开了鱼。
有一只漂亮的蚂蚁在那里安了家。
而且很美，看看这个。
好的，这里我们有鱼的鳃条。
那些是固定鳃丝的条状物。
而在鳃条之间、
所有这些圆形物体的集群、
那些是喷出的球状物。
- 抛射物球体是曾经是熔融岩石的小球。
它们可能是罗伯特所怀疑的证据 --
这里的生物都死了
在小行星撞击的那一天。
- 这些喷出的球状物最后一次见到阳光
当它们在660亿年前的空气中飞行时。
- 在一次大型小行星撞击后、
汽化和熔化的岩石混合体
被推进到太空。
在那里，它冷却了、
凝固成微小的玻璃液滴。
一些人继续向太空深处前进。
但大多数被重力拉回地球。
在一个大的小行星撞击之后、
数以万亿计的喷出物球体将从天而降。
然后，经过数百万年的时间、
地下的压力和化学反应
将使他们中的大多数人变成粘土。
它们看起来是这样的。
因此，在鱼的鳃部发现球状物、
正如罗伯特在坦尼斯所做的那样、
建议鱼把它们吸进去
而球体仍在下降。
所以这些生物可能已经死亡
在小行星撞击的时候。
一旦罗伯特开始寻找喷出物球体、
他发现越来越多、
并意识到塔尼斯的厚实、碎裂的岩石层
充满了他们。
- 我的意思是，这东西是去...哦，我的上帝，看那一个。
这些东西实在是太华丽了。
像这样的喷出物球状体
给我们一个他们来自哪里的指纹。
- 如果这些球体被连接起来
到Chicxulub撞击、
那么，整个碎石层可能充满了证据
在小行星撞击的那一天发生了什么。
- 这是个好问题。
- 哦，那是一滴水珠吗？
- 要看看是否是这样的情况、
罗伯特需要找到一个没有变成粘土的球状物。
- 哦，我的上帝，那是一个美丽的水滴。
- 好的。
- 小块的橙色材料
罗伯特和洛伦正在挖掘的
也许能够提供帮助。
它们是琥珀色的。
- 如果当时有什么东西在空中飞过、
这就是它要被抓住的地方。
- 他们正在收集的琥珀曾经是粘稠的树脂
从晚白垩世的树干中渗出。
这是树保护自己的一种方式、
就像伤口上形成的结痂。
被树脂覆盖的任何东西都会被冻结
在一个琥珀色的时间胶囊中。
如果他们发现一个保存在琥珀中的球状物、
它可以被分析
看看它是否来自Chicxulub小行星的撞击。
- 所以在这一批中、
我们非常幸运地遇到了
两个完全没有改变的球体。
- 这个球状物可能是令人惊奇的东西。
证据保存得很好，可以分析出化学线索。
如果是的话、
它可以将坦尼斯与奇克苏鲁布撞击直接联系起来
和恐龙的最后一天。
为了调查，罗伯特加入了
在钻石光源
作者：自然历史教授菲尔-曼宁、
曼彻斯特大学的。
他们已经进行了初步测试
在美国的球状体上。
到目前为止，你发现了什么？
- 这些小玻璃球，这些球状物
撞击地点的熔融物质
有一种化学信号，将其与它们的来源联系起来。
因为当小行星撞击时、
它融化了它所遇到的地面、
但同时，玻璃有
有一点来自小行星本身的污染。
而这给了你一个独特的地球化学指纹。
- 我们扫描过后就可以看到、
并查看了北达科他州其他地点的球体、
我们可以得到一个基线
对于喷出物应该是什么样子，当它与
Chicxulub火山口。
而你可以在这里看到每个元素
以及这些元素的比例。
而当我们看向坦尼斯时，就会发现它是一个匹配。
我的意思是，它完美地叠加了。
所以我认为这是有力的证据
支持Tanis和Chicxulub是有联系的。
- 这些发现又意味着什么呢？
对于你在坦尼斯发现的其他化石？
- 这个数据是整个网站的关键、
因为一旦你有了这个链接
而你知道什么影响了坦尼斯、
那么你基本上知道该网站的每个对象、
所有的动物和植物以及所有被埋葬的东西
在这些沉积物中、
是与白垩纪的最后一天有关的。
- 还有英国这里的同步加速器
揭示了一些更显著的东西。
- 所以这是在显示一个美丽的同步辐射扫描
一个球体的一半。
玻璃是一个很好的地球化学指纹、
而且我们还有钙和一些铁、
我们已经得到了锶、
但当我们看到整个事情、
我们看到了一些非常出乎意料的东西。
这是你的整个球体。
- 这是什么？
- 在这一点上，我们已经有了一点小插曲。
那里有一个小颗粒。
所以我们扫描它。
而这里面有很多铁。
在这里，我们已经得到了铬，铬的一个大峰值。
在这里，我们有一个镍的大高峰。
以及铁、镍和铬的丰度、
都在一起、
这与你期望在陨石体中看到的情况相符。
这与你在这里通常会有的情况不符。
- 那么这就是外星材料？
- 如果你是来磨练的
并将一块陨石塞进一个球体、
这就是它将会是什么样子。
- 这可能是Chicxulub小行星的碎片。
- 一块杀死恐龙的子弹。
- 不!
罗伯特本可以找到
在Tanis的一个小行星本身的碎片、
将这个地点与奇克苏鲁布撞击联系起来的实物证据。
但坦尼斯几乎在2000英里之外
从小行星撞击的地方。
那么，它究竟是如何造成这些生物的死亡的呢？
为了回答这个问题、
罗伯特正在大规模死亡层中搜寻。
- 就在这里，我们已经有了这个相互纠缠的鱼群。
这里有一条鱼，另一条鲟鱼往这边走、
桨鱼的身体下面。
还有一条鲟鱼是这样走的、
在这根木头下面，继续从另一边出来。
他的头撞上了那根木头
并以90度角向下偏转。
- 罗伯特发现了一团纠缠在一起的生物化石和原木
被球状物所包围
并被压在一起，这就是所谓的木头人。
他有一个理论，认为这些生物是被扫荡过的。
在某种湍急的水流中死亡
并迅速被埋在沉积物中、
这就是为什么它们被保存得如此完好。
但是，是什么原因导致了这一浪潮？
一种理论是海啸。
小行星在海上撞击。
最近的研究表明
它可能已经引起了几乎一英里高的波浪。
波浪的高度会逐渐减少
随着它在海洋上的传播。
在晚白垩世、
北美洲被一个狭窄的海洋分割开来
这被称为西部内陆航道。
海啸可能沿着这个方向前进、
朝着坦尼斯。
但是关于海啸的想法有一个很大的问题。
的时机。
- 哦，那是哪条鱼？
那是一个新的...这是一个新的联系人。- 新的一个。是的。
- 如果海啸杀死了鱼、
它将不得不打
而喷出的球状物正在下降...
...因为在鱼的鳃部发现了球状物。
那么，在撞击后多久，球体到达坦尼斯？
- 假设这个铝箔球是一块弹射物
从火山口出来的时候。然后，它将走上一条弧形路径、
弹道轨迹，走出火山口
并将其送到任何地方--在这种情况下，坦尼斯。
如果我们知道我自己之间的距离
和着陆点，如果我们知道那个球的大小、
我们可以准确地计算出需要多长时间才能到达那里。
- 其结果令人惊讶。
罗伯特和他的团队计算了
这些抛射物球体降落在塔尼斯岛。
撞击后13分钟至两小时之间。
如果一个波浪把鱼杀死了、
它也必须在两小时内到达坦尼斯。
近期海啸的数据显示
即使是功能强大的，也要比这长得多。
从撞击地点前往近2,000英里的地方
到坦尼斯。
所以，如果不是海啸的话、
是什么原因导致了塔尼斯的涌水？
Stein Bondevik教授是海啸方面的专家。
- 挪威的峡湾非常特别。
我们有高大的山脉围绕着水体。
因此，水面通常非常平静。
- 2011年，发生了一件非常奇怪的事情。
峡湾里的水开始剧烈地移动。
- 水的高度增加了1.5米、
如同漩涡一般的湍急的水。
有人说，峡湾正在沸腾。
- 雷声隆隆
新闻开始滚滚而来--
5,000英里外的日本发生了地震。
- 当地报纸的一名记者给我打电话、
他说，人们正在观察波浪
在这里，在峡湾。
我得到了一个关于海浪的视频剪辑。
我立即看到，他们看起来像海啸的浪潮。
所以在下午晚些时候、
你可以看到，峡湾是完全平静的。
但在这里的海滩、
你可以看到，水在来回晃动、
没有人见过这样的事情。
而有些人变得非常不安和害怕。
- 一场九级地震摧毁了日本的东北部、
福岛周围。
但这对如此遥远的峡湾有何影响？
- 所以在挪威没有人能够感觉到地震、
但我可以看到，时间是吻合的
在这里，在峡湾，波浪的到来。
- 最终，斯坦因和他的团队意识到
这可能与地震波有关。
迅速通过地球的冲击波
在地震期间。
- 因此，只用了12分钟就出现了第一个信号
日本地震的消息一直传到这里、
到挪威西部。
- 原来是地震波
导致峡湾中通常平静的海水
来回晃动。
- 仅仅想到这一点，从科学的角度来看，这真是太棒了。
- 类似的事情会不会发生在坦尼斯？
- 一个大的天气前线正在穿过西北地区...
- 试图找出
是地球物理学家马克-理查兹教授、
几年来一直在研究坦尼斯的遗址。
他正在与罗伯特合作，发现
是什么原因导致了这里的涌水。
- 海啸不可能在至少12小时内到达这里。
但是，从尤卡坦撞击地点传播的地震波
到北达科他州的人可以相当迅速地到达这里。
- 在晚白垩世，西部内陆海道
瓜分北美，可能与Tanis有关。
通过一个河流系统。
- 如果你有一个非常大的水体、
像西部内陆海路、
而且你可以来回摇晃它、
你可以产生一个大的水波
在Tanis的这条河上。
- 因此，撞击产生的地震波可能会造成
塔尼斯河系统中的水流涌动。
- 地震波很快就会到达这里、
沿着塔尼斯河而来、
淹没这一地区，同时到达的还有
这些球状物仍在从空中落下。
- 波浪的奥秘
和厚厚的碎石层已经解决了。
穿越地球的地震波
可能在塔尼斯造成强大的水流涌动...
...可能携带泥浆和海洋生物、
像氨化石一样，来自西部内陆海道的
......把他们扔在坦尼斯沙岸上，埋葬一切
在球状物落下的同时。
超过数百万年、
泥浆会变成碎石层。
- 这就是塔尼斯的魅力所在。
你所看到的是一个存款
那是字面上的记录，比如说，最后的记录、
白垩纪的45分钟到一个半小时。
- 如果恐龙的灭绝是一种犯罪、
破案的侦探会有大量的证据。
他们会看到，这颗小行星是
在正确的时间和正确的地点。
他们会看到，没有恐龙幸存下来
击后。
他们会有一块凶器 --
一个小行星的碎片。
但他们会错过一件非常重要的事情--
一个身体。
从来没有人发现过恐龙的化石
被小行星撞击的影响而死亡的。
但罗伯特确实发现了三角龙的一部分
在坦尼斯的碎石层中。
因此，这可能是遗体
的恐龙在这一天死亡？
- 我仍然对号角心存疑虑。
我有点想把喇叭放在夹克里。
- 我想如果你把它拿下来、
至少要把这一部分拿掉、
来看看这下面发生了什么。
- 是吗？
- 为了找出答案，该小组需要确定死因、
当你只有一块皮的时候，这可能是很困难的。
和一个号角去了。
这是他们清理过后的喇叭。
该团队对这里的这些线路特别感兴趣。
而他们发现，骨折的人去
贯穿喇叭的权利。
因此，与其说是因冲击而死亡、
他们想知道它是否在一场战斗中被杀。
但当他们更详细地观察这些骨折时、
他们在这里发现了新的骨骼生长的迹象。
这表明骨头已经开始愈合。
因此，看起来好像三角龙活了下来
的事件，打破了它的号角。
这只三角龙能不能活下来
直到撞击的那一天？
该小组发现了证据，包括皮肤下垂、
这表明下面有腐烂的地方。
这意味着它的身体已经开始腐烂
在它被埋葬和被涌浪保存起来之前。
这样看来，这只恐龙并没有因此而死亡
的小行星撞击。
也许，在撞击前的几个月里、
残缺的角把三角龙的
与其竞争对手相比，处于不利地位。
咕噜声
而这可能会导致饿死。
霹雳啪啦
风的嗖嗖声
罗伯特仍然没有找到直接证据
一个被小行星杀死的恐龙的。
- 我们现在已经有了所有这些骨头在地下。
但有一件事，我们只是梦想
的发现是，一只恐龙
在撞击当天死亡的。
- 而且天气对他的搜索没有帮助。
呻吟声
- 那幅治疗仪的图案被烤焦了。
- 是的，那是在一个低矮的角落里。
看，满是泥浆。- 它充满了泥浆和水。
问题是它是湿的，看。
看吧...如果我们不小心，我们就会失去印刷品。
而这是我们得到的最大的兽脚类动物图案。
我看到有些地方现在也可以使用胶水。
- 该小组正在竞相挖掘脚印、
连同几十种鱼类化石
在风暴将它们冲走之前，它们纠缠在一起，形成了一个僵局。
雷声隆隆
- 我们在这里与时间赛跑。
这些现在就可以曝光的东西
是要被雨毁掉的。
- 但后来，罗伯特遇到了一件事
这看起来很不寻常。
- 这是去那里。
那里发生了什么事？
- 我们确定这不是鳄鱼人吗？
- 这不是鳄鱼人。- 不是。
- 对了，让我在这里试试这一块。
我从上面进去，然后往上拧、
而它就在这条线上分离了。
- 哦，那是皮肤，就在那里。
那实际上是有鳞的皮肤。- 哦，我的上帝。
- 不，不，不，不，不。看，看，看。
看看这个模式，就在那里。
你以前见过这样的拉长的鳞片吗，戴夫？
- 这真是疯了。- Scuttelates - 在鸟类中。
- 只是要小心。
- 哦，我的上帝。- 它又开始变化了。
- 它又开始变化了。- 哦，我的上帝。
我们是6600万年来第一次看到它。
我认为我们已经有了自己的恐龙。
- 一块恐龙化石!
而且，与三角龙不同、
这位于日志中，是大规模死亡层、
被鳃部有球状物的鱼所包围。
- 这是我们在这里可能想象到的最不可思议的事情。
最好的情况是。
我们正在挖掘这个大规模死亡的鱼层
冲击所带来的激增、
而我们已经有了恐龙的残骸。
我们总是想在这个地方找到一件事、
而在这里，我们已经得到了它。
这是不真实的。我-我-我-我无法在我的大脑中处理这个问题。
不，我绝对被这一点所震撼。
我的心简直要从胸腔里跳出来了
想知道那后面是什么、
只是在露头的几厘米处。
后面有什么在等着我们？
把它拿出来...
这是...
- 团队继续挖掘。
- 这一边的天平又变大了。
- 所以这可能是一个肋骨、
它可能是躺在弯曲的肋骨上。
- 这里有一些东西。
这很难。- 再来点骨头。
- 那是紧挨着皮肤的骨头。
是的，那是一个关节面，就在那里、
因此，这要么是一个臀部，要么是一个肩部元素。
- 经过几个小时的艰苦工作...
- 而我们可以从动物的大腿开始。
这就是膝盖。
然后你有小腿的肌肉
的恐龙，它们隆起来了、
而你则是到了脚踝骨、
而这些是脚趾头。
我们在脚趾尖上有指甲。
这是一条保存完好的腿、
都是有关节的，用皮肤覆盖。
- 恐龙的完整腿。
- 在我最疯狂的梦想中、
我从来没有想到会在这个矿床中找到一条恐龙腿。
- 是的，我是说，然后它有皮肤和组织。
它确实看起来就像一个鼓槌。
- 它看起来像一只感恩节的火鸡、
只是铺在地上的。
还有动物大腿上的这种奇怪的鳞片图案、
这一点我们以前从未在恐龙身上见过。
- 好吧，龙族没有任何形式的防御、
所以他们必须要有伪装或其他东西。
- 这是一个很好的观点。
所以这可能是某种伪装标记。- 是的。
- 罗伯特认为他已经找到了有关的尸体------。
恐龙，它本身可能见证了
灾难性的影响。
- 恐龙化石不为人知
从白垩纪的最后几年开始。
而且还不清楚它们是否已经灭绝了
或在下降或发生了什么事。
所以他们只是有点缺席。
而这就回答了这个问题。
当时恐龙还在那里吗？
嗯，是的--这个人很可能死于那场大潮。
- 对于这种大的说法，罗伯特需要核实。
他把恐龙腿带到了伦敦
以获得第二个意见...
- 然后这里是脚趾的垫子。
我们看到所有这些美丽的鳞片排成一列。
- ...来自保罗-巴雷特教授、
鸟脚类恐龙专家
来自自然历史博物馆。
那么你认为这可能是什么呢？
- 当我们看腿的时候，它有爪子、
就像我们在小型的、敏捷的、两足的、奔跑的恐龙身上看到的爪子一样
是吃植物的。
我们可以排除像三角龙这样的东西、
部分原因只是因为它不是大块头和粗壮。
而这些腿的比例也是不同的
从我们看到的其他一些吃植物的人、
在他们有这样一个相当长的脚踝
与其大腿骨相比，小腿和胫骨。
因此，当我们缩小这些可能性时、
我们剩下的可能是什么、
是一种叫作thescelosaur的动物。
- 尖叫声
栉风沐雨的龙族生活在河流旁边
那里有大量丰富的植被可供食用。
他们有叶子形状的牙齿、
在食草动物中很常见、
和短小的前肢上的爪子 --
非常适合挖掘。
尖叫声
嘎吱嘎吱
但罗伯特的翼龙是怎么死的？
它可能是被另一只恐龙杀死的吗？
- 这是个可能性。
这是一种相对灵活的动物。
而这种速度的转变将是
它对生活在它身边的大型捕食者的主要防御。
- 所以，为了躲避饥饿的T-REX、
恐龙的第一道防线...
BARKS
......本来是要跑的。
但它可能还有另一个防御性的技巧。
咆哮
生活在河流旁边、
恐龙有可能能够游泳。
- 在我看来，似乎没有任何证据
这只动物是被捕食的
没有明显的齿痕
或食肉动物牙齿的残余碎片
以表明它已经被吃掉了。
- 那么你认为它是怎么死的？
- 它死的时候并没有什么特别讨厌的疾病、
因为我们可以看到，骨头看起来还不错。
因此，这是一种可能是活的动物
在它发生这种情况的时候，它是健康的。
- 这可能是流星撞击的受害者吗？
- 我想这是完全可能的。
这实际上是一个肩骨、
而这块骨头在一个活的动物身上
实际上会在这里的路上。
同样地，这里的这块小骨头
将从大约三分之一的方式
沿着尾部，也许是一半的位置。
因此，不知何故，这两块骨头被伸缩到了一起。
因此，也许这只动物已经被翻来覆去了。
我们已经排除了很多其他的可能
该动物的死亡原因。
因此，这很可能是一种动物
在那里，被翻来覆去的
在其死亡的阵痛中，在那条河里、
作为小行星撞击的结果。
- 嗯，这完全是类似的
对那些在庞贝古城发现的人体尸体。
- 在你得到那种快速的埋葬方面，它非常相似。
- 是的。而且它几乎是令人回味无穷的。
- 这绝对是事实。
你真的有一眨眼的时间
在白垩纪末期、
猛然间进入历史，就在那里、
准备被挖出来。- 哇哦。
笑声
经过多年的调查、
罗伯特发现了一个很大的问题
关于住在坦尼斯的生物、
他知道，他们中的许多人在那个决定性的日子里还活着。
当小行星摧毁了我们的星球。
但他们到底是怎么死的？
罗伯特的发现现在使我们能够讲述那一天的故事
并最终回答这个问题。
地球历史上最重要的日子之一
可能开始时和其他晚春的早晨一样。
我们知道这个季节是因为罗伯特发现了年轻鱼的化石，这些化石
在每年的那个时候，它们达到的规模就已经死亡。
这与已经发现的证据一致
由其他科学家。
也许这一天，会以如此多的死亡来结束、
从不同的事情开始。
一个新的生活。
咳嗽
鱿鱼
没有人可以确定一天的确切时间
当小行星与我们的星球相撞时。
但据估计，在撞击后短短40分钟内、
对坦尼斯生物的后果
将是深刻的。
根据罗伯特的发现
和其他科学家的最新证据、
这就是这场灾难可能发生的情况。
这颗小行星的宽度约为7英里、
比珠穆朗玛峰还大...
...并以接近45,000mph的速度飞行。
撞击导致爆炸
比十亿颗广岛原子弹还大。
在将近2000英里外的坦尼斯，...
...它完全无声。
但在撞击现场...
...小行星汽化了。
超过三万亿吨的岩石
被射入太空
在一场超热的暴力爆炸中。
风速高于600mph。
一场巨大的地震，接着是一圈巨大的海啸。
嗡嗡声
动物呼叫
与此同时，坦尼斯的生物们
去做他们的事...
嗷嗷叫的动物叫声
...就像其他任何一天一样。
运作
点击
沃尔贝斯
嗅觉
雷声隆隆
鱿鱼
证据表明，小翼龙
从蛋中出来，准备自食其力。
而这包括...
...飞行？
嗯，差不多。
在其他地方，随着破坏力在北美蔓延开来
朝着塔尼斯...
...恐龙和各种形状和大小的生物
在爆炸中被湮没。
在坦尼斯，还有几分宝贵的时间、
生活照常进行。
但时间在流逝。
哼哼唧唧
深色的花
撞击产生的爆炸声从未到达坦尼斯、
但地震冲击波会。
嗡嗡声
珊瑚礁
他们的力量要大得多
比有记录以来的任何地震都要大。
深色的黄褐色
颤抖吧
剑龙可能会前往一个安全的地方...
......但地震波现在正慢慢地摇晃着
整个地区，造成水的晃动和搅动。
在塔尼斯，河中的奇怪水流
给出了一个仍将到来的暗示。
霹雳啪啦
接下来，天开始下雨了。
制图
抛射物球体正在落回地球。
当球体开始下降时...
......摩擦将它们加热至红热。
然后热量转移到空气中。
温度每秒钟都在上升。
随着热量的增加，坦尼斯的生物们
正在为他们的生命而战。
咆哮
然后，作为地震波
继续慢慢震撼整个地区...
...十米高的猛烈浪潮
在塔尼斯河上奔腾。
在激增的湍流中求生存
即使对最好的游泳者来说也是一个挑战。
然后，河流系统的强大摇动
慢慢地开始把水引回原路。
游泳可能拯救了
在过去的日子里，有一种叫作 "无尾龙 "的动物、
但这次不是。
像T-rex这样的大而强壮的动物
可能在激增中幸存下来。
如同硬壳爬行动物可能一样。
但还有更多的事情要做。
随着数十亿吨的过热球体不断坠落、
大气层变得更热了...
.点燃枯叶，引发野火。
地震、
火...
...破坏性。
几乎没有人能够长期生存、
在陆地上...
咆哮
...或在空中。
震撼
咕噜声
当空气达到工业烤箱的温度时...
...那些生活在地下深处的人
可能有更好的机会。
随着河流系统的缓慢荡涤继续进行...
......另一个强大的浪潮袭来。
毁灭是无法逃避的。
对于坦尼斯的许多生物来说、
他们的故事在水下结束。
在不到两个小时的时间里，世界已经永远改变了。
海浪留下的泥土
将逐渐转变成厚厚的碎石层
埋葬那些死在这里的生物...
...直到6600万年之后、
当它们最终被挖掘出来时。
罗伯特的发现帮助我们非常详细地了解了
在坦尼斯发生的事情
在小行星撞击后的几分钟内。
但世界上其他地方呢？
冲击引发了灾难性的事件
如地球上的地震。
随着球体的不断坠落...
......野火可能已经在全球各地涌现。
随着那个可怕的日子接近尾声、
世界上的许多恐龙已经死亡。
研究表明，小行星撞击的角度
以及撞击地点的富含硫磺的岩石
扩大了破坏力。
十亿吨硫磺
被射入大气层、
挡住了太阳光。
没有光，大多数植物死亡，食物变得稀少。
随着几周和几个月的时间过去、
任何活着的恐龙都会死于饥饿。
在海洋中，情况也是如此。
世界上几乎所有的浮游生物都消失了、
导致大多数海洋生物的饥饿。
人们认为，随后的核冬天
造成全球气温下降
至少25摄氏度。
化石记录告诉我们，这种巨大的气候变化
标志着所有物种中四分之三的消失、
包括恐龙。
这个星球在半黑暗状态下大约有十年的时间、
当灰尘和烟尘慢慢落到地球上时。
但随后出现了一些奇妙的事情。
一个新的开始。
一旦灰尘从大气中清除
阳光回来了...
...植物生命逐渐恢复、
由蕨类植物领导、
它的孢子在地下深处蛰伏着、
而世界开始再次变成绿色。
但是动物们呢？
回到坦尼斯，罗伯特发现了一些东西
这可能有助于拯救一些生物
破坏性的火灾。
- 我们看到一个小东西探出头来、
因此，我们也就顺藤摸瓜。
我很高兴我们这么做了、
因为我们在这里看到的是一个化石的洞穴
来自6600万年前的一种动物。
那时候唯一的动物会在附近出现
可能会建造一个像这样的洞穴
将是小型哺乳动物，大概有雪貂大小、
还有一些爬行动物。
如果是来自哺乳动物，这算是一个窗口。
了解我们在这里的一些最古老的祖先的生活方式。
这家伙会从侧面钻进去的、
直接进入河岸。
我们实际上在那里有一些划痕
他们在挖掘的时候，从内部挖出来的、
回去后，他就会住在这里了
并寻求避开恐龙的庇护
因为他们只是不想被吃掉。
- 洞穴是部分原因
哺乳动物在大灭绝中幸存下来。
在核冬天期间、
一个洞穴可以提供温暖、
保护，以及一个储存食物的地方。
幸存下来的哺乳动物是机智的杂食动物、
和昆虫将是一个丰富的食物来源。
而且他们还有一个优势--他们的规模。
如果条件合适，许多动物物种会变得更大
因为它们经过数百万年的演变。
以T-REX为例。
这是下颌骨的石膏
的前身，称为高尔基龙、
它生活在7200万年前。
而这是T-REX的下颌骨模型、
它生活在500万年之后。
看看尺寸上的差异。
但是，越大的生物越好、
他们需要更多的能量来维持生命。
因此，当灾难来临时，食物匮乏、
规模最大的往往会消亡、
而最小的往往能生存下来。
这就是其中一个原因
为什么许多小型哺乳动物
在巨大的黑暗中生活。
而且他们并不孤单。
罗伯特的化石龟可能是不走运的、
但还有许多人活了下来。
鳄鱼也是如此、
蛇、
和许多鱼种。
而至于恐龙、
撞击真的把他们都杀死了吗？
那么，这根美丽的羽毛化石
并非来自鸟类、
但来自掠夺性恐龙。
所以我们必须小心
当我们说恐龙已经灭绝的时候、
因为我们称之为鸟类的东西最初是由
从最小的带羽毛的恐龙。
所以为了正确起见，我们应该说
所有非鸟类的恐龙都已灭绝。
罗伯特的发现为我们提供了
一个比以前更好的想法...
...关于导致灭绝的那一天发生的事情...。
...地球上有史以来最大的野兽。
恐龙也许是
一些自然界中最不寻常的生物、
主宰地球超过1.5亿年
在它们灭绝之前。
但灭绝是以不同形式出现的、
和许多惊人的生物
和今天活着的植物也受到了威胁。
有可能是人类正在发生
对世界的影响一样大
作为结束恐龙时代的小行星。
作为人类，我们的能力是独一无二的
向遥远的过去学习。
现在我们必须明智地使用这种能力，并尽最大努力
以保护数以百万计的物种
对他们来说，与我们一起，这个星球就是家。