All language subtitles for Jurassic.Ghost_.Town_.A.Mass_.Murder.Mystery.2023.720p.done

[Ronan]
The badlands of Wyoming,

the heart of the Old West,

hidden in these remote canyons

is a prehistoric murder scene.

[Phil]
I have never seen anything
like this in my whole career,

and I've been studying
dinosaurs a long time.

[Ronan] In this single square
mile of desert,

lie the remains of at least
a dozen dinosaur giants,

including their footprints...

-What do they eat?
-...their food...

[cooing]

...and signs of a brutal,
bloody showdown

...and signs of a brutal,
bloody showdown

between some
of the biggest creatures

that ever walked the planet.

[Phil] It's the whole package
on the Jurassic world.

If you want to open up
the curtains,

look back in time and say,

"What did the Jurassic
look like?"

This is where you come.

[Ronan]
Now, with this unprecedented
body of evidence,

a crack team
of world-class scientists

is carrying out an epic
crime scene investigation.

Kind of the... the ultimate
smoking gun.

It always puts the animal
at the scene of the crime.

It always puts the animal
at the scene of the crime.

[Ronan] To solve
a 150-million-year-old
mystery...

Why did so many dinosaurs
die here?

[Ronan] The dinosaur dig site
is an hour by truck

[Ronan] The dinosaur dig site
is an hour by truck

from the nearest town.

It's called the Jurassic Mile.

And its location is so secret,

it's known only to a handful
of paleontologists.

[woman] [indistinct]

[Victoria] Welcome, guys.

I think we got a pretty good
game plan for today.

So, Taylor, safety, weather.

On site, it's gonna be
about 110 degrees Fahrenheit.

If you got to work for five
and take a 10-minute break,

the dinosaurs have been here
for millions of years.

the dinosaurs have been here
for millions of years.

They can last 10 more minutes.

[Ronan] This remote corner
of the Wild West is a harsh

and inhospitable place.

Extreme summers
and brutal winters

mean there's just
a tiny window,

when people
can work out here.

We have a relatively
short dig season,

about six
to eight weeks usually,

and that is mostly due
to Mother Nature.

And it's wet out here.

The roads become impassable
and then extreme heat too.

[Ronan] But since 2017,

an international
team of scientists,

led by The Children's Museum
of Indianapolis

has endured the summer heat.

Intent on peeling back
the layers of rock,

inch by inch...

To reveal a lost world,
when today's arid desert

was covered by lush
Jurassic Forest.

[Ronan] The Jurassic Mile lies
within a vast rock bed

[Ronan] The Jurassic Mile lies
within a vast rock bed

called the Morrison Formation,

which spans 12 Western states

and is one
of the richest deposits

of dinosaur fossils
on Earth.

Nestled in the far north
of Wyoming's Bighorn Basin,

it's a one-of-a-kind sight,
even for seasoned experts.

So far, over 3000 bones
have been unearthed,

including skeletons
of 10 sauropods,

including skeletons
of 10 sauropods,

remains of at least
five predatory allosauruses,

and parts of a Stegosaurus.

This year, the team
is unearthing so many fossils

that it's struggled
to keep on.

[Jennifer]
This site is the gift
that keeps on giving.

We've got large theropod
coming out over there.

We've got this very exciting,
articulated tail

We've got this very exciting,
articulated tail

from a sauropod
coming over here.

[Ronan] Paleontologist,
Dr. Jennifer Anne

manages the dig site.

[Jennifer] As you can see,
it's all hands on deck.

There's a lot of pressure

to get done
as much as possible.

You really want to see
what's there.

You want to get it out
of the ground.

[Ronan] But digging up
fragile fossils is a gamble.

After 150 million years
in their safe,

After 150 million years
in their safe,

rocky tomb,

every bone is at the mercy
of the elements

from the moment
it's exposed.

Wyoming's wild weather
could destroy

vital clues
in a matter of days.

The day has barely begun
for Prof. Phil Manning,

one of the lead scientists
here,

and he's already been called

and he's already been called

to check out
a potential new dinosaur.

[Phil] What have you got?

So, I was cleaning up the wall

for the stratigraphic column

and found this nice big
limb bone right here--

[Phil] Ooh.

Can I have that?

Wow.

[man] It's a bit cracked--

Oh, it's going into that,
it's going in, it's going in.

[Ronan] Another bone means
another chance

to solve the mystery of why
so many dinosaurs died here.

to solve the mystery of why
so many dinosaurs died here.

[Phil] Some sites
you find bones.

Some you find tracks,

and some you find
fossil plants

or other creatures that lived
at the time of the dinosaurs.

Here, you find everything.

That's what makes
this site so important.

[Ronan]
First question for Phil.

What kind of dinosaur
did this bone belong to?

Well, it,
it's definitely a limb bone.

-[woman] Yeah.
-There's no question
on that.

And it's from a big animal.

So judging
by the... the depth
and the size of this,

we're probably dealing
with a sauropod dinosaur.

we're probably dealing
with a sauropod dinosaur.

[Ronan] These huge
plant-eating reptiles

dominated
the Jurassic Wild West.

At least 24 different kinds
roamed the forest,

including
the famous diplodocus

and brachiosaurus.

Sauropods were
the biggest creatures

ever to walk the planet.

Sauropod dinosaurs really were
the giants of the Jurassic,

at over 90 feet in length.

That's like putting
three Greyhound buses
end to end.

The next could be over
25 feet in length

and their tails twice
as long as that.

[Ronan] At the far end
of the site,

another huge bone
is now Phil's biggest problem.

This is a massive
shoulder blade

This is a massive
shoulder blade

from this vast
sauropod dinosaur.

[Ronan]
He believes this fossil
could be a crucial key

in understanding
how some of the dinosaurs

might have died here.

[Phil] Hopefully,
by close of play today,

we can lift this thing.

It will move
for the first time

in 150 million years.

[Ronan]
It's not just the bone itself
he's interested in,

the way it's buried and even
what's hidden beneath it

could all help to answer
the question.

But to reach that evidence,
Phil has to dig up the bone.

But to reach that evidence,
Phil has to dig up the bone.

To protect the crime scene,

Phil needs to stabilize
the bone

inside a protective jacket.

[Phil] You cannot flip
the bone this big

without having a nice bandage

holding everything
in or hugging it.

[Ronan] Just like a cast
on a broken limb,

this mixture of plaster
and burlap

should hold
everything together.

But it's extremely heavy.

And how much do you reckon
is the weight, Peter?

Two, three hundred pounds.

Yeah.

A mere 200, 300 pounds.

A mere 200 to 300 pounds
of dinosaur.

And that's just the scapula.

[Ronan] It's the riskiest part
of the whole job.

[Phil] At some digs,
you can see

these horrific situations

where bones
or even whole skeletons

have been lifted up
and the jacket utterly fails.

And the animal then sort
of turns to dust

and drops out of the underside
of the jacket.

That's the worst-case
scenario.

-[man] Oh, we can...
-[man] Keep moving.

[man] Keep going.
Can you touch it there?

Yeah. Just checking,
it's flat. Go for it.

[man]
Do you want to put a couple
of chisels under there?

-The long chisels?
-[man] Yeah.

[man] One, two, three.

[man] Keep going,
keep going, keep going.

Nice one.

Woo-hoo.

Ho-ho, look scapula.

That's amazing.

That's beautiful.

There... there you go.

There... there you go.

Six foot four.

When we talk about
our own height,

we think of like,
"I'm five foot nine."

This bone
is a little over six feet.

So standing next to me,

this is the length
of the bone.

[laughing]

[Ronan] Keeping the bone
in one piece

isn't the only good news.

Underneath it,
Phil has struck gold,

a jumble of different fossils,
including parts of a tree.

[Phil] You've got
a complete mash of bones

[Phil] You've got
a complete mash of bones

and plants and trunks
washed together,

creating this complete mess,
basically.

[Ronan] To Phil's trained eye,
it all points to a potential

cause of death
being swept away

by a fast flowing river.

[Phil] Large chunks of rock

being dragged along
the bed of the river.

That means the river
is in flood to pick up,

move big chunks of rock along.

And if you ever look
at a river,

where there's a log-jam
and piled up logs,

um, this is the sort
of structure

that would have caught
the bodies of these dinosaurs.

that would have caught
the bodies of these dinosaurs.

[Ronan] Phil reckons
that a river flowed here

150 million years ago.

Oh, yes.

Oh, that's beautiful.

Looks like a trunk
and some branches coming off.

[Ronan] And he thinks
that a violent storm

once turned it
into a death trap

for at least one dinosaur.

It ended up in a watery grave,

washed in
with a huge flood deposit.

[Ronan]
But did the dinosaur drown

or was it dead
before the flood?

Phil can't be sure,

but there was certainly
water here

and lots of it.

Could this be the reason

so many dinosaurs
came to visit the site?

Lower down the hill,

the team has discovered
more evidence of water.

Ripples like
geological fingerprints,

preserved in mud,
that may once have lain

preserved in mud,
that may once have lain

at the bottom
of a very shallow pool.

These ripples
didn't form yesterday.

They formed
150 million years ago,

when there was
a few millimeters of water

covering
what was this mudflat.

[Ronan]
Phil thinks this was not
a dangerous river,

but a life-saving
watering hole.

So like this pond-like
environment, shallow water,

the wind was blowing,

the surface
of the water creating

these beautiful ripple marks.

[Ronan] It could have drawn
dinosaurs to drink here

[Ronan] It could have drawn
dinosaurs to drink here

in huge numbers.

If you go to a waterhole today
on the savanna of Africa,

you will see a lot of animals

drinking at the side
of that waterhole.

It's a very, very busy place.

[Ronan]
Dr. Victoria Egerton wants
to find out

if the area was some kind
of sauropods' Garden of Eden,

if the area was some kind
of sauropods' Garden of Eden,

an oasis of plentiful food.

You can see the bits of fossil
give things a light--

[Ronan]
It's the kind of evidence

that's usually
very hard to find.

But once again,

the Jurassic Mile
is different.

Not only do we get some
really awesome dinosaur bones,

but we get plants.

This is incredibly rare.

It is a treasure trove
of information
for the Jurassic,

It is a treasure trove
of information
for the Jurassic,

not just about the dinosaurs,

but about the environment
that they lived in as well.

[Ronan]
Uncovering these secrets
from the remote past

is what brings Victoria
back here year after year.

What I enjoy
most about paleontology

is that it's storytelling.

You're recreating
this environment

and trying to understand
how these animals live

and what the world
looked like.

[cooing]

[Ronan] Victoria finds
plant fossils everywhere.

It's clear evidence
that this area
was green and lush,

but in a way
that was very alien to us.

During the Jurassic,

the plants and landscape
was pretty different.

We had no flowering plants.

That means no fruits,
no vegetables, and no grass.

You're gonna eat
what's available.

Everything from ferns
to cycads,

Everything from ferns
to cycads,

as well as lots
and lots of conifers

like monkey puzzle trees.

[Ronan]
She soon finds evidence
of a water-loving weed

called horsetails.

That's really nice.

So, right here,
if you look at this one,

what we have here
is Equisetum or horsetail.

And you can see
the stem right there.

And we've got some
little tiny leaves attached.

[Ronan] There may be
plenty of them,

but they're tough
and hard to digest.

but they're tough
and hard to digest.

If this was all there
was to eat,

how did these giant dinosaurs
get enough nutrition?

Did these sauropods starve
to death?

[Ronan] High
in the Wyoming desert,

a dinosaur graveyard
is emerging from the ground,

and a team of scientists
is investigating

the scene of the crime.

They want to know what killed
these Jurassic giants.

[Phil] Wow.

[Ronan] So far,
the team has found

the fossilized remains
of 10 dead sauropods,

huge, long-necked dinosaurs

like diplodocus
and brachiosaurus,

like diplodocus
and brachiosaurus,

along with evidence of their
strictly herbivorous diet.

These super-sized animals
had appetites to match,

but only tough,
low-nutrition plants
to sustain them.

Was the Jurassic Mile

too popular
as a dinosaur diner?

Did they run out of food,
too weak to move on

to the next
life-saving Eden?

[Ronan] The answer may come
from living animals.

[Ronan] The answer may come
from living animals.

These enormous reptiles
are giant tortoises.

Together with birds
and crocodiles,

they form a group of animals

that are the closest
living relatives to dinosaurs.

Biologist, Dr. Stephen Blake
and wildlife vet,

Dr. Sharon Deem

have been researching
these animals for 12 years,

both here at the zoo

and in the animal's
natural habitat

on the Galapagos Islands.

on the Galapagos Islands.

[Stephen] All right.

See how big this one is.

Here we go.

[Ronan] They're investigating

how tortoises maintain
a healthy diet.

Here in the zoo,
the tortoises are treated

to a daily vegetable buffet.

But in the wild,
it's a very different story.

In the wild,
the tortoises have to,

uh, eat both low-quality
forage and lots of it.

[Ronan] Just like
Jurassic sauropods,

[Ronan] Just like
Jurassic sauropods,

the tortoises can survive
on poor-quality food

that would be unable
to support other large animals

because a cocktail of bacteria

in their gut helps
to break it down,

extracting precious nutrients
locked inside.

[Sharon] They can really get
a lot of energy,

calories, minerals, vitamins

out of food that may be
less, less quality

than it would be
for someone like us.

[Ronan]
But they're eating strategy

[Ronan]
But they're eating strategy

leaves them
with the same problem

as our sauropods.

Even with their
specialist digestion,

their food is so low
in nutrition

that they need
to eat huge quantities.

Eventually, they eat
everything in sight.

In the dry season,
on the Galapagos,

the lowlands receive
no rainfall

and are very dry
and become very desert like.

There's very little
food around.

[Ronan] Sharon and Steve
decided to find out

how they get around
this problem.

By fitting GPS trackers

to a group
of Galapagos tortoises,

what they discovered
was a huge surprise.

As their own
graphic model reveals

when they run out of food,

hungry giant tortoises
go on a hike.

Well, nobody knew tortoises
migrated, within six months,

we realized that
this phenomenon was real.

we realized that
this phenomenon was real.

When the food runs out
in the lowlands,

they moved to a higher ground.

[Sharon] Giant tortoises go
from the lowlands,

where the food quality is low
to the highland,

where they have a...
what we call
a salad bowl of choices.

[Ronan] Slowly clambering
more than six miles

through volcanic
boulder fields,

its equivalent
to a human walking

from New York City
to Philadelphia.

[Stephen] Tortoises
are not known
for their sprinting abilities.

[Stephen] Tortoises
are not known
for their sprinting abilities.

Having said that,

they're a lot more mobile
than people

give them credit for.

[Ronan] Finding enough food
throughout the year

is a major challenge
for big animals.

As they grow larger,
so does their need to feed.

We always say giant tortoises
need a lot of food,

but you imagine a sauropod

needs a colossal
amount of food,

so they got to move
and to get out

of one habitat into another.

You've probably got
to move a long way,

maybe hundreds of miles.

It's the same
evolutionary solution

It's the same
evolutionary solution

to the same problem.

[Ronan]
As food supplies withered
in the Jurassic dry season,

the watering hole

could have been
a vital rest stop

on the way to higher,
greener ground.

But sauropods were many times
bigger than giant tortoises.

How can we know
if they were just as mobile?

Animal movement expert,
Prof. Bill Sellers,

is trying to find out
if sauropods

weighing up to 80 tons

were capable
of making long journeys.

He's discovered
extraordinary evidence

that could help
to answer that question.

Super-sized
dinosaur footprints.

I'm interested
in how dinosaurs moved.

And one of the best pieces
of evidence we have

about dinosaur movement
is footprints.

about dinosaur movement
is footprints.

[Ronan] These fallen rocks

were once a patch
of fine sand,

higher up the hill,
and baked into them,

are the tracks of a sauropod

that walked
by 150 million years ago.

You can see the toe marks here
and you can see

the base of the foot
in some detail

'cause they have
rather cylindrical feet

that stick into the ground.

[Ronan] Just one preserved
footprint is a precious find.

But a trackway
of multiple prints

is an information goldmine.

If we actually
go higher up the cliff,

we can start
to find other footprints.

So, here, we have another
sauropod footprint,

and it's been
cut in half here.

This is almost certainly
from the same, um,

the same trackway as that.

[Ronan] From the pattern
of the footprints,

Bill can use a finely-tuned
computer program

to find out
how this leviathan walked.

to find out
how this leviathan walked.

We can take measurements
from things

like the length of the stride
and the size of the foot,

and then we can use
that to produce a scaled

model of the dinosaur
we think made the tracks.

We have put on the muscles

that we expect to find
for an animal this size.

And then, we can use
the computer simulation

to try and make it
actually walk in

the trackways
that we'd measured.

[Ronan] Best of all,
Bill's program can calculate

[Ronan] Best of all,
Bill's program can calculate

the dinosaur's top speed.

It's surprisingly high.

Diplodocus didn't dawdle.

These guys can walk at about
7.5 meters per second

simply because they can walk
with really long legs.

So, in fact, um,
it's quite fast.

[Ronan] At more than 15 miles
an hour,

sauropods were as swift
as Olympic athletes.

And easily capable
of the long journey

to summer-feeding grounds.

Along the way,

stopping off
at the Jurassic Mile,

like a roadside diner,

for life-saving
food and water.

So, if it wasn't starvation

or exhaustion that killed
all these giants, what did?

[cooing]

[Ronan]
Phil is eager to find out.

[Ronan]
Phil is eager to find out.

He's sifting carefully
through the death site

in search of clues.

But approaching clouds
are a warning

that should never be ignored.

Bad weather is bad news
for fossils,

and many of the most crucial
new discoveries

are also the most delicate.

Ripples in the sand,
footprints,

Ripples in the sand,
footprints,

and fragile plant fossils
could be destroyed overnight
by heavy rains.

[Phil] This is the first time
they've seen the light of day

for 150 million years.

If the weather hits before
the bones are
out of the ground,

it's a potential disaster.

[Ronan] Jen's team rushes
to protect the fossils,

but the rain can quickly
cut off the site.

They need
to make their escape.

Nice weather for ducks.

The storm is coming.
We got to go.

The storm is coming.
We got to go.

Go, go, go.

[Ronan] Now all that protects
this open grave

are a few layers of plaster
and tarpaulins.

Phil can only hope
it's enough.

[Ronan] In the high desert
of Wyoming,

a mysterious
dinosaur boneyard

is emerging from the rock
after 150 million years.

Up here,
conditions change fast.

And last night,
a ferocious storm
battered the site.

The lightning show
that that one put on
was really amazing.

I've never really seen

I've never really seen

lightning that widespread
and constant.

[Ronan] Storms can destroy
crucial evidence

that could solve the mystery

of what killed
these dinosaurs.

First job of the day
is to check for damage,

starting with a mound

where Phil's spotted
signs of bone

from an unidentified dinosaur.

It's a pain when the site
gets wet

'cause it means
you start picking up bone

and stuff on your feet
and that damages the site.

and stuff on your feet
and that damages the site.

[Ronan]
But the team is in luck.

All the evidence is intact.

Phil's investigation
can continue.

So far, the team has found
the fossilized bones

from 10 sauropods.

Giant dinosaurs like
diplodocus and brachiosaurus

that dominated
the Jurassic landscape.

They're trying to reconstruct
this prehistoric crime scene

to figure out why so many
of them died here.

Victoria is examining some
very special bones

from another
sauropod dinosaur.

They reveal an ancient link

between dinosaurs
and modern birds,

which could provide
the best evidence yet

of what killed
these giant beasts.

What we have is the neck bone

and curving
into this one

and getting smaller
as we go this way.

[Ronan] There could be
as many as 15
of these sauropod neck bones

containing crucial clues.

containing crucial clues.

With a tiny head
on the end of a 20-foot neck,

sauropods looked like

one of nature's
great mistakes.

Imagine having
to hold your arm out

and hold a giant rock,

and that's what you have
to do the rest of your life.

Your muscles
would get really tired.

[Ronan] Their long necks look
almost impossible to hold up.

But to get
around this problem,

sauropods had a surprising
evolutionary secret

sauropods had a surprising
evolutionary secret

hidden inside their necks.

Sauropod dinosaurs are some
of the weirdest animals

ever to have walked
on the planet.

And the adaptations

that these organisms
evolved over

millions of years to become
so big are fascinating.

They are the walking
suspension bridges

of the fossil world.

[Ronan] But new research
reveals this secret

may have occasionally
been their undoing.

At the Museum of the Rockies,

sauropod expert,
Dr. Cary Woodruff

is investigating
a collection of fossils,

unearthed from another site
in the Morrison formation.

This is from
a long-necked dinosaur

that we discovered,
and we named this animal,
Dolly.

It gets that name
after country Western singer,

It gets that name
after country Western singer,

Dolly Parton.

So Dolly was alive
about 150 million years ago.

[Ronan]
Examining Dolly's neck bones,

Cary spotted a clue
that gives

an unprecedented glimpse
into the life
and death of this dinosaur.

Well, if we look
at a normal sauropod
vertebra here,

you see the bone
along these areas

is incredibly smooth

and sometimes
almost glassy like.

But I knew something
was special about Dolly

But I knew something
was special about Dolly

because as soon as I looked
at those same areas,

we see that rough
and wrinkled bone

and even coming outside
of some of those sockets

are this weird,

almost broccoli-like
irregular bone growths.

[Ronan] The growths appeared

on several
of Dolly's neck vertebrae.

Puzzled,
Cary shared his discovery

with colleagues
around the world.

I literally took a picture
of these features

and posted it on social media

and said,
"What the heck are these?"

[Ronan] One reply
was from a veterinarian,

who recognized these marks
as a serious bone infection.

And the only way
they could explain
the infection

was by a respiratory disease
that normally affects birds.

The group answer was,
"Holy cow,

we've never seen
a respiratory infection
in a dinosaur before."

[Ronan] Cary wondered
how a bird lung disease

could affect Dolly's bones.

The answer lies
in the surprising way

The answer lies
in the surprising way

that sauropods
solve the problem

of holding up
their massive necks.

Paleontologists
think sauropod chests

held large chambers
called air sacs.

They kept the lungs constantly
supplied with oxygen.

Smaller tube-shaped air sacs

ran all the way
along the neck,

surrounding the bones

and filling
their hollow cavities.

This may be the secret

This may be the secret

to how sauropods held up
their long necks.

Taking the place
of dense bone,

the air-filled tubes made them
light enough to lift.

Modern birds

are distant descendants
of dinosaurs,

and birds too have air sacs.

They reduce weight enough
to allow for flight,

but they have a big downside.

They increase birds' risk
of serious infection.

We were able to hypothesize
that Dolly had air sacculitis,

We were able to hypothesize
that Dolly had air sacculitis,

and that
respiratory infection,

the air sacculitis was so bad

that it actually caused
a secondary bone infection.

[Ronan] Using modern
CT-scanning technology,

Cary can work out

just how advanced
the infection was.

[Cary] Dolly would have
had labored breathing,

probably sneezing
and nasal discharge,

and, basically,
the same symptoms

that we think
of that we've all had

with the cold or flu
or pneumonia.

with the cold or flu
or pneumonia.

[Ronan] The scans reveal
that Dolly's air sac infection

had spread
deep inside the bones,

causing illness far more
serious than a cold.

Here we have a case,
from 150 million years ago,

of an individual dinosaur
that was sick.

And it was so sick,
it probably died

from that illness.

And I think those are

the closest thing
to time machines

we'll ever get
these little windows

and literally moments
in the life of a dinosaur.

[Ronan] Were the dinosaurs
at the Jurassic Mile

victims of their own design
and died of disease?

So far, Dolly's
are the only sauropod bones

discovered
with this type of infection.

Until similar evidence
is found at the Jurassic Mile,

the team will need
to keep looking

for other potential killers.

The answer
may soon be at hand.

Back on site,

Jen has unearthed
another spectacular discovery

that may be the lead
they're looking for.

[Ronan] This new find revealed

that the long-necked sauropods

weren't the only visitors
to this watering hole.

And the others may have
had murder on their mind.

In the Wyoming Badlands,

a 150-million-year-old
crime scene

is emerging from the ground.

A team of paleontologists
is trying to figure out

how 10 giant
sauropod dinosaurs

met their end right here.

Investigations have revealed
that some of the dinosaurs

may have been killed
in sudden floods

and also that their
neck-lightening air sacs

and also that their
neck-lightening air sacs

could risk severe infections.

Now, Jen may have discovered
a major new suspect...

A skeleton that reveals
the long-necked sauropods

weren't the only visitors
to this watering hole.

Right here,
we have a large theropod.

We've got back, we've got hip,

all the way back
to a lovely tail.

[Ronan] Lying just feet away
from the emerging tail bones

of a plant-eating sauropod,

of a plant-eating sauropod,

her diggers have uncovered

the backbone
of a ferocious carnivore.

Jen thinks this may be
a skeleton

of the apex predator
of the Jurassic Wild West,

Allosaurus.

[Ronan] Eighty million years
before T. rex,

allosaurus was the king
of the Jurassic Frontier.

[cooing]

[Ronan] It attacked its prey
with razor sharp,

serrated teeth
and powerful grasping arms.

serrated teeth
and powerful grasping arms.

So was this watering hole
the site of a bloody clash

between predator and prey?

And since
both bodies fell here,

who came out on top?

To find out, Jen needs
to study this apex predator.

That means getting it out
of the ground

intact to look
for signs of violence.

But it's lying in a bed
of super hard rock.

We've actually
broken rock saws

and crowbars on this.

So it's gonna take some
special kinds of equipment.

[Ronan]
They've had to bring in
an air-powered mini jackhammer

to chip away at the stone.

The first thing is just like
feeling the vibrations

and feeling a bit scared

that you have something
powerful in your hand.

[Ronan] This tool brings
its own danger.

'Cause the scribes
are powerful enough

to go through sandstone,
they, of course,

are powerful enough
to go through the fossil.

are powerful enough
to go through the fossil.

[Ronan]
It's painstaking work.

Just one slip could shatter
a 150-million-year-old relic,

ruining the evidence
of what killed this dinosaur.

Jen's crack team
is starting to make up time.

But the badlands
don't always play fair.

Out of nowhere,

squalls are whipping up
sand and dust

into an abrasive blast.

into an abrasive blast.

[woman] Yeah, it's got
to come down now, guys.

[woman 1] Okay.

[woman] We got to move
towards Jen and Liz.

Yeah, back this way.

There's another dust devil
coming over, so.

[Ronan] Dust devils can create
winds up to 60 miles an hour.

[woman] Can we get some help,
guys?

Thank you.

[Ronan] Every fossil exposed
to the winds is in danger

from this sudden
sandblasting storm.

[woman] Welcome to Wyoming.

Raise for a second.

Yeah, yeah.

Yeah, yeah.

We're hanging on.

Moving.

Let your fingers hold in.

[woman] [indistinct]

Ooh, another one coming.

Out of nowhere.

[screaming]

Ooh.

[Ronan] Six years of work
is at the mercy
of the wild weather.

But it's getting dangerous

and they need
to make a run for cover.

Next morning,
Jen arrives on site early

to assess the damage.

Come on, buddy.

How'd you survive?

Ooh.

Oh, thank God. You look good.

This fossil
is already very exposed,

so it could have gotten
a lot of abrasion damage.

Looks like maybe
one piece broke.

So, uh, that's the only thing
that broke.

That's good.

[Ronan]
They've had a lucky escape,

but Jen isn't going
to take any chances.

Another dust storm
could hit any time.

They quickly cover
the exposed bones
in protective plaster.

And as soon
as the jacket is set...

Yeah.

Yeah, well, I think, I think
this one's going to be tricky.

...it's time to get them out
of the ground.

First, they need to flip
the jacket over.

First, they need to flip
the jacket over.

[Jennifer] What I'm gonna
have you do

is, if you all of a sudden
can't reach anymore,

I'm here to help
pull this part

because we have the femur
and all that there,

so we have to be careful.

[Ronan] But there's a chance
the bones will fall out

as they leave the surface,
destroying precious evidence.

[Jennifer]
Phil's got the middle,
Rachel's got this side.

We're flipping it towards me.

Things are gonna fall,
probably.

Don't freak out.

We'll just cry later.

Okay, Rachel, go.

-[Rachel] Are we ready?
-We are ready.

-[Rachel] Are we ready?
-We are ready.

Three, two, one.

Let's go. Go, go, go, go.

Go, go, go, go,
go, go, go, go, go!

Oh, my God. That worked.

Ah! Ah!

-Yes.
-[Ronan] They've done it.

The jacket has held firm.

Oh!

Oh, my God.

I thought so much
was gonna fall out.

[woman] I thought everything
is gonna fall out.

[woman] Yay!

[Jennifer] Boom,
that's how you flip
an allosaurus.

It looks pretty darn good.

[Ronan] Jen's allosaurus
could be the chief suspect

in a multiple
sauropod murder mystery.

But was this predator
powerful enough

and fast enough
to kill an 80-foot giant

that they now know

was as fast
as an Olympic athlete?

[Ronan] High in the desert
of the Old West,

a team of scientists

is unearthing
a remarkable story,

frozen in time
for 150 million years.

They're discovering evidence
of an epic showdown

between predator, prey,

the fearsome allosaurus
and the gigantic sauropod.

Their Jurassic crime scene
places allosaurus

as the main suspect
in a case of dinosaur murder.

as the main suspect
in a case of dinosaur murder.

But was it up to the task?

Biomechanics expert,

Pasha Van Bijlert
wants to find out.

He's investigating
if allosaurus

could catch
a fleeing sauropod.

He's pioneering a new method
of calculating dinosaur speeds

with a detailed
computer model,

based on the size
of their bones

based on the size
of their bones

and the bounce of their tails.

Potentially,
it might have been
able to run very fast,

but we don't know yet.

[Ronan] He's found
the ideal specimen

to answer the question.

Its leg bones
are perfectly preserved.

Right now,
I'm measuring the left tibia,

which is the left shin bone.

It's about 23.5 inches.

[Ronan] Pasha soon has
all the measurements he needs

to see how this predator moves

to see how this predator moves

for the first time
in 150 million years.

And to find out
if allosaurus had the pace

to catch a speedy sauropod.

It's actually a bit more work
than I would have liked.

Right.

[Ronan] Bill Sellers
is teaming up with Pasha

after discovering
that sauropods

could move
at 15 miles an hour,

as fast as Olympic athletes.

Bill has researched
the top speeds

of different predatory
dinosaurs

of different predatory
dinosaurs

in past studies.

You have these
wonderful pointy sources,

but we did a T. rex
and allosaurus,

various other theropods.

We came up with top speeds

from this of about 8 meters
per second for the T. rex.

Uh, so, it's the slowest.

And then, just over 10 meters
per second for the allosaurus.

[Ronan] Using his models,

Bill estimated
that both predators

might be able to run
at nearly 20 miles an hour.

But he discovered
a big problem for big T. rex.

But he discovered
a big problem for big T. rex.

It was only when we started
looking at the bone loading

that the really high speeds
on the T. rex seemed unlikely

because, as you know,
when you run faster,

you put more stress
on the bone.

[Ronan] Bill concluded that
if T. rex tried to run,

it would break its own legs.

At best, it could manage

little more than
a 10-mile-an-hour walk,

not even enough to catch
a sauropod at full tilt.

not even enough to catch
a sauropod at full tilt.

But can Pasha's
prototype model

reveal whether allosaurus
was fast enough

to catch a speeding sauropod?

Allosaurus was further away

from T. rex than T. rex
was from us.

So there are bound to be

many differences
between these animals.

[Ronan] His research takes
into account

the built-in bounce
of allosaurus' tail.

He's shown that their tails
had a natural rhythm

like a pendulum,

and he believes that
if they stepped in time

with that rhythm,
they could walk much faster.

with that rhythm,
they could walk much faster.

We treated the entire tail
as this big

rod suspended by springs.

And if you find
the natural frequency of this,

um, I think this gives you
a good idea

of the step frequency.

So, it's much more sort
of pogo-stick-type locomotion,

relying on elastic storage.

[Ronan]
With all the data entered
into Pasha's test model,

his allosaurus
quickly gathers speed...

And runs at an astonishing
25 miles an hour.

And runs at an astonishing
25 miles an hour.

Compared to T. rex,

allosaurus was like
a thoroughbred racehorse.

It could easily outpace

a retreating sauropod
like diplodocus.

The team has shown that
sauropods and allosauruses

both visited
this watering hole

and allosaurus
had the speed to run down

the giant herbivores.

But maybe
it wasn't just about speed,

But maybe
it wasn't just about speed,

it was about surprise too.

If so, how could
a three-ton allosaurus

creep up on a sauropod

and launch an attack
without being noticed?

To answer that,

scientists are studying
living animals.

At Whipsnade Zoo
in England...

Dr. Beth Mortimer

Dr. Beth Mortimer

and Dr.Tarje Nissen-Meyer

are researching animal senses.

Hopefully, they would come
through the fence here

and we can pick up
the vibrations--

Hopefully.

[Ronan] Beth and Tarje
want to find out

how today's
biggest land animals

detect threats
like approaching predators.

In particular,

they want to see
whether elephants

can use
a special sixth sense,

which tunes in
to seismic vibrations

in the ground.

in the ground.

How far away do you think

we'll be able to pick up
the elephants?

Huh, completely depends on
what they're doing.

Let me try here.

[Ronan] Elephants
are the modern-day equivalent

of the Jurassic's giant
sauropods.

[Beth] The reason we studied
elephants to start off

with is because of their size.

Because elephants
are really large,

they're generating
a lot of motion in the ground,

kind of mini earthquakes,
if you like,

kind of mini earthquakes,
if you like,

just as they're moving around.

[Ronan] So, the way
they detect threats may shed

light on the way their ancient
counterparts did.

Ground vibrations are almost
undetectable to humans,

but can be picked up
by elephants through

special sensors in their feet.

We've got sensors
that are embedded

in our skin, uh,
which can detect vibrations,

um, and elephants
have a large number

of these types of sensors
on their feet.

[Ronan] Beth and Tarje
use a geophone,

[Ronan] Beth and Tarje
use a geophone,

a sensor that can detect
ultra-low vibrations.

-[Tarje] The audible sound,
are you recording them?
-[Beth] Yes.

We got the elephant coming
over here,

so we're just picking up, uh,
the vibrations
that she's making.

[Ronan] In her fieldwork
in Kenya, Africa,

Beth has shown that
seismic senses

are a vital part
of an elephant's
defensive system.

Her team records
seismic ground vibrations

Her team records
seismic ground vibrations

made by humans.

When these vibrations
are played back to elephants,

they are able
to interpret them

as dangerous
and quickly retreat.

Elephants are not alone
in tuning
into this infrasonic world.

Beth and Tarje have studied
this kind of seismic detection

in a number
of different animals.

And Tarje thinks that
one making vibrations

And Tarje thinks that
one making vibrations

as large as a sauropod
would also evolve
to detect them.

[Tarje] So, we know
many examples
in the animal world

that use seismic sensing.

So, it's... I think,
the best assumption to...

to think, well,
if there's a signal, um,

why shouldn't they use it?

[Ronan] It's likely these
giants could have detected

seismic signals
from a very long way away.

[Beth] Essentially,
the bigger they are,

the larger distances over
which they can communicate.

So, if you have
a larger dinosaur source

So, if you have
a larger dinosaur source

that might be generating
a vibration

through the ground, in theory,

that's then information that
could be propagating over
larger distances.

[Ronan] Just like their giant
modern-day equivalents,

Jurassic sauropods
would most likely be alerted

to any approaching allosaurus
by the quaking ground,

signaling every step
the predator took

and make their getaway
long before they were
in any real danger.

and make their getaway
long before they were
in any real danger.

But allosaurus
may have had one more

evolutionary trump card
to play.

In Montevideo, Uruguay,
Doctors, Nicolas Benech

and Ernesto Blanco
are researching

how predators like allosaurus
could fool their prey's
defense systems.

They visualize seismic waves
as ripples on the surface
of a water tank.

They visualize seismic waves
as ripples on the surface
of a water tank.

[Nicolas speaking]

[Ronan] In their test,
sauropod's round-shaped feet

cause vibrations to spread out
equally in all directions.

But predators like allosaurus
had triangular-shaped feet.

And when they took a step,
most of the vibrations

traveled out to the sides.

The waves ahead of them
were much weaker.

[Ernesto speaking]

[Ernesto speaking]

[Ronan] The scientists believe
this effect gave predators

like allosaurus
a crucial advantage.

Their sauropod prey
couldn't tell how close
they were,

which meant they could launch
a lethal lightning attack.

[Ernesto speaking]
[cooing]

[Ronan] It points
the finger of suspicion back

at allosaurus,
but it's circumstantial
evidence.

To finally prove the sauropods
at the Jurassic Mile
were its victims,

the team needs to place
these predators right next
to their prey.

And back on site,
Phil believes

he may have found
clear-cut evidence
that does just that.

Oh, look at that.

Beyond ridiculous.
It's beautiful.

[Ronan] A whole host
of dinosaur footfalls

preserved in Jurassic mud,
including one filled in

with rock in the exact shape
of the dinosaur's foot.

[Phil]
These are the coolest thing
on the whole site.

They're good ones.

[Phil] We've got footprints
literally all over this
whole surface.

[Phil] We've got footprints
literally all over this
whole surface.

These are some
of the best trackways
I have seen in the Jurassic.

They're absolutely beautiful.

[Ronan] Dinosaur footprints
are every bit as rare
as dinosaur bones,

but to find both
in the same place
is rarer still.

It's what makes
the Jurassic Mile so special.

And it shows Phil,
these animals did come
to the same place,

maybe even at the same time.

From these
shallow depressions,

we got both the hind feet

and the forefeet of
these big plant eaters.

and the forefeet of
these big plant eaters.

Right next to it,
there are huge tracks

of a big predator,

which I think is pretty nice.

That's behavior.

Kind of the,
the ultimate smoking gun.

It puts the animal
at the scene of the crime.

[Ronan] Phil's evidence
puts the predator

and prey together
in the same place.

But if they were here
at the same time,

a giant like diplodocus
would not have gone down
without a fight.

So, the team wants to know,
is there any evidence
of a struggle?

So, the team wants to know,
is there any evidence
of a struggle?

Did diplodocus
battle for its life?

In the wilds of Wyoming,
a dinosaur dig site

like no other
was being unearthed.

It tells the story
of a giant sauropod

facing off against
the deadly predator,
allosaurus.

Fossil evidence has put
the hunter at the scene
of the crime.

But was it really responsible
for the deaths

of the giant herbivores,

or were sauropods able
to defend themselves?

or were sauropods able
to defend themselves?

Lower down the hill,
Jen's team has found clues

of what could be
a defensive weapon.

The first bones
of an enormous sauropod tail.

[Jennifer]
One of the very interesting
discoveries

we have of this year
that was only found
a couple of days ago.

So, we've got a tail going
into the wall.

So, this is something
we really want to focus
on this year.

[Ronan] A sauropod's tail
could exceed 25 feet

in length and weigh
5,000 pounds.

in length and weigh
5,000 pounds.

Right now, we have one, two,
three, four,

five, six,
seven is poking out.

They can have about
80 bones in just the tail.

[Ronan] The tail was more
than five feet thick

at the base and tapered down
to the thickness

of a pencil at the tip.

[Jennifer] And the good news
is they're getting larger.

They're going from the size
of my pinky to something

that's gonna be like
serving plate size.

[Ronan] For decades,
paleontologists have wondered

[Ronan] For decades,
paleontologists have wondered

why sauropods
had such long whip like tails.

Was it part
of their defensive armory?

In Seattle, Washington,
a team is trying to find out.

They're headed up
by tech pioneer,
Dr. Nathan Myhrvold.

[Nathan] I was always
fascinated by dinosaurs
as a child.

And ever since the discovery
of the sauropod dinosaurs,

people wondered
what was this
enormous tail for.

people wondered
what was this
enormous tail for.

[Ronan] Nathan's company
specializes in solving

scientific mysteries
by thinking outside the box.

To decipher the riddle
of the sauropod tail,

they came up with this.

[Nathan] So, this is
a physical model of a tail

of a sauropod dinosaur.

Specifically, it's an exact
replica of an apatosaurus

that's in the American Museum
of Natural History.

that's in the American Museum
of Natural History.

So... So, this is
a one-quarter scale model.

So, it's around 12-feet long.

[Ronan] Even without
any soft tissue,

the lightweight
aluminum construction

is as close to the real thing
as Nathan's engineering team
can create.

The scale mass is correct
within less than a percent.

So, it's very accurate.

[Ronan] Now, it's time to see
what this model can do.

[Ronan] Now, it's time to see
what this model can do.

Immediately, Nathan detects
a problem with the fine,

delicate tip of the tail.

[Nathan] There are dinosaurs
that use tails

as defensive weapons,
and they almost always
have clubs or spikes

or something really nasty
on the end
to get something with.

The trouble is the end
of it is really skinny,

it's less than a garden hose.

It didn't seem plausible to me
that they were a weapon.

[Ronan] He believes the tail
wasn't designed for fighting.

Instead, he wonders
if they may have had

Instead, he wonders
if they may have had

a much less violent purpose,
communication.

Nathan believes
the tail's shape
could make it perfect

to act like a bullwhip.

Cracked with enough force
to create a sonic boom.

So, in the same way
that a human can pick up

a bullwhip and
with a very ordinary arm
can make it crack,

I think this would require
a negligible amount of energy

in the sauropod's part.

[Ronan] High-speed cameras
record the tail in action.

[Ronan] High-speed cameras
record the tail in action.

So, here, we are moving
the tail.

And what's gonna happen
is that tail...

this part here will get
flipped up, and boom,

there it gets flipped up
and that would be
the sonic boom.

[Ronan] Nathan calculates
that the tip of the tail

exceeds 760 miles per hour,
faster than the speed
of sound.

Scaled up to sauropod size,

the sonic boom it will create
may have traveled for miles.

the sonic boom it will create
may have traveled for miles.

It would be as loud as

the guns on a big battleship
going off,

an enormous cannon.

Kaboom!

[Ronan] Nathan thinks
sauropods may have
used their tails

to get a dinosaur date.

[Nathan] I think
it's a good chance

that they used this amazingly
loud noise

that they create
with their tails

as a form of competition.

You know, "Kaboom! See?

I can really crack my tail."

I can really crack my tail."

And then, the next guy says,
"Oh, yeah, you heard that?"

Kaboom.

[Ronan] Nathan doesn't claim
his is the only answer

to the mystery
of the sauropod's tail.

[Nathan] Just a question
of, okay,

what does the mathematics say?

If we do an accurate
engineering model,

what is the answer?

The answer comes out,
of course,

that it cracks supersonically.
[cooing]

[Ronan] If they didn't use
their tails as weapons,

their only real defense
against attacking

their only real defense
against attacking

Allosauruses was their size.

So, at more than 10 times
the weight
of its alleged assailant

was a sauropod just too big
for an allosaurus
to bring down.

This missing piece
of the predatory puzzle

could change everything.

Allosaurus
may not have hunted alone.

Victoria is examining evidence
that could solve that mystery.

[woman] Yeah.

[Victoria] Hey, guys.
What you got?

Hey.

[Ronan] Inside this large
stone slab are the jumbled

remains
of several allosauruses.

Within this block,
we have at least two,

maybe three allosaurus.

We've got a leg bone here
and then another leg bone
up there.

And one is significantly
smaller than at least one
other one.

So, the smaller one
was probably a juvenile.

So, the smaller one
was probably a juvenile.

[Ronan] Victoria thinks
it's no coincidence

that several predators are
buried together here.

If they died together,

it may mean
they lived together
in family groups.

That raises the possibility
that they hunted in packs

to take on
more massive prey.

[Victoria] To take down one
of those sauropods

would have been
incredibly difficult

because they're 10 times

or more than the size
of these allosaurus.

or more than the size
of these allosaurus.

So, the question is,
would the allosaurus

have tried to take down
an adult?

And if they did,
they would probably

have to do it together
and work as a pack.

[Ronan] Hunting in packs
would give allosaurus

a much better chance
of bringing down
a 16-ton sauropod.

But to nail this predator
as the killer,

the team needs evidence
of a murder weapon.

the team needs evidence
of a murder weapon.

[Jennifer] These are marks
left from teeth,

from the meat-eating
dinosaurs.

So, we're kind of
finding the...

the bullet wound
and the bullet.

[Ronan] At a secret location
in Wyoming,

the scene of a Jurassic
murder mystery

is revealing an astonishing
array of fossil evidence.

Clues that could solve
the mysterious deaths

of 10 giant
sauropod dinosaurs.

Chief suspects,
a marauding pack
of allosauruses.

[indistinct chatter]

[Ronan] Now, Jen is looking
for a smoking gun.

Nice parallel scraping
looking lines into it.

[Ronan] She's an expert
on ancient injuries
in fossilized bones...

and she's found something
that puts an allosaurus pack

as the prime suspects
in at least one giant
dinosaur death.

These are marks left
from teeth, from theropods,

so,
the meat-eating dinosaurs'

tooth marks are decent size.

So, it could be an allosaurus.

So, one of our...

our main culprits
for who's snacking
on our sauropod here.

[Ronan] Many of the sauropod
bones here
at the Jurassic Mile

are scarred with scrapes
from predator teeth.

And there's even stronger
evidence lying just nearby.

[Jennifer] So, Victoria found
this lovely tooth here

[Jennifer] So, Victoria found
this lovely tooth here

from a theropod,
a meat-eating dinosaur.

And it's probably
an allosaurus.

So, we're kind of finding,
like, the...

the bullet wound
and the bullet.

[Ronan] These razor-sharp,
serrated teeth

were highly specialized,
flesh-tearing tools.

And like, modern crocodiles,
allosaurus would constantly
replace them.

So, you could lose a couple
of teeth in one meal.

Some of these guys
are still fairly sharp

when you pop them
out of the ground,

even though
they're millions of years old.

even though
they're millions of years old.

Holding a tooth
from an allosaurus,
every time I do it,

I still have that little kid
go hee-hee, hee-hee,

inside, and it...

it's, it just reminds me
of one of the reasons

why I got into paleontology.

[Ronan] And there's not
just one tooth alongside

this sauropod skeleton.

[Jennifer] We have at least

50 teeth
from this site.

We've got a lot
of nibbling going on.

You know, what's,
what's the reason?

Is it that everybody
came in for one big feast?

So, the family is coming over
for Sunday roast kind of deal.

So, the family is coming over
for Sunday roast kind of deal.

[Ronan] Skeletons of multiple
allosauruses buried together

and dozens of teeth
from different animals.

This evidence could add up
to a feeding frenzy

by a whole pack of predators.

But this theory opens up
a new mystery.

Only the most intelligent
of modern animals

are capable of coordinating
pack hunting.

So, did allosaurus
have the smarts to team up
against its prey?

So, did allosaurus
have the smarts to team up
against its prey?

To find out, paleontologists
need to get inside its head.

In Athens, Ohio...

Prof. Larry Witmer
has amassed

one of the world's most
impressive collections

of dinosaur skulls and casts,
which he uses to study

their brain anatomy.

their brain anatomy.

This is the skull
of allosaurus,

a very famous specimen
known as Big Al.

I mean, just looking
at the skull,
we can tell a lot.

[Ronan] Larry uses
a CT scanner to look
inside skulls.

[Larry] CT scanning
has revolutionized our field,

but we can actually look
through the bone.

[Ronan] The scanner
measures differences

in density and builds up
a 3D model
of the internal structure.

[Larry] We can actually work
our way back

to where that brain would be.

And so, we can actually see
the brain cavity.

It looks kind of small inside
this really big skull.

[Ronan] This relatively small
brain cavity in a large skull

is common amongst dinosaurs.

This is why some scientists
have wondered if dinosaurs
were dumb.

But Larry believes
that size isn't everything.

So, we now know that
brain size is important

and how big your brain
is relative to your body.

What we've discovered is that
actually the structure

of the brain itself winds up
being potentially

even more important.

even more important.

[Ronan] Larry wants to know
what's going
on inside

an allosaurus' brain.

To find out,
he's turning to birds.

Birds are the direct
descendant of dinosaurs
like allosaurus.

And just like their ancestors,
they have very small brains.

But that doesn't stop them
from being clever,

versatile hunters
and even using tools.

Birds, it turns out,
have pretty remarkable
cognitive ability,

something we've discovered,
um, and really in the past
10 or 15 years.

something we've discovered,
um, and really in the past
10 or 15 years.

[Ronan] The secret
of a bird brain success

is in its compact structure.

[Larry] They actually have
a huge number of neurons

in that brain,
but they're smaller

and packed together,
much more tightly than
what we see in mammals.

[Ronan] By cramming
more brain cells
into a small space,

they have greater
thinking power

than was ever
thought possible.

Larry's scans revealed
that allosaurus brains

Larry's scans revealed
that allosaurus brains

had some strikingly
birdlike features.

We used to look
at a brain like this
and sort of say, like,

"Well, there's probably not
a whole lot going on here."

But the reality
is allosaurus probably

had much greater
cognitive abilities

than what we would have
ever thought in the past.

[Ronan]
This could have made it
a sophisticated hunter.

Perhaps even capable
of working in teams

to bring down
a 16-ton sauropod.

[Larry] Was allosaurus able
to solve problems,

[Larry] Was allosaurus able
to solve problems,

was it able to defeat
the defenses of...

of the prey species
and be an effective predator

because it was smart?

Was it capable of things
like cooperative hunting?

You know, 15 years ago,
we would have said,

"No, absolutely not."

But now
we're kind of going, "Maybe."

[Ronan] Fossil evidence
from the Jurassic Mile,

together with research
from around the world

is building
a compelling case that

is building
a compelling case that

pack hunting allosauruses
might have been responsible

for the deaths
of the super-sized sauropods

buried at the site.

But before they settle
on this solution,

Jen's team has one more lead
to investigate.

One that could blow
the whole case wide open.

At a secret location
in Wyoming,

the scene
of a Jurassic murder mystery,

a crack team has unearthed
an astonishing array
of fossil evidence.

The chief suspect is a pack
of marauding allosauruses.

But did these
ferocious predators really

have the upper hand
in this showdown?

Jen is trying to find out.

She thinks that allosaurus
may well have shared

many behaviors with successful
modern predators.

[Jennifer]
It's just remembering

that dinosaurs are animals.

Because we didn't get
to observe these animals,

we have to use what we,
we can observe in nature today

to understand
what went on in the past.

[Ronan] Nature follows rules
that stretch over
the eons of time.

And less than 150 miles away
in Yellowstone National Park

And less than 150 miles away
in Yellowstone National Park

live predators
that seem to have a lot

in common with allosaurus,
gray wolves.

They, too,
are intelligent pack hunters

and are often dwarfed
by their prey.

The 2,000-pound
American plains bison

is the wolves' most
dangerous quarry,

even when they're working
as a pack.

But according
to brand new research,

the predators are smart enough
to avoid a risky hunt.

the predators are smart enough
to avoid a risky hunt.

Like in summer,
bison rutting season,

males fight to the death
over mates.

Wolves wisely wait it out.

And when opportunity knocks,
switch up their behavior
from hunter to scavenger.

A bison is more than ten times
the size of a wolf,

just like allosaurus,
matching up to a sauropod.

[Jennifer] We've got
very large sauropods

that can get up
to 90 feet long.

that can get up
to 90 feet long.

In this landscape of giants,
the allosaurus

is a little guy compared
to everybody else.

[Ronan] And to Jen,
it's likely allosaurus

may have shared
wolves' cautious approach.

If this is the case,
her team may not be looking

at evidence of a murder here.

[Jennifer] And so, we've got
a lot of these little marks
from the teeth.

But if it happened
right before it died,

right after it died,
that gets to be
a more of a CSI question.

right after it died,
that gets to be
a more of a CSI question.

[Ronan] To expert eyes,
the injuries

on the sauropod skeletons
will look different

if they were caused
by scavenging
or frenzied attack.

But it's almost impossible
to tell in the field.

The remains will need
a careful autopsy.

For that, the bones
must be taken away
for cleaning and preparation,

which means
an 1800-mile journey

which means
an 1800-mile journey

to one of the most specialized
facilities on the planet.

Research Casting International
is a world leader

in assembling
dinosaur skeletons.

They're working
on two complete sauropods

from the Jurassic Mile.

There you go.

-Like this?
-All right.
Tilt towards Jamie a little.

Yeah.

Yeah.

[man] Okay.

[Ronan] They're destined
to become the centerpiece

of the brand new
dinosphere exhibit

at the Children's Museum
of Indianapolis.

With the bones cleaned
and mounted,

it's the first opportunity
for Phil and Victoria

to examine them properly.

Oh, wow.

[Phil] That...
that is awesome.

[Ronan] Phil is looking
for the telltale signs

[Ronan] Phil is looking
for the telltale signs

of careful butchery
by an intelligent scavenger.

[Phil] You get back to the lab
and you've removed

all of this caked dirt
and mud.

You can suddenly see
the wood for the trees.

[Ronan] On the cleaned bones,
bite marks
are clearly visible.

[Victoria] The predatory
dinosaur tried to bite it

multiple times, or maybe
other predatory dinosaurs

also tried to take off
a little bit of meat as well.

[Ronan] But the location
and nature of these marks

[Ronan] But the location
and nature of these marks

leaves Phil certain
they're not the result
of a frenzied kill.

He thinks they're too measured
and precise,

like the cuts
of a butcher's knife.

[Phil] The animal
was deliberately going
for the joint capsules.

It's trying to pop
the joint capsules

with its sharp teeth
'cause those capsules

are incredibly strong
and that...

that enables the animal
then to remove
a chunk of tail.

And that's fascinating.
That's not just feeding.

Feeding would have bite marks
all over the vertebrae.

Feeding would have bite marks
all over the vertebrae.

[Ronan] Phil is convinced
these aren't the signs
of a killing blow.

But probably happened
long after death.

[Phil] This fossil shows
evidence of a predator.

But probably from scavenging,
we can see

what is very precise
bite marks,

which were associated
with behavior.

That was really hard to work
out in the field,

but here it's clear as day.

[Ronan] The team
is building a theory.

[Ronan] The team
is building a theory.

One hundred
and fifty million years ago,

a group of allosauruses

took advantage
of an unmissable
scavenging opportunity.

They expertly picked apart
a mountain of free meat,

left after a sauropod
died here.

But if the apex predator
of the Jurassic

didn't kill the giant
herbivore, what did?

To solve this mystery
once and for all,

the team needs
to find evidence
of some other cause of death.

the team needs
to find evidence
of some other cause of death.

But with only days left
before the site closes down
for the winter,

the tough rock of the badlands
is holding them up.

We have concrete
hard rock, where the bones

have been embedded
in some of the toughest rocks

I've ever come across.

[Ronan] They throw
everything at it.

[indistinct chatter]

[Phil] Rock is winning.

[Phil] Rock is winning.

But we have another trick
up our sleeve,

and it's a rather
large jackhammer

which we can attach
to the front of the bobcat.

[Ronan] It's a risk.

Big machinery
can destroy fragile bones,

but it's their only chance
to get at the fossils

beneath this rock
and potentially

to solve the mystery
of the dinosaur deaths

before the season ends
and evidence is lost.

Phil hopes to claw back
precious time,

but his hope
doesn't last long.

but his hope
doesn't last long.

Pieces are shaking off
of this thing.

It looks like
it's leaking right here.

So, we're losing
hydraulic fluid.

Think one of
the seals is gone.

[Ronan] The team now
has a big problem.

Let's call the bobcat place.

-Oh, yes.
-I'll do it now.

[Ronan] Until a replacement
part arrives,

they'll have to dig by hand.

In the badlands of Wyoming,
a boneyard of giant

dinosaur fossils is seeing
the sky again
after 150 million years.

And a team of world-class
paleontologists is racing

to finally figure out
what killed them all.

After an exhaustive
investigation,

they're running out of time.

Their dig season
is almost over

Their dig season
is almost over

and a vital piece
of heavy machinery has broken.

Leaking from this thread,
which I don't have a way
to tighten it.

[Ronan] They've had
an anxious night,

but there is finally
some good news.

So, a new part.

[Ronan]
The vital replacement seal

for their jackhammer
has arrived.

We can plug our breaker
back up over there

and get through this really
thick piece of sandstone

that has been causing trouble
for us for the past few days.

that has been causing trouble
for us for the past few days.

[grunting]

[Ronan] It's a big relief.

Now the team can get on
with building
their final case.

The team has found evidence
here of a fast-flowing river

that may have swept some
of the dinosaurs
to their death.

And clues
to a deadly infection
that could have felled them.

They've investigated
whether there was a standoff

They've investigated
whether there was a standoff

between giant sauropods
and a pack
of predatory allosauruses.

But autopsies
have convinced them

that the herbivores
were probably scavenged
after death.

So, with more
than a dozen dinosaur deaths

to account for,
how did they die?

With the hard rock
now cleared away,

Phil is searching for evidence
of what could have killed

the sauropods,
if they weren't victims
of the Jurassic's

the sauropods,
if they weren't victims
of the Jurassic's

apex predator, allosaurus.

And he's found a new clue
right next to the skeleton

of one of the giant sauropods.

Here, a pool of water
created ripples in the sand

150 million years ago.

At different times in the life
of this pond, it dried out.

And you can see
when the water shallowed

that the wind was blowing
the surface of the water

creating these beautiful
ripple marks.

creating these beautiful
ripple marks.

[Ronan] Phil thinks this pond
often shallowed out
in the dry season.

But that in extreme
dry seasons,

something more
dramatic happened.

The pool dried up completely.

And it looks like the water
continued drying up

to a point where we got
a cracked surface,

literally desiccation cracks.

[Ronan] For Phil,
these faint cracks

in the mud are a vital clue.

[Phil] It's such
an extreme event,

it got incredibly hot and dry,
and this whole area dried out.

This animal was looking
for the place

where it knew it could
find water and couldn't.

And it's days ended here
in a dried out pond.

[Ronan] Phil believes
he's solved the mystery

of why so many
sauropod skeletons
are buried here.

His theory is that
the Jurassic Mile was home

to a watering hole,
where many sauropods passed

to a watering hole,
where many sauropods passed

on their way
between feeding grounds.

But just like an extreme
wet season could flood it,

an extreme dry season
could turn it
into a wasteland.

When that happened,
some dinosaurs arrived

too late for food and water,
instead finding
only a fetid mud pit.

too late for food and water,
instead finding
only a fetid mud pit.

They succumb to thirst
and starvation,
dying right here.

And Phil believes
this explains

why so many allosauruses
were here, too.

The carcass was rotting away
and it would have stunk
to high heaven,

and was probably
a signal for all predators

and scavengers around
the landscape

and they'd have come here
for a free meal.

[Ronan] But for at least
one allosaurus, whose bones

lie a few feet
from this sauropod,

this may have been
the last meal it ever ate,

which leaves
one final mystery to solve,

what killed
this ferocious predator?

Jen may have found
an answer at last.

To her expert eye,
the bones of this allosaurus

To her expert eye,
the bones of this allosaurus

reveal something about life
in the Jurassic.

It was incredibly dangerous,
even for apex predators.

They're the kings,
if you will, of the Jurassic.

When you have
all these different animals
living together,

you're gonna have
different conflicts.

This is the kind of world that
the allosaurus is living in.

[Ronan] Most allosaurus bones
here have scars

from serious injuries
and infections that
affected them in life.

Just as they are
for predators today,

Just as they are
for predators today,

hunting injuries were common
and there was always
competition for meat.

Allosauruses tend
to be a pretty beat up lot.

You're dealing with big preys,
there's also other

allosauruses and other
meat-eating dinosaurs
they have to interact with,

they have to defend territory,
they could probably be
fighting over a mate.

[Ronan] Sometimes,
these injuries

could be very serious.

The bones already excavated
from this allosaurus

have made her wonder
if it may have suffered
a broken leg.

have made her wonder
if it may have suffered
a broken leg.

[Jennifer] This is where I saw
a split down the femur.

And so, right on what looks
to be maybe a fracture,

so an injury, didn't look like
it got to heal too much.

It was starting to heal,
but it didn't get
all the way there.

[Ronan] With such an injury,
this allosaurus

would have been
at a big disadvantage
in the hunt,

or if challenged
by another large predator.

[Jennifer] Probably
wasn't gonna be sprinting

after healthy animals.

So probably
it's scavenging, but it...

So probably
it's scavenging, but it...

it definitely found
a way to...

to live at least a couple
of weeks more.

[Ronan] Maybe this allosaurus
had made its final journey.

Attracted here
to feast, injury,

mud and ferocious rivals
may have proved too much

and it died right next
to its last meal.

As the season changed
and the rains returned,

As the season changed
and the rains returned,

its remains were lost
below the water.

Predator and prey
entombed together

for 150 million years.

Jen has found
this crucial evidence
in the nick of time.

It's the last day
of the summer's dig season.

Phil and the team are wrapping
and protecting
any exposed bones.

Phil and the team are wrapping
and protecting
any exposed bones.

[Phil] Don't have it taut.
Remember?
There should be no...

Yeah, no tension.

[Phil] No... no...
That's it. No tension.

[Ronan] Until they return
next year,

they want all evidence
to be safe against
the harsh Wyoming winter.

[Phil]
You're protecting the fossils

from the extreme
weather conditions

that persist here in winter,

can get down to -37 or more,
it's pretty terrifying.

[Ronan] There are still
some major finds to cover.

[Phil] There's so much bone
that's been exposed.

This is the last day,
everyone's stressed.

[Ronan] So,
it's all hands on deck.

[Bill] We just, we want
a few longer ones

just so we can wrap them
absolutely all the way around.

It makes it stronger.

[Ronan] And with one
final push, time is up.

[Ronan] And with one
final push, time is up.

At the Children's Museum
of Indianapolis,

the completed
dinosaur skeletons

from the Jurassic Mile
are finally resurrected
after 150 million years.

from the Jurassic Mile
are finally resurrected
after 150 million years.

[Jennifer] Dinosaurs
are so bizarre.

They're the closest things
we have to like

mystical beasts,
but they're real.

[Ronan] For those left
in the ground,

silence will return
for another long winter.

But the team will be back.

I think the Jurassic Mile
will yield

hundreds of dinosaurs over
the next 20, 30, 40 years.

[Ronan] They may have
solved this particular
murder mystery.

[Ronan] They may have
solved this particular
murder mystery.

But this extraordinary place
has many more secrets
to unearth.

I've been very lucky
to chase dinosaurs

around the globe
for the last 30 years,

but I've never found
a site like this one.

I mean, it... it could keep
100 paleontologists busy
for 100 years.

[Ronan] For many years
to come,

this remarkable site
will continue

to give these scientists
a unique window

into a long lost world.

into a long lost world.

The Jurassic Mile
is dinosaur country.