All language subtitles for Nova S41E20 Bigger Than T. Rex.DVDRip.en.PBS

It's one of the most mysterious
dinosaurs ever discovered

Head like a crocodile,

meter-long jaws,

a spectacular sail,

and an overall body
larger than T. rex.

There is no animal
alive or extinct

that we know of that looks
anything like Spinosaurus

Spinosaurus

Only one skeleton
has ever been found

And in a single night,

it was destroyed

It was a catastrophic loss

to science overall

Now, after a century
of searching,

a new skeleton has emerged
from the Sahara

When this skeleton is revealed,

it's going to change
our understanding of this animal

in pretty fundamental ways

And already,
it's pushing the limits

of what scientists
thought dinosaurs could do

We're going to be figuring out
things as we look at the bones

that we never dreamed possible
in a dinosaur before

From the deserts of Africa
to Nazi Germany,

from the underground
fossil trade

to the cutting edge
of digital paleontology,

can we solve the mystery
of the world's biggest predator?

I think Spinosaurus

is ready now to occupy its space
in the pantheon of dinosaurs

Resurrecting a lost killer,

right now on this NOVA/
National Geographic special

The Moroccan Sahara,
seven hours east of Marrakech

A remote, barren desert

But hidden beneath
the endless sands

lies a treasure trove of fossils

Morocco's ancient rock

has preserved an amazingly
complete record of life here,

from prehistoric insects
and sea creatures

to crocodiles and dinosaurs

Today, they're
a precious resource

The Moroccan fossil trade

brings in tens of millions
of dollars a year

What you have here,

it's a little bit like
a geology book, you know,

so you have fossils,
you have trilobites,

you have corals, minerals

It's literally the history
of life on our planet

laid out on these benches

That's why paleontologist
Nizar Ibrahim is here

He's come to Morocco's
fossil capital, Erfoud,

in search of one of the rarest,

most mysterious animals
ever discovered

A killer even larger
than T. rex.

Its name is Spinosaurus

Spinosaurus even by dinosaur
standards

is one of the strangest,
weirdest creatures

anyone can imagine

This animal's a fabled beast

I make the comparison to Nessie,
the Loch Ness monster,

or the Sasquatch
or the Abominable Snowman

Yes, there are pictures
in books,

but we can't put our hands
on the real fossils

Spinosaurus is one of the great
mysteries of the dinosaur world

This is an animal
that we know was enormous,

we know was very strange,

but short of that, we don't know
that much about it

Spinosaurus tooth

Sharp, conical
and very large teeth

discovered all across
North Africa

offer telltale signs
of this powerful predator

The problem is,

very few Spinosaurus bones
have been found to go with them

Spinosaurus fossils
are very rare

Teeth are actually
a fairly common find,

but an associated skeleton?

Several bones that belong
to the same animal?

That's something that happens
once every hundred years

Nizar, a specialist in North
Africa's ancient fossil beds,

has spent the last decade
scouring museum collections

and fossil shops
around the world

for elusive Spinosaurus bones

I was looking at everything

just hoping to find something
that someone hadn't seen before

So I was starting
to piece together

a basic outline of the skeleton,

but there was so many
missing parts

It was very frustrating

Frustrating, but not unusual
for North Africa

Fossilized remains of dinosaurs

have been notoriously difficult
to find here

because of the vast distances
and harsh desert conditions

It brings new meaning to, you
know, a needle in a haystack

Nizar recently joined forces
with paleontologist Paul Sereno,

a leading expert
in African dinosaurs

You know what it's like
digging in some places

in North America and China?

I mean, it's littered with bones

We've got dozens of skeletons
of T. rex.

In Africa, it's a totally
different story

You have this great
Sahara Desert,

which extends literally
in different directions

thousands of miles
from where we are sitting here,

many without roads

You could spend a week here
easily with an entire team

and not find one piece of bone

It's a challenge

Sereno has had more luck
than most

In 1997, he discovered
a predator named Suchomimus

in nearby Niger

The name means "croc mimic"

because of its long,
narrow snout

He also found the only
well-preserved skull

of Carcharodontosaurus,
the shark-tooth lizard

That was an incredible find,
this giant T. rex-sized skull

It had these stabbing
six-inch teeth

Together with the remains
of giant crocodiles,

flesh-eating birds,
and Spinosaurus,

the few fossils found here
indicate

that 95 million years ago,

this may have been
the most dangerous place

in the history of earth

a habitat of giant carnivores
covering much of North Africa

This is possibly unprecedented
in Earth history

Big predators tend to be rare

It takes a lot of food

to feed a population
of large carnivorous animals

It just seemed like a place
that shouldn't really exist

It's a mystery
Nizar believes he can solve

if he can just find
another specimen

of the enigmatic Spinosaurus

But before venturing further
into the desert,

Nizar's quest takes him
to Germany

and the castle of an eccentric
aristocrat, Ernst Stromer

The little we know about
Spinosaurus begins with him

Ernst Stromer was
a German paleontologist

He was really an explorer
that wanted to find fossils

on virgin grounds

The year is 1910

Fossils are hard to come by
in Germany

But across the Mediterranean
in the deserts of Egypt

come reports of vast formations
of ancient rock

Stromer is eager
to explore them,

not for dinosaur fossils,
but for early mammals,

to chart their diverse evolution

With the help
of an Austrian fossil hunter

named Richard Markgraf,
he scopes out several locations

The most promising, according
to their crude geological maps,

appears to be the Bahariya Oasis

on the edge of the Sahara Desert

Stromer was used to going
to nice restaurants in Munich,

living in a castle,

and here he is
in the middle of the desert

It's hot, he's hungry,

he's not happy with the speed
of the camels,

and it's a really difficult
situation for him

Ever the meticulous scientist,

Stromer recorded
his many travails

His granddaughter, Rotraut,

still has his many journals
and photographs

My grandfather didn't throw
anything away

If every generation
were to do that,

the biggest castle
would soon be full

Half German and half Moroccan,

Nizar feels a special connection
to Stromer

His works offer valuable insight

into a man whose discoveries
have been largely overlooked

The fact that Ernst Stromer
was a great paleontologist,

one of the best paleontologists
in the world,

had been forgotten,

was something that I thought
was really tragic

So from a relatively early age,
I thought,

"Well, one day, you know, we're
going to restore his legacy"

Stromer's journals make it easy,

documenting every step
of his three-week desert trek

He writes of rainstorms
and sandstorms,

of frustrations with his crew

But when he finally reaches
Bahariya,

his luck begins to change

Stromer describes some
of the first-ever evidence

of the Sahara's turbulent past

and the creatures
that lived here

"I find red layers

"preserving shark fin spines,
fish teeth,

and to my joy, also small
vertebrae of reptiles"

And then, at 8:40 a m
on January 18

"I find three large bones
lying next to each other"

"The better one
is probably a thigh bone"

Poking out of the rocks,

Stromer finds enormous thighs,
ribs, vertebrae and claws

They're not early mammals,
but something much bigger

"Apparently, these are the first
of Egypt's dinosaurs

I don't know how to conserve
such gigantic pieces!"

Stromer wandered into an oasis

and wandered out
with the first dinosaur bones,

really good dinosaur bones
from Egypt

He didn't even know grossly
how old these beds were

and he was going
for a different reason,

and he found some
of the weirdest dinosaurs

on the planet

The important thing
is that he realized it

Stromer changes course
from mammals to dinosaurs

and dispatches Markgraf

on more fossil-finding
expeditions to Bahariya

Together, they introduce many
new dinosaurs to the world

A large plant-eater,
Aegyptosaurus

Killer carnivores Bahariasaurus
and Carcharodontosaurus

And the biggest,
most bizarre dinosaur of all

In 1912, Markgraf makes
a remarkable find

in Bahariya's
95 million-year-old sandstone

Long chunks of spine,
massive ribs, pointy teeth

and a well-preserved lower jaw

Back in Munich,
it takes Stromer several years

to piece this unique creature
together

He describes an animal with jaws
like a crocodile,

smooth, cone-shaped teeth,

razor-sharp claws,

six-foot spines
comprising a magnificent sail

and an overall size

larger than any other predatory
dinosaur, including T. rex,

which had only recently been
discovered in North America

Stromer was amazing

at how well he understood
this animal

from the pieces that he had

He realized that he was dealing
with something that was

like nothing else
that had been found

anywhere else in the world

In 1915, Stromer dubs his animal
Spinosaurus aegyptiacus,

the "spined lizard of Egypt"

For the next several decades,

the skeleton becomes
a popular attraction

at Munich's
Natural History Museum

But that all changes
when the Nazis rise to power

An outspoken critic
of the regime,

Stromer suffers terribly
during the war

All three of his sons are sent
to the front lines

Only one, his granddaughter
Rotraut's father, survives

And if that isn't enough,

even Stromer's life's work
becomes a casualty of war

We're in Munich here,
Neuhauser Straße 51

This is the exact place

where the Spinosaurus skeleton
was mounted

It was a great collection,

one of the biggest natural
history collections in Europe,

so Stromer was very proud
of the things he had found,

and he tried very, very hard

to have them put
into a safer location

But the museum director,
a dedicated Nazi,

refuses to move the fossils

And on the night
of April 24, 1944,

hundreds of Allied bombers drop
thousands of bombs on Munich

The museum is destroyed

Spinosaurus is lost to history

This is the only surviving image

of the mounted Spinosaurus
skeleton

Just imagine you spend decades
of your life doing research

and then in one night,
everything is destroyed

The loss of his sons, of course,

was the biggest loss
in his life,

but the dinosaurs were
a very close second

Those were unique specimens,

and I think he knew that
it was very difficult

to find fossils in the Sahara,
and he was right

Stromer died in 1952

His journals and photographs
survive

But without skeletons
to grace exhibit halls

or fossils to study,

his dinosaurs are overshadowed
by T. rex

and other more familiar beasts

Not having the original
Spinosaurus skeleton

is a tremendous loss
to dinosaur paleontology

We can't go and examine
his observations directly

You had this fleeting glimpse
of something,

and then it's gone

I mean, this is
about as frustrating as it gets

for a paleontologist

60 years later,

Spinosaurus and the terrifying
world it lived in

is as mysterious as ever

Over the decades,
a few Spinosaurus bones

have turned up from
across North Africa:

teeth, vertebrae
and this partial snout

They're isolated pieces mostly,
dug by amateur fossil hunters

and sold to private collectors
on the black market

But if scientists don't know
where they come from

or what they were attached to,
they hold little value

We were tempted and teased
by teeth and little tiny pieces,

and then a snout here,

but no skeleton,
nothing associated,

nothing bone to bone

Nothing to piece together
more than what Stromer had done

100 years ago

But then suddenly,
everything changes

At the Natural History Museum
in Milan, Italy,

Cristiano Dal Sasso receives
a large collection of bones

from an Italian fossil trader

He's told they're from Morocco,
likely spirited out illegally

They all seem to be
from a single specimen

And they bear
a striking resemblance

to Stromer's lost Spinosaurus

Cristiano quickly connects
with Nizar,

knowing he'd been obsessing
over Spinosaurus bones

for the last decade

They said that it's
a large predatory dinosaur

and that I should see it

So I traveled to Italy

on my small
doctoral student budget

and I saw this really amazing
layout of bones on a table

Tall spines

Leg bones

Foot bones

Skull fragments

It was a collection of fossils

even more complete
than Stromer's

I was just amazed

It was, you know

I had difficulty breathing,
you know?

I was just thinking, "My God,
is this what I think it is?"

Convinced the skeleton
is Spinosaurus,

Nizar arranges to have
all 60-odd bone fragments

moved to Paul Sereno's lab
at the University of Chicago

to be systematically studied

When finally this specimen
of Spinosaurus showed up,

we were picking our jaw up
off the ground

Nothing made sense

Sereno expected Spinosaurus
to be similar to Suchomimus,

the other meat-eater he had
discovered in North Africa

Suchomimus lived 15 million
years earlier than Spinosaurus,

around 110 million years ago

It too had a long snout,
conical teeth and a sail,

so Sereno determined
that it was actually a cousin

of Spinosaurus

But Spinosaurus had taken those
adaptations to the extreme

We began to realize
pretty quickly on

that this animal
was no ordinary dinosaur

The team could see immediately

that some of the new
Spinosaurus bones

matched the ones
in Stromer's old photographs,

especially those
characteristic spines

But now they had new bones
that Stromer never had:

flat feet, hand and thigh bones,

pieces from the back
of the skull...

The makings of an animal

more bizarre than even Stromer
could have imagined

So this is really the jackpot

But all these bones are missing
one crucial bit of information:

where they're from

Most fossils from Morocco
are found by private collectors

and actually bought and sold
on the open market,

and so when you do this,

the critical contextual
information is lost

To truly understand a dinosaur,

we need to understand the rocks
that it came from

Nizar has no idea
where these bones originated,

but as he studies them closely,

he notices something
eerily familiar

The cross-section of the spines

have unusual lines
running through them,

perhaps fossilized traces
of blood vessels

No one knows what they are,

but to Nizar,
they're a smoking gun

He remembers seeing
similar bones in Morocco

just a few years earlier

I thought, "This is something
I've seen before

I've seen a small chunk of bone
just like that one"

And I thought,

"Wow, I wonder if this is
maybe the same specimen?"

If it is the same specimen
and the bones match,

Nizar might be able
to track down

the fossil hunter
who dug them up,

the only person
who could take Nizar

to the exact spot
the dinosaur was pulled from

It's a long shot,
but worth a trip back to Erfoud

Nizar has to rack his brain
to remember details

of the fossil dealer who first
showed him the chunk of bone

He vaguely recalls a tall,
mustached man in a white tunic

It became clear very quickly

that that description fit many,
many men in Erfoud

Everybody thought that
I was crazy

This had never been done before

Moroccan fossils had been
described for many, many years

and nobody has ever been able
to trace them

back to the original site

With the help of British
paleontologist Dave Martill

and Moroccan Samir Zouhri,

Nizar goes village to village,
shop to shop,

chatting up the locals for clues

to the fossil hunter's
whereabouts

I'm trying to find a needle
in a haystack

Actually, it's much bigger
than a haystack

It's a needle in the Sahara

Given Morocco's vague
export laws,

Nizar needs to tread carefully

Dealers here are allowed
to dig up and sell

all the common fossils
they want...

Trilobites, ammonites,
even dinosaur teeth...

But exporting rare fossils
out of Morocco

without a license is illegal

Even if Nizar does find the man
he's looking for,

there's no guarantee
he'll agree to help

Those are some big teeth

There's some really nice
specimens here,

but it's all isolated pieces,

so that's all
they're finding here:

no associated skeletons

This is not where our skeleton
came from, that's for sure

The trail in the fossil shops
is going cold

Nizar decides to head south
from Erfoud

toward Morocco's ill-defined
border with Algeria,

where most of the country's
fossils are found

Is he one of the diggers?

Yeah, he's one of the diggers

Oh, excellent

He should know
where he's going, then

Diggers here don't have
any special training

With shovels
and other crude tools,

they bore tunnels
straight into the rock,

pulling out any fossils
they can,

often damaging them
in the process

They're just digging
to get out what is in essence

strange-looking rocks

They don't document
the circumstances,

they don't document
in most cases

where something
actually came from

It's really like a Swiss cheese,
lots of holes and openings

And of course
there is no scaffolding,

no support structures,
and it's pretty soft sandstone

People have died, and of course
they are breathing in

all the dust every day

Very difficult work

Despite the risks,
diggers depend on the income,

and paleontologists
depend on them,

crude as their techniques may be

This is how most fossils
are found

Most fossils are not found
by professionals

You know,
if they weren't doing this,

there's nobody else
that has been out here

collecting things
in a systematic fashion

So far, there's no sign
of the mystery fossil hunter

Back in Erfoud,
Nizar is ready to give up

My morale is very low

I'm just trying to figure out
what to do next

You know, it's just being back
at square one

And right in that moment

when I am
at the very lowest point,

this figure walks past me,

and after just a few seconds,
it became clear

that he was the man
I was looking for

He was the one

Against all odds,

the man actually remembers
meeting Nizar several years ago

He recalls showing him
a chunk of bone

with lines running through them

And yes, he did dig up
the rest of that skeleton

I can't believe my luck

Worried that the skeleton
is now illegally abroad,

the man insists that his
identity be concealed

Nizar tries to convince him
in Arabic

to lead them to the dig site

He's concerned because he thinks

that if someone recognizes him,
he might get into trouble,

so I explained to him

that this is not a fossil dealer
situation

I am studying these fossils

I want to know
where exactly they came from

and they'll return
to the country of origin

The man agrees, finally,
to take Nizar

to the site where the fossils
were pulled from the ground

After nearly an hour drive,
most of it off-road,

and a 30-minute trek
up the side of a mountain,

the dealer leads Nizar

to a nondescript-looking hole
in a hillside

Within minutes, in the fill
surrounding the dig site,

they discover fragments
of bones and teeth,

all but certainly Spinosaurus

This is amazing!

I mean, this will take some time
to sink in, but this is amazing

It feels really surreal

The dealer explains

how it took two people
digging for two months straight

to get the skeleton out,

and how he sold it
to an Italian fossil dealer

for the equivalent
of 14,000 U S dollars

This is the best thing
he's ever found,

and he's never found
anything even close to that

in terms of completeness

You find pretty bones,

but never, ever
a partial skeleton

The fact that they were able

to relocate the discovery site
of the skeleton is remarkable,

and it's going to provide

much needed information

about the environmental context
of Spinosaurus

Within months,

Nizar rallies Paul Sereno,
Cristiano Dal Sasso from Milan,

and colleagues
from the UK and Morocco

to conduct a more thorough
excavation

Wow, so this is it?

Wow

Their goal now is simple:

characterize the rock
and landscape

to see when and how
Spinosaurus lived,

and if they can, find more bones

Rather than boring tunnels
straight into the rock

as the fossil hunter did,

the paleontologists excavate
from the top

This is the overburden,
the very hard rock

over the layer
that had the Spinosaurus bones,

so we are widening this opening
to the cave

until we can get a surface here

that is just about
where the bones were found

We know they were found
in a layer right down here,

so to move this layer
is the pay dirt here

At the bottom of the hill,

Dave Martill takes
a different tack,

sifting through the tons of fill

the local digger
already discarded

All this stuff here
is the overburden

that the original guy who made
the discovery threw to the side

while he was trying
to excavate the bones

But I don't think he was looking
carefully enough,

so I'm going through all of this

He needs to pass
a massive amount of material

through his sieve,

but after several hours,
Dave strikes pay dirt:

chunks of cone-shaped teeth,
even a piece of jawbone,

that are all classic Spinosaurus

Even from small bits like that,

I stand a chance
of rebuilding the entire tooth,

which is what I intend to do

It's just that I've got

about three tons of material
to sift through

The scientists scramble
over the rocks for days,

retrieving and assembling

as many bits and pieces
of the skeleton as they can

Cristiano exposes
one of Spinosaurus's

characteristic spines,

similar to the ones Nizar
recognized years ago

This is the same shape,

same size of the specimen
we already know well

It is another confirmation

that this is the specimen
we're looking for

As they piece together
the bones,

the scientists
are also looking carefully

at the rocks they come from

These layers comprise millions
of years of geologic history

But can they reveal the habitat
Spinosaurus lived in

and how he survived alongside
the other giant carnivores?

We're above the dig site now

and we're looking at the cliffs
that dominate this valley,

and you can see beautiful
stripes, gorgeous colors

Each one of these layers

represents a change
in the environment

Forests, lakes, rivers

As we go down through
each of the layers,

we're going further and further
back in time

And eventually, we get down to
the layer with our Spinosaurus

Buried along with Spinosaurus

are very different
kinds of fossils,

ones you might not expect
to find

halfway up a mountain
in the Sahara

This is full of lots of shells

We got this

That's, uh

That's a little sea urchin

Sea urchins, mollusks

Oh, that's lovely

That's a nautilus

Fossils of marine animals

dating back to the Cretaceous
Period 95 million years ago

Back then, sea levels
were over 100 meters higher

than they are today

Much of this place
was underwater,

inundated by rivers and lakes
and a massive ancient sea

Fossils of similar age
found across North Africa

reveal that this lush ecosystem
once stretched

from here in Morocco
all the way to Egypt

And Spinosaurus, along with
the other giant predators,

lived throughout all of it

It's meat-eaters, meat-eaters,
and more meat-eaters

Here it is,
this chamber of horrors,

this scene of carnage
and destruction

It's a very, very striking image

Problem is, it's a scene

that continues
to confound paleontologists

They've found all these fossils
of carnivores from this period,

but relatively few herbivores
for them to eat

This is unheard of

There's too many predators,

and when you look
for the herbivores

that are found in the formation,
you really have a tough time

I mean, they are not only
underrepresented

in bones and teeth,

but it's hard to find
a herbivore footprint

Stromer himself
realized this puzzle

You know, there's all these big
carnivorous things around,

but nothing, you know,
nothing obvious for them to eat

Unless they were eating
something else

There's another bivalve

There's lots and lots
of bivalves

There are lots of shellfish
in the fossil record,

but also much larger
sea creatures,

like coelacanth, sawfish
and lungfish:

a perfect meal for any dinosaur
that could catch them

We're not talking about
small little salmon

We're talking about giant

12-foot, 16-foot
aquatic creatures

So one of these animals
can easily feed

an animal the size
of Spinosaurus, no problem

That Spinosaurus,

with its croc-like snout
and conical teeth,

was built to catch fish

is an idea even Stromer
had considered

Hey, guys, I've got
some more of this tooth

Look at this

But in the history
of paleontology,

no one has found evidence
that any dinosaur

spent much of its life in water

If the new bones reveal
Spinosaurus could,

it would be the first

And that may help
solve the mystery

of North Africa's predators

Back at the University
of Chicago,

the team quickly gets to work

prepping and analyzing
their new fossils,

searching for any clues

that Spinosaurus
may have been aquatic

A full century
after Ernst Stromer

first studied and described
Spinosaurus,

Nizar and Paul finally have
a new skeleton to study

Extremely exciting

To hear that there was
a skeleton, I was like, "Wow"

Paleontologists have been
awaiting the discovery

of a new Spinosaurus skeleton

ever since the first one
was destroyed

Now just imagine if we lost
all of this in a single night

Yeah, well,
if there is any threat

of a bombing raid here,

we are hiding these fossils
in the deepest cave

Just to be safe,
the first order of business:

copy the bones

While Stromer described
all of his bones by hand,

Nizar and team use a CT scanner

to digitize theirs in
bone by bone,

producing a three-dimensional
picture

accurate down to a fraction
of a millimeter

Back in the lab,
paleo-artist Tyler Keillor

then manipulates
the hundreds of files

and begins assembling
a virtual Spinosaurus

We have just now

moved into the digital age
for dinosaur reconstruction

in the sense that you can go
literally from a bone

to a digital model of the bone
to a digital skeleton,

which you can simplify enough
that you can make it move

You can make it walk

You can ultimately
put skin on it

The skeleton is
about 40% complete,

a surprisingly high number
compared to most specimens

Very few dinosaurs are known
from a complete skeleton

There are lots that are known
from a toe bone, a tooth,

in most cases
just distinctive enough

to just tell you, "Yes,
there was something there,

but that's all there is"

The digital model
allows the team

to take their skeleton
much further,

even incorporating some bones
they don't actually have

Using scans of Stromer's
original photos

and resizing the bones
to match their specimen,

they can add in bits of jaw
and spine that they're missing

For the parts on the back
that we didn't have,

we're looking
at Stromer's figures

That's a Stromer specimen?

Right, those are Stromer's

Scans of Suchomimus,

Spinosaurus's
croc-snouted cousin,

help fill out the skull

Here is actually
the Suchomimus brain case

It fills in the back end
very nicely

Scaling and incorporating bones
from other specimens,

they up their total from 40%
to over 60%

Then it's a matter
of fitting the bones together

Just getting the jaws to close
properly takes 14 days

Our knowledge of Spinosaurus

comes from several
different specimens

These aren't all the same size,

and so you can't just
hodgepodge them together

like some kind of giant
Frankenstein

You have to build the digital
model in the computer

so you can get
all the proportions correct

and give us a better conception
of what the skeleton

of one of these animals
would have been like

Taken together,
the new specimen:

Stromer's, Suchomimus,
and other isolated bones

The digital skeleton
reveals an animal

every bit as extraordinary
as Stromer imagined

50 feet from snout to tail,

the model confirms
that Spinosaurus

is the biggest predator
ever to walk the planet,

at least nine feet longer
than the largest known T. rex.

Size does matter
biologically speaking

because you wonder,

what are the ecological
circumstances

that support
such a large animal,

and that gets back
to Stromer's conundrum:

how do you feed all these giant
T rex-sized predators?

Stromer speculated that
Spinosaurus could eat fish

But does that play out
in the bones?

The foot is a good place
to start

It's got a flat bottom

I'd never seen anything
like this

The first time I set eyes on it,
I said,

"What is this doing
on this dinosaur?"

Most predatory dinosaurs
scampered around

with narrower feet
and curved claws

This foot's completely flat

I've never seen
anything else like it

To make sense of it,

the scientists compare it
to animals that are living...

At least they were
until relatively recently...

Starting with dinosaurs'
closest living relatives

When you're starting
with a predatory dinosaur,

you think "bird"
as your living analogy

And you have to start there,
because they're bipedal

For all we know,
this dinosaur had feathers

We don't know for sure

Turns out flat feet

are a handy feature
for wading birds like flamingos

They help keep them stable
in wet sediment

In lush Cretaceous Africa,

could Spinosaurus have used them
the same way?

Surely a sensible interpretation
to argue

that a fairly flat foot
would help an animal,

particularly a large animal
like Spinosaurus,

walking over a soupy substrate

You know, you don't want
to get stuck there

The flat surface may even help
propel them through the water

If potentially, they use
their feet as paddle,

that's a whole other chapter

It reinforces the aquatic model
for this animal

We may not be able to prove it
in a court of law,

but it certainly makes the
probability of our inferences

much, much more secure

For more evidence,
the scientists look

to Spinosaurus's
other living relatives,

crocodilians, which
branched off from dinosaurs

about 200 million years ago...

Animals like this 250-pound
tame alligator named Bubba

Bubba's a reptilian ambassador
of sorts,

allowing Paul and Nizar to get
much closer to a large reptile

than they probably should

Bubba is so kind to be able
to lift up its hand

and spread the toes

so you can really see the
anatomy of a live crocodilian

The potential for webbing
on its feet

Its smooth, cone-like teeth

No bumps, no ridges,
just basically a conical tooth,

which is your basic
fish-eating tooth

Its long, narrow skull

Crocodilians in general,

when they become
more fish specialized,

the skull becomes
narrower and longer

Right, because you want

as little water resistance
as possible

Even the sensitivity
of its snout

Every little polka dot
on every scale

is a special sensory cell

And we see all these openings

on the front of the snout
of Spinosaurus

Used for detecting motion
in dark, murky water,

the tail may also have helped

Combined with the flat foot,

it may have gracefully propelled
Spinosaurus through the water,

much like this animal

Whoa, there he goes

See, look at that

He uses the tail to get going

The comparisons all point
to a creature

that was well suited
for getting around in the water

and hunting fish

But what about that giant sail?

Neither birds nor crocs
have that

From the old research journals,

Nizar learns that Stromer
had asked the same question

and had found one animal
to compare it to:

the crested chameleon

Look at this

Right where that ligament
attaches,

there is an expansion

That's right, they all have
this broad base

Wow, that is absolutely neat

Sails evolved independently
many times

Why isn't always clear

For storing fat?

Shedding heat?

Or as a display to warn off
predators or attract mates?

A likely use for thin,
narrow spines like these

I think this was display

It was to make yourself
look bigger

Maybe there was competition
for mates

Maybe the health,
the size of your spine

was an important factor

With the animal comparisons in
and the digital model complete,

there's only one thing
left to do

The original bones will be
repatriated to Morocco

But the team isn't confining its
dinosaur to a computer forever

Thanks to machining facilities
in Chicago and Toronto,

virtual Spinosaurus is becoming

the first life-size
predatory dinosaur

fully realized
from a digital model

Seeing it for the first time
up close and personal,

Paul and Nizar are confronted

with just how massive
Spinosaurus is

and how bizarre

It's front-heavy

You've got
an eight-foot-plus sail

made of solid bone,

you've got an elongate trunk
longer than most dinosaurs,

you've got massive forelimbs,

the most massive
of any dinosaur,

a long neck,

and then a long skull
cantilevered on this side

Where's the balance?

The skeleton towering over them

forces the scientists to rethink
how Spinosaurus got around

you know, very different

from the mode of locomotion
of any other dinosaur

It may have needed to use
its long forelimbs for walking,

a first for predatory dinosaurs,

which so far have been
strictly bipedal

While it hails

from the two-legged dinosaur
group of carnivores,

it might be using
those grabbing, grasping hands

to walk

Otherwise, it's going to fall on
its lovely crocodile-like head

Of course, that's only
when it was walking on land

More likely, the finding
is another strong indicator

that Spinosaurus is different

from any other dinosaur
ever discovered

It appears to have forsaken
the land,

evolving over millions of years
to thrive in water

It is one of the great mysteries
of the dinosaur era

that every other major group
has seemed to invade the water,

and no dinosaur
had ever done this

Never a dinosaur
with a fin for swimming

Never a dinosaur
with anything we could point to

to say, "That was adapted
for being in water"

This is the first time,
and it's really exciting

With this revelation comes
a long-awaited explanation

for how Spinosaurus and all
the other monster predators

of Africa's Late Cretaceous
competed for prey

Quite simply, they didn't

Some large dinosaurs
would have preyed

on the region's
limited meat supply

Spinosaurus may have only
come up on land

when it needed to,

to lay eggs
or move to another river

But put it in the water,

and it was perfectly adapted to
hunt a boundless supply of fish

If one of you is feeding on fish

and the other one is feeding
on large dinosaurs,

you're not in direct competition

And that means more
large carnivorous animals

can occupy the same habitat

Paddle-like feet
and powerful tail

propel it through the murky,
turbid water

Sensors in the snout
help home in on prey

And at precisely
the right moment,

Spinosaurus does what its body
is built to do

It all makes sense, you know...

Being big, having
these strange proportions,

having these unusual feet,
this big sail

Once you really understand
the world Spinosaurus lived in,

all these adaptations make sense

And now Spinosaurus
makes sense too

It's been an odyssey
spanning three continents

and a hundred million years

But finally, it can take
its place among giants

It is the weirdest large

largest predatory dinosaur

that we may ever find
in our lifetime

But the saga
behind this dinosaur...

The man who was associated
with the first bones,

world wars,
the contraband fossils...

It's a story that has
so many dimensions,

it's going to be hard to top

Spinosaurus hadn't really
captured

the public's imagination
because it just wasn't real

It was like a made-up dragon

But with this skeleton,
you know,

things are going to change

It's absolutely going to capture
the imagination of the world

Spinosaurus, the world's
first aquatic dinosaur

The largest predator is the lost
killer of the Cretaceous