Dinosaurs: The Hunt for Life Horizon

For 100 million years, dinosaurs dominated the Earth.

But they remain enigmatic creatures.

That's because all that scientists had to work with

were fossilized bones.

Ah! Woo!

But now, the seemingly impossible has been discovered...

-Oh, look!

-Yeah.

..signs of life inside these long-dead skeletons.

It opened the door to the possibility

that we could begin to understand dinosaurs in a different way.

For the first time,

they've been able to look at the blood of a T-rex...

..touch 68 million-year-old soft tissue...

It was, you know, goosebump-inducing -

just about everything that we saw.

And Dr Mary Schweitzer may be on the verge

of turning Hollywood fantasy into scientific reality...

..finding dinosaur DNA.

It looks like it, it acts like it, it smells like it.

You know what, if you have cells, if you have soft tissue,

if you have proteins,

why rule out DNA?

For the past few decades,

dinosaur hunters have been drawn to the American West.

It's pretty much Dr Mary Schweitzer's back yard.

She lives for part of the year in the Rocky Mountain state of Montana,

where some of the richest dinosaur remains have been uncovered.

A lot of dinosaurs lived in this area because just to the East of us,

in Eastern Montana, North and South Dakota,

was a big, shallow, warm inland sea.

And so the dinosaurs would follow the seaway,

migrating up and down, North and South,

so there was a lot of them here.

More T-rexes have been found here in Montana

than anywhere else in the world.

But we know very little about the world's most iconic dinosaur...

..apart from a few very simple facts, like it was 12m long

and could weigh seven tonnes.

That's a good boy. Come on.

There you go.

And that's because, according to Dr Schweitzer,

the male-dominated world of dinosaur science

tends to ask the wrong questions.

I think for men a lot of it is, "Can we quantify it?"

You know - bigger teeth, meaner animal.

And I think for women, we're...

I can't say that it's all that way

but I think mostly we ask different questions.

We ask, "How did they function? What was their biology?"

SHE LAUGHS

Ah! Woo!

Today, she isn't riding the range in search of another T-rex.

She's hunting more recent remains that might help to reveal

some of the hidden secrets of the world's best-known dinosaur.

And that's because she's interested in how

the once-living tissue of this dead buffalo

decays and gets broken down over time.

In palaeontology, we can't watch our dinosaurs die.

And we can't see what's going to happen to them.

But we know that obviously, if all we have is a skeleton,

we don't have the whole dinosaur.

There's a lot of information missing.

But again, when you see parts in the fossil record...

this is skin right there.

That has a high preservation potential

and it's because of the molecular make-up of the skin itself.

The guts are gone, the intestines are gone.

But the skin and the cartilage, the bone and the teeth

are what remain.

Good boy.

Your buddies are jealous, huh?

It's long been Mary's dream to do this

with a 65 million-year-old fossil.

To be able to get her hands on blood,

soft tissue and even the DNA of a T-rex.

Come on, play with me.

It might seem an impossible task

but she believes that finding signs of life,

uncovering ancient biology,

is the only way to put flesh on the bones

of the most iconic creatures ever to stalk the Earth.

I mean, a lot of the things that have been done in the past,

with respect to dinosaurs, have been untestable hypotheses.

I mean, really, you could say dinosaurs were invisible and green

and how would I prove you wrong? There's no data.

I love the way they smell.

'So I think that getting at some of these questions

'about how their proteins are put together

'can get us at their function,

'get us at why they had an evolutionary advantage.'

And if we can understand that, there's a lot we can learn from them.

You're falling asleep! Look at, those eyes are starting to get shut.

Imagine trying to figure out how a horse might look,

just from its skeleton.

Without the biology - the cells, protein and DNA...

..we couldn't tell what colour its eyes were...

..how far it could see...

..the way it smelt...

..the texture of its coat...

..the make and shape of its muscles.

Without its biology, the horse just isn't a horse.

But most palaeontologists believed that finding any biological material

in 65 million-year-old dinosaur bones

was impossible.

And that's because it was thought that the process of fossilisation

destroyed every living thing in the bone.

Once the dead animal is covered in sand or mud,

the fleshy parts then decay.

And the mineral and organic elements of the bone

are replaced by the minerals in the soil.

In essence,

they get turned to stone.

But what if this wasn't the case?

What if some of this biological material was still with us?

The only way to find out

would be to look inside the bones...

..to conduct a dinosaur autopsy.

And that's exactly what's going on here.

A dinosaur leg bone is being cut up for analysis...

..in a process known as histology.

The bone then needs to be carved into thin slices...

..and embedded in plastic so it can be examined under a microscope.

It's a bit like cutting down a tree and looking at the rings.

They reveal how fast or slowly the tree grew.

And you can see the same kind of pattern in dinosaur bones.

Is this the first femur?

It was pioneered by Mary's mentor and the world's leading dinosaur scientist,

Dr Jack Horner.

Let's say that section.

'Looking at the bone histology of dinosaurs'

and looking at babies and juveniles and some adults,

we've learned that

when baby dinosaurs hatched out of their eggs, they grew really fast.

Do you know what side it is yet?

'They had sustained high growth periods.'

INDISTINCT CHATTER

'If you hatch out of the egg at a half a metre long,'

you're not very big.

And if you're going to grow to the size of a house,

you'd better get busy.

And that's all I can say

because the longer you are small, the longer you're vulnerable.

Mary started out as Jack's student.

And back in 1991, he gave her pieces of a T-rex leg bone to analyse.

At first, there appeared to be nothing out of the ordinary

about this bone.

But THIS bone turned out to be rather special.

Because what she was looking at,

when she placed the slide under the microscope,

had never been seen before.

Staring back at her was something that shouldn't have been there.

It looked like a red blood cell.

And its chemical composition included a heme -

a part of haemoglobin which helps carry oxygen in blood

and gives it its red colour.

MARY: I was shocked, I was really surprised.

The thing that was cool about it is we know very little, really,

about these beasts that once walked on the surface of our planet.

And all vertebrate organisms except, well, almost all,

except for mammals, have nucleated red blood cells.

And these things that I was seeing in the vessel channels of the bone

were nucleated. They were translucent red with a dark centre.

This evidence seemed to suggest that organic matter could in some way

survive the process of fossilisation.

And what was so exciting about it...

..is that the new tools and technology of molecular biology

might now be used to understand these long-vanished creatures.

'It opened the door to the possibility that we could begin to understand

'the function and the physiology of dinosaurs in a different way.

If we could get at the elemental molecular structure,

that's where the real evolutionary information is housed.

And so being able to recover those things from a dinosaur

would open the door to understanding them at a completely different level.

She now set out to look for other evidence.

That's if there was anything else to recover.

Mary's new techniques now started to play into

one of the most long-standing questions in palaeontology.

Just what kind of creatures were dinosaurs?

For decades, scientists relied on unearthing clues from the bones -

the anatomy.

And for the people who invented palaeontology in the 19th century...

..the bones they saw mostly looked like giant lizards.

It wasn't just the size of the bones - they're obviously colossal.

It was the teeth that really helped them understand

what sort of creatures dinosaurs were.

-DR HORNER:

-The teeth that they were finding were very similar,

or at least somewhat similar, to lizards.

And in particular,

one was particularly close to an iguana lizard.

And so they didn't have much of the skeleton of the dinosaur

but they knew what an iguana lizard looks like

and an iguana lizard is a reptile.

But for modern scientists, the teeth are now seen as a distraction.

A more comprehensive analysis of their skeletons

suggests they're not related to lizards, but birds.

And there's one bone in particular, familiar from the dinner table,

that's helped to prove the case.

It's a very special bone called the furcula.

And the furcula we find in meat-eating dinosaurs

is otherwise known as the wishbone.

And so when we think about what characteristics define a bird -

the wishbone, hollow bones, feathers, hard-shelled eggs,

I mean, there's a whole list of them.

And what's interesting is, through the ages we've discovered

that dinosaurs actually invented all of those characteristics.

Dinosaurs had all of those characteristics...

..those that we consider bird characteristics.

Anatomy has helped to establish the size, weight,

even the strength of dinosaurs.

But on questions of their bird-like biology -

the colour of their skin, whether they were warm- or cold-blooded,

even how they evolved -

the bones are silent.

Making them talk would require luck, skill

and knowing the right people.

This is Bob Harmon.

For decades, he's worked closely with Jack Horner.

And he's something of a legend in palaeontology.

He has a special gift for sniffing out fossils.

And back in 2000, there was something about the lay of the land

in the Hell's Creek area of Montana that looked promising.

One day, I came to this one area, kind of a box canyon type area,

and I actually sat down to eat my lunch

and figure out how to get up to this next cliff I was going to look at.

So I was eating lunch, turned around, looked,

and here's a bleached-out white bone sticking out of the cliff.

So...

And then I got to looking a little farther and I could see it,

the cross-section of a tyrannosaur vertebrate.

It has a very distinct shape,

something we look for when we're out prospecting.

It's a honeycomb shape.

So when you see that, you get all excited

cos it's probably a T-rex.

You know, heart started beating pretty good

and then I start looking up and up and up

at 50 feet of rock sitting on top of this bone.

And pretty much just went, "My God, what have I done?" You know?

That's because he knew he'd have to remove

all of that 50 foot of rock to get at the fossil.

It took them nearly three years' careful digging

to extricate the whole skeleton.

But there was another problem.

The area was so remote - there were no roads in or out -

that every single piece of it had to be choppered out.

But one of the bones, a femur, was just too big to carry.

And Bob had to do something he really didn't want to.

I said, "Jeez, we are going to have to break this thing in half."

And tyrannosaur bone does not break well.

I mean, it's so dense, you know, it's hollow in the middle

then it just shatters like glass when you break it.

-So I knew it was going to be bad.

-HE LAUGHS

But I said, "OK. I don't think we have any choice. Let's just do it."

So we broke it in half and it shattered all over.

The bones get removed with the soil surrounding them.

It's what the scientists call context.

They still don't really know why but the Hell's Creek soil

seems to have special preservation properties.

And when some of these Hell's Creek bones are cracked open,

there's something about them that marks them out as different.

And it's got nothing to do with how they look.

-JACK:

-In many bones that are broken up,

we do have a very biological smell.

Kind of a...almost like oil or rotting something. Um...

And, you know,

it was certainly weird back in the days before we knew

what it possibly was.

As it turned out,

this smell was a clue to what lay within the bones.

This was just the kind of material

Mary Schweitzer wanted to get her hands on.

But it wasn't the smell of the fragments of T-rex femur

that Jack sent her that set her pulse racing.

It was how they looked.

T-rex bones might appear solid but they're not.

They are in fact hollow.

But when she peered through the microscope,

she saw something that shouldn't have been there.

And this is it.

The yellow area should have been hollow.

The fossilised bone on the outside,

which is all that remains of cortical bone,

was all she expected to find.

This tissue right here is what most dinosaur bone looks like.

Everybody has this.

This tissue right here had not been seen before.

She saw what appeared to be a group of specialised cells.

And these cells were utterly unique.

They're only found in birds.

And they use this tissue to make eggs.

And that could only mean one thing.

And I looked at it and I held it in my hand

and I said to my technician,

"Oh, my gosh, this is a girl and it's pregnant."

If Mary really was looking at the bones of a pregnant T-rex,

it'd be a first in palaeontology.

But the microscope slide on its own wasn't enough.

MARY: I love her wings from the back. Can you get that picture?

MARY GIGGLES

Ow!

To be sure, she needed to compare it with the medullary bone

from one of the most primitive birds still alive -

the ostrich.

Its evolutionary history can be traced back 23 million years.

So just how does an ostrich compare with a dinosaur?

I am in love. Look at this. Look at her wing.

Can you see how the feather's attached to the skin?

Look at, their arms are like T-rex...

..with skin on. They're short, little, stubby things.

But you see how the feathers are inserting into the skin like that?

Do we have any more grapes?

The problem was that she couldn't do the test

on a living pregnant ostrich.

She needed a dead one.

So she put out a plea for help

and fortunately a local ostrich farmer answered the call.

He had a pregnant bird

but it had been dead for over a week.

I could definitely smell it before I could see it.

It was all, you know, bloated from death and...

..you touched the stomach and it kind of went "goosh!"

It was so gross and it was really smelly.

So I sawed the leg off

and tasted really rotten ostrich meat for about two weeks after that,

in my mouth.

But it was really gross and he had a whole bunch more ostriches

so they were all kind of standing around me in a circle,

watching as I dismembered their friend

and I felt a little weird about that.

Holding her nose, she took the bone back into the lab

and placed it under a microscope.

And what she saw was ground-breaking.

The pregnant ostrich had medullary bone

and in exactly the same position as the pregnant T-rex.

It was really cool that we had a pregnant dinosaur

but this had been predicted and it was just verifying that,

you know, if birds and dinosaurs

were as closely related as we had been thinking, as a field,

it should have been there.

It was the first time that anyone had ever been able

to establish the sex of a dinosaur.

And it confirmed the importance

of trying to understand the biology of these ancient creatures.

MARY: I couldn't believe it. It was, you know, it was just a gift.

In my kind of palaeontology, everybody's eyes glass over.

If you want to go to a talk on palaeontology

you think field pictures and badlands and really pretty...dinosaurs.

And I study under the microscope.

So this was exciting in that I thought, "Well,

"maybe this is the time I can really contribute to the field

"in a way that my colleagues will understand and care about."

Rather than just letting Mary do her own weird thing!

So, yeah, I was excited.

One of the first implications of her work

was to make the biological case that dinosaurs were indeed birds.

MARY: They're so fun!

See their feet?

And Mary, along with other scientists,

has been figuring out what this might mean

for how we see these iconic animals.

He's so pretty.

For a start, it would be difficult to read their expressions.

Well, if you notice their skulls, their head, it's just...

skin stretched over the bone.

And so they don't have the muscles, they don't have the additional fat.

And that's what gives animals expression like your dog

that looks at you with the cocked head and the ears

and the little furrow in its brow.

These guys aren't capable of doing that.

They don't convey any emotion at all.

And if you look directly in his eye, it almost looks dead.

That's what they might look like in a one-on-one

but what about collectively, when they're all gathered together?

-DR HORNER:

-I think that when we're imagining dinosaurs on a plain,

we have to really think of them like flocks of birds,

walking and then shifting and then, you know, I mean just, you know,

Not just mulling around like mammals do.

I mean, mammals are just sort of mulling around.

Birds, you know, really have some, you know,

some overall shape to their groups.

I mean, they all are travelling in one area and then they shift

and, I mean, it's just very different.

And what about the best-known dinosaur of all,

T-rex?

What kind of bird was it?

So, if we think about Tyrannosaurus with its bone-crushing teeth,

I envision it to be much like a vulture.

And when you think about a big vulture eating carcasses,

they're nasty.

He wants to eat me for lunch.

SHE SHRIEKS

That was my Velociraptor experience. That's as close as I want to have.

Look at, there he goes again.

SHE LAUGHS

I think there would be no hesitation, no pulling back.

And I think once they decide they want you for lunch,

you might as well just give up.

Ooh!

All this started to show that her work,

hunting for organic matter within ancient fossils,

had the potential to really transform our understanding

of dinosaurs.

The next step, the most important one,

came from re-examining the basics of bone biology.

Bone is a composite. It's like plywood.

It has a hard part, which is the minerals that make up bone,

and it has a soft part, which is the collagen.

So bone is both protein and it's mineral.

And when you put the two together, it gives it great strength.

But it is alive and the cells that are part of bone maintain it

and they give it nutrients

and they continue to just maintain the bone as living structure.

Take away the mineral element of this chicken bone

by sticking it in an acid bath and all you're left with

is the bendy, flexible, collagen, protein part.

So Mary wondered,

could you find that organic material in a T-rex fossil?

We have always assumed that all of the organics go away.

And so what you're left with is basically a mineral morph.

And it's got lots of holes in it where the protein used to sit,

where the blood vessels used to run

and the little houses where the bone cells are,

that's all empty now.

So, I mean, if we're right about that process

then if you remove the mineral, you should have nothing left. Right?

Because the organics are already gone.

So she set up a deceptively simple experiment.

She dropped the T-rex fossil, packed full of medullary bone,

in an acid bath...

..and left it overnight.

When her assistant came back to check in the morning,

something remarkable had happened.

Something that didn't seem possible.

The process went faster than either of us predicted.

And so when she went to stop it by taking the piece of medullary bone

and putting it in water, she went to pick it up with her tweezers

and it went like that...

And she called me immediately and said, "Something's really wrong."

And, you know, I mean, I had the same expectation as anyone else -

if you dissolve away your dinosaur bone,

you're going to have nothing left.

But we did.

And this is what it looked like under a microscope.

In a sense, she was able to reach back through 68 million years

and touch a dinosaur.

And not just any dinosaur -

this was a soft, pliable piece of a T-rex.

So, we saw this, where basically this is the medullary bone

with the mineral removed.

And you can see...see the blood vessels inside the bone?

They stretch with the matrix themselves.

This was really hard to hang on to!

But there you go, you see it stretch?

This was a combination of my absolute worst nightmare and Christmas,

every day in the lab for about a month.

I couldn't wait to get to work

but I was scared to death at what had happened overnight.

Um...it was, you know, goosebump-inducing -

just about everything that we saw.

It was...

I can't even explain it

and I know I'll never have that experience again

but it was magic - just magic.

Finding the soft tissue

opened the door to a new world of possibilities.

She now set out to do something that no-one had ever done before...

..to try and find proteins - the building blocks of life.

She started with this T-rex bone cell.

If there was a chemical signature of ancient proteins,

it should be hidden away inside.

Because birds are descended from dinosaurs,

the chicken would be the key to this quest.

Mary took a classic tool of modern biology,

one that helps to identify proteins in chicken bones,

and she applied this same test to the T-rex soft tissue.

If there were no proteins in the cell,

the slide on the right would remain black.

Anything green would be a sign of life.

The green glow made palaeontological history.

It was very exciting, yes. I was very happy.

Very cool!

When it was first published in 2005,

this research wasn't universally accepted.

Some scientists said her samples might be contaminated.

Others were dismissive.

Because I was a middle-aged housewife from Bozeman, Montana -

I had no credentials at all.

And I think that...I think that came into play.

I know it came into play later.

Um...yeah.

I had a reviewer on one of my papers once say

that he didn't care what the data said, he knew it wasn't possible.

And for me, it's like, if you can't be convinced by data,

then how is this science?

But over the past decade,

her work at the North Carolina State University

is gaining acceptance.

She's ruled out the possibility of contamination

and painstakingly analysed other dinosaur bones.

And she's gone even further,

potentially turning Hollywood fantasy into scientific reality.

She's taken some of the cells from the 68 million-year-old soft T-rex tissue

and began to look for the impossible -

DNA.

You know what, if you have cells, if you have soft tissue,

if you have proteins,

why rule out DNA?

So she took a single T-rex bone cell and ran a series of chemical tests

using a classic DNA staining procedure.

If the DNA was present in the cell, it would show up in yellow.

And astonishingly,

it did.

You can see there's this little light point right here,

that's internal to the cell membrane - it's inside the cell.

It's very specific, a single point.

We have a visual signal of something that chemically reacts like DNA.

It looks like it, it acts like it, it smells like it, you know, yeah!

If I didn't tell you where those cells came from

but I told you the chemistry of what we did, you'd say, "Yeah. Yeah, so?

"It should be there. It's a bone cell, for Pete's sakes."

Now, if I tell you it's a dinosaur bone cell, all bets are off

because everyone knows that DNA can't persist for 65 million years.

I personally think that DNA is way more hardy

than people give it credit for.

But the challenge now is to try and sequence it.

This will allow her to see how the genes fit together

and figure out their exact biological function.

I don't believe that you should publish

if you just have one line of evidence.

Especially not something like this in a field full of controversy,

like ancient DNA. I want lots and lots of evidence.

And so if we were ever to get to the point where we could sequence it,

and that may be problematic for several reasons,

I want to be able to say,

"We've got the chemistry to back it up."

This is proving really difficult because the fragments of DNA she has

are very small and degraded.

So there's a lot more work still to do.

But there's one thing for sure -

this new approach to studying dinosaurs is set to continue.

There's a sort of a shift now to look at bones from the inside out.

Where people generally thought of bones as being really precious,

we're now realising that there's more information inside

than there is on the outside.

-This one?

-No.

Finding this material has recently become much more difficult.

This is Sue, the most complete T-rex ever discovered.

And the story of how this dinosaur ended up here in this room

takes us to the heart of why getting ancient biological material

is so problematic.

And I begin with a bid of 500,000.

Now bidding at 500,000, Now bidding at 500.

600,000. 700,000, now.

At 900,000, now bidding at 9.

At 900,000 now. Two bids at 1 million.

It all started in the auction room of Sotheby's in New York

when Sue was put up for sale.

5 million.

THE CROWD GASP

5.3 in a new place.

It fetched 7.6 million.

Seven million six hundred...

The Fields Museum, in Chicago, bought it.

And Sue, named after the woman who found her,

now occupies pride of place in the main exhibition room.

Suddenly, Sue's sale price sparked a dinosaur gold rush.

-Tell what you got.

-It's...

But the commercialisation of collecting is a major problem

for scientists like Mary Schweitzer and Jack Horner.

'When people are in the business of selling something,'

they're in the business of making as much money as they can.

And therefore, the specimen is all that matters.

So the specimen is what they're going to sell.

Wouldn't we just plan on, you know, taking that off

and leaving the thing in the jacket?

'The scientific data that comes with the specimen

'when it's in the ground is overhead.'

In other words, it costs them money to get it

and therefore they will make less if they get it.

Have you seen the other side of that pubis?

Is it good bone on the other side?

'So the problem is, is that, you know, when we want

'to study dinosaurs and learn about them as living animals,

'we have to have that data.'

And so a commercially collected dinosaur is useless to science.

The pressure from private collectors

has forced dinosaur scientists to scour the globe

in search of pristine fossils.

Preservation is of course the key for Mary.

And one of the most promising places she's found is here in Mongolia.

The evidence is locked away in a specially constructed building

in the middle of the main square of the nation's capital, Ulan Bator.

It's quite the specimen you found...

-Yeah.

-..brought back here.

-Yeah.

-It's home at last.

-Exactly.

-Mongolians are very happy to see the dinosaur.

-He's beautiful.

Occupying pride of place is a Tarbosaurus bataar,

an Asian relative of T-rex,

recently returned to the country after it was stolen.

Doctor Bolor Minjin, one of Mongolia's leading palaeontologists,

has invited Mary Schweitzer to see it in all its glory.

-It's amazing, the colour of the bones.

-Yeah.

That's very different than what we have back home.

All the pictures I've seen of Gobi bone show it like this, like white.

-Mm-hm.

-Not discoloured like we have back home.

-Oh, yeah.

-You know, T-rex is much darker colour.

-Yeah.

-Yeah, mahogany-coloured almost.

-Exactly. So it's much lighter.

-Mm-hm.

The bones usually take on the colour of the sediments that they're from.

-Right.

-And since this probably comes from more red sediment...

-Yes,

-a lot iron-rich.

-..and the colour is so white...

-Yeah.

..that's got to be because it's such a dry environment

that you don't have the transfer between the sediment and the bone...

-Yeah.

-..as much as you do back home.

I mean, that's an indicator that this might be really good

for preservation of organics.

But these bones are unfortunately useless to her.

Any organics that might lurk inside them

have been fatally compromised

because they were excavated by looters, not scientists.

To find the potentially well-preserved fossils she needs,

Mary is taken by Dr Minjin to the Gobi Desert.

This seemingly endless expanse of rough grass and sand

is a dinosaur hunter's El Dorado.

Out here is where the first fossilised nest of dinosaur eggs

was discovered.

And it's the first time ever that Dr Schweitzer's been here.

I feel incredibly lucky.

And I'm quite sure that most of my palaeo colleagues would be jealous.

Because Mongolia holds a special magic for palaeontology

as a community.

It's, you know, it's the place where dinosaurs

-first entered the public mindset.

-Right.

They were introduced to the American public, at least,

-from Mongolia, from right here.

-Mm-hm.

-Yeah.

-It's amazing.

And this is where they're heading...

..the place that's become the natural cathedral

of dinosaur hunting...

..the appropriately named Flaming Cliffs.

-Wow.

-Beautiful.

-It is so pretty.

-Yeah.

It is an incredible honour to be here. It's magic.

It's...hmm, I don't know.

It's like going to Rome if you're a Catholic

or going to Mecca if you're, you know, if you're a Muslim. It's...

If you're a palaeontologist,

this is one site that is in everyone's dreams.

This area is so rich in fossils

that they're virtually stumbling over ancient bones.

MARY SIGHS

-Hope there's something up here!

-I hope so.

-Make it all worthwhile.

-Yep.

Oh, look! Bolor.

-Bone!

-Oh, look at that.

-Look, and more over here.

That possibly looks like, kind of, skull. Could be.

-Really?

-Interesting shape.

-Right here, you're right!

-It does, see the way it bends?

-Yeah. Oh, wow.

-OK.

-I need to get all the sand out of my shoes.

-Oh, look.

-Speaking of bone!

-Yep!

Nice!

-Look at that.

-Yeah.

-Could be a jaw.

-This almost looks skullish.

-And look at this.

-That looks like a cross-section of a long bone.

-Yeah.

-Amazing it can persist for this long.

-Mm-hm.

So why are these fossilised bones so white and seemingly well-preserved?

The answer lies in the soil.

The Gobi has been a desert since the time of the dinosaurs.

It's been dry for more than 65 million years.

And that's potentially good news for Mary,

in her quest to find ancient organic material.

Scientists think that wet soil pushes out organics from the fossil.

The water effectively seeps through the bones,

flushing the cells as it goes.

And so if you have a very long protein,

like a whole collagen molecule or a whole haemoglobin molecule,

you put it in a wet environment and it gets broken up into little chunks.

And of course the chunks

are a lot easier to move away from muscle or from bone

and into the environment, where they're lost for ever.

In theory, if it's dry, the bone proteins, molecules

and even possibly DNA should be better preserved.

We think dry is good for preservation.

A lot of the incredibly preserved mummies from Peru,

they are preserved with their skin intact,

the colour intact, the clothing intact

because it's dry.

I didn't see any at work...

The problem is that around here, fossils are so easy to find.

Now that might not seem like an obstacle but it is.

It seems like if we saw it that easily,

other people would too.

-Yeah, the colour - it's very white.

-It's very white.

-I've never seen that.

-And they're a distinct shape.

-Yeah.

You know, shape is the thing people really easily pick up.

And if you know... if you're here to find bone

-and you know anything at all about it...

-Yeah.

-Yeah.

-Hmm.

INDISTINCT CHATTER

Not surprisingly, then,

there has been a spate of fossil looting at this historic site.

Oh, look at that.

Looks very suspicious! Something...

And the looters rarely take the trouble to cover their tracks.

This is not good.

-Who would leave something like that here?

-Yeah.

-What the heck is it?

Strange bits of plastic, sometimes used as markers for a site,

are scattered around these cliffs.

Look.

Oh, my gosh.

Other clues include general litter,

like these discarded plastic bottles.

-Wow, long day. Huh?

-Yeah!

Sun is going down very soon.

It all leads to the inevitable discovery

of a tell-tale hole in the ground.

Oh, look at here.

-Yeah, that looks kind of weird.

-This is clearly excavation.

-Right there, see the sharp line?

-Yeah.

-That's exactly. Look at how perfect, you know?

-Yeah.

-This is not natural.

-Could have been something available for science.

-Yeah.

-So this is what's happening here.

-See the thing is, you know,

when somebody takes something out of context like this, it's lost.

-It's valueless.

-Exactly....

It might look pretty but you might as well go get a coffee table book.

-Yeah.

-It just... It's just not right.

But things are changing here in Mongolia.

The government is now planning

to take much firmer action against the looters.

And Mary has her own plan to help combat the problem.

She's setting up a project with Bolor to mount a dig in the Gobi

using all the techniques she's helped to pioneer.

The fossil record is always surprising us

with things that we said couldn't be preserved.

Why not look a little deeper now that we have new technologies

and maybe what we've said all along that couldn't last this long

maybe does.

And her ground-breaking work -

the discovery of cells...

..proteins...

..and even possibly DNA...

..is pioneering a new era in our understanding of dinosaurs.

But even if she was able to find dinosaur DNA

out here in the wilds of the Gobi,

we might have to wait a very long time for a Hollywood ending.

You know, if you want to build a dinosaur

out of DNA you pull from a dinosaur bone,

there are so many things that you have to answer.

You know, you might get little chunks of DNA,

maybe you might even get the whole genome.

But it's going to be fragmented,

it's going to be split up, it's going to be broken.

So how are you going to piece it together in the right order?

Because if you get chromosomes and genes in the wrong order,

you're toast.

It may not possible to bring a dinosaur back to life

but Mary's bringing them closer to us than ever before.

And the well-preserved remains

which lie buried beneath these Flaming Cliffs

might allow her to put even more flesh on the bones

of the most fearsome and forbidding creatures ever to walk the earth.

Subtitles by Red Bee Media Ltd