Over 66 million years ago...
SCREECHING WAIL
HIGH-PITCHED CLUCKS ..our world...
DEEP SNORT ..was ruled...
..by dinosaurs...
DEEP BELLOW
HISSES
..the largest animals that have ever walked the Earth.
Today, dinosaur experts across the globe
are uncovering the bones they left behind...
..allowing us to imagine how these extraordinary creatures
may have lived...
..so that we can tell their stories...
..and they...
..can walk again.
Eastern Montana.
A vast untamed wilderness...
..with extraordinary stories to tell.
This is dinosaur country.
Here, a team from the North Carolina Museum of Natural Sciences
is excavating an iconic species,
a triceratops.
- Oh, sweet.
- But this is no ancient giant.
- But it's really small, a very young individual.
- Got a nice baby drake.
A phenomenal find.
- The team calls her Clover.
Studying her bones,
we can begin to imagine her world...
..and tell her story for the first time.
At the end of the Cretaceous,
North America is a vast expanse of green.
Where Montana is today,
there is a lush landscape of sprawling subtropical forests...
..crisscrossed by waterways.
This is Laramidia...
..home to prehistoric giants...
THUDDING FOOTSTEPS
..and the occasional...
..not so giant.
TRILLING CALL
Meet Clover, the triceratops.
Barely half a metre tall,
she's the size of a large dog.
PANTS
Despite her size, Clover roams the jungle alone.
These strange white objects mean one thing.
Playtime.
SNUFFLES
But curiosity can be a dangerous thing...
CROAKING CALL
..when you're living in a land of monsters.
Clover is rare.
The vast majority of triceratops fossils discovered
are from adults.
Clover's remains are a chance to uncover the story
of a youngster...
..a once-in-a-lifetime opportunity for team leader
Eric Lund.
- Check out these teeth. - Oh, wow.
- Clover's tiny jawbone has been painstakingly reconstructed
by fossil restorer Nikki Simon.
- Isn't she gorgeous?
- She is gorgeous. It's beautiful.
Don't often find upper jaws this complete,
let alone with all the teeth in 'em.
No wear on them.
- The teeth's edges, for slicing through plant material,
are still razor sharp.
- Check 'em out. - Sure.
Oh, yeah.
- These have barely been used.
- They almost look carnivorous.
- The teeth are a clue to Clover's young age.
- Look at how small this upper arm bone is.
- Yeah. Let's see
- By measuring Clover's arm bone...
- A little over a foot. - 34cm.
- ..they can more accurately estimate how old she was.
- She must only have been about three years old.
- Which means she was just a baby.
- A baby...buried all alone.
- Seems to be by herself.
Haven't found any adult bones in this quarry.
- Without the herd, without her mother,
very vulnerable.
- We'll never know why Clover was alone.
What we do know is that in the Late Cretaceous...
..young, solitary dinosaurs don't last long.
WINGS FLAP
SQUAWKS
HISSES
An infernodrakon...
..a giant pterosaur, common at the end of the Cretaceous.
With a five-metre wingspan, it tries to intimidate Clover.
INFERNODRAKON HISSES
And then there's the razor-sharp beak.
But Clover is nimble.
And this mother just wants her egg back.
This time, the little triceratops was lucky.
But danger lurks everywhere...
BELLOWING ROAR
..and it gets much, much bigger.
A mile from Clover's dig site...
..more fossilised remains are emerging.
HAMMER TAPS
- We've got a bone over here that's very thin,
very slender and very long.
This looks like one of the processes
off of the tail vertebrae, and it helps lock the tail
into a much more rigid structure.
- These thin bones may once have formed
part of a thick, muscular tail six metres long.
But this was no triceratops.
- This is sort of a meat-eating dinosaur feature.
- Palaeontologist Ellis Mulready holds the final clue.
- It's a little bit beat up.
- It's a really thick tooth, designed for crushing bones.
- It's got those kind of drawn-together serrations.
- You can still feel them.
I would love to meet the creature that had this tooth,
but it'd be a bit scary!
- THEY LAUGH - Yeah.
It's a tooth that can only belong to one animal.
LOW, RUMBLING GROWL
SLOW FOOTSTEPS
LOW GROWL
Standing four metres tall...
..and weighing in at eight tonnes...
..Tyrannosaurus rex.
With 1.5-metre-long jaws,
the Earth's most infamous predator could swallow Clover whole.
LOW GROWL
Fortunately, the hunter's focus is elsewhere.
Padded feet act like shock absorbers,
keeping its approach quiet.
For T-rex, a light snack.
GROWLS
PANTS
For Clover, a terrifying first encounter.
And it won't be her last.
Up to 20,000 T-rex roam Laramidia.
To survive, Clover needs protection...
..and fast.
- You ready? - Ready.
- In the search for more clues,
Eric and evolutionary ecologist John Kanipe
are heading deeper into the wilderness.
- So, you asked me about snakes earlier.
- Oh, yeah.
- There's just a baby rattler in the bottom there.
- They want to understand who was sharing the forest with Clover.
- All right. I'm ready when you are.
- It's obvious from the evidence on the ground...
- Got a bit of bone here coming out.
- ..that Clover's world was teeming with other dinosaurs.
- Some bigger pieces.
Pretty busted up.
That's got a bit more surface.
- One familiar species is turning up more than any other.
- Most of them belong to triceratops.
- Triceratops once dominated this area.
- They've been sitting on the surface a really long time.
They're pretty weathered.
- One fossil shows why triceratops were so successful.
- It's like a big brow horn.
Oh, man! It's a bit busted up.
- You can still see where all the blood vessels would be,
even on the horn. - Yeah.
- In life, this horn would have been over a metre long,
and behind it a protective bony shield almost two metres wide.
Here was a creature seemingly custom built
for fighting off large predators.
- Got these big horns on the front of your face, wave them around
and maybe make a T-rex think twice before attacking you.
- Triceratops' formidable defences made it
one of the most successful dinosaur species of its day...
..meaning an adult triceratops
would be the perfect protector for Clover.
LOW GRUNTS
CLOVER YELPS
This old bull will do nicely.
CLOVER CALLS SOFTLY
LOW GRUNTS
But there's a problem.
Who needs a troublesome youngster following you around?
CALLS SOFTLY
GRUNTS LOUDLY
TRILLING CALL
As another day ends...
..Clover is still alone...
..and darkness is setting in.
Eric thinks Clover may have had good reason
to fear the night-time most of all.
Back at base camp, he uses a scan of a T-rex skull
to print a 3D model...
..of the killer's brain cavity.
- This is the endocast of a T-rex.
For an animal that has a head a metre and a half long,
not a real big brain - a dinosaur's not doing calculus -
but it was enough to do what the animal needed to do.
It was very successful. - Right.
It just needs to process the information.
- Exactly. - It's got a lot of sensory input.
- Though small compared to a human's,
this brain is fine-tuned for hunting.
- We've got these really big olfactory bulbs in the front.
- That's for smell. - That's for smell, yeah.
- T-rex probably had one of the most sensitive noses
of any dinosaur.
- It's probably picking up on minuscule parts per million.
- And it wasn't just the killer's sense of smell
that was supercharged.
- Here, in the middle,
would be the part of the brain that controls vision.
T-rex does...really big eyes, just like an owl,
that take in a lot of light.
- These incredible senses likely made T-rex
a lethal nocturnal hunter.
THUNDER RUMBLES
CREATURES CALL
As darkness descends...
..it's time to begin the hunt.
Locking on to a telltale scent...
SNUFFLES
..it seems that supper is nearby.
Whilst most creatures have sought safe places to sleep...
..Clover is awake.
She must bulk up by a tonne
each year to reach full size,
so feeds often through the night.
In the darkness, she sees little...
..but T-rex sees her
perfectly.
GRUNTS
THUDDING
SNUFFLES
Saved by her size.
GRUNTS SOFTLY
Luck seems to be on Clover's side.
DISTANT GRUNTS
CLOVER GRUNTS
She survived a close encounter with T-rex.
And from the sound of things...
HOOTING CALL
..a new ally may be close at hand.
LOW GRUNT
In the search for more giants, the team is putting to the test
the very latest fossil-hunting techniques.
A 66-million-year-old treasure hunt
using 21st-century technology.
- If we fly out towards those badlands,
that would be a great spot.
- BEEPING
- The gyros stabilise.
- Eric's teamed up with palaeontologists Thomas Kaye...
- BEEP - Going for arm.
..and Dr Michael Pittman.
- Ready to launch.
- Their prototype laser drone scans the ground with UV light...
..searching for the telltale glow of minerals within ancient fossils...
..to create a treasure map of prehistoric remains.
- See, here, we've got some specks.
Maybe the size of a tennis ball.
Interesting but, you know, we want the big stuff.
- It's early days for the technology,
and it has limitations.
But one spot on the ground...
- Bang! Look at that.
- ..is glowing brightly.
- So that must be a really big piece. - Yeah, that's big!
- As dawn breaks,
Eric and Nikki head into the badlands
to see this enormous fossil.
- Look how big it is!
- It's the lower leg bone of a truly colossal dinosaur.
- Seems to have been sitting out on the surface for quite some time.
This is a big bone.
This animal would have been, you know, maybe around
six, seven metres long.
- But this is no triceratops.
It's not a T-rex either.
BELLOWING CALLS
Echoing through towering trees...
BELLOWING CALL
..the calls of perhaps the strangest dinosaurs who roam here..
BELLOWS CONTINUE
..Edmontosaurs...
..herd animals known as the cows of the Cretaceous.
Weighing over six tonnes,
these social creatures tolerate Clover.
As a fellow plant-eater, she's no threat to them.
The herd could give Clover the protection she needs.
CHIRPS
And it's not just safety they offer.
A playmate.
ALL GRUNT AND CALL
In amongst these giants...
..Clover can begin to feel safe.
But danger is never far away.
HAMMER TAPS
66 million years ago, T-rex ruled over these lands...
..the apex predator for over two million years.
- As it rolls over, just get your hands under it.
- The team wants to discover how this fearsome hunter
took down its prey.
Inside this protective plaster coat
is the predator's leg bone.
Eric thinks there might be more underneath.
- One, two, three.
- Protruding from the rock...
- That's a bone.
- ..one of the giant's vertebrae.
- Beautiful preservation.
It was a big, big animal.
- It allows Eric to estimate more accurately T-rex's full size.
- On the order of 30 feet, maybe more.
Ten metres, something like that.
- They wrap their discoveries in a protective plaster jacket.
It's just a tiny fraction of T-rex's skeleton...
..but it's enormous.
- This jacket's probably about 150kg,
200lb, 300lb.
It's just so huge.
- Alive, adult T-rex weighed over eight tonnes,
but this enormous weight may actually have been a hindrance.
- Certainly not the 40mph Jeep-chasing animal of Jurassic Park!
Their physiology just wouldn't allow them to run that fast.
Probably speed walker.
- T-rex probably couldn't run for fear of breaking its own legs...
..with a top speed of just 15mph or 20mph.
Not exactly slow, but a fast human could outsprint one.
- I think you could.
I think I'm going to take a sharp turn,
and it's going to have a hard time following me.
- You think we only just got - THEY LAUGH
- LAUGHTER to be faster than him.
- Maybe I'm a little overconfident!
- So adult T-rex weren't sprinting after their prey.
This killer relied on another tactic...
..the element of surprise.
LOW GROWL
As Clover and the Edmontosaurs sleep soundly...
..T-rex approaches slowly from downwind.
But it's not easy being stealthy...
CRACK
..when you're the size of a bus.
BLEATS LOUDLY
ROARING
The Edmontosaurs form a defensive line...
..rearing up on their hind legs
to appear as big as possible.
But holding your nerve isn't easy.
And it only takes one of the herd to panic.
SQUEALS
CHOMPS
A lucky escape for Clover...
..not for her new friend.
CALLS SOFTLY
With the adult Edmontosaurs on the move...
..Clover is alone once more.
Survival was a game of chance in the Late Cretaceous,
and the odds were stacked against young dinosaurs like Clover.
The team has tracked down a remarkable fossil
with a chilling tale to tell.
- That's the weirdest baby bundle ever.
- It may look like a nondescript lump of rock
but its shape and texture tell the experts
this is a coprolite - fossilised faeces.
Eric works with fossil-restorer Aubrey Knowles...
- 67.5 centimetres, or 26.5 inches.
- ..to examine this prehistoric poo.
- This is a massive turd. - It's a really big turd.
- ERIC CHUCKLES
Most coprolites can't be attributed to any specific species...
..but bone fragments within the dino dung
reveal this was the waste product of a meat-eater.
And then there's the matter of size.
- So we're at 15.7 centimetres across, or 6.2 inches.
- That's a wide cloaca.
- SHE LAUGHS - That is a very wide bumhole.
- The only large-bodied carnivorous dinosaur
that could have possibly dropped this
would be a T-rex,
so very, very cool.
- It's an astonishing fossil...
..the excrement of the most notorious predator in history.
- It's interesting how many bones there are
preserved in the dropping.
- By examining coprolites,
it's even possible to identify the killer's victims.
T-rex faeces have been found to contain bones
that are small and smooth.
- That speaks to a more juvenile or young prey.
- The bones of babies.
- Baby dinosaurs would be very vulnerable.
Bite-sized.
- Energy is precious. - Yeah. - Go after easy prey.
- Needing a quarter of a tonne of meat a week
to sustain their enormous bulk,
baby dinosaurs like Clover were a common meal for T-rex.
Nothing is off the menu.
Naive, defenceless
and small enough to swallow whole...
..Clover would make an excellent snack.
SHRIEKS
GRUNTS
With nowhere to hide...
..it's a good time
to bump into an old acquaintance.
Few creatures can challenge T-rex,
but a full-grown triceratops might be the only animal
that doesn't need to turn and run.
Who wins in a fight - triceratops or T-rex?
The two giants were locked in an evolutionary arms race,
adapted to battle each other.
But Eric thinks triceratops may have had
a surprising trump card.
This fossilised fragment was once part of the huge frill
extending from the back of the skull,
but it wasn't solid bone.
- All these vascular channels on the surface,
all these pits and grooves that are in it,
go all over the surface of the frill.
This surface was covered in a lot of blood vessels.
- The blood flow suggests to Eric
a triceratops frill was more than just a shield.
- The idea is they could change the colour pattern of their frill,
flash these different colours.
- Pushing all this blood up into its frill,
this would be a great way to send a message.
It would have been really intimidating.
- BELLOWING ROAR
The giants are evenly matched.
Each weighs over eight tonnes.
Each with fearsome weaponry.
But triceratops plays his trump card.
Flushing blood into his frill
creates huge colourful eye spots.
They make triceratops seem even bigger.
But T-rex isn't apex predator for nothing.
Stalemate.
But for T-rex, there's still an easier meal close by.
Most young dinosaurs never made it to adulthood,
and Clover was no exception.
But as the dig season draws to a close...
..her exact cause of death is still unknown.
- You know, we're not sure how baby Clover died.
In digging her bones up, we haven't found any evidence of predation.
There doesn't seem to be any injuries,
no bite marks, things like that.
Up to this point, it remains a mystery.
- Got it? - All right.
- But we do know one thing.
If Clover had died as a meal for T-rex...
..there probably wouldn't be any remains at all.
For Clover, it seems as if time has run out.
But she still has one advantage -
her size.
With T-rex distracted...
..a moment of surprise.
Clover has survived her encounter
with history's most infamous killer.
For now, she's safe.
CALLS SOFTLY
GRUMBLING GRUNTS
And while this old bull may not seek the company of a youngster...
..Clover's not giving up just yet.
We take the plunge
in the most dangerous river...
GRUNTS CALLS
..in Earths' history...
..join the smallest member of the biggest herd...
..on an epic journey...
..get up close with the deadliest pack of predators...
..follow an island giant looking for love...
..and meet the band of brothers on the run
from a ferocious and cunning adversary.
SQUAWKS
Over 66 million years ago...
SCREECHING WAIL
..our world was ruled...
BELLOWS
..by dinosaurs.
The largest animals that have ever walked the Earth.
Today, dinosaur experts across the globe
are uncovering the bones they left behind...
..allowing us to imagine how these extraordinary creatures
may have lived...
..so that we can tell their stories.
SHRIEKS
And they...
..can walk again.
ROARS
Nine million square kilometres of parched sand.
The Sahara Desert is one of the most inhospitable environments
on Earth.
But for dinosaur hunters, like Dr Nizar Ibrahim,
it's a gateway to a lost world.
Deep in a remote part of the desert, known as the Kem Kem,
Nizar and his team are excavating the remains
of one of the largest predatory dinosaurs that ever lived.
- Is it broken there?
- I don't know. It seems to be one bone here and one here.
- Wow.
- A spinosaurus.
- Oh, that is beautiful.
What do you reckon? Maybe a rib?
- Or a rib, yeah.
- I knew we'd find one.
- Using the team's discoveries,
we can imagine how it lived and died...
..100 million years ago.
In the Late Cretaceous period...
..Africa has just broken away from South America.
And the land that will become the Sahara...
..is a river system.
Its waters support acres of scrub and forest
that provide shade from the intense Cretaceous sun.
Perfect for an afternoon nap.
GENTLE SNORTING
This is Sobek the spinosaurus.
11 metres long.
His powerful jaws packed with teeth.
Disturbing this monster's sleep...
..could have deadly consequences.
HIGH-PITCHED CLUCKING
HIGH-PITCHED CLUCK
LOW GROWL
HIGH-PITCHED WAIL
But this isn't lunch.
HIGH-PITCHED CLUCKING
It's one of his babies.
Sobek is a father.
Like some species of modern birds, once the eggs are laid,
the job of looking after the kids falls to him.
YELPS
Sobek must keep his young family alive...
..until they can fend for themselves.
PNEUMATIC DRILLING
100 million years later...
- Looks like bone.
- You got the location mark all right?
- ...Nizar and the team are starting to uncover evidence
that could shed light on how spinosaurus raised their young.
- See more? Any luck on that side?
- Bones that show Sobek wasn't built like other dinosaurs.
- So, Marco, you can see this nice little curvature here.
I think this is certainly a vertebra.
It's a little fragile, this one.
This vertebra was part of Sobek's six-metre tail.
All right, let's get it out, and let's see if we can find more.
- In total, the team has recovered more than 40 tail bones.
- This will be vertebra number...22?
- Yeah. - OK.
Starting from the smallest one? - We're starting distally, yes.
- And for Nizar and fellow palaeontologist Francesca Borchi,
they reveal something unique.
- What I think is really remarkable is, like, you get close
to the tip of the tail, and you still have these really long spines.
- Spines like these are not found
on the tail bones of other predatory dinosaurs.
- Once you see the shape of the spines, it's quite narrow.
- Yes. - And...and flat.
- Basically just a giant paddle.
- Yeah.
- The more we collect, the more aquatic this thing becomes. - Yeah.
- For Nizar, a thin flat tail can mean only one thing...
..Spinosaurus was a swimmer.
WATER SPLASHES
Underwater, Sobek is in his element...
...using his huge tail to power him through the water.
He's guarding a nursery pool,
the place he and his babies call home.
And with Dad's back turned, the kids take to the water.
This secluded backwater is the perfect learner pool.
CROAKS
So, while Sobek's patrolling,
the babies hone their hunting skills.
But it's not long before one of them gets into trouble.
If it doesn't get help soon...
..this baby will drown.
Dad to the rescue.
CROAKING CALL
With everyone safely back on the bank,
the family settles down to sleep.
But they must soon leave the safety of the nursery pool
and travel somewhere Sobek knows they can catch
far more substantial prey.
And the journey ahead will be fraught with dangers.
Because, although the dig site is barren and lifeless today...
..Nizar and the team have evidence that when Sobek was alive,
the Kem Kem was far more perilous.
- Lots of big predatory fish.
There's a nice...nice jaw.
Absolute monster.
- Its rivers teemed with massive carnivorous fish...
- Ah, this is nice.
- ..and enormous crocodiles.
- Look at that.
- OK.
- Tip of the snout, right?
This is where the nose end is, essentially.
This will be the size of the biggest crocs today.
Big, nasty elosuchus.
- Elosuchus is an extinct species of croc,
with jaws over a metre long.
- This tooth is very nice. Still here.
- Yeah, they're pretty, er, robust.
- If the rivers were dangerous...
- Carcharodontosaurus tooth.
- ..the land was home to an even more deadly predator.
- Yes, it's very well preserved.
I can see all of the serrations here.
- Like a steak knife, right?
- Carcharodontosaurus was the T-rex of Africa...
..three metres tall
and armed with more than 50 flesh-cutting teeth.
- Got several T-rex-size predatory dinosaurs,
or even bigger than T-rex, big crocs, giant fish.
- Not very safe. - Yeah.
You know, there are really many different ways to die.
- These lands were once home to more large predators
than anywhere else in Earth's history.
A fearsome collection of carnivores...
..that Sobek must navigate...
..if he's to feed his family.
And there's danger lurking at every turn.
CROAKING CALL
Hidden from view, the murky waters are patrolled
by at least eight species of ferocious crocodile.
CROAKING CALL
But that's the least of their worries...
RUSTLING
..because the family has just entered the territory...
LOW SNARL
..of carcharodontosaurus.
This fearsome six-tonne killing machine...
..is also on the hunt for food.
ROARS
SCREECHING
LOW GROWLING
ROARS
ROARING
Time to get the babies to safety.
ROARS
With so many deadly predators around,
it will take everything Sobek's got to reach his destination...
..without his family becoming someone else's meal.
And not far from the dig site, on a remote plateau...
..the team has discovered signs of another monster...
- You good? - OK.
- Good. I'm ready to go whenever you are.
- ..evidence that's best seen from the air.
DRONE WHIRS
- So, how many pictures are we taking in total?
- About 500, 600.
- So, if we start down that ridge,
and then work our way over and do that whole site.
- The photographic survey reveals what's hidden here.
Arranged in rows, these aren't just boulders...
..they're footprints.
This is a dinosaur trackway.
And to identify which dinosaur made it...
- Really big one. - Wow.
- ..Nizar and colleague, Dr Roy Smith, take a closer look.
- You've got this edge here,
and then quite a nice shape around that side, as well.
- Yeah, very nice.
- Each footprint is a cast of the foot that made it.
- So, the claw over there, right? - Yeah, yeah.
And I think there's two more there. - Yeah.
- The back of the foot. - Yeah.
- And at over a metre across,
they're some of the biggest ever found.
- No. - No.
- This is really impressive. - Yeah.
- There's a bit missing, or it would have been even bigger.
- It would have been even bigger.
- We've got a giant here. - Yeah, yeah.
- These footprints were made
by one of the largest dinosaurs that's ever lived.
Titanosaurs - huge long-necked dinosaurs, 14 metres high.
At more than 60 tonnes,
each one weighs as much as a herd of elephants.
DEEP BELLOW
But for one elderly member of the group...
..this has become its final resting place.
And it could provide Sobek with the food he needs
for his hungry babies.
But they're not the only ones
on the lookout for a free lunch.
LOW GROWL
An adult carcharodontosaurus...
ROARS
CHITTERING
..has already laid claim to the carcass.
ROARS
With his babies to look after, Sobek can't risk injury...
..so he must now decide if it's a prize worth fighting for.
GROWLING
Sobek is bigger.
But one bite from these jaws could be fatal.
Sobek's fearsome claws could give him the advantage.
But, crucially, the carcharodontosaurus...
..is built for hunting on land.
ROARING
HISSES
So Sobek backs down.
BABIES CHITTER
His family won't eat today.
But if they can survive their journey,
a much bigger prize awaits.
As night falls,
Nizar and the team examine an astonishing fossil.
NIZAR: - The place where this was found, it was so narrow
you could only just crawl on your belly, essentially.
- Discovered close to the dig site,
it's the remains of an extinct species of fish.
- This is the head of onchopristis.
The brain case,
the blade-shaped snout, it's all there.
- Onchopristis is commonly known as a sawskate
because of the long snout, lined with barbs,
it used to stun its prey.
- This would have been a fairly slow,
bottom-dwelling skate-like animal.
OK.
But that's insane.
- And with spinosaurus so at home in water,
Nizar has a theory.
- So, this would have been
one of the primary food sources for spinosaurus.
- Incredible. - God, it's amazing. Wow.
- Sawskate could grow up to four metres in length...
..so a single fish would make a sizeable meal.
But once a year, like rays do today,
it's thought they gathered to breed...
..in their thousands...
..providing an incredible feast...
..that awaits Sobek and his family.
BABIES CHITTER
But in this predator-infested land,
danger can strike at any time.
SCREECHING
HAMMERING AND DRILLING
And 100 million years ago...
..there weren't just predators on land and in the water.
They were also in the air.
NIZAR: - So, this is a lower jaw of alanqa.
This is a Kem Kem pterosaur.
It is a pretty remarkable specimen.
- Uh-huh.
- Alanqa was a huge flying reptile
with a seven-metre wing span...
..twice that of any bird alive today.
- Essentially, what we're looking at here is
the skull would be going back, you know.
- Like this. - Yeah, something like this.
- A metre, more or less.
- Yeah. - Pretty big.
- Yeah, it's probably the largest Kem Kem pterosaur.
- Its jaws reveal
what this flying monster would have eaten.
- It's got this really interesting
raised structure here.
It's got, like, a Y shape. - Mm-hm.
- There's a corresponding matching part
in the upper jaw,
and so maybe this was something
that was used to crush hard-shelled prey.
- Although it's adapted to eat shellfish,
alanqa was so big, it didn't need to be picky.
- It's possible that these things
were catching little things on the ground,
you know, when they walk on the ground.
- Maybe little dinosaurs, little crocs, amphibians,
whatever they could catch.
- Yes, yes.
- With alanqa about, no small creature was safe.
ALANQA SHRIEKS
SHRIEKS
To reach the sawskate breeding ground,
Sobek must lead his young family through the forest.
It's their final challenge...
..but the most deadly.
For alanqa, a young spinosaurus would make a tasty meal.
SQUEAKS
LOW GROWL
And the dense foliage provides perfect cover...
..for an ambush.
SQUEAKS
SNAP
TWIG SNAPS
SQUEAKS
SQUEALS
GRUNTS
Too late.
ROARS
Having come so far...
..losing one of his babies is a huge blow.
CROAKING CALL
But if Sobek is to keep the others alive,
he must keep moving.
As the family emerges from the forest...
..their journey's end is in sight.
The sawskate breeding ground...
..and the promise of plentiful food
for Sobek and his family.
But for his babies to eat,
Sobek will have to fight his way
to the front of the queue.
HAMMERING
INDISTINCT CHATTER
And at the dig,
Nizar and palaeontologist Dr Gabriele Bindellini
have evidence that could reveal
how spinosaurus settled their differences.
NIZAR: - So, I think this is the tallest we've got.
- GABRIELE: - Mm-hm.
And it still miss a good portion at the tip.
- Yeah, I mean, I think we're missing 30, 35,
maybe even 40 centimetres.
- Mm-hm. Which makes it super long.
- Yes.
Do you want to take this end? I'll hold it here. - Mm-hm.
- Over 1.5 metres long,
this is one of the 15 bones that rose up from Sobek's back,
supporting his enormous sail.
- I've tried to visualise all of his other spines. - Mm-hm.
- I mean, it's a massive structure.
- Spinosaurus sails are so big...
..they must have had an important function.
- It's probably, like, primarily
a display structure to, you know...
- To be seen from the distance. - Yeah, like...
- Peacock. - Yeah, like a peacock's train.
- But unlike a peacock, Nizar believes
the main function of spinosaurus's sail
might not have been to find a mate.
- So, you're one spinosaurus, and you come close
to another spinosaurus's territory...
- Yes. - And what are you going to see?
You're going to see this big sail, right?
And just by looking at the sail, you can go,
"Ooh, there's a really big spinosaurus.
"I'd better not get close to this guy."
- "Stay away from here."
- I think it would be very efficient
at scaring off, erm, other predators or rivals. - Yeah.
- Sobek's intimidating sail
could be just what he needs...
..to win a prime fishing spot.
Having run the gauntlet of Kem Kem predators,
there's now only one thing
standing between him and feeding his babies.
A rival spinosaurus.
LOW GROWL
ROARS
Sobek must try to intimidate this older male...
..and take his place on the bank.
ROARS
So he initiates a ritual dance...
BOTH GROWL
..showing off his sail.
But as a young male, Sobek's sail is smaller...
BOTH GROWL
ROARS
..and not intimidating enough.
ROARS
Forced from the bank where the fish are easier to catch,
the job of feeding his hungry babies...
..has just got much more difficult.
HAMMERING AND SCRAPING
- Can we get some measurements, Marco?
- But evidence from the dig...
- 140.
- ..suggests Sobek may have been
well-equipped for the challenge.
CAMERA CLICKS
- It's something we haven't really seen before.
Something new. - Yeah?
- One of the missing foot bones.
- Yeah.
- Sobek's foot bones are similar to those of water birds,
meaning his feet could have been webbed...
- Here we are.
We're going to wrap it in this, tape it,
and this one we're going to put in a plaster jacket.
- ..helping him to swim after his prey.
INDISTINCT CHATTER
- It's a tibia.
Where's the box?
- And if he caught it, Sobek had another adaptation...
- The teeth are really amazing.
- ..that made him a formidable underwater predator.
- If I didn't know spinosaurus was here,
I would say this is a crocodile tooth.
Looking at it, the shape is basically the same, you know?
- Unlike the broad blade-like teeth
of other predatory dinosaurs...
..spinosaurus teeth are smooth and conical like a crocodile's,
because they both eat the same food.
- This is basically
your main piece of anatomical weaponry
if you're going after fish. - Oh, yeah.
- We're talking really big fish.
Stabbing slippery prey.
- With more than 60 of these teeth
in its long jaws...
- It's conical, it's...
- ..spinosaurus was able to tackle the largest fish.
- Imagine having to hold on to a big sawskate
fighting for its life.
- Yeah, it definitely wasn't an easy catch.
- Yeah, I mean, they put up a real fight.
You need these kind of killing tools, right,
to hold on to the prey.
- Webbed feet and spiky teeth are critical adaptations...
..that Sobek will need to make a catch.
But even so...
..success...
..is far from guaranteed.
Although Sobek is faster...
..the sawskate is more agile.
Time for a change of tactics.
Attacking from below...
..like a shark.
Success.
But getting his catch to his family won't be easy.
LOW GROWL
ROARS
WAILS
BOTH ROAR
This time, Sobek is in no mood to give up his kill.
BABIES CHITTER
By leading them to this land of plenty,
Sobek has ensured his babies' survival.
But his moment of triumph...
..has come at a terrible cost.
- So, these are small parts
of the femur,
of the thigh bone, of our spinosaurus.
- Yeah, wow. - That's really nice, right?
- Slices cut through Sobek's bones
have a disturbing story to tell.
- We looked at some of the sections.
We looked at the growth lines under the microscope,
trying to look at the age.
- Oh, yeah. - They came out pretty nice.
You know, it's not as easy
as reading growth lines on a tree,
but we can narrow it down to an age
of 17 to 19 years at death.
- OK, so he wasn't that old.
- Yeah, like a young adult-ish, you know.
- Mm-hm.
- Other large predatory dinosaurs
are thought to have had a lifespan of about 30 years.
But Sobek's bones reveal
he was barely an adult when he died.
- So, maybe he could have lived a little bit longer.
- Yeah, if we assume a similar kind of lifespan
for a spinosaurus, you know, late 20s, early 30s,
it's a life cut short.
- The evidence hidden within his bones...
BABIES CHITTER
..suggests Sobek may not have lived
to see his family grow up.
In providing for his babies...
..he has paid the ultimate price.
BREATHES HEAVILY
GASPS
EXHALES
GROANS SOFTLY
BREATHES SOFTLY
And as the great river ebbs and flows,
it covers his body
with layer upon layer of sediment...
..preserving Sobek's story
beneath the desert's shifting sands...
..until he is eventually found...
..100 million years later.
Next time...
..a gang of armoured dinosaurs
battles to reach adulthood...
..hunted by one of the most fearsome predators...
..that's ever lived.
Over 66 million years ago...
SCREECHING WAIL
HIGH-PITCHED CLUCKS ..our world...
..was ruled...
..by dinosaurs. SHRIEKS
DEEP BELLOW
HISSES
GRUNTS
The largest animals that have ever walked the Earth.
Today, dinosaur experts across the globe
are uncovering the bones they left behind...
..allowing us to imagine how these extraordinary creatures
may have lived...
..so that we can tell their stories...
..and they...
..can walk again.
ROARS
Utah - in the heart of the American West.
Home to some of the most spectacular scenery on Earth.
And the forces that shaped the landscape
also make it a paradise...
..for dinosaur hunters.
In a remote part of the desert,
palaeontologists Dr Jim Kirkland...
..and Dr Josh Lively...
..have made a remarkable discovery.
- So we've exposed quite a bit of bone, Jim.
- Yeah.
- The bones of one of the most heavily armoured dinosaurs...
..that ever lived...
- Oh, that's cool.
- ..a gastonia.
- Yeah, you might have a leg there.
- Using their discoveries,
we can imagine how this youngster lived and died...
..113 million years ago.
In the Early Cretaceous period...
..the land that will become Utah
was warmer and wetter.
BIRDSONG
And what is desert today
is covered by conifer forests...
..and rolling meadows of ferns.
DEEP ROAR
Plentiful food...
..for groups of plant-eating gastonia...
..including youngster...George.
LOW BELLOWING
Like all young gastonia,
he must stick close to his parents...
..because danger...
..is never far away.
CHITTERING
Utahraptor.
SNARLS
A heavyweight cousin of velociraptor,
the size of a grizzly bear.
And they hunt vulnerable young gastonia.
The ferns providing ideal cover
for a surprise attack.
Just yards away,
George and his family are oblivious...
..to the approaching danger.
SNARLING
With the raptors within striking distance,
the gastonia get a lucky break.
CRUNCH
SHRIEKING AND ROARING
Like many modern herd animals,
the adults form a defensive ring around their young.
Weighing over a tonne each,
covered in thick armour...
..a group of adult gastonia is virtually invulnerable.
With one of their group injured,
the raptors cut their losses.
But George can't rely on the safety of the herd
for much longer.
He's reached adolescence, when, like all young male gastonia,
it's thought he'll be pushed out of the group.
SOLITARY BELLOW
George must now grow up
without his family to protect him.
- We'll probably do Dakota,
and at least one other person too.
- At the dig, the team is starting to uncover evidence...
- Is there a bone there coming up from somewhere?
Try and get your fingers under that if you can reach over.
- ..that might explain how young gastonia like George
survived to adulthood...
- You got one over there. - There's a big guy here.
- Oh, OK. Looks like a limb bone.
Might connect to some of this bone right here.
- ..and the clues are coming thick and fast.
- Beautiful! - That's bone.
- Looks like the rib might go into this one.
- Everywhere they dig,
bone after bone emerges from the ground.
- Found a couple of ribs right here,
going over top of a vertebra,
and then several pieces of armour.
A ton of bones just in this small spot.
It's too many to be from just one individual.
- Got these thin rib-like sections.
- Right. - I mean, so far, you know, right in here,
there's probably parts of two animals.
- And, intriguingly, all the gastonia found across the site
appear to be of a similar age.
- From looking at skeletal remains,
we're looking at half-grown individuals,
you know, sub-adults to full adults.
- Kind of analogous to teenagers, right? - Yeah.
- All these teenagers found together
suggests something unexpected.
BELLOWS
Since leaving his family group,
George has been living on his own...
..keeping deep in the forest...
..where it's easier to hide from predators.
SNUFFLES AND GRUNTS
But it's not long before he comes face-to-face...
..with another young male.
GRUMBLING ROARS
And it looks...
..like he means business.
Gastonia's skulls and necks are specially adapted
to act like shock absorbers.
But this isn't a fight.
This is how gastonia make friends.
Of all the armoured dinosaurs...
..they're one of the only known social species.
George has just joined a group.
It's a huge step forward,
dramatically increasing his chances
of making it to adulthood.
This gang of teenage boys will stay together
until they're tough enough to fend for themselves...
..because until their armour is fully developed,
they're vulnerable.
- Just working our way around these elements,
trying to get around this big femur here.
- At the dig, amongst the gastonia bones....
- Hey, Josh? Check this out. What is that?
- ..the team makes an unexpected discovery.
- Oh, wow.
That's really neat.
It's definitely not gastonia.
Hey, Jim? - Yeah.
- Heather found something interesting
and, uh, I'm wondering if you could tell me
whether or not it is what I think it is.
- A nice curve.
Yeah, that's a small
therapod metacarpal end bone.
Could be a juvenile Utahraptor.
- Utahraptor bones found alongside the young gastonia...
- All right, I was right! It's a therapod metacarpal.
- Yeah, confirm.
- ..suggest that throughout the gastonia's adolescence...
CHUCKLES
..Utahraptor was an ever-present threat.
TAPPING
And Josh and Jim have evidence that shows
just how deadly they could be.
A cast of a Utahraptor toe claw.
- You know, you put the claw itself - you know,
this is the bone underlying it.
Just to be conservative, we could say it comes out
to about there, you know, in length. - Yeah.
- 30cm long,
these killing claws were Utahraptor's primary weapon.
- This thing might be kicking through inch-thick hide,
so fast you can barely see it.
Wam-wam-wam-wam! This thing's just punching lots of holes,
which would do a lot of damage.
- These claws are the perfect tool
for puncturing the weak armour of young gastonia.
- Maybe you have to think of it more as a can-opener.
- Yeah, if it can flip it over,
use that to slice open the belly.
- Yeah. These things are one of the most formidable predators
that ever lived.
- Holding their toe claws off the ground
to keep them razor-sharp...
HISSES
..Utahraptor...
..is a finely tuned killing machine.
GRUNTS
SCREECHES
And this adult male...
..and the group he leads
have just entered the forest...
LOW BELLOWING
..following the trail of George and the gastonia gang.
But hidden beneath the thick undergrowth...
SCREECHES
..finding them won't be easy.
So the young raptors streak ahead...
SQUAWKING
..to try and flush them out...
..while the adults follow behind,
ready to make the kill.
With Utahraptor's eyesight
as sharp as modern birds of prey...
..even the slightest movement...
..could be fatal.
HISSES
So when they hear the raptors coming...
SCREECH
..the gastonia freeze.
LOW GRUNTING
The juveniles have missed them.
PANTS
But George must hold his nerve
because the deadliest threat is still to come.
SNUFFLING GRUNT
THUDDING FOOTSTEPS
The group leader.
HISSES
GRUNTS
It's a close call.
GRUNTS QUIETLY
But every day George and the gang survive
is a day closer to the safety of adulthood.
And emerging from the ground...
..clues that reveal even young gastonia...
..would have been no pushover.
BLOWS
- Well, you should be getting close, I think.
- Hey, Josh.
Get in my section, tell me what you think.
- So...
- There's so much here.
Plenty of osteoderms.
- And they're coming out pretty solid, then? - Yeah.
- Osteoderms are the bones that made up the gastonia's armour.
- That's a real nice one. - Oh, yeah.
So you can kind of see on this one that kind of ridge right there,
that keel, that would point up.
- Makes for a spikey dinosaur. - It really does, yeah.
- In life, each osteoderm was covered by a thick scale...
- Now, this is one of the nicest ones we've had so far.
This would have been on the back of the animal.
- ..which would have created an armoured plate.
- Where you see the hollow base that these have,
they're for blood vessels,
bringing nutrients up into this bone,
to grow that big scale that was on top.
There's a lot of armour on these animals.
- It's a discovery that reveals the gastonia's armour
was nearly fully formed.
But the team has evidence
Utahraptor was one step ahead.
Revealed by an astonishing fossil found near the site
and taken to the lab for analysis.
- Ah, it's a gold mine.
Yeah. - It really is.
- Entombed in this nine-ton block of sandstone...
..the team has discovered the remains of an entire group
of Utahraptors.
- And over here,
we've got the string of articulated vertebrae.
- Yeah. I mean, that's just beautiful.
- And hidden amongst the hundreds
of perfectly preserved teeth and claws and bones...
- Yeah, that's the great thing about this block.
We'll have so much material.
- ..curator Don DeBlieux has found something that could be
Utahraptor's deadliest weapon.
- We got this beautiful little top of a skull,
and then we flipped it over.
Right here is the impression of the brain.
- For a dinosaur,
this young Utahraptor brain is very large.
- Yeah, certainly remarkable, given the size.
Yeah, that would be a very intelligent animal.
- They would have been the most intelligent animal of its time.
- Oh, certainly. Utahraptor would have been capable of
some pretty complex behaviours.
- Spring has turned to summer.
And as the dry season sets in...
GRUNTING
..George and the gastonia gang leave the forest to find water.
They're still unruly teenagers...
GRUNTING
..but now in near-adult bodies.
And at the edge of the water hole,
clay-rich soil provides the gang
with essential minerals...
..vital for strengthening their armour.
And now the gastonia are tougher,
they're no longer an easy kill.
So the raptors change tactics.
DEEP BELLOWING
The group leader attracts their attention.
HISSES
..and uses his brightly coloured wing feathers...
..to create...
..a diversion.
Like a fox in a henhouse...
..the kill triggers the leader's predatory instinct.
SCREECHES
Trapped at the water's edge...
..it looks like George's luck has run out.
GRUNTS
INDISTINCT CONVERSATION
But at the dig,
Josh and the team have made a discovery.
They've come to retrieve a fossil
that may shed light on events that happened here
130 million years ago.
- So, Don, I was originally thinking
it was down this drainage,
but looking at it now, I actually think
it's further over that way. - Yeah, I think you're right.
- But collecting it from the steep cliff face...
- Damn! This is going to be tough.
- ..won't be easy.
- It might be further that way, that's the thing.
- Oh, there it is. - Yeah, that's totally it.
- Yeah. - So, Don, I think
if you want to bring the back board over here
and then we can go ahead and start strapping it down.
With your legs. - Do it.
- This is a fossilised foot cast.
- Big man on campus. - All right.
- All right, you got it. March on. - Got it.
- It formed when a dinosaur footprint
filled with silt and dust,
but over millions of years was compressed into solid rock...
- Like that, OK? Just like that.
- Luckily, it's not super fragile.
- ..creating a cast of the foot that made it.
- All right.
- One, two, three. - It definitely gets easier up here.
- OK.
OK.
- But which dinosaur does it belong to?
- Wow.
That's really cool.
We've got three big, wide toes on this footprint,
so that eliminates a couple dinosaurs right off the bat.
- Yeah.
- If it was gastonia, it'd have four toes.
And it's unlikely to be a predator
because there are no claws.
- Most likely a plant-eater.
- Yeah, I think a good candidate could be some sort of bipedal
plant-eating dinosaur, kind of like planicoxa.
- Right, we're at the right level for those guys.
Or close. - Absolutely.
- Planicoxa were beaked, stocky dinosaurs that lived in herds.
- You can imagine them travelling together
and moving long distances.
- For sure. - Maybe gastonia was year-round
and these dinosaurs were more seasonal.
- All right.
You guide us, Steph.
- Finding planicoxa footprints here
is an important discovery...
..because it suggests they migrated through this landscape.
BELLOWING
SNARLS
BELLOWS
As the group leader closes in on George...
HIGH-PITCHED ROARING
..a herd of planicoxa pass close by.
HIGH-PITCHED ROARING
And without any armour,
they're a much easier kill...
GRUNTING
..handing George...
..a very lucky escape.
But as the dry season intensifies,
the planicoxa herds will move on.
So, as George and the gastonia gang return to the forest,
they know it won't be long
until the raptors are hunting them down once more.
But coming out of the ground...
- Let's see how long this is.
- ..further evidence the gastonia buried here...
- We're looking at about 31.5cm long.
- ..were more than capable of defending themselves.
- The proximal width, where it attaches to the tail,
looks like about 17.5cm wide. - Yeah.
- So, yeah, this is one of these specialised spikes
along the tail. - Like, sticking out?
- Yeah, yeah. So it'll be sticking out
from the sides of the tail.
You can imagine this with a big scale over top of it,
a bit piece of keratin,
so this would have come to a very sharp point.
And these, we think, were used as a weapon.
- These blade-like spikes
were positioned along the entire length
of the gastonias' tails.
And Jim and Don have uncovered something
that shows just how these weapons were used.
- And then, as I was trying to work on that,
I hit something over here.
So this is a femur, the upper-leg bone.
- That's a pretty sizeable femur.
- And then as I dug around,
I see we have a complete tibia, lower-leg bone.
- Yeah.
You can see how short, you know, the lower leg is,
while the upper leg, about half the length...
- Right. - ..which is, you know, the exact opposite
than what you see in a running animal.
- Gastonia had a top speed of around 5mph...
..because their hind legs weren't built for running.
They were adapted for a very different purpose.
- Certainly, these things are not just simple bones.
They have huge muscle attachment points,
so they've developed powerful legs for serious,
strong manoeuvrability. - Stocky guys,
just standing their ground.
- You just see these things just holding on the ground
and swinging their tail with those big blades,
just like the one over there they already pulled out.
- Yeah, that big boy.
- Yeah. Slashing across,
and probably reach head-high easily,
and literally slap a Utahraptor, you know, right in the face.
- Gastonia's powerful hind legs and spiked tails...
..mean George and the gang are now formidable adversaries.
RUNNING STEPS
But with the dry season now at its height,
and the planicoxa gone...
..the raptors are starving.
Desperate for food, they must take any opportunity...
..to make a kill.
But now nearly fully grown,
the gastonia gang will stand and fight.
HISSES
BELLOWING
HISSES
And this time,
they've got the weapons to defend themselves.
The gastonia now have the upper hand.
But driven by hunger,
the raptors have no choice but to attack.
HISSES
BELLOWS
With the group leader fatally wounded...
..the remaining raptors back down.
BELLOWS
But George's moment of triumph will be short-lived.
The hot summer months bring a new danger.
Something revealed by
a completely different type of evidence...
..found alongside the gastonia bones.
Palaeobotanist Dr Carol Hotton
is an expert in ancient pollen.
- Howdy, Carol. - Hey, Jim, take a look.
There's some interesting grains right in the centre.
So, if you see those little round grains
that look like flat tyres,
that's pollen from an extinct conifer.
And, um, there's another grain.
That's a member of the cypress family.
- Hmm.
- That was well adapted to dry conditions.
- All the pollen Carol has identified
belongs to trees that lived in a parched, arid environment.
130 million years ago,
the forest that covered the dig site was a tinder box.
- You can see all through the field
black pieces. - Yeah, little shards.
- Twiggy-looking things
that are pretty small for twigs.
- Right. In all probability, they represent charcoal.
It's unlikely to be anything else,
and I see that in all my pollen samples.
- There's only one thing
that could have produced so much charcoal.
THUNDER ROLLS
The long, dry summer months
have created a time bomb.
As wildfire rages through the parched forest...
..it threatens the gastonia
and the surviving raptors.
CHITTERS
SCREECHES
BELLOWING
But George is slow to react to the danger.
BELLOWS
SQUAWKS
With a top speed around 20mph,
the raptors soon reach a clearing in the forest.
SQUAWKS
But they're trapped between the flames
and a treacherous marshy swamp.
And George and the gastonia gang aren't far behind.
The flames driving the two mortal enemies together...
..for one final showdown.
GRUNTS
- This one is...
- But back at the lab...
- Oh, that's just...
- ..the sandstone block filled with raptor bones...
- Now, this one here...
- ..has one last secret to reveal.
- ..right size...
Nice little jaw right there.
- Oh, yeah. I see the teeth on that.
- The amazing thing is that all these delicate little teeth
are all still in place in their sockets.
- Oh, it's really remarkable to have it so well preserved.
- Such high levels of preservation...
- Hard to tell. - And certainly this,
you know, still has the teeth included.
- ..tell the team the bones have not been disturbed.
The block captures the very moment the raptors died.
- And interesting that
all the best-preserved bones all seem to be in this sand.
- Yeah. It suggests that sand is part of why they died,
why they're so well preserved.
- Although the sand is solid today,
Jim believes that when the raptors died,
it was liquid.
- You know, what killed them is what buried them.
Given the geology of the setting,
most likely we're looking at a mass mortality tied to quicksand.
- SQUAWKS
BELLOWS
HISSING
SHRIEKS
SQUAWKING
Panicked, the raptors run into trouble.
BLEATS
With the raptors out of the way...
..George has the chance to escape.
LOW BELLOWING
But they're struggling.
The very things that protected them from the raptors...
..heavy armour and short, stocky legs...
GRUNTS AND PANTS
..mean George and the gang
are too slow to escape the fire.
PANTS
One by one...
..the smoke takes its toll.
Buried where they fell...
..the landscape is transformed around them.
Layer upon layer of rock builds up...
..as the aeons pass...
..and the continents silently drift across the face of the Earth...
..until George and the gang are finally found...
..130 million years later.
Next time...
..T-Rex's lethal, faster cousin.
A young hunter fighting for her place
in the most ferocious pack on Earth.
Over 66 million years ago...
SCREECHING WAIL
HIGH-PITCHED CLUCKS ..our world...
DEEP SNORT ..was ruled...
..by dinosaurs.
DEEP BELLOW
HISSES
The largest animals that have ever walked the Earth.
ROARS
Today, dinosaur experts across the globe
are uncovering the bones they left behind...
..allowing us to imagine how these creatures may have lived...
..so that we can tell their stories, and they...
..can walk again.
Western Canada.
Today, a majestic landscape of snow-capped peaks...
..turquoise lakes...
..and mighty rivers...
..that erode the ancient bedrock.
The perfect conditions for dinosaur-hunting.
Here, on the banks of Red Deer River...
..palaeontologists from the University of Alberta...
..are unearthing the final resting place of a super-predator.
- Oh, wow. Yeah, that's really nice.
- Looks like a toe claw. - Wonderful find.
- Albertosaurus - T-rex's deadly cousin.
These are the remains of a teenager.
The team calls her Rose.
- Holy cow!
- Oh, wow. - It keeps going.
- Inspired by their discoveries...
..we can imagine her story.
In the Late Cretaceous,
North America is split in two by a vast inland sea.
On its western shores, a sprawling expanse of dense forests
and rugged coastlines.
Laramidia.
A land in crisis.
Atmospheric changes have forced temperatures down by two degrees.
A seemingly small change,
but enough to push the delicate ecosystem out of balance.
SQUAWKS
SHRIEKING CRIES
Food is scarce.
Even...
..for an apex predator.
RUMBLING BREATHS
Standing two-and-a-half metres tall,
and weighing in at one tonne...
..this is Rose...
..the Albertosaurus.
It's been a week since she last ate.
But in her sights...
..an arrhinoceratops,
an older cousin of triceratops.
A chance for Rose to satisfy her hunger.
Rose might just be the fastest land predator on the planet...
..sprinting at up to 30mph.
BELLOWS
ROARS
But Rose has miscalculated.
At two tonnes, her target is twice her weight...
..with horns almost a metre long.
Rose is starving.
But the risk of injury is just too great.
Dinner will have to wait.
71 million years later,
this team of palaeontologists...
- Hey, guys, how's it going? - Hey, Mark, look at this.
- ..led by Mark Powers,
is uncovering Rose's secrets...
- Found new bones! - Whoa, no way!
- ..piece by piece.
- You couldn't ask for better...
- No. - ..better separation. - You really couldn't.
- Each day, more remains emerge from the ground.
- Ohh! - Whoa! - Oh, my God.
- Yeah! Yeah, clean it off.
- CHEERING - There it is!
Today's discovery - Rose's leg bones.
- Oh, that's so cool.
- Each fossil is exposed and restored,
allowing the team to delve deeper into the story of
this long-lost super-predator.
- This is looking really good.
- Mark works with limb specialist Christiana Garros
to examine the bones from Rose's shin.
- The tibia is not actually that huge,
compared to some of the bigger ones I've seen, at least. - No.
- Albertosaurus is an older relative of Tyrannosaurus Rex...
- It's about 79cm. - OK.
- Something like that.
- ..but it's becoming clear she was a very different beast
to her more famous cousin.
- So, long limbs, but the ones of T-rex are quite a bit bulkier,
aren't they? - Absolutely.
Rose kind of really embodies what Albertosaurus is.
It's a very legsy animal, especially compared to things like T-rex,
which was incredibly huge. - Yeah. - Incredibly chunky.
Quick, fast, dangerous.
Still has powerful jaws. - Yeah.
Maybe the optimal amount of scary for my taste,
that's for sure. - Absolutely.
- But speed was far from the only weapon
in the Albertosaurus arsenal.
More bones are coming out of the ground.
- Oh, that's bone.
- But these don't belong to Rose.
- It does look like a bone from one of the digits.
- And that's definitely Albertosaurus, right?
- Yeah, absolutely.
- And each bone seems to come from a different-sized Albertosaurus.
- This is a huge one.
- Dinosaur hunters have discovered
as many as 26 individuals buried here.
- To try and say any piece belongs to any one individual
is kind of tough to do, cos there are so many of them.
It's clearly a mass grave of Albertosaurus,
where many individuals died together in this spot.
- And if they died together...
..they likely lived together, too.
LOW GROWLING
In the cave Rose calls home,
she's far from alone.
SNIFFS
GRUNTS
Albertosaurus are social animals.
They live and hunt together,
forming strong, intimate bonds.
Rose has paired with this male Albertosaurus the same age.
A source of comfort...
..in times of scarcity.
It's been over a week since the Albertosaurus last made a kill.
And starvation isn't the only threat hanging over Rose.
RUMBLING GRUNT
The matriarch.
Racked with intense hunger,
she could turn on her own.
And Rose is bottom of the pecking order.
If she hopes to survive,
she'll have to prove herself when it matters most.
It's time to go hunting.
- Ready? - Let's go.
- Mark's teamed up with dinosaur anatomy specialist Henry Sharpe.
They're venturing further up Red Deer River
on the hunt for more giants.
- There's some wonderful prospecting rocks up there.
- They reach an ancient river system,
dating from the same time period as Rose.
And the first clue...
- We got a rib here.
- ..to what might have fed the Albertosaurus pack.
- Given its cross-section and its size, maybe Edmontosaurus.
- I'd say Edmontosaurus, yeah.
- Edmontosaurus - a plant-eating, duck-billed dinosaur.
- Edmontosaurus can get up to 30 feet long.
- Ten metres here. - Jeez!
- Yeah. These things were huge.
- But a single Edmontosaurus
wouldn't feed a hungry pack of Albertosaurus for long.
- Holy cow!
- PANTING: - Oh, my God.
- At the top of an escarpment...
- Look at the size of these honkers!
- ..more fossils.
Not bone...
..but footprints.
- You can see, they got the big front toe
and the two toes on the side.
It's much wider than it is long,
which is classic Edmontosaurus, duck-billed dinosaur.
- From the pattern of these prints,
it looks as though these trackways couldn't have been made
by a single creature.
- I've got about 16-17 tracks exposed here.
- Today, there are just a few footprints.
But when they were created,
there would have been many, many more.
- We have lots of footprints from various different individuals,
various different ages all congregating together,
so they definitely moved in herds, lived in herds.
- Yeah. You imagine, like, herds of wildebeest,
and these animals were the size of one to two elephants.
- These fossilised footsteps suggest
this corner of Canada once played host...
TRUMPETING ROARS
..to one of the most remarkable sights in Earth's history.
A migrating Edmontosaurus herd.
Thousands of plant-eating dinosaurs moving as one.
But an individual adult Edmontosaurus can be
three times the weight of even the largest Albertosaurus.
BIRDSONG
Working as a pack is the only way to take down such colossal prey.
Higher ground will provide the perfect vantage point...
..to mount an attack.
At this time of year,
this area should be teeming with Edmontosaurus...
..but the herds are nowhere to be seen.
LOW GROWLING
ROARS
This is a time of intense geological upheaval.
As the continents move...
..the land buckles and splits.
Lava and ash engulf the landscape...
..forcing this Edmontosaurus herd
to take a much longer route north this year.
They're still many miles away from the starving Albertosaurus.
For the pack, the delay spells disaster.
But on the horizon...
..Rose spots an opportunity.
From the wind-carved rocks by Rose's dig site,
palaeontologist Colton Coppock has made an important discovery.
- Yeah.
- So, here's a bit of the shaft.
- Tiny fragments of finger bone
belonging to one of the most bizarre creatures of the Cretaceous...
- And here's the condyle. - What?!
- So, it looks like it might be from a digit.
- There's a condyle? - Yeah.
- ..including a rare condyle, part of the knuckle joint.
- Very nice. - I'm afraid to touch it.
- Yeah. It's just so small and so delicate. - Yeah.
- You can see the internal structure of the bone right there.
- The fossil's paper-thin exterior
tells Mark this bone was built for flying.
But this was no bird.
- Even in birds, the bone is usually a lot thicker on the outer surface.
- This is very strange.
- It can only belong to one creature.
SQUAWKING
A colossal flying reptile with a six-metre wingspan.
Cryodrakon - a giant pterosaur.
They feed on an enormous ammonite washed up on the spring tide.
SQUAWKS
The cryodrakon would make a fine meal for Rose and her mate...
..if they can catch one.
SQUAWKS
Approaching from downwind,
and with the pterosaurs' attention on their meal...
..the youngsters close in.
SQUAWKING
SCREECHES
At last, a chance to feed.
But the pair's absence from the pack...
..hasn't gone unnoticed.
RUMBLING GRUNT
Life in an Albertosaurus pack was fraught with brutality.
And 71 million years later,
this violence is still written in the bones.
Mark and anatomist Dr Greg Funston examine the jawbones of
one of the largest Albertosaurus ever discovered.
- We do actually get a few scars along here,
and they're kind of evenly spaced.
Some are raised, and some are deep gouges.
- So, could these be bite marks?
- An astonishing 65% of Albertosaurus skulls found here
have teeth marks scratched into the bone itself.
- Near your finger, there's a little gouge in that one, too.
- Look at that. - That's deep. - Yeah.
It actually looks like the tooth came down from over the top.
That would've required tremendous amount of force,
from this diving angle, to actually remove that piece of bone.
- Only another Albertosaurus could inflict this injury.
- The biggest predator in this ecosystem,
and it's still getting beaten up day to day.
They're maybe tussling for food,
like you see on the savanna today,
where lions will eat in a certain order.
- You got two hungry Albertosaurus.
One of them is going to want to eat first.
Only one can.
- RUMBLING GROWL
As pack leader...
..the matriarch is eyeing up the youngsters' kill.
GROWLING
Rose is determined to defend her prize.
But the matriarch...
..leaves her in no doubt who's in charge.
GRUNTS
Hungry and badly wounded,
Rose has learnt a painful lesson.
She'll have to play by the rules
if she wants to survive.
But the evidence coming out of the ground suggests
not all of the Albertosaurus behaviour was violent.
Mark and Henry examine one of the most intriguing discoveries.
Rose's tiny, fossilised arm bones.
- So, we got the upper arm here, and the forearm down there.
And up here, this is the hand, right?
- This is like the palm of the hand.
- Nobody's quite sure what Albertosaurus used
its minuscule arms for...
..but the strange positioning has given Mark an idea.
- It's quite possible the resting position of the arm
was to have a more flared finger,
sticking outwards rather than, you know, kind of down by the side,
like a chicken wing.
- So, if this was my arm, it would kind of be flared out like that?
- Yeah, you'd be kind of doing one of these things.
- Almost jazz hands. - Yeah, exactly.
- So, Albertosaurus is clearly using its arms for something.
I mean, modern birds have a wide variety of mating displays
and behaviours. - Mm-hm, yeah.
- Mark believes these seemingly useless arms may have been
vital tools for bonding.
- So, if you're going to live in a group, you've got to have ways
of communicating with one another that go beyond just, you know,
grunting and staring at each other,
so maybe they're using their hands side by side on the flank,
reassuring one another.
- Telling each other, "It's going to be OK, it's fine".
- A morale boost. - Yeah, exactly. - Yeah.
- SNORTS AND GRUNTS
Starving, shaken, and badly wounded...
..Rose needs comfort.
DEEP GRUNT
The young Albertosaurus take time out together to groom.
A soothing ritual...
SOFT GRUNTS
..that strengthens their bond.
As a new day dawns...
..the pack's luck may be about to change.
The Edmontosaurus have finally made it to
their summer feeding ground.
Not a moment too soon for the starving Albertosaurus.
And despite their young age, Rose, her mate,
and the other youngsters will play a crucial role in the hunt.
The fate of the whole pack depends on them.
Close to Rose's dig site,
a remarkable new fossil is emerging.
- Wow.
Very cool.
- An Edmontosaurus jawbone.
- Maybe this is the dentary going in here?
That could be the back part, yeah.
- But this fossil holds another secret.
- What have we got up here?
- That looks like enamel.
- Look here - serrations.
- That's incredible.
- This is no Edmontosaurus tooth.
This came from a meat-eater.
- Albertosaurus tooth?
I think you're right.
And, since we don't have much of the root,
it was probably lost during feeding.
- That is an awesome find.
- It's clear evidence that the Albertosaurus pack
did feast on Edmontosaurus.
But it doesn't help explain how they bought down such enormous prey...
..and what role Rose might have played in the hunt.
- These are Rose's metatarsals from the right leg.
- Quite narrow and compact for an animal that people usually
envision as being huge, huh?
- Mark and Christiana investigate Rose's foot bones...
- They get a heck of a lot bigger.
- ..comparing them with the outer foot bones of a fully-grown adult.
While they're similar in length, they're a very different thickness.
- So, we can see this one is only about
three-and-a-half centimetres in width,
whereas, we look at this one,
we have...almost double that.
So, it's about 6cm in width.
Absolutely a beast - and the same thing can be said
about the other metatarsal.
- Rose was almost as tall as the largest Albertosaurus,
but just half the weight.
- She was definitely going to be much more agile and quick
than these big individuals,
which probably had a lot more difficulty picking up speed.
- Large Albertosaurus were unlikely to reach high speeds
due to their enormous weight.
Meaning Rose and the other youngsters must take on
the most dangerous of jobs.
LOW GROWLING
Rose and her mate split off from the pack.
As the swiftest runners, they must identify a target...
..and separate it from the herd.
But they're a fraction of the weight of the largest Edmontosaurus.
HISSING
Impulsive and inexperienced,
Rose's mate blindly charges into the herd...
BELLOWING
..trying to take down one of these enormous creatures alone.
DISTANT ROAR
DISTANT ROAR SCREECHES
Rose has lost her closest companion.
And each failed hunt brings her and the rest of the pack
closer to starvation.
BIRDS CALL
But Albertosaurus were successful,
even in times of adversity.
They were the dominant predator in Western Canada
for over three million years.
At Rose's dig site,
part of the reason behind their success might be emerging.
- This bit right here.
- An unassuming fragment of bone.
- It looks interesting.
- I thought it was a rock, actually.
But it's got a pretty interesting texture.
It looks like Albertosaurus.
And this roughened area looks to me like the border of an eye socket.
- Is this a part of Rose's skull?
- That is part of the skull.
It's probably an indication that the skull is in several pieces at least,
so we'll have to keep our eyes out for any loose skull bones
that might be scattered about amongst the site.
- Whoa!
It's Rose's ghost!
- The team estimates Rose's skull would have been about
two-thirds of a metre long.
Big, but not big enough to take down huge prey like Edmontosaurus.
But maybe she didn't have to.
Mark and Colton re-examine the jawbones of one of
the largest Albertosaurus.
- Just look how big and robust this jaw is.
It's absolutely crazy.
- There's quite a few tooth sockets on this side.
- It's the final piece of the puzzle,
revealing the pack's sophisticated hunting strategy.
- Altogether, 68 teeth in the jaw.
- Lots of points of entry into the body,
so, basically, instead of using the arms to grapple with prey,
it's all about the head.
- These jaws were built to apply brutal force.
- A bite force that's probably upwards of several tonnes.
There's not much that can, you know, protect itself from that,
once they have their eyes on you. - Yeah.
- Rose's speed and the bite force of these bigger animals...
..make for a deadly combination.
- We could say that Rose was the runner, and this was the muscle.
When Rose got the animals out on their own,
big predator like this probably would've come out
and just finished the job.
- LOW GRUNTING
Rose may have lost her mate
but she must now work with the other youngsters
to find the easiest target.
But with one failed hunt already,
the pressure is on.
SNORTS
BELLOWS
Rearing up on their hind legs,
the Edmontosaurus are too powerful.
BELLOWS
But Rose bides her time...
..until she spots an older individual.
One that might be weaker than the others.
BELLOWS
Rose can't take this Edmontosaurus down alone.
But she can steer her prey...
..right towards the killing jaws
of the matriarch.
BELLOWS SNARLS
But there's still fight in this old bull.
SCREECHES
GROWLS
Rose has played her part to perfection.
Finally, the pack can feed.
And this time...
...Rose gets her share of the spoils.
- All right. Who's ready to jacket?
Coming your way!
- Grab those.
- The team is eager to get their finds back to the lab...
...to learn more about this extraordinary creature.
They carefully wrap their discoveries in protective plaster.
- Sorry, everyone in the vicinity is going to receive plaster
on their clothes and body, so...
- One, two, three.
- Oh-oh-oh...
- It's OK, it's OK, there's lots of rock, there's lots of rock.
- They flip them, ready for transport back to base.
- Perfect. Beautiful.
Now just the third one.
Go! Flip.
- Watch your feet, watch your feet.
- But some of Rose's remains are too heavy
to carry down the hillside.
So, Mark has called in a little help.
- Oh...love that sound.
Hold on to your hats!
- One false move, and all the team's work would be destroyed.
With ropes attached...
..Rose soars through the air.
- Go, Rose! - Yeah!
- But these ancient lands hold one final surprise
for the dino hunters.
- What have you got there, champ?
- Colton has made a once-in-a-lifetime discovery.
- Oh, what? - What is that?
- Wait, hold on, that's a... What?! - Whoa.
- A tiny jawbone.
- What's this a jaw of?
- It's an Albertosaurus.
- It's so tiny.
- This is a baby Albertosaurus.
- That's beautiful. - Like a baby.
- Yeah, probably only about a year old.
Think this is the youngest individual we have.
I mean, I had to put it down for a sec to make sure
- CHRISTINA LAUGHS I wasn't hallucinating.
- Just scratch it like a puppy. - Yeah. - Look.
- THEY LAUGH
It's more evidence of the success of the Albertosaurus.
And maybe, the baby belonged to one of the pack females.
Perhaps even Rose herself.
LOW GROWLING
As to how Rose died, we may never know.
- Show-and-tell time.
- Causes of death rarely fossilise.
- So cute! - That's awesome.
- Wow, the comparison really pulled it together. - Yeah.
It's not even as long as the tooth.
- Oh, my God!
- And, though her death is a mystery...
..now at least, we can tell the story
of how she may have lived.
Rose, the young Albertosaurus...
..earned her rightful place...
..hunting and surviving...
..with her pack by her side.
Next time...
..a toddler makes a perilous journey...
..joining one of the largest dinosaur herds
that ever lived...
..in its fight for survival.
Over 66 million years ago...
SCREECHING
..our world was ruled...
SNARLS
ROARS
..by dinosaurs.
GROWLS
BELLOWING
The largest animals that have ever walked the Earth.
SCREECHES
Today, dinosaur experts across the globe
are uncovering the bones they left behind...
..allowing us to imagine how these extraordinary creatures
may have lived...
..so that we can tell their stories...
..and they...
..can walk again.
ROARS
Deep in the ancient forests of Alberta, Canada...
LOW CONVERSATION
..a team of dinosaur hunters
has come to unearth an astonishing find.
- We've got at least three bones sticking out here.
- Discovered on the edge of a creek...
..are the bones of a pachyrhinosaurus...
..a unique horned dinosaur.
Lying here is a toddler...
- It's such a tiny little bone.
- ..they call Albie.
- Don't think I've seen one that small before.
- And he's not alone.
He's part of one of the largest dinosaur herds ever found...
..numbering in the thousands.
- We have big adults, we have little babies,
we have every age in between.
This was a huge herd of animals.
- Why so many are buried here is a mystery.
But by studying the bones,
we can begin to tell their extraordinary story.
73 million years ago.
What will one day be north-western Canada
is part of a landmass called Laramidia.
Mountain ranges extend for thousands of miles...
WIND WHISTLES
..towering over a wilderness of dense forested valleys.
BIRDSONG
BELLOWING
This vast terrain is roamed by gigantic groups
of plant-eating dinosaurs...
..that, like today's caribou or elk,
migrate each season.
And by far the largest of these prehistoric herds...
..are the pachyrhinosaurus.
A close relative of triceratops,
these social dinosaurs have spent the winter in the south.
But with the land now almost completely bare...
..staying here would mean starvation.
So the herd is setting out on an epic 400-mile trek north...
..where, by summer,
the vegetation should be abundant.
SNORTING AND GRUNTING
It will be a gruelling journey...
..especially if you're one of the youngest...
..like Albie.
At less than a year old, he's only half a metre tall...
..which makes keeping up...
..a bit of a challenge.
HE YOWLS
Even so, he must stay close to his mother...
HE YOWLS
..because the herd aren't the only ones that are hungry.
SQUAWKING
Following in their wake,
an azhdarchid pterosaur.
With a six-metre wingspan and estimated speed of 60mph...
..a young pachyrhinosaurus makes for an easy target.
HE CALLS
BELLOWS
A close call.
But it's only the start of the challenges they will face...
..as the search for food takes them across
the prehistoric wilderness.
LOW CONVERSATION
73 million years later...
..the work to understand this enormous herd
is well under way.
- There's a pretty large cluster of bones there.
- Seem to belong, potentially, to a large animal.
- It's a painstaking process...
..led by Dr Emily Bamforth...
..who is piecing together
the journey that brought the herd here.
And in one corner of the site...
- Is that a little vertebra?
- ..something has caught her eye.
- Oh, man, that is so little!
- Right in this corner.
Baby bone, baby bone, baby bone.
- Emerging from the rock are not just Albie's bones,
but those of other youngsters.
And comparing their size...
- Juvenile vertebra is 7cm.
That's another really young animal.
- ..reveals something significant.
- All of the juveniles here, these are all about a year old. - Wow.
- They're all the same age...
..born around the same time.
- They have to have been born
on the previous summer's migration.
That, to me, is interesting.
- Emily's findings suggest the herd was making
its yearly journey for more than just food.
They were returning to their summer nesting ground.
And joining them are thousands more...
..as every pachyrhinosaurus on the continent...
..heads north...
..merging into one of the greatest spectacles
of the prehistoric world.
BELLOWS
But with such a colossal gathering...
..tension is in the air.
Breeding season is upon them...
..so bulls in the herd must compete
for their right to mate.
BELLOWS LOUDLY
From old veterans...
..to their younger rivals.
And there's only one way...
..to prove their worth.
In a contest as brutal as this...
ALBIE SQUEAKS
..Albie's mother must keep a watchful eye...
..making sure he isn't trampled, or even killed.
But as one of the youngest,
curiosity gets the better of him.
ALBIE SQUEAKS
Using their thick armoured noses...
..each male seeks to deliver a bone-shattering blow.
And the ultimate target...
..is behind the other's horned armour.
The young rival...
BELLOWS
..gains the upper hand.
GRUNTS
- That is weird.
- At the dig site, uncovering what appears to be
the rib of a huge bull...
- Seems like the rib trends this way
but then starts back up that way.
- ..Emily and her teammate Max Scott
are finding evidence of a punishing injury.
- This part of the rib and that part of the rib are slightly offset,
so it looks as if this rib
has actually been broken in the middle.
- Gosh. It seems like it was almost shoved off to one side.
- The rib is twice as thick as a bear's.
The fact it snapped
means this bull suffered a potentially-fatal blow.
- It would have to be a considerable impact,
so either the opponent striking it really hard,
or when it fell sideways.
Whatever happened, it would have been very painful.
Like, with an impact this size,
the rib could puncture the lung.
- But examining the fossil reveals something curious.
- It's really bulgy there.
- So I think that's a bone callus.
- Bone calluses form over a break as part of the healing process.
- The bone has broken
and has actually shifted sideways while the animal was alive,
and this big bony bump
healed around it and set it.
Would have been very painful for the animal,
but they would have survived it.
- It's really quite an impressive feat.
Really shows just how tough he really was.
- The healed injury is important evidence.
LABOURED BREATHS
It suggests the strongest bulls in the herd...
..were capable of taking severe punishment...
BELLOWING
..and getting back on their feet.
BELLOWS
An ability they'd need...
..to come out on top.
BELLOWS
GRUNTS
With a winner firmly established...
..the monumental herd continues its journey to the fertile north.
ALBIE SQUEAKS
But though the fighting may have subsided...
..for Albie, the danger is only just beginning.
HE WHINES
In the chaos,
he has become separated from his mother...
..and lost in the crowd.
In a herd of this magnitude...
..finding her won't be easy.
- Look at this.
- But at the dig site,
evidence is emerging that suggests every one of this enormous herd
may have looked unique.
- It looks like it's relatively complete
and this is a big one.
- Buried in the rock is an incredibly rare find -
an adult's bony headdress...
..known as the frill.
- This might be the front and that's the back.
- Yeah, that's what I was thinking too.
So, like, the nose is over here somewhere,
and, like, the body is back there.
- I don't think I've ever seen any
where one of the middle horns
is going the opposite direction of the other.
- Given this frill's highly unusual shape,
Emily is keen to compare it with others found in the creek.
- So, on this individual,
the horns that stick out the side of the frill,
they're straight,
whereas this one is interesting.
This is an asymmetrical frill,
so this horn is straight
and that one is curled.
- Each frill is distinct from the other.
- It is very striking that these frills,
despite being from almost exactly the same place
in the bone bed, from the same community of animals,
like, they're still very different from one another.
- Remarkably, no two frills found at the site
have ever looked the same...
..leading the team to think their variation
served a crucial purpose.
- Based on the differences in these frill horns,
it would be very easy for the individuals
to recognise each other.
- Yeah. In a herd environment like this,
it's very important to be able to recognise
your friends and your family easily.
- With every member of the herd displaying their own unique frill...
ALBIE YOWLS
..it could help a youngster like Albie...
..pick out his mother from the masses...
..by scanning each and every one...
..for her familiar features.
HE CALLS
But in the sea of pachyrhinosaurus streaming past...
..she is still...
..nowhere to be seen.
HE YOWLS
Without his mother's protection...
..he has little chance of surviving the long journey...
..alone.
PLAINTIVE BELLOWS
FOLIAGE SNAPPING
Until...
GENTLE GRUNT
..finally...
..the distinctive outline of a frill...
..he knows better than any other.
And a mother relieved to have found her young.
YOWLS AND GRUNTS
BOTH GRUNT SOFTLY
But though reunited...
..there is much danger still ahead.
30 miles from the main dig site...
..Emily and palaeontologist Jackson Sweder...
..have travelled to the edge of a forest.
Here, ancient footprints follow the herd's route.
- That's a toe. - Yeah.
- And that's a toe. You seen the third one here?
See it again, missing that toe? - Maybe... Yeah, missing. - Yeah.
Once you get your eye in,
they're actually all over the place. - LAUGHING: - They're everywhere.
- And one stands out from all the others.
- Clearly a carnivore.
And you can even see the claws.
- That's a point.
- Big, big animal as well.
- What, eight metres? - Yeah.
- To confirm the identity of this large predator...
..Emily and Jackson use liquid rubber
to make a cast that reveals how it moved.
- The back of the track is shallower than these toes here.
- The toes are super deep.
- So it's moving on the front of its feet,
sort of like the fast animals today, like cheetahs, would do.
- Definitely wider than it is deep,
so it can move side to side if it has to.
- So probably a very agile animal as well.
- This kind of speed and agility
belongs to only one predator in the region.
A terrifying relative of T-rex
that hunted in packs.
- Those pachyrhinosaurus
definitely would have had to worry about this animal. - Yeah.
- It's very efficient at moving long distances.
It could follow them for miles
and just wait for an opportunity.
- The gorgosaurus.
QUIET SNARLING
With exceptional hearing...
..and a sense of smell more powerful than any other dinosaur...
..it's thought they could track their prey
from up to ten miles away...
..allowing them to ambush at a moment of their choosing.
Unaware of the approaching threat,
the herd moves deeper into the forest.
Surrounded by its narrow pathways...
..an attack could come from any direction.
HE SNUFFLES
BRANCH SNAPS
But there is no sign of the danger...yet.
SNORING
DISTANT BELLOWING
SNORTS
QUIET THUDDING
DISTANT FOLIAGE SNAPPING
The sound of intruders...
..draws Albie away from the herd.
FOLIAGE SNAPPING
But these aren't the stealthy footsteps of a gorgosaurus.
Something else is closing in.
- Take care with your footing.
- Journeying along the herd's migration route,
Emily and her team have discovered evidence
of another mysterious dinosaur...
..which has emerged on the edge of what is now a river.
- Oh!
- Yeah, it's a little chilly. - Oh, yeah, it's cold.
- Exposed by receding water,
its fossilised remains are all along the river bank.
- It's huge.
It's just packed with stuff.
It's crazy that it's just kind of sitting out here on the surface.
Man, that's big.
It definitely seems to be in a layer here...
- Whatever this is.
- And it isn't long before the team hits the jackpot.
- Oh, my goodness!
That's a huge bone.
- Buried in the rock is part of its gigantic hind limb.
- Do you have a measuring tape?
- Yeah, let's just take a quick measurement.
- They can use this to estimate the animal's full size.
- It's really long.
Even if it's only to there,
that's still definitely over a metre.
- Yeah. I would say, with legs like this,
it's probably about the size of a school bus,
around nine metres long or so. That's huge.
- There's not much that gets bigger than this.
- Even larger than a gorgosaurus...
..its nine-metre length means it could be only one dinosaur.
And the forest is the ideal place
for it to find its next meal.
FOLIAGE SNAPS
SNORTING
MUNCHING
But this isn't a killer.
ALBIE SQUEAKS
It's an Edmontosaurus...
THUDDING STEPS
MUNCHING
..which, along with its herd, is on the same migration north.
BELLOWS
As plant-eaters, they pose no threat...
..but these six-tonne giants...
FOLIAGE SNAPS
..make a lot of noise.
FOLIAGE SNAPPING
DISTANT SQUAWKING
DISTANT ROARING
RUMBLING GRUNTS
..and it's drawing the pack of hungry gorgosaurus
straight towards them.
GRUNTS
BELLOWS
BELLOWING
SNARLING
IT ROARS
FOLIAGE SNAPPING
MUNCHING
For Albie, it's another narrow escape.
And as the herd pushes on,
the aurora lighting up the skies above...
..is a sign their journey north is almost over.
- Do you have a chisel? - Yep.
- Not far from the main dig site...
..Emily and Jackson are finding evidence
of exactly what the herd was looking for.
- That's huge. - Yeah.
- An abundance of food just waiting to be discovered.
- There's so many different plants here,
just on this one slab.
- Not just big leaves like this.
- Also lots of flowering plants as well.
All these things would be really great food for pachyrhinosaurus.
- The plants in these rocks
would have flourished in the summer...
..in time for the herd's nesting season.
- Looking at all of these plants,
there's enough food for the adults and the juveniles.
- More than enough to draw the pachyrhinosaurus up here.
- And when the babies hatch,
there's food for the babies as well.
- This place would mark the end of the herd's long migration.
A haven
where they could settle
and begin to nest.
BIRDSONG
LOWING AND GRUNTING
But while the exhausting 400-mile walk...
..may finally be over...
..there is one problem they haven't left behind.
NEARBY SNARLING
The gorgosaurus have stayed close.
BELLOWING
And with the pachyrhinosaurus backed up against the river...
..it gives these ferocious predators
the perfect opportunity...
..to pick off one of the herd's more vulnerable members.
SQUEAKING
ALBIE SQUEAKS
SNARLS
ROARS
HE SQUEAKS
But Albie is not alone.
SHE BELLOWS
His mother's instinct is to fight.
But their confrontation is about to pale into insignificance.
THUNDER CRASHES
Both predator...
..and prey
face a far greater threat.
Investigating what happened at the end of the herd's journey...
- OK, move to the next point.
- ..and why so many are buried here...
..Emily's team is mapping the bones.
- We've obviously got a pretty large cluster in that corner.
- Those two are so close together... - They are so, so close together, man.
It's pretty much, like, right up against... - Yeah.
All right. - Let's go.
- They can then scan to create a full 3D model of the site.
- It's coming through really well.
- Yeah. You can see the patterning on the surface of the bone.
- The imaging allows them to see exactly how the fossils are laid out.
- You can see how the bones are stacked
on top of each other.
Everything here is bone.
There's actually very little rock in between there.
It's just a solid mass of bone material.
- You can kind of see ribs of just about every size,
just even in this one pocket here.
- And they're clearly all from different individuals,
cos they're all different sizes.
- The bones of young and old are jumbled together.
And there's even more in the ground
than the team first realised.
- You think of the sheer density of bones
in just this little area that we've scanned
and then put that together with the grid mapping
- Perfect. - Perfect.
- ..there's something like 100 to 300 bones per square metre.
And then we know the bone bed goes back into the hill
for another kilometre.
- Good for now.
- Their findings bring their estimate of pachyrhinosaurus
preserved at the site...
..into the tens of thousands.
To have died in such large numbers,
they must have faced a catastrophic event.
SAW BUZZES
Looking for answers...
..Emily and Max cut deep into the rock that encases the herd.
EMILY STRAINS
- Tilt it up.
I just want to take a look at the cross-section.
- It reveals a vital clue.
- Look at this piece! All of that black,
it's plant material that's been shredded.
Something has picked up the mud
and has, like, twisted it with enough energy
to move the amount of material
and to shred the plants up like that.
And that's right in with the bones.
And all these swirls in here?
Something dramatic has happened that's involved water.
You can see where it's actually cut down
into the rock underneath it, like a fossilised wave.
And so this was a huge energy event.
- The evidence all points to one thing.
THUNDER CRASHES
PANICKED BELLOWING
A devastating flash flood...
..triggered by huge storms...
..raging over the mountains.
Water cascades into the valley...
..swelling into an unstoppable torrent...
..that destroys everything in its path.
DEEP RUMBLING
GRUNTING AND BELLOWING
HE SQUEAKS
As the floodwaters near...
..the herd begins to panic.
Mother and child...
..waiting by each other's side.
ALBIE YOWLS
HE SQUEAKS
WATER RUSHING
Little could have withstood a flood on this scale.
And for Albie and much of his herd...
..it marks a tragic end.
But despite the devastation,
this was perhaps not the end for them all.
Just under 30 miles north of the main dig site...
- Come on, Esther.
- ..Emily and Jackson
have travelled out into the hills of Canada's Grande Prairie...
..to investigate an incredible find.
- So, there's three sites that have been identified.
- Right. - I think that's one of them.
And the other two...
I think there's one over there
and there's one behind us as well.
- Across the area, a series of fossils has been unearthed...
..that point to an extraordinary possibility.
- Looks like a toe bone.
But absolutely tiny.
- That also is from a very, very small animal.
Like, that, to me, looks like it's from an animal
that has either just hatched, like a hatchling,
or is actually still in the egg,
an embryonic dinosaur.
An animal this size has to have been born here.
- The young belong to both pachyrhinosaurus
and Edmontosaurus.
Dinosaurs that were heading for the same destination.
- To me, it's not a coincidence that they're both here.
We're only 30 or 40km away from the site of the flood
so surviving animals could eventually
have made their way here.
This might have been the nesting ground
for both of these megaherbivores after the flood.
- Emily and Jackson are continuing to look for more evidence.
But this remarkable discovery...
SQUAWKING
..means that maybe...
..despite all the odds...
..some of the herd did survive...
..continuing on to find another place to nest.
Survivors...
BELLOWS
..with a chance to pave the way...
..for the next generation to thrive.
So that one day...
..their herd can rise again.
BELLOWS
One of the largest dinosaurs ever to walk the Earth...
..goes looking...
..for love.
A quest...
..that will become a life-and-death struggle.
Over 66 million years ago...
SCREECHING
..our world...
..was ruled...
..by dinosaurs...
SNARLS
..the largest animals
that have ever walked the Earth.
Today, dinosaur experts across the globe
are uncovering the bones they left behind...
..allowing us to imagine
how these extraordinary creatures may have lived...
..so that we can tell their stories...
..and they...
..can walk again.
ROARS
Amongst the jagged mountain peaks...
..majestic valleys...
..and scattered hill towns of central Portugal...
..an astonishing discovery has been made...
A find so remarkable
it's drawn a team of dinosaur hunters
from across Europe.
Buried here are the remains
of a colossus.
A monumental long-necked Lusotitan.
Known as Old Grande...
..he's one of the largest dinosaurs
ever to have lived.
And using his bones,
we can begin to imagine this giant's story.
In the Late Jurassic,
our planet looks very different.
Amongst its shifting continents,
a small landmass known as the Iberian Meseta,
that one day will include Portugal,
lies surrounded by ocean.
An island cut off from the rest of the world.
CHIRPING
Dense coniferous forest covers much of the land...
..giving way to windswept beaches on the coast.
SQUAWKING
MUNCHING
Here, if you're in luck...
..an easy lunch can be found.
For torvosaurus, the island's top predator,
it's an opportunity
worth fighting for.
SNARLS
LOW GROWLING
THUDDING
But even these four-tonne carnivores...
..are no match
for the enormous Lusotitan -
Old Grande.
LOW GRUNTING
At a staggering 40 tonnes...
..he is the undisputed king of the island.
But as a herbivore,
he isn't on the hunt for food.
He's been drawn to the beach by the allure...
BELLOWS GENTLY
..of a female.
BELLOWS GENTLY
As an ageing male,
this may be his last chance to mate.
But female Lusotitans are only receptive
for a few weeks of the year...
..so he doesn't have long to make an impression.
150 million years later...
..the true scale of Old Grande is emerging
from deep beneath the ground.
As the most complete Lusotitan ever found,
his remains allow the team,
led by Professor Francisco Ortega
and Drs Elisabete Malafaia
and Pedro Mocho...
..to piece together the extraordinary dimensions
of this animal.
They're starting with how tall he was...
..which they can estimate
using the bones from his gigantic front limb.
Their calculations make Old Grande
one of the tallest of his species ever discovered...
..which is certainly one way to impress a mate.
Female Lusotitans may have been most attracted
to the biggest males...
SNORTS
..a sign their offspring will be healthy and strong.
So it should be easy for Old Grande to make his mark.
But it's not all about him.
Before they will mate,
female Lusotitans must first wait for the seasonal rains...
..making sure there is enough fresh vegetation
for their young.
And this year, the rains are late.
Old Grande has no choice but to wait.
He must guard her closely
and hope there is no other suitor close by.
LOWING
But love rarely runs smoothly.
Three miles from where Old Grande was found,
the team has made an important discovery.
The fossilised rib is a similar size to Old Grande's.
But given its distance from the main dig,
it's unlikely to be his.
Unearthing two Lusotitans so close together
is unheard of.
So the team is keen to learn more.
They cover the sections of rib in a layer of plaster...
..so they can be removed safely...
..and examined in one piece,
which is a massive 3m long.
Like elephants and rhinos today,
Lusotitan bulls were likely solitary
and very territorial.
Just like Old Grande,
this rival male would have been searching for a mate,
creating the potential...
..for a dangerous confrontation.
LOW GROWL
Although this contender may be younger than Old Grande...
..he's not afraid to challenge him
for the attentions of the female.
GROWLS
Old Grande is a seasoned fighter
and the largest bull on the island.
A stern warning...
..should be enough to make this upstart back off.
But all is fair in love...
..and war.
BELLOWING
The surprise attack leaves Old Grande seriously hurt...
GRUNTING
..his leg badly injured.
Struggling under his colossal weight...
..he is unable to right himself.
He can only watch...
..as the rival takes his place at the female's side.
For a dinosaur of his size,
a badly damaged leg could mean the end of the road.
So could a Lusotitan survive this kind of injury?
On the coast, a significant piece of evidence might provide the answer.
But reaching it won't be easy...
..because what was once flat ground during the Jurassic
is now a near-vertical cliff face.
So Francisco must descend over 100m.
Etched into the cliff face are footprints
thought to have been made by a large Lusotitan.
And they reveal something surprising.
The discovery of a limping Lusotitan
is important evidence.
It suggests that injuries to their enormous limbs...
..were survivable.
Even so, Old Grande is still weak...
..and won't last long
on a damaged leg.
But he does have a remarkable way...
..to speed up the healing process.
It's known as osteophagia.
Like modern-day giraffes,
he supplements his diet
by breaking apart and swallowing
the skeletons of dead animals.
Like the carcass of this pliosaur,
whose bones are rich in the minerals he needs...
..to repair his own body.
But he's still a long way from recovery...
..and a limp like his...
..may not have gone unnoticed.
Following the path of the Lusotitan footprints...
..something has caught Francisco's eye.
The second set of prints is another 85m
down the sheer cliff face.
Unable to reach the prints by land,
the team decides...
..to take to the air.
- Whoa, whoa, whoa.
I think...
Oh...
See?
- Yeah.
- The second set of prints follows the same path
as the Lusotitan.
But from their distinctive shape,
it's clear they've been made by a different species.
Theropods are a group of dinosaurs that includes T-rex.
But on this island,
the prints are likely to come from a predator...
..Old Grande would be much more familiar with.
The torvosaurus.
10m long and over 3m tall,
this adult female would normally be no match
for a heathy Lusotitan.
But the pain in Old Grande's leg
has become unbearable.
And he must rest until he can recover.
It could mean days without food or water,
leaving him exhausted...
..and vulnerable.
An opportunity this big...
..is rare.
LOW GROWL
But Old Grande is too strong to take on now.
So she's prepared to stay close...
..and wait.
As the days pass...
..Old Grande rests.
LOW GRUNTING
The torvosaurus...
..risks an approach.
SCREECHES
ROARS
A close call.
BELLOWING
Old Grande must recover soon,
because next time
he may not be so lucky.
BELLOWING
At long last...
..Old Grande's leg is finally on the mend...
..and he has unfinished business -
finding the female that left him behind.
But both she and his rival are now miles away...
..and the clock is ticking.
He must move as quickly as he can.
150 million years later...
..the team has made a discovery
that could reveal how fast
a giant like Old Grande travelled.
The new find gives the team an almost-complete profile
of Old Grande's front limb.
Putting these measurements together
with their findings from the cliff-side footprints...
..they can now calculate his speed.
It may sound slow, but like modern elephants,
it's thought Lusotitans could keep up this pace
over huge distances.
This is just what Old Grande needs to do
as he travels miles across the island,
looking for the female.
But he's almost out of time.
THUNDER RUMBLES
A distant storm
heralds the arrival of the seasonal rains.
LOWING
THUNDER CRACKS
The female will finally be ready to mate...
..leaving Old Grande in danger of missing out to his rival.
THUD RESOUNDS
But he's not just relying on his pace alone.
He's using an extraordinary ability to locate the female...
..one he's thought to share with modern-day elephants.
His stomps send powerful seismic waves
through the ground.
SNORTS
QUIET LOWING
Many miles away,
she feels the earth move...
..through specialised nerve endings in her feet...
LOWING
BELLOWS QUIETLY
..and she answers...
..her suitor's call.
THUNDER RUMBLES AND RAIN FALLS
Detecting her response
keeps Grande heading in the right direction.
THUNDER CRACKS
But he must reach her before he misses his chance.
At the dig site, a new section of Old Grande's bones
is emerging from the rock.
- ..this vertebra. - OK.
- So perhaps, OK, this is...
- ..including fossils that belong to his giant tail.
But laying them out from the biggest on the right...
..to the tip on the left,
Pedro has noticed something unusual.
One of the bones doesn't belong in the sequence,
and it's too small to be part of Old Grande.
It's a significant find...
..because a second adult so close to Old Grande
could mean he did find his mate.
After miles of walking...
..he's reached the area
where the female last responded to his call.
BELLOWS QUIETLY
BELLOWING
DISTANT BELLOW
Reunited at last.
DISTANT BELLOW
But the moment...
..is short-lived.
THUDDING
BELLOWING
The rival male has stayed close...
..and he isn't going to give up without a fight.
BELLOWING
THUNDER RUMBLES
Each bull uses his colossal weight...
..as a battering ram.
But these giants are too closely matched.
So, changing tactics...
..they use their teeth
to inflict intense pain.
But neither is backing down.
Taking his chance,
the rival pins Old Grande.
BELLOWING
Rearing up to the height of a four-storey building...
..he bears down with his enormous weight.
But this time...
..Old Grande refuses to go down.
GROANS
A decisive victory.
BELLOWING
But Old Grande still faces one last challenge.
Persuading the female...
..he really is the bull for her.
MACHINERY WHIRS
And it could be that Francisco has discovered the key
to what made Old Grande irresistible.
It's a series of disc-shaped vertebrae
that once formed part of his long neck.
The bones are incredibly fragile...
..so the team covers them in a protective membrane.
But these neck bones are not delicate
simply because of their age.
Each one has a hollow structure,
which may have served a vital purpose.
This dynamic movement would have allowed Old Grande
to walk, fight, and, crucially, display.
It's exactly what he needs to charm the female...
..because he hasn't won her over yet.
LOWING
Like many birds today...
..it's thought he would use his long, lightweight neck
and flexible tail
in an elaborate courtship display...
..with every move he makes
carefully assessed by this most discerning of judges.
And she responds.
Staying in sync with each other's moves...
..will be crucial to proving they're compatible.
But just as everything was going so well...
..Old Grande gets a little overexcited.
GRUNTS
LOWING
Fortunately, he has one last trick up his sleeve.
Just like modern birds such as frigates...
..Old Grande has an inflatable sac to attract attention.
It seems to have worked.
LOWING
And in the hills of central Portugal,
Pedro, Elisabete,
and Francisco have also completed their mission...
..finishing this year's dig
with a treasure trove of fossils.
Even as they pack up, they're already making plans
to return next year.
While they may never know how Old Grande met his end...
..his bones appear to be entwined
with a female Lusotitan.
And so, just maybe,
with her, he was able to secure his legacy.
A batch of giant eggs.
Buried safely beneath the ground...
..this next generation of Lusotitans...
CRACKING
..will soon begin their own story.