(wind howling)
The Arctic.
66 million years ago.
The world of snow and ice is home to dinosaurs.
But dinosaurs aren't supposed to be able
to live in such cold climates, are they?
And these vibrantly colored animals
are not the familiar image of dinosaurs
we know from the movies.
And how about a dinosaur that uses bugs
as bait to catch fish?
(water splashing)
Were dinosaurs really that smart?
Humanity has only known about the existence
of dinosaurs for a little more than 150 years.
Now our picture of their appearance
and behavior is being radically redrawn.
Yes, it turns out that the world of dinosaurs
is even more amazing than we thought.
(light music)
Our new understanding comes from the latest discoveries
made by researchers across the globe.
Vividly rendered in computer graphics
to bring the world of dinosaurs back to life.
Dinosaurs ruled the Earth for a remarkable
150 million years.
What was the secret to their extraordinary success?
Scientists now think feathers played a significant role.
Feathers may have given the dinosaurs
the revolutionary advantage.
Today we journey back in time,
back to the age of the dinosaurs.
(wind whistling)
Our first stop is the Gobi Desert in Mongolia.
This is known as one of the richest dinosaur
fossil sites on the planet.
50 years ago in this desert,
a curious fossil was found.
(scratching)
Here is that famous fossil.
Two giant arms.
(light dramatic music)
Each a little over two meters long
and tipped with gigantic 30-centimeter-long claws.
From the shape of the bones,
experts concluded this was a relative of tyrannosaurs rex.
But extrapolating from the size of the arms
suggested a creature triple the size of T-Rex.
A monster 30 meters long.
(speaking foreign language)
This dig attracted attention
from researchers in the field of dinosaur studies
through much interest and surprise
because no digs of carnivorous dinosaurs
ever excavated in the past had such huge arms as these.
It was given the name Deinocheirus,
meaning horrible hand.
Ever since, scientists have been hunting
for the rest of the skeleton to shed
more light on its true form.
It's been discovered and now a complete skeleton
of Deinocheirus will be assembles for the first time.
Yoshitsugu Kobayashi of Hokkaido University
was part of the team that discovered these fossils.
We have seen it in bits and pieces,
but this is our first time trying
to assemble the complete skeleton.
I can't wait.
Here they assemble 100 pieces
to get a full glimpse of the huge-armed dinosaur
for the first time ever.
Four hours later, the whole skeleton has been laid out.
This is Deinocheirus. (speaking foreign language)
It turns out that the Deinocheirus was 11 meters long,
far shorter than 30.
The giant arms are far out of proportion
to the rest of its body.
A dinosaur of unbalanced appearance.
In addition, though its supposed to be carnivorous,
it had no teeth.
So how did it eat?
Another unusual anatomical feature is now evident;
a huge sail along its back.
In the 150-year history of fossil hunting,
no dinosaur like this has ever been found.
Its far beyond our common understanding.
(speaking foreign language)
Our new discovery gives a complete
and mind boggling picture of the Deinocheirus.
What was life like for
this outlandish looking dinosaur?
Based on the latest research,
we reconstructed its appearance and behavior.
To travel back to prehistoric Mongolia,
a flourishing habitat for dinosaurs
and watch as the dramatic life story
of one Deinocheirus unfolds.
Although today the Gobi is desert,
long ago it was lush with vegetation
and rich with wildlife.
(squawking)
A herd of Avimimus.
Colorful feathers cover their two-meter-long bodies
just like birds.
A larger species of dinosaur
comes running right behind them.
(thudding)
It's Deinocheirus with its long arms.
Deinocheirus also has a full coat of feathers.
Recent fossil discoveries reveal
that there were far more feathered dinosaurs
than previously thought.
(squawking)
One, two, three.
Looks like a whole dinosaur family
plus a smaller one running behind.
(thudding)
A bite has been taken out of its sail.
It appears the Deinocheirus family
is chasing after prey.
(dramatic music)
Things are not always as they appear.
They are the prey being chased, too,
by a 10-meter-long carnivore called Tarbosaurus.
(roaring)
This species preys on Deinocheirus,
and four of them are after the young straggler.
(roaring)
(dramatic music)
(roaring)
The pursuing Tarbosaurus are unable
to descend the steep cliff and go after
the remaining Deinocheirus family.
(light dramatic music)
(grass rustling)
Now, this young Deinocheirus is alone
and must fend for itself in this dino-eat-dino world.
(light somber music)
We now know many dinosaurs were feathered.
The first fossil specimen feathered dinosaur
was found in China in 1996.
Called Sinosauropteryx.
It was about one meter long.
Notice the black markings that surround its body.
Paleontologists realized that each
of these lines was a single feather.
(light music)
Then, in 2012, a fossil of a much larger
10 meter dinosaur with feathers was found.
Until this discovery, scientists thought it was only
small dinosaurs that were feathered.
But this fossil, from a large one,
shows clear traces of feathers.
It was a ground-breaking discovery.
After that came further discoveries
of many different feathered dinosaurs.
Now it's clear that they were.
And feathers overturned long-held ideas about dinosaurs.
They indicate that the dinosaurs were
the ancestors of another clan of feathered creature.
The birds.
Birds are the descendants of dinosaurs.
Their living legacy.
Before these discoveries, scientists thought
dinosaurs were scaly cold-blooded animals
like lizards and snakes.
Cold-blooded animals cannot maintain
high body temperatures without sunning,
meaning they can't move quickly in a cold environment.
But birds are different.
They're warm-blooded.
Feathers help them maintain a stable body temperature
so they can be active at any time of day or night.
Feathered dinosaurs, the ancestors of the birds,
may also have had colorful feathers.
And these feathers should have enabled them
to maintain a stable body temperature.
The weird looking Deinocheirus was also
a member of the feathered dinosaurs.
The fossil also gives a clue to their life.
Curiously, its stomach was filled with rocks.
These are not just ordinary rocks,
they're called gastroliths.
The dinosaur swallows them intentionally.
It's another weird fact about Deinocheirus.
A body suggesting a carnivore but with no teeth.
But these rocks in its stomach reveal what they ate.
(wind whistling)
Let's return to the Mongolian Plateau
of 66 million years ago.
(birds chirping)
(mouse squeaking)
There's the orphan juvenile Deinocheirus.
(branches rustling)
It's eating leaves.
This carnivorous looking dinosaur is actually an herbivore.
Having no teeth, Deinocheirus gulps food down unchewed.
Then, the gastroliths in its stomach
grind up the food for digestion.
The Deinocheirus begins roaming around in search of food.
A smaller dinosaur pops out of a tunnel in the ground.
It's a Protoceratops.
Recently, a fossil of a Protoceratops
was found trapped inside a tunnel.
Den-dwelling dinosaurs.
Once again, a find that upended the long-held idea
that dinosaurs did not burrow.
Alone, she arrives at the shore of a lake.
(water trickling)
She's joined by a small white dinosaur.
One was just discovered in 2017.
Called Halszkaraptor.
It specializes in diving.
Dinosaurs that dive underwater
are another major recent discovery.
Based on their body features,
scientists believe they maneuvered underwater
to snap up fish.
(water sloshing)
In fact, Deinocheirus fossils have been found
with fish bones inside their stomach.
(splashing)
It can catch fish with a swipe of its arm.
(light music)
Those big, awkward looking arms prove their usefulness.
Deinocheirus evolved from carnivorous species,
but gave up eating meat for a diet of plants and fish.
The first known omnivorous dinosaur.
Deinocheirus really is weird and wonderful.
Even though she's all on her own,
she seems to be making her way in this world of dinosaurs.
Feathers did not only make dinosaurs colorful
and help them keep warm,
they also made possible another great change.
For more on that, let's consult Kohei Tanaka
of Tsukuba University.
Tanaka is a dinosaur expert, of course,
but his research focus is a bit unusual.
It's what's here in his hand; pieces of dinosaur egg.
Fossilized eggs contain a lot of information
about reproductive behavior,
rearing of offspring, and so on.
I like eggs more than bones.
What do eggs have to do
with the dinosaurs' feather revolution?
The fossil that provided a key clue was found in China.
Today, with special permission from the museum,
Tanaka is examining the precious fossil directly.
(light music)
Dinosaur eggs.
But apparently conspicuous as their size,
it's a set of huge eggs, 40 centimeters each,
laid a ring formation.
They belong to a species of Oviraptor.
A fairly close relative of Deinocheirus
that was also a large-sized feathered dinosaur
with an eight-meter-long body.
Tanaka says that this fossil's proof
that dinosaurs used feathers to make
a big change in their behavior.
But how does a donut-shaped ring of dinosaur eggs
relate to feathers?
(fly buzzing)
Let's head back to the age of the dinosaurs again.
Mongolia, 66 million years ago.
The Deinocheirus orphan has survived
and has grown much bigger.
And her feathers have turned redder.
(branches rustling)
Scientists say it's possible that dinosaur down
and feathers may have changed color as they matured.
Like modern birds.
Now another Deinocheirus approaches.
This one's neck and sail are blue.
It seems to be a male.
Feathers may have also been useful
to visually distinguish the sexes.
(light music)
The male raises his head and spread his long arms.
It's a mating behavior.
Like modern birds, plumage could've also
been important to mating.
(dinosaur grumbling)
(squawking)
Some time later.
Our survivor is squatting on the ground.
Beneath her is a clutch of eggs.
A breakthrough made possible by feathers.
(light music)
Like modern birds, feathered dinosaurs sat
over their eggs to keep them warm.
But this dinosaur nest has a clever feature
not found in birds' nests.
The arrangement of the eggs in a donut-shaped ring.
The dinosaur that laid these eggs
is quite large.
So to avoid trampling on its own eggs,
it left an open space in the center of a circle
where the parent could sit without crushing any eggs.
Then, using the feathers on its arms, perhaps,
it kept the eggs warm, it incubated them.
(light music)
This behavior is exhibited by many birds.
By covering them with feathers,
the parent can keep eggs at a stable temperature.
So that eggs can be hatched even
in bad weather and cold climates.
From fossil evidence, researchers thought many smaller
feathered dinosaurs may have incubated their eggs
as modern birds do.
But it was long believed that large dinosaurs did not
because of the risk of crushing their eggs.
However, this fossil clutch showed some larger feathered
dinosaurs could also incubate their eggs
by cleverly avoiding that problem.
This is a fantastic specimen
as it shows how dinosaur parents cared for their young.
Tanaka believes that Deinocheirus
also incubated their eggs using their large feathered arms.
By regularly shifting its seating position
to cover different groups of eggs in turn,
it may have kept them all warm.
This led to higher rates of hatching
than leaving the eggs alone.
By keeping close to the eggs,
the parent dinosaur could also protect
its offspring from predators.
A small carnivorous dinosaur species called Zanabazar
lurks in the background.
They wanna feast on the eggs.
(light dramatic music)
(squawking)
(grass rustling)
(dinosaur screeching)
(suspenseful music)
One of the Zanabazars sneaks past her defenses.
By the time she notices, it's too late.
(squawking)
(light dramatic music)
(thunder rumbling)
(feet thudding)
(light music) ♪ Lying ♪
Based on the size of the eggs,
the incubating period for Deinocheirus
was probably 90 days.
♪ I wonder if they ♪ (egg crackles)
♪ If it weren't for me ♪
♪ Me and ♪
The hatchlings are about 50
centimeters in size.
♪ Heaven I can ♪
♪ Almost hear them ♪ (baby dinosaur squawking)
♪ Remember all for one ♪
She was once an orphan.
Now she's a mother.
♪ Feeling ♪
♪ But who am I ♪
With the help of feathers,
dinosaurs could be more active and mobile.
They gained the ability to incubate eggs
and greatly increased their hatchling rate.
This was the feather revolution.
(light music)
It propelled the dinosaurs to expand their habitat range
into further reaches of the globe.
And even colonizing a region where scientists
had long believed it would be impossible
for dinosaurs to survive.
The Arctic.
A recent series of fossil finds have revealed
that many dinosaurs did inhabit the Arctic year round.
It's early winter in the Arctic.
Temperatures can plunge to a freezing
20 degrees Celsius below zero.
This is a herd of Pachyrhinosaurus.
They're seven meters long.
Recent fossils have been found which indicate
that Pachyrhinosaurus had feather-like fur.
The covering of bushy fur would've made living
in snowy conditions much more feasible.
(dinosaurs grumbling)
The harsh Arctic was also home to a species
of feathered dinosaur just as revolutionary as Deinocheirus.
Called Troodon.
It adapted to life in a frigid climate
by acquiring an usual capability.
(squawking)
They're thought to have some kind of intelligence.
Troodon is believed to be the most sophisticated
of all dinosaurs.
What made Troodon so smart?
Lawrence Witmer of Ohio University in the U.S.
figured it out.
Based on Troodon's skull fossils,
he created this 3D model.
The size of the brain is shown in blue.
(light dramatic music)
When we compare its brain-for-skull ratio
with that of a Tyrannosaurus,
Troodon's is three times bigger.
Witmer believes it had the biggest brain
in the dinosaur world.
He said feathers had a considerable influence
on the development of a big brain in dinosaurs.
The key factor in it is brain energy consumption.
That is, the brain is a very energy-hungry organ.
The evolution of feathers provided
insulation that allowed them evolve endothermy
which may have been very important
for them to develop large brains and high intelligence.
As a result, they actually need bodies
that can feed the brain.
And so the feathers and the endothermy contribute
to the agility and the ability to capture all that food.
Thanks to feathers,
Troodon could inhabit the frigid cold Arctic,
and there they further developed their brains
to adapt to smart survival behaviors.
Troodon uses his intelligence to survive
in the harsh conditions of the Arctic.
(squawking)
The Troodon male comes across a fallen log.
(rustling)
He knows where to find bugs at this time of year.
But he's not swallowing it.
Why not?
With the bug in his teeth,
he heads over to a nearby stream.
(water trickling)
And now a fish is lured in by the bug.
(water splashing)
He is fishing.
(light music)
This behavior is found among modern herons.
It's possible Troodon may have used this strategy, too.
A small bug wouldn't have been a filling meal.
Troodon may have used his intelligence
to turn small bugs into bigger prey.
Such smart behaviors may have greatly helped them survive.
(wind whistling)
The next day the weather has turned rough for the Troodon.
When a storm hits here in the harsh Arctic,
animals hunker down.
When the blizzard lets up,
he'll need a smart strategy to get a meal.
(snow crunching)
(squawking)
Quickly, he digs the ground.
In fact, he's buried these nuts himself in the fall.
This food-stashing behavior is observed
in modern birds like crows.
But while the Troodon is busy feeding,
an enemy stalks him.
It's a Nanuqsaurus.
The apex predator of the Arctic.
(roaring) (thudding)
The Nanuqsaurus also uses its brain
to survive in the harsh Arctic.
(dramatic music)
He drives the Troodon out onto a snowy plain
with no place to hide.
(feet crunching)
(ice shattering) (dinosaur screeching)
It's a life and death battle of wits.
The pressure to survive in the harsh climate
surely pushed Troodon to boost its intelligence.
(wind howling)
(light music)
Deep winter is almost here.
His highly developed brain is his weapon
to fight through the dark, brutal winter.
The idea of dinosaur intelligence
arose from recent discoveries
about the high intelligence of birds,
the descendants of dinosaurs.
Let's watch a demonstration of bird intelligence
by this parrot.
The tiny basket inside this tube contains nuts.
The tube sits on a table along
with a pipe cleaner and a string.
(muffled talking)
The parrot picks up the pipe cleaner
and deftly bends the tip of the wire.
Now, it flips the wire around
and uses it to hook the basket.
Yay!
Good job.
(light music)
Recent research has revealed
that bird brains are twice as dense
with neurons as mammal brains.
This enables some birds to have intelligence
comparable to a human child.
We don't really know whether Troodon
had that kind of brain structure,
but if it did, that might suggest that Troodon
might've had the kinds of behaviors
that are fairly widespread in birds.
That all of these dinosaurs may have had
some kind of intellectual capacity,
the intelligence that we see in many birds today.
Which in turn may have provided the ability
to have the high intelligence and the behavioral complexity.
So everything may ultimately come back
to the evolution of feathers
and feather-like structures in dinosaurs.
(light music)
Let's return to the Troodon in the Arctic
of 66 million years ago.
(cawing)
It's spring now, and the winter snow is melting.
A herd of Pachyrhinosaurus is agitated.
What's going on?
(squawking)
A group of Troodon.
They're confronting the herd.
But Pachyrhinosaurus are herbivores.
They wouldn't attack Troodon.
(hissing)
So why are the Troodon trying to drive them off?
(water trickling)
Nearby there are more Troodon incubating eggs.
Our Troodon and his group prevented
the Pachyrhinosaurus from trampling their eggs.
Just as in modern birds of similar size,
Troodon males may have incubated the eggs.
He heads back to his nest.
His own eggs are broken.
Did a predator make it through after all?
Hatchlings.
(squeaking)
They must've hatched a little earlier than the other eggs.
(light music)
Now the Troodon has something he wants
to teach his offspring.
(squeaking)
Fishing.
(water splashing)
(squeaking)
He's passing down hunting techniques to his offspring.
One immediately tries to imitate him.
(splashing)
(squeaking)
The techniques he passes on will help
more of his offspring to survive
in this harsh environment.
Feathers also paved the way for such caring
dinosaur family traditions.
Back in Mongolia.
(leaves rustling)
The Deinocheirus is a mother now,
busy raising her brood.
(chirping)
She and her young are in the midst of feeding.
(cracking)
She may have taught them which plants
are edible in this way.
Tragically orphaned when young,
she has made it to this fulfilling stage of life.
But the predators that took her family are still out there.
(roaring)
(dramatic music)
Again, a Tarbosaurus attacks her.
(roaring)
Using her long arms and sharp claws,
she fights back ferociously to protect her young.
(thudding)
(screeching)
And manages to drive off the Tarbosaurus.
(babies squeaking)
(thudding)
The dinosaurs reigned on Earth for more
than 150 million years by caring for
and fiercely protecting their offspring.
(babies squeaking)
Feathers not only transformed the dinosaurs physically,
but also mentally.
This is the picture of the amazing world of dinosaurs
supported by the latest research.
(light dramatic music)
Land that was roamed by dinosaurs
is now roamed by researchers who are seeking clues
left behind by the dinosaurs.
There are probably hundreds
of thousands of dinosaur species, perhaps millions,
but we have only found about a thousand species to date.
It's like all we've done is chip away
at the edges of a glacier.
There are so many yet unknown unique kinds
of dinosaurs out there,
but we will keep finding more of them.
Today, we are finally starting
to glimpse what the world of the dinosaurs was really like.
The amazing dino world is still a vast
and barely explored frontier
of the history of life on Earth.
(light music)