(mysterious music)
(dramatic music)
(roaring)
Where do birds come from
and who were their ancestors?
For a long time, these questions have remained unanswered.
Their family trees stopped abruptly at the oldest
known species, a fossil found in 19th century Germany.
Archaeopteryx whose name comes from the Greek
for ancient wing.
But since 1996, thousands of animals unearthed in China
have shed new light on the origin of birds.
(screeching) (intense music)
This abundance of discoveries proves that most dinosaurs
were not covered in scales but clad in feathers.
Some of these feathered dragons could even fly.
The extent of the Asian jigsaw puzzle is so vast
that it ties modern day birds to remarkable distant
cousins and suggests a multitude of relatives.
(snarling)
During the Jurassic Period,
between 200 and 145 million years ago,
the supercontinent Pangaea opened up
creating separate land masses.
At the edges of this world, China and Siberia formed
a huge peninsula with a temperate climate
similar to that of modern Europe.
(mysterious music)
The break up of the continents was accompanied
by volcanic eruptions, particularly in China.
A paradise in waiting, inhabited by strange creatures
like Anchiornis.
(chirping)
Meaning near bird, this little dinosaur
is completely covered in feathers.
The size of a modern day pigeon, Anchiornis
is a long lost relation.
The descendants of this light weight dinosaur
survived better than other large Theropods
The group that includes all carnivorous dinosaurs.
(snarling)
Including Guanlongs.
They are efficient hunters, three meters long
and weighing 50 kilograms.
(snarling)
To escape, Anchiornis was capable
of short gliding flights while its pursuer
was firmly stuck on the ground.
(intense music)
(snarling)
And yet, Guanlong also had feathers.
What were they used for?
(dramatic music)
(roaring)
Erupting volcanoes spewing fine ash
and noxious gases froze a moment of Jurassic life
for eternity, helping us answer some of these questions.
This dinosaur paradise has become
the feathered dinosaur's Pompeii.
A huge range of new species has recently
been discovered in one of China's many construction sites.
Over the last two decades,
in the Liaoning region, paleontologists have collected
thousands of specimens hidden for millions of years.
These magnificent fossils are in a state
of almost perfect preservation.
Thanks to the mixture of extremely fine clay
and volcanic ash sediment.
Those volcanic eruptions (mumbles)
and bury their bodies so that's why we have
such beautiful skeleton and I include soft tissue
preserved, so that's why we come here.
Paleontologist Xu Xing and his colleagues
from around the world can trace the chaotic history
of flight and feathers in these rocks.
The feather preservation is really amazing.
Like detectives, they examine the clues
to understand what feathers were used for.
And discover how some dinosaurs from the Theropods family
turned over the course of millions of years into birds.
The first piece of evidence in their inquiry
was discovered at the end of the 19th century in Germany.
Towards the end of the Jurassic Period,
Europe was partly submerged under a shallow body of water
called The Tethys Sea.
About 150 million years ago,
Germany was dotted with tropical islands.
(ominous music)
Pterosaurs the first flying vertebrates
have dominated the skies for 80 million years.
This is Germanodactylus one of 150 species
of Pterosaurs discovered.
These flying reptiles are not dinosaurs.
Their fine skin stretches over their elongated fingers
to create leathery wings.
This membrane along with powerful muscles
and hollow bones makes them masters of the skies.
(tense music)
But the Pterosaur's aerial supremacy is about
to be challenged by the very first birds.
Such as Archaeopteryx
A primitive bird whose claws are the ends of its wings
raise suspicions among 19th century paleontologists.
Its fossils were found around the modern
German town of Sondershausen.
A tropical acapellago during the late Jurassic Period.
Some islands harbored salted lagoons
where dying animals avoided scavengers.
And were buried by soft mud that preserved them
in minute detail.
(soft piano music)
Eberhard Frey commonly known as Dino Frey
is the resident expert.
This is the famous Sondershausen laminated limestone
and you can actually see the sediments stapled
up like the leaves of a book.
Inside the leaves of this rocky book,
this is where Archaeopteryx was found together
with many other fossils and it's the specialty
of this rock that it is very, very, very fine grained
and inside this mud, fossils are preserved
like in a tin and this is why this entire area
is so valuable as a window in Jurassic times.
The locals use these stones
to tile their houses.
In the process, uncovering highly prized treasures
in the history of paleontology.
(mysterious music)
In 1868, faced with the Archaeopteryx,
British biologist Thomas Henry Huxley asserted
that this was a transitional fossil
between reptiles and birds.
(dramatic music)
A friend of Darwin and an ardent defender
of the Theory of Evolution, Huxley was an expert anatomist
capable of skilled fossil analysis.
Until the year 1861,
before Archaeopteryx first discovered,
the only creatures that were known to have feathers
were the birds.
It was apparent that this is a fossil bird.
Thomas Huxley looked at it very closely
and he discovered signs that this bird
could also be a dinosaur actually, a carnivorous dinosaur,
actually shares characters of the two
making it the mixing link between dinosaurs and birds.
That was a sensation at the time.
(bouncy music)
The Darwinian idea of natural selection
is therefore very recent.
Huxley had the insight to see that Archaeopteryx's teeth,
clawed wings and bony tail meant that it had similarities
with kon-sog-ni-sus dinosaurs.
Predatory relations with the Velociraptors.
(snarling)
Archaeopteryx was certainly no acrobat but it had feathers
and it could fly.
Its collar bones had already fused together.
A vital step enabling the wings to flap efficiently
and gain altitude, allowing it to hunt and nest in trees.
(gentle music)
Throughout the 20th and 21st centuries,
more Archaeopteryx fossils were unearthed in Germany.
(mysterious music)
This is specimen number 11.
It's the latest specimen and it came to light
in the year 2011.
Despite its fragmentary, it's not completely preserved
because its skull is missing.
It still shows us some features which are previously
unknown, one of them is that the tail end
shows a V shaped feather configuration
and the second is that you can see in this specimen
the extent of the feather travels along the legs.
The feathers on its feet are intriguing
since modern birds no longer show this characteristic.
Is this an exception?
What is sure is that this feature
has not been selected by evolution.
Just like this giant marine reptile.
A Liopleurodon.
(insects buzzing)
Washed up on the shores of the lagoon,
it is a godsend for Archaeopteryx.
The flies attracted by the carcass provide a hearty meal
for this insect eater.
But being out in the open is dangerous for Archaeopteryx.
An opportunistic Germanodactylus sees the prospect
of a protein rich meal.
(tense music)
And doesn't appreciate the competition.
(dramatic music)
Once the mightiest creatures in the skies,
Pterosaurs became extinct by the end
of the Cretaceous Period 65 million years ago.
While Archaeopteryx descendants grew in number.
Bogged down at the bottom of the song-hil-fan lagoon,
this remarkable fossil launched the debate
on the relationship between birds and dinosaurs.
But with insufficient proof, this theory was shelled
for more than 100 years.
Until new evidence came to light,
at the end of the 20th century in China.
In 1993, in Liaoning,
a huge fossil deposit was found dating
from the Cretaceous Period.
125 million years ago.
This region formerly known as Manchuria
comprises fertile farm land with fields of corn and pasture.
Farmers were the first one to uncover fossils inadvertently.
You can see her tomb at a foot of a cliff fashioned
by volcanic eruptions.
Layers of gray mud alternate with red ash.
Transported to Beijing, these fossils allow 21st century
researchers new insights into the feathered dragons.
Like Sinocalliopteryx, the first discovered in 1996.
This specimen remains a source of fascination
for one of China's most famous paleontologists Xu Xing.
I remember clearly at that time when this discover
was announced, everyone got so excited.
We are kind of shocked by the beauty of the fossil.
If you look at this specimen closely you see the feathers
cover the whole body.
Over the hair, over the back, cover all the tail.
A little bit here also I mean lame.
Basically feathers are quite simple.
They are more like your hair.
Before this discovery, some paleontologists believe
some bird like that should have feathers
but no, we have real (mumbles) so that's totally different.
The discovery of this feathered covered
fossil was astounding.
For the first time, they had found a dinosaur
with avian characteristics.
Proof that they were part of the same lineage.
In conifer forests, growing in the shadow
of volcanoes, lived Sinocalliopteryx.
It belonged to a group
of carnivorous dinosaurs called Theropods
These predators use sight and smell to hunt.
(ominous music)
One of his favorite victims is zang-e-o-tier-ium.
One of the first mammals.
Sinocalliopteryx's feathers looked like the down
covering modern day chicks.
They are so different from bird feathers
that for a long time, skeptics dismissed them
as mere hares.
(screeching)
In 2010, Xu Xing focused
on Sinocalliopteryx's strange feathers
which looked like the down covering modern day chicks.
He began with careful observation of these feathers.
By taking a sample and putting it under the microscope,
scientists discovered fossilized pigments.
These are melanosomes, cells that give feathers their color.
Xu Xing discovered circular shapes
that produce a brown pigment and stick like shapes
that create a gray color.
He deduced the Sinocalliopteryx was the color
of a squirrel with lighter stripes on its tail
but that's not all.
We can use melanosomes to infer the color,
but more importantly for us,
we wanted to use that information to support
the hypothesis that those dark impression
in this particle space-ment are part of feathers,
not something else because if melanosomes are present
we can say quite confidently those are primitive feathers.
Sinocalliopteryx was undoubtedly
covered in feathers but this land animal
was incapable of flight.
So what use was this dino fuzz?
Did it protect this warm blooded animal from the cold?
Possibly, but this theory is not easy to prove.
To learn more about the climate in Liaoning
during this period, Xu Xing teamed up
with the laboratory in France.
This Theropod tooth bought back from China
by geologist Romain Amiot holds the key
to this meteorological mystery.
A lot of researchers thought that fossils
from that time couldn't preserve the weather conditions
recorded during the animal's lifetime.
It was a big challenge.
We were going to test something unknown.
Could we find out climate information or not?
In a sense, we can test the water
the dinosaurs drank.
A chemical reaction with the oxygen preserved
in tooth enamel reveals the temperature
of the atmosphere 120 million years ago.
Romain made a major discovery that radically
altered our preconceptions.
At the time, there was a global climate
that was similar or a little colder
than current temperatures which is very different
from what we thought about the period of the dinosaurs
that we had imagined as hot, tropical
and the same throughout the world.
Where Liaoning is, the climate was similar
to what we have in the north of France
with very harsh winters.
So dinosaurs would have seen snow in winter.
So feathers were an insulating material.
It meant they could keep warm and keep active
throughout the year like any other warm blooded animal.
Coincidentally just as Romain published
his research, the discovery of large sized dinosaurs
confirmed his work.
Yutyrannus, the aptly named feathered tyrants,
were the super predators of the time.
Due to their large size, the remains of T-Rex's cousins
are kept in a warehouse in a suburb of Beijing.
(mysterious music)
Yutyrannus is really an amazing animal.
It's a really big animal, about one half tons
in body mass.
Its body covered by feathers, really long feathers,
so this is unexpected.
Traditionally we thought,
when an animal get bigger (mumbles) the same.
The loss feathers, reduce feathers,
at least feathers are kind of sparse,
but here we have a large body that dinosaur
with dense, and long feathers.
So this is bizarre.
The fact that such a large warm blooded
animal was covered in feathers suggests
that its body size was not sufficient
to regulate its temperature.
So the climate must have been very cold.
The discovery of the largest feathered animal ever found
confirms the hypotheses of a temperate climate
with harsh winters.
(solemn music)
It proves that the Theropod dinosaur of Liaoning
wandered into the winter snow 125 million years ago.
And that the feathers of the little Sinocalliopteryx,
the huge Yutyrannus, protected them from cold temperatures
in this region of the northern hemisphere.
(tense music)
(roaring)
The insulating property of feathers remains
a feature in modern birds.
But it is not sufficient to explain how surface
dwelling dinosaurs evolved over millions of years
to become birds.
Among the Theropods living in Liaoning,
was there only one type of feather?
And at what state did dinosaurs begin to fly?
Over time, Chinese paleontologists have unearthed
many feathered creatures.
On some fossils, like the Caudipteryx,
discovered in 1998, Xu Xing found feathers
that were not just simple filaments.
With its large feet, it looks much like an ostrich.
In this fossil, there's some really feather impression.
Here you see two hands of this animal
and here is a middle finger.
You see feathers attached to the finger, this surface.
They go this way so quite a big feathers.
(soft music)
Caudipteryx literally meaning tail feather
comes from the same Chinese site
as Sinocalliopteryx, in the same period,
125 million years ago.
(screeching) (gentle music)
Scientists imagine that these chicks were imprinted
on their mothers just like modern birds
and followed them everywhere more or less.
(squeaking)
Weighing almost 20 kilograms,
the female Caudipteryx can't fly,
neither can her youngsters.
So why do these animals have long feathers?
Could they serve a purpose other than warmth?
Feathers begin as a simple filament.
Which divides to form a pom pom before barbs
appear around the hollow shaft.
But at this stage in their development,
feathers are symmetrical and air passes through them.
So it is not fly animals, it's fast running animal
leaving on the ground, so what's the function?
Apparently those feathers are not used for flight.
That was a possibility most people believe
is a display.
Just like many birds,
the males and females were physically very different.
Paleontologists believe that the male Caudipteryx
displayed his shimmering feathers in order
to attract females.
(screeching)
These cultured rituals along with natural selection
stimulated an anatomical transformation.
Caudipteryx were among the first Theropods
to possess a shorter tail that supported their display furs.
(screeching)
In order to fly, they were still missing
a fundamental element, flight feathers.
(tense music)
Seen under a microscope, this feather comes
from another dinosaur discovered in 2000
by Xu Xing himself.
It is a vital clue to solving the mystery
of the origin of flight.
Here the feathers are highly asymmetrical.
Asymmetrical feathers are normally considered
to be associated with flight capability.
These feathers are identical to those
of modern birds.
It may be proof that some dinosaurs could fly.
Microraptor is definitely the most amazing species
that discovered so far.
It is dinosaur but you see it has asymmetric flat feathers.
Not only are the feathers on the arms,
but also on the feet.
We call the (mumbles) condition.
This is really, really bizarre.
I don't know, we have quite good evidence
suggesting this foreign condition is related
to the origin of flight.
For a long time, paleontologists
believed that two legged dinosaurs run along the ground
in order to take off,
but Microraptor's climbing claws opened
up a new possibility.
125 million years ago in the part of China
that Microraptor called home,
the ground was fertilized by volcanic ash
that encouraged the growth of lush vegetation.
Tall trees add a vertical dimension to the landscape
and the Microraptor, meaning small thief,
takes advantage of them.
(chirping)
Microraptors sported feathers on its arms and legs.
With its full wings, it was probably the world's
first base jumper.
(chirping)
Full wings offer an advantage for gliding,
but not for walking.
A Microraptor on the ground, is a Microraptor in danger.
(tense music)
(screeching)
According to Xu Xing, tree dwelling feathered dinosaurs
like these would evolve to become birds.
To better understand this transition,
paleontologists teamed up
with an ornithologist Zhongue Zhou.
In front of him is an incredible collection
of primitive birds found at sia-tomb.
Like the feathered dinosaurs from the same site,
they all date from the Cretaceous period
125 million years ago.
I think there are over 500s of specimens
of Confuciusornis collected in this museum alone.
I think this is the largest collection
Confuciusornis in the whole world.
This bird, like Confuciusornis, they're only later
than the earliest bird Archaeopteryx
and they are transitionally many flight-er apparatus,
many features.
Despite the claws on their wings,
they are very similar to modern birds.
They no longer have teeth or a long bony tail.
They also have a focular, the famous chicken wishbone
for attaching muscles to wings and the males
have two ceremonial ribbons ornamenting their behinds.
(solemn music)
This sexual variation is similar to that
of the feather dinosaur called Dipteryx.
Like him, the male has long feathers that he uses
to lure the ladies.
(screeching)
Competition is tough and courting displays
are often interrupted.
(volcano rumbling)
Also you can see the bird start climbing the trunk
with very big claws in the wing.
Now you see the bird can perch on the branches
of the trees because the hallux of the foot
is already reversed, much like a modern bird.
(screeching)
Confuciusornis narrow feathers were not well
adapted to gliding, but would've allowed it to fly
by flapping its wings, albeit clumsily.
But natural selection is at work,
retaining only the most adapt genes.
Yet the presence of many birds found
at the same location as feathered dinosaurs
does not necessarily prove that they were related.
If birds had already diversified 125 million years ago,
Yutyrannus and other Theropods may have been merely
an evolutionary dead end.
So when did the first birds appear?
Did they share a common ancestor with feathered dinosaurs?
And how did their ancestors begin flying?
To answer these questions, Chinese paleontologists
have one last card up their sleeves.
West of Liaoning, a new fossil bed was revealed
during the construction of a motorway.
In 2009, a finely preserved Anchiornis dating
from the Jurassic Period was found near here.
It's become a crucial piece in Xu Xing's puzzle.
This site is very important for at least one reason.
We know that Archaeopteryx, the earliest known bird
is from about 145 million years but most other feathered
dinosaurs are from early Cretaceous or even later.
So this dinosaur was living in 160 million years ago.
Earlier than Archaeopteryx so that means there are some
feathered dinosaurs predates Archaeopteryx,
the earliest bird.
That's cracked the time sequence.
This new fossil puts an end to the debate.
Feathered dinosaurs are undoubtedly older
than the first birds.
Today, Xu Xing discovers a fish.
Confirmation that Anchiornis lived in a rich ecosystem.
This little four winged Theropod must've been
a victim to giant predators.
(screeching)
In the Jurassic Period, Pterosaurs like these Darwinopterus
ruled the skies.
With talon like claws and a wing span of over a meter wide,
they were the equivalent of modern day birds of prey.
Their ability to fly and perform aerial acrobatics
was beyond that of the feathered dinosaurs.
Faced with this constant danger,
Anchiornis sought shelter in the forest.
But this little dinosaur was also threatened
from the ground.
Its only shelter lies in the restricted area
between the ground and the sky, the trees.
It glides down to feed in the under growth.
Its surface area is smaller than Microraptor
so it falls more quickly.
With its long back legs, Anchiornis is built
like a sprinter, but its lengthy feathers are a hindrance
on the ground.
Its long legs are an advantage for foraging
or rushing to the nearest shelter.
If such a thing exists.
(tense music)
(screeching)
Though clumsy, Anchiornis showed the dinosaurs
attempted to fly from trees using fall wings.
On this rare fossil, the rear leg feathers are visible
to the naked eye.
To refine his theory, Xu Xing continues his research
using a medical scanner.
X-rays of Anchiornis' skeleton will be digitized in 3D
in order to study its biomechanics.
But honestly there are some debates
how exactly the animals use their leg wings.
Some people believe the leg wings are not really
related to flight, maybe it's a display structure.
If you look at other dinosaurs, their leg normally
is underneath the body.
(mumbles)
One possibility may be Anchiornis can project
its leg slightly laterally.
To compensate for the lack of a wishbone,
Anchiornis used its rear leg feathers to improve
its gliding ability.
The discovery of Anchiornis proves that dinosaur flight
was a result of trail and error in the evolution
of anatomy and feathers.
Surprisingly, new information about the origin
of feathers was soon to appear from over the border.
In Siberia, in the summer of 2013,
the first Russian feathered fossils made their appearance.
1500 kilometers north of Beijing,
in the Transbaikal Step, a team of Russians and Belgians
worked together at the excavation site.
When local geologists found the first bones,
they invited paleontologist Pascal Godefroit
from the Royal Institute of Belgium
to take part in this revolutionary discovery.
We're at the Kulinda deposit
in southeast Siberia.
The hills you can see behind me, date from the Jurassic
Period between 145 and 160 million years ago
and Russian geologists who were prospecting in the area
in 2010 found the first dinosaur bones
which have been extremely important for reconstructing
the evolution of plumage and feathers in dinosaurs.
As curiosity aroused,
Pascal assembled a team to search the site for themselves.
It's a lengthy process, requiring a deep layer
of soil to be removed to get to the fossils.
But after several days, the teams work starts
to show results.
Look at that.
That's quite a big deal.
Just there at the edge.
Oh wow, that's one.
(speaks foreign language)
So here at the edge of the plate,
you can see very fine little filaments
and these are feathers, dinosaur feathers.
You can see that the filaments converge towards the base
so these are composite feathers.
It's a primitive kind of down that we find
on some primitive dinosaurs.
Compared to the impressive Chinese discoveries
these fossils may seem a little underwhelming
but the paleontologists are thrilled to discover
a completely new animal species.
During the Jurassic Period, the Chinese peninsula
was covered in a vast forest of conifers.
While Siberia was much more hostile.
The arid climate had a huge seasonal
variations in temperature and intense volcanic activity.
One of the keys to conserving precious fossils.
Only fragments of skeletons are found at Kulinda.
To begin with, the Russians thought that the feathers
came from fossilized birds.
The scales from crocodiles.
And the bones from a small predatory dinosaur.
But Pascal was not convinced by this hypothesis.
In 2014, he reanalyzed all the fossils
and suggested an entirely different explanation.
It's a bit like going into a cemetery
and gathering up loose bones.
You have small tibias, large tibias,
little femurs and big femurs but they all have
the same ornithology so we can tell they all come
from the same type of dinosaur
that we called Kulindadromeus.
Because of the large number of disconnected bones
that we found at Kulinda,
we now know that Kulindadromeus was a small
herbivore dinosaur that was fast, slender and agile.
This is the first ever feathered herbivore
dinosaur to be discovered.
A separate branch of the dinosaur family tree
from the carnivorous Theropods.
Kulindadromeus lived in herds.
Just like wildebeest migrations in Africa,
large predators such as Sinraptor must've closely
followed the movements of these dinosaurs.
(roaring)
This is a real revolution.
What it means is that all dinosaurs who potentially
have had feathers.
Feathers would have appeared
on an ancestor that was common to both groups.
It could be as old as dinosaurs themselves.
First seen in the Triassic Period 220 million years ago.
(ominous music)
The misfortunes of this group of herbivores
have led paleontologists to the origins of feathers.
(roaring)
Thanks to Kulindadromeus, we now know that the first
feathered dinosaur, the common ancestor
of the carnivores and the herbivores
remains to be found in fossil beds going back
to before the Jurassic Period.
(roaring)
But who knows what other secrets could be found in Siberia?
And what clues could be hidden in other parts of the world
to document the early history of the bird dynasty?
(whimpering) (solemn music)
(volcano rumbling)
(dramatic music)