(dramatic music)
Narrator: Earth is born out of chaos and catastrophe.
(object banging)
Despite such hostile conditions,
life emerges on our planet.
(water flowing)
but it must withstand deadly disasters again and again.
(wind whooshing)
Planet Earth is a wild world
shaken by unimaginable impacts,
volcanic eruptions that flood the landscape
and drastic climate changes that lead to ice ages
that freeze the world from pole to pole.
Yet each assault creates a path for something new.
(birds chirping)
Life always finds a way
despite being constantly put to the test.
Without these catastrophes, life as we know it
would not exist on our fateful planet.
Life evolved on earth four billion years ago
when a series of severe ice ages froze our planet.
They almost destroyed everything alive,
but when the last glaciation ended,
earth became a giant greenhouse.
Oceans turned tropical
and made way for an unprecedented explosion of life.
This profound change marked the beginning
of the Paleozoic era 541 million years ago.
(water splashing)
Life experienced significant evolutionary developments
and took on much larger dimensions,
thriving in new forms and conquering new habitats.
But during this era, which lasted close
to 300 million years, the planet was stuck
by deadly catastrophes.
The last and worst was a mass extinction
that wiped out almost all life on earth.
(animal growling)
Scientists around the world are investigating
how life in the Paleozoic evolved
and which events ultimately resulted in the disaster
known as the Great Dying.
Morocco, in this dry, dusty north African landscape
there is fossilized evidence of the biological revolution
that became known as the Cambrian explosion.
Paleontologist Philipe Havlik is here to find out more
about how that complex life evolved.
The story unfolded underwater
and what was once a vast ocean.
Speaker: The Cambrian explosion being the beginning
of the Cambrian period is the most exciting thing
for any evolutionary researcher.
It was the moment when almost all invertebrate animal groups
suddenly appeared overnight, as if out of nowhere
they started to divide into all kinds of species.
We found hundreds of species
within a very short period of time.
We still require an enormous amount of research on this
and still don't know exactly what happened.
Narrator: Philipe has arranged
to meet with a local fossil trader
who will help him decipher the story.
Like many people in the area,
Mohan Imati has traded in fossils his entire life.
-: We can look at this layer.
-: Maybe first some on the rocks, huh?
Narrator: Soon the experts find something interesting.
-: What do you think about this one?
-: Yeah, yeah, that is good fossil, it's trilobyte.
-: It's almost complete, huh?
-: Yes, it's complete, yeah.
Speaker: Trilobites
are kind of like cockroaches among fossils.
Their body is divided into three parts.
We have the head, the cephalon, the thorax,
the body, and the pyridium.
Basically, the rear end of the Trilobites.
Narrator: Trilobites emerged
at the beginning of the Cambrian.
These arthropods are one of the earliest
and most diverse groups of multicellular organisms on earth.
(water flowing)
Along with their unique body shape,
Trilobites had a hard exoskeleton made of chitin.
This protected their soft bodies
and allowed their fossils to be well preserved.
While Trilobites were a huge part of the marine ecosystem,
they weren't the apex predators at the time.
(water flowing)
A terrifying giant shrimp like creature
known as Anomalocaris claimed that honor.
Speaker: Anomalocaris was the fighting machine
of the Cambria, four feet long
equipped with long eye stalks,
giving it 360 degree vision.
It had large grappling arms at the very front.
Anything that came close to it was eaten.
(speaking in foreign language)
(gentle music)
(water flowing)
Speaker: Philipe sees the Cambrian
as more of a revolution than an explosion
because it marked the beginning of competition
among living things.
Speaker: Some developed a shell
and others developed weapons to crack this shell,
and so it came to an extreme arms race.
One had stronger tools.
The next had spikes and used them to fight back,
and in the end, the sea creatures we know today emerged.
Narrator: Life exploded in the oceans.
Rising oxygen levels, genetic inventions
and environmental changes created a complex cocktail
that led to new and abundant diversity.
Within just a few million years,
mats of microbes covering the sea floor
evolved into complex life.
Simple unicellular organisms were replaced
by highly mobile creatures
that sported advanced anatomical features
like legs and eyes.
The Cambrian lasted until 485 million years ago.
It was followed by the Ordovician,
a second period of the Paleozoic,
where life continued to diversify through the emergence
of new marine species and ecosystems.
Organisms that were dominant in the Cambrian
were now replaced by a wide range
of new marine invertebrates.
The Moroccan rocks have an exquisitely preserved
record of the Ordovician.
Mohan takes Philipe to a site
where he recently found a Cephalopod,
a squid like creature
that was even larger than Anomalocaris.
-: That's what we found.
-: Oh, whoa, whoa, whoa, whoa, whoa.
It's actually a pretty nice piece.
And do you know the biggest of this one?
They reached up to nine meters
and just to shell its Camarasaurus, it was found in Russia.
Narrator: Camarasaurus was the largest predator
in the Ordovician.
10 tentacles projected from its cone like body,
allowing it to catch and feed
on Trilobites and other creatures.
(water whooshing)
(dramatic music)
The tentacles grabbed the prey,
then sucked it inwards to be devoured.
This massive increase in size
is attributed to the evolutionary pressures
that develop in predator, prey dynamics.
Being big can help creatures avoid predators
or become more effective predators themselves.
Scientists believe the environment
also affected this growth.
Speaker: In the Ordovician,
the first plants emerged on land,
which increased the oxygen levels
and thereby led to climate fluctuations.
This, of course, is a trigger
that significantly advances evolution.
Life must deal with new situations time and time again.
(gentle music)
Narrator: The Moroccan fossil record
reveals a bustling Ordovician world
full of increasingly complex creatures.
But about 444 million years ago,
things suddenly changed.
The fossils show that there was a massive die off.
Even with their new adaptations, more than 85%
of marine life was wiped out.
(vehicle whirring)
Philipe is searching for clues about what happened
on the northern edge of the Sahara desert.
Speaker: Here we have a seabed
in which numerous different fossils are preserved.
They indicate that we are exactly
at the right point in time.
(object banging)
Narrator: But then he finds something unusual.
Speaker: Here I have a stone within a stone,
and that shouldn't happen in this marine deposit.
We are relatively far out at sea here,
so there simply shouldn't be any pebbles,
especially not angular ones.
There's only one way to get them so far into the sea.
A small iceberg must have drifted out here.
(gentle music)
Narrator: When glaciers move over land, they grind rocks
beneath them, picking up and transporting bits
and pieces until the ice melts.
Havlik believes that when an iceberg melted
in the Ordovician ocean, it dropped this pedal here
about 444 million years ago.
A glaciation event seems to be the only explanation
for the pebble trapped in older stone.
Speaker: We also find such evidence in other places
around the world, not only in North Africa,
it's also in South America.
It's the same in Southern Europe.
It's something that appears everywhere.
That means the moment there is large scale cooling,
most creatures, at that time only sea creatures,
have no chance of survival.
In other words, most of them simply go extinct.
Narrator: Complex life was flourishing
until suddenly everything changed.
Because the glacial deposits occurred at the same time
as the mass extinction event,
it seems plausible that an ice age was responsible
for the death of so many new species.
But how did the climate suddenly change
from tropical to Arctic?
Iceland, to uncover what could have caused
such a huge glacial event,
geologist Professor Colin Devey has come to a unique place.
-: We're in the Silfra gap,
and this is where you can really see
plate tectonics in action.
You can really see one side
of the earth moving away from the other side of the earth.
This is where tectonics really happens.
Narrator: Rocks here reveal how earth
is shaped by internal forces
deep below its crust, the thin outer shell of our planet.
Collin believes these forces played a crucial role
in the extinction event at the end of the Ordovician.
-: Iceland is a place on the planet
where you can see wet tectonic plates, where the surface
of the earth actually splits apart.
Narrator: Tectonic plates provide clues
about what's happening beneath the surface of earth.
Today we have seven major plates and numerous smaller ones.
They all rest on the molten rock of earth's mantle
and fit closely together.
The tectonic plates move due to heat
from radioactive processes inside earth.
At times, they move closer together
and at others, farther apart.
(dramatic music)
-: This is the edge of a plate.
This continental drift is what this is all about.
This is the result of Europe going that way
and America going that way, not very fast.
It's about as fast as your fingernail grows.
Narrator: The gap is part of the Mid-Atlantic ridge
between the North American and the Eurasian tectonic plates.
-: Okay, that was the easiest
transatlantic flight I've ever done
and the quickest, probably not the warmest,
but hey, you can't have everything.
Narrator: When the plates move apart from each other,
the land between them suffers enormous tension.
A major earthquake eventually rips through the rock
to release pressure, creating enormous fissures
like the Silfra gap.
-: What's happening here normally happens on the sea floor
at about 2,500 meters depth,
in the Atlantic, even deeper, 4,000, 5,000 meters.
This is how the earth has changed its face,
has changed life on earth,
has changed everything about the earth.
-: Since they first formed,
the tectonic plates have continued
to move around the planet.
Over time, the continents they create also change.
About 444 million years ago,
our world looked very different, which could be important
to the Ordovician mass extinction
-: Plate tectonics is the thing that drives the puzzle.
It moves the continents around.
At the end of the Ordovician,
plate tectonics had pushed the continents together
into a big lump,
into a big mass of continent called Gondwana.
Narrator: Gondwana was a super continent
covering almost 1/3 of the earth's surface.
The giant landmass almost stretched from the equator
to the south pole,
and included the modern continents of South America, Africa,
most of Antarctica and Australia and some of India.
-: And life in the Ordovician
was mainly on the shelves around the Gondwanan continent.
Gondwana had moved quite a long way down south,
so it was at the South Pole,
or part of it was at the South Pole,
and that seems to have set the world up
for very bad environmental conditions
for life in the oceans.
(dramatic music)
Narrator: Life thrived on the super continent.
Sea animals like Conodonts and Trilobites flourished.
But as the continent began
to move farther towards the South Pole,
it had a catastrophic effect on living things.
-: And if the ice builds up, sea level drops,
then those shallow water regions
around the continent are all of a sudden dry land
and there's no place to live.
And it seems like that is probably one of the pressures
that really hurt life in the Ordovician earth.
Narrator: Major glaciation at the end
of the Ordovician caused sea levels to drop.
The consequences were dire.
85% of marine species were wiped out.
It was a colossal loss of life.
(water whirring)
The Ordovician mass extinction led to the Silurian period
that began 443 million years ago.
It is characterized by the recovery
and triumphant reemergence of life
after just a few million years,
creatures were rapidly evolving
and becoming even more complex.
They exploited new habitats, found new sources of food,
and moved in new ways.
The Silurian ended 419 million years ago
and gave rise to the Devonian period.
Back in Morocco,
Philipe Havlik has rejoined fossil trader, Mohan Imati
to investigate how life evolved
in this important chapter in Earth's history.
The Devonian is also well preserved in Moroccan rocks.
Over the years, Mohan has collected many fossils
from this period, especially Trilobites.
-: It is my Devonian stuff I collect long time ago.
(person laughing)
-: So this is 20 years of collecting or how much?
-: More, yes.
Speaker: The Trilobites in the Devonian in particular,
show an incredible diversity.
There are some that have huge eyes
with many complex facets on them.
They can basically see everything.
Some even have appendages on their heads
so that they can swim through open water.
There is really everything you can imagine,
a biodiversity that we have never seen before,
and probably the greatest variety of trilobite species ever.
Narrator: But other animal groups also evolved rapidly
during the Devonian to become more dominant.
Speaker: You could call it the age of the fish.
These had an exoskeleton that consisted of a certain number
of plates, and so did the chewing tools.
Narrator: Dunkleosteus
was one of the largest of these armored fish.
It was a colossal sea creature
that may have reached 26 feet in length
while ruling the oceans
and devouring everything in its path.
Speaker: Dunkleosteus had a huge pair
of crushing shears at the front,
which it could consistently resharpen.
They simply crushed on top of each other.
It cut through everything that got in its way.
(water whooshing)
Narrator: As the oceans grew busier during the Devonian,
some creatures began looking
for alternative, less crowded environments.
A fish known as Tiktaalik
attempted a revolutionary strategy.
It tried to transition out of the water, onto land.
Speaker: For a vertebrate, life in the water
cannot be compared with life on land.
If you make a swimming movement,
you can have wobbly fins,
but on land, it's a completely different situation.
You need a rigid frame so that you can move around.
That's exactly what Tiktaalik had.
It had fingers, it had arm bones.
It had an internal skeleton, a spine that allowed it
to use its four legs to move around perfectly.
(speaking in foreign language)
Narrator: Tiktaalik was challenged
to develop the ability to breathe air,
but was successful becoming the first vertebra
to conquer land.
But just as animals
and plants were gaining a foothold on land,
a new threat emerged once again.
(tense music)
Effenberg, Germany.
Geology professor David De Vleeschouwer
and a team of students are searching a quarry
for clues about the fateful events
that took shape at the end of the Devonian.
(gentle music)
-: This is the wall that we're going to sample,
today, as you can see,
there are two very pronounced black shale layers
that you can readily see.
So when we find a black shale like this one
in the geological record, it's a clear indication
that we had low oxygen
or even no oxygen condition in the sea water.
And of course, that means that all the life
that was living in the water column had a difficult time
because all Devonian life,
late Devonian life in the water column
was dependent on oxygen.
(gentle music)
Narrator: David and his team must collect rock samples
to understand how the Devonian climate changed over time.
They are time capsules of an ancient apocalypse.
(gentle music)
Back at the University of Münster in Germany, David
and PhD student Nina Visan use a special x-ray device
that allows them to analyze the rocks
and draw conclusions about the prehistoric climate.
-: So the sample we just analyzed came from a rock layer
just below the black shale level.
And what we've seen is very sharp transitions
between humid phases and arid phases.
So climate change was certainly going on
and playing its role in the dynamics
just prior to the anoxic event.
(gentle music)
Narrator: David suspects
that the alternating phases of wet and dry climates
and the black layers of death follow a certain pattern,
a rhythm that can be linked to a cosmic event.
By the 17th century, scientists already realized
that earth doesn't follow
a perfectly stable orbit around the sun.
And Serbian mathematician Milutin Milanković
later calculated how the Earth's astronomical position
relative to the sun changes over time,
including the shape of its orbit.
-: That's what we call eccentricity,
and it's changing from a perfect circle
towards a more elliptical form
every 100,000 and every 400,000 years.
Narrator: This leads to fluctuations
in how the sun's energy gets distributed on the planet,
which in turn triggers climate changes.
In addition, the elliptical orbit
coincided with an evolutionary development.
During the late Devonian vegetation on land flourished,
and some trees grew to heights of more than 100 feet.
Over time, ancient forest became established,
transforming land
that was once barren into a lush landscape.
Our planet gradually emerged as the familiar green
and blue earth we recognize today.
-: So during the Devonian, land plants really evolved widely
and developed deep root systems.
And that is important
because deep roots, they create a lot of area
where weathering and erosion can take place,
and a lot of weathering and erosion,
that means that a lot of nutrients
and detrital material can be transported, for example,
by rivers from the continent towards the ocean,
towards the seas.
(tense music)
Narrator: At the same time,
Earth's orbit was becoming more elliptical,
which led to climate chaos.
The combination triggered a catastrophic chain of events.
-: And that is what we think is going on.
An enhanced hydrological cycle, much stronger monsoons
during those high eccentricity orbits,
bringing those extreme precipitation events
and flushing those nutrients towards the ocean,
they're acting as food for everything
that was alive in the water column.
When that life decomposed, when it was sinking
to the sea floor, it was consuming oxygen.
Thereby the oxygen levels in the oceans
were going down and suffocating life in the oceans.
Narrator: Ironically, it was the evolution
of life on land
that was responsible for the demise of life in the oceans.
The astronomically forced climate change acted as a trigger,
pushing the system past a tipping point and into chaos.
Every animal in the intricate food web felt the impact
as four extinction events took their toll.
Ultimately, between 70
and 80% of all Devonian species vanished.
(gentle music)
Yet life was not to be defeated.
Despite the devastating mass extinctions
during the Devonian, these catastrophic events
paved the way for new species to emerge.
It was the start of an evolutionary pathway
that would one day forge the beginning of our own species.
A pathway Philipe Havlik
is especially interested in exploring.
Speaker: Around 360 million years ago
in the Carboniferous period,
life had really arrived on land.
There were extensive swamp forests
and everything was lush and green.
And in the undergrowth, there was a lot of life,
including huge insects.
One of the most impressive
is this little dragonfly I am holding here.
Meganeura, an animal that had a wingspan of 20 inches,
so it was at least five times the size of today's dragonfly.
They really got big.
Narrator: But while insects became supersized
and amphibians ruled the ancient swamps, a new group
of animals would make the most important evolutionary jump
during this era.
Speaker: In the Carboniferous period,
vertebrates had already conquered
the entire coastal areas of the continent.
However, a very important step was still missing
in order to venture deeper onto land.
(speaking in foreign language)
Narrator: Reptiles would make this leap.
For the first time in the history of life,
creatures would be able to fully live away from water.
But how?
Speaker: The solution was as ingenious as it was simple,
the vertebrates simply took the ocean with them.
They packed it into a small bowl,
and were able to put it down anywhere on the continent.
We still recognize the shell and the small ocean today,
it is the egg, the amniotic egg.
(gentle music)
(object banging)
Narrator: A key property of reptile eggs
is an amniotic membrane.
It's a protective envelope
that surrounds the growing life from external influences.
But another substance inside the egg
is also critical to this evolutionary step.
(speaking in foreign language)
Speaker: What's inside the egg is the ocean,
what we call egg white.
This transparent liquid enables the developing life
to swim around in a small sea.
Not only does this ocean contain the embryo,
which is somewhere in the slippery stuff here,
it also contains huge food storage.
The egg yolk must be enough to feed the little one
until it is big enough to go ashore, survive on its own,
crack the shell, and start its own life.
(speaking in foreign language)
Narrator: This key innovation
represented a major transition in evolution,
and because of it, reptiles were ready to conquer land.
The continents aligned to form a new super continent
known as Pangaea at the end of the Carboniferous period.
(tense music)
This heralded the beginning of the Permian
299 million years ago,
and would be the final chapter in the Paleozoic era.
South Africa,
the Karoo Basin is one of the best places in the world
to search for remnants of the Permian Period.
Paleontologist Professor Roger Smith
is trying to piece together
the evolution of terrestrial ecosystems
by searching for fossils that illustrate changes.
-: This level is at about 253 million years ago,
you would've been standing on a vast flat,
featureless alluvial plane,
but way off in the distance
you would've seen a mountain range.
The Gondwanan mountains.
Narrator: The mountains were formed when the continent
of Gondwana came together.
Huge peaks were pushed up
as the continental plates converged
into a gigantic landmass.
Millions of years later,
when Gondwana began to break up into smaller continents,
it created a huge rift valley.
The rift widened and deepened over time,
filling with sediments washed down
from the surrounding mountains.
What is left today is known as the Karoo Basin.
In the late 1960s, near the town of Fraserburgh,
an incredible fossil site was discovered by accident.
It reveals a rare peak into the ancient past here.
-: This is really an amazing paleo surface.
It's a part of the ancient floodplain
that has been captured and frozen in time.
It's like a paleo Polaroid
of the middle Permian period showing us everything
that was happening on those ancient Karoo floodplains.
Look at these ripples, they are just as fresh
and as sharp as if they were made just the other day.
And there's the other right hand there.
So it would've been a movement like this,
rotate this, rotate this,
rotate this.
(gentle music)
Narrator: The footprints may have been left by,
an herbivore that weighed as much as two tons
and reached 15 feet in length.
This species belongs to the Therapsids, a group of animals
that represents a crucial step in the evolution of mammals.
While not fully erect, Therapsids already had
a more upright posture and other mammal like features.
There was an abundance
of food in this area 260 million years ago
and life thrived in the warm climate.
Vegetation along the river banks
fed the fast herds of grazing herbivores,
which were dominated by moscops,
but there were carnivorous Therapsids too.
Towards the end of the Permian, a new type
of predatory evolved, the gorgonopsians.
They were large beasts with powerful jaws
and distinct saber like teeth.
The masses of herbivores were the perfect prey for them.
-: This is a gorgonopsian.
It's is a carnivore, clearly
because of its sharp saber like tusk or canine.
And these intermission sharp incisors.
Narrator: With predatory carnivores
and a vast array of potential prey,
a dynamic and diverse food chain thrived here
for millions of years.
(animal growling)
But the Karoo Basin also reveals that something changed
around 252 million years ago.
A dramatic shift that can clearly be seen in the rocks.
(gentle music)
-: We're now up at this dramatic color change,
which I could see from a distance.
And you can now see that this blue, gray,
wet floodplain mud rocks here
have rapidly transitioned, rapidly at this point here
into something very red, very semi arid if you like.
And the most likely cause of that drying out
is climate change, rapid climate change,
and the effect that that rapid climate change had
on the environment and then on the animals
and plants is quite dramatic.
We can see that it's abrupt.
It's very fast, and it could be as little as 10,000 years
or up to 100,000 years,
but it's in that timeframe.
Narrator: The change in color
not only marks a change in climate,
it also marks a change in the amount of fossils.
It's simple, below this line, there are abundant fossils
and above it, almost none.
This only mean one thing.
The change in climate led to a mass extinction.
-: The effect of that rapid climate change
on the animals and plants was dramatic.
So dramatic that 95%
of species worldwide went extinct.
The worst mass extinction that has been recorded on earth.
Narrator: The once lush Permian environment
suddenly dried up.
Something drastic happened that caused the extinction
of most species on our planet.
An event that became known as the Great Dying.
(animal growling)
(tense music)
Iceland, the land of fire and ice
offers scientists a firsthand glimpse
of the tremendous forces our planet can unleash.
In the barren landscape of Laki,
geologist Colin Devey hopes to uncover remnants
of a historic volcanic event.
-: The great dying at the end of the Permian
coincided with a huge volcanic eruption.
And to get an idea of what might have happened then,
I've come here to Laki on Iceland, where in 1783,
a massive eruption covered the land here
with lava affecting the local population,
but actually affecting half the globe.
That's Mount Laki.
And I'm gonna go to the top
so I can get an overview of what this looks like.
(gentle music)
Narrator: The event was called a fissure eruption.
It occurs when an elongated linear crack
opens on the earth's surface, which allows magma
to rise and erupt.
-: Look at that, it's amazing.
It's a row of volcanoes.
They disappear into the horizon.
I mean, that's got to be 20, 30 kilometers long.
The whole countrysides just covered in lava.
I presume the lava's come out of these volcanoes.
Narrator: The eruption lasted eight months
and is thought to be one
of the largest volcanic events ever recorded.
-: I'm standing here right on the crack.
This is where the magma came out.
When the eruption was taking place,
you couldn't be anywhere in here
'cause it's all full of magma.
This was a magma channel.
This one obviously produced a lot of magma, a lot of lava
that got out of this crack
and covered the landscape around
what we saw from the top of the volcano.
Narrator: The amount of lava produced
by the Laki fissure volcano in 1783 over the course
of eight months is staggering.
-: It produced 14 cubic kilometers of magma,
which is impossible to imagine.
But if you were to actually spread that out over the whole
of the USA, you'd have about like the icing on a cake,
1.4 millimeters of lava over the whole USA.
It's a lot.
Narrator: But it's nothing
compared to what took place at the end of the Permian.
(fire whirring)
252 million years ago,
a massive volcanic event created one
of the most extensive volcanic landscapes in the world,
known as the Siberian Traps.
-: This is minuscule compared to the Siberian Traps.
This was 14 cubic kilometers.
The Siberian Traps were four million cubic kilometers.
So if you were to spread
the Siberian Traps all over the USA,
you'd not have 1.4 millimeters like you have with Laki.
You'd have 400 meters of lava.
It's a different beast altogether.
(gentle music)
Narrator: Colin is looking closely
at data from the Laki eruption
to better understand the monumental impact
of the ancient eruption.
-: I found it really interesting,
but also very important document
on what happened here at Laki.
Normally, we geologists
get to situations like this after the event.
We can look at the rocks when everything's happened
and try and find out what happened.
But here, the pastor in a church 50 kilometers away
from here, so near enough to be influenced
by the eruption, wrote down what happened.
He describes how the lava advances down the valley
towards his church, towards his congregation,
destroying farms, destroying people's livelihoods
and actually killing those people
'cause they just died of hunger.
They died of starvation.
(fire whirring)
Narrator: In the summer of 1783, the Earth shook
with fury when Mount Laki erupted in Iceland,
a 15 mile long fissure tore open,
spewing molten lava into the air.
Villages were engulfed by the flows.
People ran for their lives
as their surroundings went up in flames
and the sky turned blood red.
-: The pastor also describes how both the animals
and the people at that time, at the same time,
started to develop
what appeared to be strange diseases.
The animals had deformed claws
or very deformed teeth.
The people also had lumps under their skin, also problems
with their mouths and their teeth and were dying.
The animals were dying and the people were dying as well.
And of course, for people at that time,
this was like a visitation from God.
This was something they'd never before.
This was the wrath of God is what they thought.
I really don't think that's the correct explanation.
I think it's to do with how volcanoes work.
Narrator: Colin Devey examines the volcanic rocks
for clues about why both humans
and animals succumb to this strange, mysterious disease.
-: What I can read in the rocks is that they're full
of bubbles, and that's probably the most important thing
'cause it says that these were very gas rich lavas.
Obviously, the gas is no longer in these bubbles now,
but people have been able to analyze
what gases came out of there.
Narrator: Along with carbon dioxide,
traces of two other gases were found.
-: The first one was fluorine, it's a poison.
And the symptoms of fluorine poison are exactly the things
that the pastor wrote about.
That's what caused those deformities of animals and humans.
The second gas was sulfur,
sulfur dioxide.
Now, sulfur dioxide spread around half the globe
and caused in Europe, for example, a year without summer.
Now it does that because sulfur dioxide in the atmosphere
connects to water, makes tiny, tiny droplets
of sulfuric acid, which block the sunlight.
So they reduce the temperature of the earth,
a year without summer, the plants don't grow as well.
Harvests fail, people starve.
Narrator: These gases were also emitted
at the end of the Permian,
but on a completely different scale.
(gentle music)
-: Now imagine that happening over a million years,
over and over again.
We know the Siberian Traps are a great big pile
of huge lava flows.
So maybe every 100 years, 1000 years,
the world was faced with a global catastrophe of cooling,
of no sunlight.
(gentle music)
Narrator: Because of the simultaneous emission of CO2,
a warm greenhouse climate was repeatedly established
before it would give way to the next cold phase.
-: And you've just got adapted to that.
And then the world turns into a balmy paradise.
I mean, how do you make that U-turn?
It's like riding a rollercoaster.
You're on the steep hill
and all of a sudden you're going up the other side
in terms of climate and your environment.
And that's probably, it's probably like a heavyweight boxer.
You know, the sulfur dioxide kind of pummeled you
and then the carbon dioxide took your chin off.
Narrator: This could be one explanation
for the global mass extinction on land.
But the great dying
had an even greater impact on marine life.
So, were the volcanic eruptions truly responsible
for the catastrophe?
Kiel, Germany,
at the GEOMAR Helmholtz Center for Ocean Research,
geochemist, Dr Hana Jurikova
takes a close look at certain marine animals
for clues about what led to the disaster.
-: So what we have here are Brachiopods.
These are really unique animals
that have been around on earth for more than 500 million
of year since the beginning of Cambrian.
And they have changed very little since.
Narrator: By analyzing the Brachiopods,
Hana hopes to find out
how the worst mass extinction in Earth's history unfolded.
-: So these fossils that we have here were deposited
at the bottom of the TEUs Ocean 252 million of years ago.
And what is really important is that some of them deposited
before the Permiandransic mass extinction,
and some of them like this one right after.
Narrator: The fossil remains
of organisms like Brachiopod contain clues
about what happened on earth in the past.
-: By comparing the chemical composition of Brachiopod shells
that lived before the mass extinction
and after the mass extinction, I hope to find out
what caused a great dying.
Narrator: The Brachiopod record a history
of the ocean's acidity in their shells,
and the analysis reveals that it increased significantly
at the end of the Permian, Hana can determine
historic acidification in an experiment
with living brachial pots, by measuring the pH levels.
(water bubbling)
-: Now I know that the ocean pH in the late Permian Ocean
was around eight.
In fact, very similar to what we have in the oceans today.
Right after the mass extinction,
the oceans have become very acidic
and the pH have dropped values of 7.5.
This has happened in a very short time,
only maybe 10,000s of years.
This is just a habit in the geological time.
It's way too fast for any organisms to really adapt to it.
This was way too swift, this was a death sentence.
Narrator: Acid has dire consequences for animals
that build calcium carbonate shells.
-: Many organisms living in the late Permian Ocean
build calcium carbonate shells
just like this coral over here.
When the ocean becomes way too acidic,
they can no longer build their shells or skeletons.
Let's see what happens if we put some acid
on this coral here.
Narrator: Hana wants to show
how acidic waters impact marine life.
The experiment reveals the devastating effects
of acidification on organisms
that rely on calcium carbonate shells,
the coral dissolves.
Countless animals were doomed to die in the acidic oceans
of the late Permian.
(tense music)
Food chains began to collapse
and one species after another died out.
It was the last gasp for prehistoric life on earth
and the deadliest time in our planet's history.
But what caused this massive acidification?
Increased levels of CO2
in the atmosphere would certainly acidify the oceans.
But was the CO2 released
by the Siberian Traps significant enough?
-: From research we know today
that the Siberian Traps released more than 387 billion
of tons CO2 to the atmosphere.
For comparison,
this is more than 40 times the amount of carbon
if we were to fire up all the fossil fuels on earth today.
Narrator: Despite the huge amount of CO2, Hana knows
that it wouldn't have been enough.
Something else must have happened.
-: Although this was unbelievably extreme, I do not think
that the Siberian Traps were enough
to acidify the oceans in such a short time.
The huge amount of CO2 must have come from lava burning
available fossil fuel reserves on Earth
during that time, I think
that the Lake Permian world was just burning.
Narrator: When ancient fuels ignite,
they set off widespread wildfires
that release even more carbon into the atmosphere.
As the oceans acidified, the land burned.
It was hell on earth.
How could any life survive this inferno?
(birds chirping)
In South Africa, paleontologist Roger Smith
is trying to answer this question.
The famous South African fossil hunter James Kitching
left notes about a Gorgonopsian
that he found in a Triassic formation.
The scientific community believes
that this predatory species
did not survive the Permian mass extinction.
So finding one in Triassic soil would be incredible.
(gentle music)
-: Here we are on Fairydale,
and this is that point on the map on James Kitching's map
where he put the pencil mark
and he had marked where the Gorgonopsian had come from.
And that mark is just down over there,
that's the position of it.
So our job now is to see whether we can find another one.
So students, this is a Gorgonopsian.
This was the apex predator.
And your mission today is to find more of this, so let's go.
(gentle music)
Narrator: Dr. Julian Benoit from the University of
has done the research.
His students have scanned the entire area,
marked by James Kitching,
but didn't find anything resembling a Gorgonopsian fossil.
Roger and Julian decide to examine the area themselves.
-: So what's this, Roger?
-: Yes, look at this.
This is a sandstone tube going down
into the floodplain mud drops.
You can see the levels of the floodplain,
and this is definitely cutting down through it.
It used to be an open hole, so it must have been dug
by an animal.
And if that animal was digging holes here,
it must have been a survivor of the mass extinction.
So we need to find this animal.
Narrator: The team hasn't found anything yet,
but they are certain that the fossil remains
of the tunnel building animal
in the Triassic formation will be found nearby.
(gentle music)
-: Look this bone over there, Roger,
here, some bone there.
-: Look at that.
-: Yeah, something exposed right here.
-: Okay.
-: What is that?
-: I think that is a skull.
Yes, this is the right orbit or the right eyeball.
And that's the top of the skull.
And this must then be the snout.
Yeah, it's the mouth coming in here.
You know, I think this is Lystrosaurus
and it could well have been the animal
that dug that burrow.
(upbeat music)
Narrator: Like other Dicynodons, Lystrosaurus
only had two tusk like teeth, which had used for defense
and to tear apart small predators.
Even though it was a herbivore,
it had a horny beak for snipping off parts of plants
and was about the size of a powerfully built pig.
Its shoulders and hip structures
indicate that it moved with a semi crawling gate.
Its front legs were even more robust than the hind ones,
and were used to create burrows
where it sheltered and nested.
Roger decides to bring the fossil
to the University of Cape Town.
Here, Poaleo biologist, Professor Anusuya Chinsamy-Turan
will look at it to see if there are clues
as to how the animal survived the mass extinction.
-: Hey, Anusuya.
-: Roger, wow, what have you got this?
-: Yes, so I've just been out in the field
and collected this for you.
I haven't actually looked underneath it yet.
It's all there, and lower jaw.
-: Wow, that's amazing.
Narrator: While Lystrosaurus lived in the Permian,
this one clearly survived the Great Dying.
By taking thin slices of its bone, Anusuya is able
to learn more about the animal.
-: So when we look at the bones of the Triassic Lystrosaurus,
it clearly indicates
that they had a faster growth rate
than the Permian relatives.
And this is an important adaptive strategy
because it means that they would be able
to grow more quickly, reach adulthood quicker,
and be able to reproduce quickly.
And this is a very classic strategy for survivors
of such a catastrophic event.
Narrator: But Professor Chinsamy-Turan
can determine more about this Lystrosaurus
from the makeup of its head.
-: So one of the very distinctive characteristics
of Lystrosaurus
as compared to any other Dicynodons is the fact
that it's snout turns downward.
So if you look at the skull here,
these would've been the orbits
and the snout actually turns down.
So compared to the other Dicynodons where the skull,
where the snout actually projects forward,
this immediately tells us
that they were eating different food substances.
Narrator: The paleo biologist is certain
that diet played a key role in the Lystrosaurus survival.
-: When we think about the end of the Permian, we know
that it was a very tough time
for both the plants and the animals.
And during the drying out times,
only the really tough vegetation probably would've survived.
So if Lystrosaurus survived,
we think that it probably survived
because it was able to eat the tough vegetation
that may also have survived at the end of the Permian.
Narrator: The ability to dig tunnels
for shelter from harsh climate shifts,
along with the capacity to feed
on the few things that remained were essential for survival.
Lystrosaurus is a prime example of how life
always seems to find a way.
Even in the face of the worst catastrophes.
Throughout the Paleozoic era,
many fascinating animals emerged
and the three major extinction events
wiped out most of them.
But even the great dying,
the worst extinction in Earth's history
couldn't destroy all life.
The emerging Mesozoic era would see the rise of the largest
and most fearsome of all land creatures
that ever roamed our planet.
The dinosaurs, each catastrophe
and its extinction event drove evolution forward
and ultimately led to the life we know today.
(dramatic music)