Millions of years ago,
Earth looked very different.
All the continents were fused into one,
teeming with life
both beautiful and terrifying.
When you think of prehistoric times,
you might picture a T. rex
rampaging through the jungle
with its razor-sharp teeth.
But even before the dinosaurs,
there were other
giant creatures ruling the Earth.
Yeah, welcome to the Permian period.
This epoch started 300 million years ago.
Back then,
our planet had one supercontinent,
Pangaea.
Surrounded by a world ocean
called Panthalassa.
The Permian period began
at the end of an ice age
when temperatures were much cooler than today.
Then, during the Early Permian days,
Earth warmed to a lush environment
with a diversity of plants
and a rapid evolution
of insect and animal life.
Only, as you probably know,
everything is ever-changing
on our blue marble.
Over the next 50 million years,
Earth kept growing hotter and drier.
Eventually,
the most deadly event in the history of our planet
wiped out nearly
everything that ever lived here.
Scientists call this event the Great Dying.
It was the most catastrophic
mass extinction event
the Earth has ever seen.
And the Earth has seen five of them.
But before we get to all this doom and gloom,
let me take you on an epic journey back in time.
Here, in the Permian period,
some of the most incredible species
that roamed our young planet
are about to emerge.
If you could time travel nearly
300 million years into the past,
you'd land smack-dab in the middle of the supercontinent,
Pangaea.
Earth's smaller continents
would have just finished colliding with each other
to form this enormous landmass,
taking up one-third of the planet's surface.
There was likely less
oxygen in the air than there is now.
But you still might be able to breathe.
Oh, and bring a jacket,
because it would likely be chilly,
with some areas averaging
no more than a brisk 4 °C (39 °F).
But don't worry.
Things will soon start heating up.
By the end of the Early Permian,
the ice age was on its way out,
and Pangea was becoming a lush world.
Plants and animals started to thrive.
This was a volcanic world.
Violent eruptions changed the climate,
shaped the landscape
and paved the way for evolution.
When giant swamp forests began drying out,
plant life had to adapt.
And so,
290 million years ago,
Earth saw the very first seed-bearing plants,
called gymnosperms.
These plants carried seeds on their cones,
and they spread across
the supercontinent like wildfire.
The ancient evergreen forest of the Early Permian was
hiding something familiar.
Just like today,
you could find cicadas
and beetles piercing
and sucking on the plants.
And the cutest of them all?
Cockroaches.
Only these weren't the cockroaches you know today.
These prehistoric vermin were gigantic,
the size of birds.
But despite their size,
cockroaches never ruled prehistoric land.
And that's good news, am I right?
No, something much more
fascinating was roaming Pangea.
The now-extinct ancestor
of primitive mammals.
Dimetrodon.
This animal was as fascinating as
it was terrifying.
Encountering a Dimetrodon
would be quite a sight to behold.
This ancient lizard grew to 5 m (16 ft) long
and weighed 225 kg (500 lb).
It had a large sail running down its spine.
Scientists think the sail helped
the reptile regulate its body temperature,
soaking up warmth during the daytime
and dissipating excess heat
during the cooler nights.
It would walk toward you
like a crocodile,
and act like a total menace.
Dimetrodon was an apex predator of its time,
watch out for a mix of sharp
and flat teeth that would slice you open
and grind you up.
In the Middle Permian period,
other mammal-like reptiles
took over the planet.
Therapsids.
They had strong jaws with sharp teeth,
and a somewhat upright stance,
thanks to their legs
being situated underneath their bodies.
Therapsid reptiles
varied from the 5 m (16 ft) long,
likely omnivorous Deuterosaurus
to the 5 times smaller,
meat-eating Lycaenops.
You could meet plenty more Therapsids
if you stuck around for
another 20 million years.
During the Middle Permian period,
Earth kept getting hotter.
The average global temperature on Pangea
grew to about 25 °C (77 °F),
and volcanoes
were spitting greenhouse gases
out into the atmosphere.
Due to the changing climate,
sea levels were shifting.
But marine life found ways to thrive.
If you were to take a dip
in the prehistoric superocean,
you'd be swimming alongside
ancient sharks and bony,
primitive fish.
Many more complex marine species
came and went as the environment
kept changing.
In the Late Permian period,
you could have a friendly encounter
with another reptile,
Lystrosaurus.
These looked like a cross
between a lizard and a pig.
But unlike all the scary prehistoric monsters out there,
Lystrosaurus was a herbivore.
It was just 1 m (3 ft) long
and had powerful front legs for burrowing.
Soon, another cute mammal-like lizard evolved.
The Cynodont.
The Cynodont
looked like a giant rodent.
It was about 1 m (3 ft) long,
had whiskers,
and fed on small
animals and insects.
Now, during this time,
something bad was brewing in the air.
A large amount of volcanic activity
was displacing oxygen
from the atmosphere.
Scientists think there was as little as
10% oxygen in the air.
Compare that to 21% today.
You'd have a hard time breathing
in that environment.
And the temperature kept rising and rising.
With an average temperature
of about 28 °C (84 °F),
this lush prehistoric world
was turning into an oven.
All good things must come to an end,
and sadly,
this period came to
a particularly brutal one.
About 252 million years ago,
about 90% of all plant
and animal life was wiped out.
This tragic moment is called the Great Dying,
and it was Earth's
most devastating mass extinction event.
Scientists still debate what caused
this catastrophic extinction.
Most theories suggest
it was the result of explosive
volcanic activity.
As huge volcanic eruptions
swept the continent,
massive amounts of ash
were unleashed into the atmosphere.
So much ash that
it blocked out most,
if not all,
of the incoming sunlight.
And with no sunlight,
global temperatures dropped suddenly.
Plants couldn't perform
their photosynthetic processes
and died off.
And without plants,
the very basis of their food chain,
animals soon followed.
Things got worse before they got better.
Because of all the carbon dioxide
emitted during the volcanic eruptions,
global temperatures rose again.
And not just to where they were,
but higher.
Much higher.
And this caused the superocean
to lose most of its oxygen.
And unable to breathe,
a majority of the Permian sea animals perished.
Eventually,
over 95% of marine species
and more than 70% of land animals
became extinct.
This mass extinction event
could make you sad enough
to want to bring back
all the animals
that have ever gone away.
Dinosaurs too.
But that's a story for another WHAT IF.