In the dead of night, a lightning storm occurs as thunder rumbles and lightning bolts flashed in the dark sky crackling over the ocean lighting a poignant night show.
At the ocean below, a massive churns and crashes.
For billions of years, much of our world was fiercely inhospitable...
The storm continues as crackling thunder flashes in the dark sky as the waves rolled.
...ravaged by the elements and the forces of nature.
A large wave crests through the howling wind as the ocean heavily stirs from the storm.
But this is the story of what was happening beneath the waves.
Under the surface, it was just as pitch black as the sky.
Here, shielded from the storms, life had taken hold...
The rumbling thunder echoes through the water as lightning flashes gave away a number of strange cone-shaped silhouettes.
...and was about to change our wild planet forever.
The lightning continues flashing through the water as silhouettes as a sinister shape of tentacles as they belonged to creatures that were some of the first top predators.
Lightning flashed more as the creature's eye similar to a modern-era octopus shifts as they were ancient shelled relatives.
Orthocones.
A NETFLIX DOCUMENTARY SERIES
A plant chute sprouts out from the ground in a rousing matter, and soon it grows into a tree.
On the shore of a marsh, a fish-like creature called Strepsodus crawls out of the water and onto dry land as another followed. And the ground turns green and a large amphibian called Anthracosaurus chomps down on the creature.
An Scutosaur stood still as it made a low growling, and a Gorgonopsid called Inostrancevia sniffs the ground following a trail, and a Lystrosaurus stood by a tree as a forest grows more green. And the tree trunk turns green as well as vines grew.
Then a Tyrannosaurus Rex, the greatest predator ever known snarls out as a forest grew, and an Anchiornis stood on a rock trilling.
A massive explosion spreads out on the surface of the Earth, and a pair of Triceratops were trapped in a forest fire as one screeches. And the flames grew in an immense rousing rate on the tree.
A terror bird scans the area for prey like how modern Birds of Prey would, like falcons and eagles.
Plants soon regrew around the tree, and the branches spread out. Then the forest turns white with a layer of snow and a growling Smilodon stalks and the wild howls out as a herd of Woolly Mammoths treks across the frozen land. And an rumbling avalanche races down a mountainside.
And the snow melts away, and the natural rousing scene intensifies as plants grew and a massive fig tree stood.
LIFE ON
OUR WILD PLANET
In a dark void, sunlight pierced over an ominous shape.
CHAPTER 2
THE FIRST FRONTIER
More sunlight shines over the shape giving off a yellow glow.
2.4 BILLION YEARS AGO
The shape was soon revealed to be the young Earth, already covered in ocean yet with a yellow layer.
Far back in the depths of time, Earth looked nothing like the world we know today.
Amongst the young oceans of Earth, a few masses of land stood out through the yellow haze.
Nearly 90% of its surface was water, yet this was no blue planet.
The Tortuga flies just a few miles over the atmosphere as they stared at their young yellow planet and a land below showed traces of orange of a series of volcanic eruptions.
"You guys sure this is Earth?" Aviva asked.
"Yeah, this is a time before Earth had oxygen." Chris said.
"What are all those clouds?" Jimmy inquired.
"These readings are showing that they're methane." Koki explained looking at a screen. "There's not a single trace of oxygen in this atmosphere."
Instead, vast clouds of methane had turned the atmosphere yellow.
Over the land mass, thunder rumbles. And they soon flew down to the young continents as volcanic peaks unleashed explosive blasts of lava.
On land, conditions were even worse.
The lava bubbles and sloshes with repeated blasts as the Wild Kratts watched from inside the Tortuga as they flew over. As they were seeing that Earth was nothing more than reality's Hellfire at this time.
Volcanoes had been erupting for millions of years.
The Wild Kratts as the lava below rumbles and creaks as it flows.
"Man, I'd hate to be down there right now." Jimmy nervously said.
"Yeah, even the air alone is toxic." Martin said. "No oxygen, and more carbon dioxide than at our home time."
Their explosive power, one of the few sounds in this otherwise silent realm.
The Tortuga flew over the harden ominous lavafield with fiery glows through the cracks.
With the world made up of nothing but toxic air and rivers of molten rock...
The lava below continues flowing with patches of harden surface rock over it.
life as we know it was impossible.
The lava continues crackling and hissing through the cool harden surface rock.
"Boy, with all these conditions going on, it's like the Earth was destined to be devoid of life." Aviva said.
"Yeah, it sure looks like at first." Chris said.
"But what made it possible?" Koki asked.
"Well, the first step of life actually occurred two billion years earlier." Martin working a screen and shows a scene Walking with Monsters of another planet crashing into Earth. "Another planet, Theia, smashed into Earth. And the two planets fused, creating a brand new world. Our world."
"Even today, Theia lies right beneath our feet." Chris said. "A smaller chuck of Theia our moon. And slowly, our oceans formed. Until life on Earth to begin."
Later, they flew over the ocean as it was nothing but a vast silent of stillness.
But out in the prehistoric seas, something is stirring.
The ocean gave an intriguing greenish tinge of color under the surface, and the Tortuga rests on the surface in Sea Turtle Mode as they saw something familiar.
"Is that... what I think it is?" Aviva asked.
"Looks like it." Martin said.
Beneath the surface hangs a great swathe of plankton.
Chris scans the bloom and they saw it saw plankton.
"Amazing, I didn't think plankton was around in this time." Koki said astonished.
"Yeah, plankton is some of the earliest plant life on Earth." Chris said.
Microscopic cells like these have just evolved something new, photosynthesis.
"And what does every plant have in common?" Martin questioned.
"Um..." Jimmy pondered trying to think.
"Wait, photosynthesis!" Aviva said.
"Exactly." Chris said.
This means they can harness the sun's energy to grow, a breakthrough so important that plankton will one day give rise to every single plant on Earth.
"And not only that, but plants absorb carbon dioxide and releases oxygen that we breathe in." Koki added.
The big screen then showed tiny particles floating upwards.
But that's not all.
"And I think we're seeing it now." Chris said.
They watched the screen as tiny bubbles of air were seen.
One byproduct of photosynthesis is a gas, the missing ingredient for animal life to exist...
They watched as the rousing wall of tiny bubbles floated upwards to the surface.
...oxygen.
"And in time, the oxygen levels will increase enough for this atmosphere to turn into the blue sky will know today." Chris said.
For nearly two billion years, plankton produced so much oxygen that it transformed our planet.
A stirring moment rose in Earth's history making a breakthrough as the yellow methane atmosphere slowly turns blue with oxygen.
No longer hostile, Earth became a new world, where life could finally run wild.
The wind blows as the Tortuga flies over the young ocean almost recognizable to their home time.
"Ah, now this is more like it." Martin sighed.
Below, a wave rolls and crashes over the ocean.
Today, millions of years later, it's still possible to get a glimpse of what that next wave of life was like.
The waves continue pounding as they churn and roll over the surface of the ocean.
Because in some parts of our shallow seas... life still resembles that more primitive time.
On the seafloor, a number of primitive-looking creatures stood on the mud of the seabed giving a whimsical scene. And a section of coral extends its tentacles out. And the Wild Kratts as many of these creatures went about their daily business.
They may not look like it... but these are animals... very similar to the first complex life forms.
They explored more of the seafloor as many of the early lifeforms went about their daily life, and the Wild Kratts were amazed by their vibrant bright colors.
Most are soft-bodied and rooted to the seafloor.
Close by, a scallop opens up and watches.
All have senses. And some can even see their surroundings.
"You know, a scallop surprisingly has eyes." Chris said.
"Really?" Koki frowned.
"Yeah, they're these tiny blue dots." Martin said. "A scallop has 200 of them."
"How were some of these early creatures eating?" Aviva asked.
"Filter-feeding, of course." Chris said.
Many get their food by filter-feeding, picking out plankton, sometimes in the most curious ways.
They watched as many of the soft-bodied creatures feed on plankton and other tiny bits of food either by strains of feather-like structures, or tentacles reaching out and bringing them to an anemone's mouth as it slurps them up.
But not all animals here are stuck in one place.
Amongst the many soft-bodied creatures, the group soon spotted a sea snail.
Some can move, exploring the seafloor like their pioneering relatives millions of years ago.
On some rocks, they saw urchins slowly crawling about, as well as many starfish.
It may seem like these shallows are a kind of Eden, a safe haven for life.
But this is no paradise.
An ominous moment began as an anemone stood on the seafloor.
Living off modern-day California...
On the seabed, a pink sea slug slowly crawls on the mud.
this is a Rainbow Nudibranch.
"What's that?" Koki said.
"A Rainbow Nudibranch." Martin said.
"It's pretty." Aviva said.
"Yeah, but with a dangerous secret." Martin said.
They watched as the nudibranch approaches the anemone.
And its sluggish nature hides a sinister side... because, like its ancestors, it's here to hunt.
They watched as the Rainbow Nudibranch climbs up the anemone's stalk.
"What's it doing?" Aviva asked.
"Rainbow Nudibranchs are not you're average slug." Martin said. "This is predatory slug."
"You're kidding me." Aviva said shocked.
It's adapted to a life of predation. And its prey of choice, anemones.
"Rainbow Nudibranchs are an anemone's worst nightmare." Martin said.
They watched as the nudibranch made it's approach the anemone's tentacles.
But like the very first predators, the nudibranch has room for improvement...
The Wild Kratts watched as things slowly tense up as the nudibranch touches the anemone, but it then tucks into it's stalk.
...because here, timing...
The Wild Kratts watched as the nudibranch tries to make an attack, but the anemones keep tucking in.
is everything.
They watched the Rainbow Nudibranch on another anemone, but it tucks in before it could attack.
"A near-miss this time." Chris said.
It wasn't long before the nudibranch was trying again.
Luckily for the hunter, its prey is anchored to the seafloor and can't hide forever.
The Wild Kratts watched as the Rainbow Nudibranch begins another approach as it sinisterly crawls up it's stalk. And the anemone soon tucks in with the slug's head much inside.
"Whoa, it's a catch!" Martin declared.
"Don't the tentacles sting?" Koki asked.
"Yeah, but they don't even bother the slug." Chris said.
The anemone's fate? To be eaten from the inside out.
The Wild Kratts watched as they can hear the Rainbow Nudibranch chomping on the anemone as it starts release digestive juices to dissolve.
530 MILLION YEARS AGO
At an ancient coral reef of the Cambrian, anemones stood on sections of rock as their tentacles twitch around.
The arrival of predation was a seismic shift in the ancient seas.
The Wild Kratts watched the many anemones.
"So, this is a point in history where life is beginning to appear in such numbers?" Aviva asked.
"Yeah, we're in a moment of time called the Cambrian Explosion." Chris explained.
"But what caused it?" Koki asked.
"Scientist are still working on that answer." Martin said. "But a small theory suggests that a temporary small increase of oxygen. That gave the predators of this time an advantage."
The hunted had to adapt or risk extinction.
The many anemones and other soft-bodied creatures stood as the Wild Kratts watched.
And one group adapted in a way never seen before.
"Those creatures look kinda familiar." Martin said.
"Polyps of some kind?" Chris wondered.
Despite being single animals, they were able to separate into layers of individuals, that then broke free.
One polyp had several layers as then one broke free as Chris scans the creature with his CreaturePod and soon identifies it.
Jellyfish.
"Whoa, it's a jellyfish." Chris said. "I thought it looked familiar."
"Oh, of course." Martin said. "Jellyfish have been around for some half a billion years. This must be among the very first jellyfish to exist."
"They're living fossils themselves." Koki said. "They've been around some 250 million years before the first dinosaurs appeared."
530 million years ago, they were the very first animals to escape the seafloor and swim.
The Wild Kratts as the graceful-looking young jellyfish swam around with a flapping motion where it's tentacles will form. But then things slowly tense as it sinks down.
But predators were already everywhere.
The young jellyfish sinks as it blindly got too close to an anemone and then it was as it's tentacles brought the helpless jellyfish to it's mouth. A half-billion year dramatic wildlife moment began as more young jellyfish break free from their polyps, but were caught by the anemones being so close to them.
"Yikes, these anemones are making short work." Aviva said.
"Yeah, and with good weaponry of their own." Chris said.
Armed with venomous harpoons, these anemones make quick work of baby jellyfish.
Two other jellyfish break free from their polyp, but sank down and was soon caught by an anemone. One jellyfish struggles to break free from it's polyp, and then a moment occur as an anemone snatches an entire polyp as the Wild Kratts watched.
"Whoa, it's almost like the anemones are top predators." Chris said.
And they are so abundant escape seems impossible.
The Wild Kratts watched as things grew tense as another jellyfish breaks free as the anemones below got ready as the group nervously watched as the jellyfish sinks dangerously close to them, and then it gets stuck on one.
Caught.
Then miraculously, the jellyfish manages to get free and swims off.
But not for long.
The Wild Kratts watched as jellyfish drifts along over the anemones and a tranquil moment rose as it swims off away from them.
Free at last.
"Off it goes." Chris said.
"One small swim for creatures, one giant leap for creature kind." Martin said.
They watched as the young jellyfish swims off.
Thanks to their ability to swim, jellyfish were the first to venture out of the shallows and into the big blue.
The Wild Kratts caught up to the young jellyfish as several others swam around. And over time, a stirring moment occurred as the Wild Kratts eventually found a swarm of adult jellyfish.
"I can't believe how many jellyfish are here." Koki said amazed.
"Yeah, this was still a time before fish evolved." Martin said. "So jellyfish for a time being rule the seas."
Here, with fish yet to evolve, jellyfish were entirely free of predation. In time, others would follow.
The Wild Kratts watched as dozens of jellyfish swam about.
But more than half a billon years ago, the open ocean belonged to them.
The sun shines over the shallow sea of the Late Cambrian.
508 MILLION YEARS AGO
The water laps gently over the seabed giving off a greenish color with black markings belong.
For those still stuck on the seabed, escaping predation required a different approach.
Chris, Martin, and Aviva swam around over the rocky reef looking for any form of life.
"There's gotta be something around here." Chris said.
"Wait, there!" Martin said spotting something.
A pair of antennas were seen feeling around, and then an odd creature slowly starts crawling out of hiding.
This curious creature is a trilobite.
"Whoa, a trilobite." The brothers said astonished.
They watched as the trilobite comes out of hiding as they got a good look at it.
"In this point of time, creatures made several breakthroughs." Martin said. "The trilobite is one of them."
"I see that." Aviva said noticing it's shell.
And its breakthrough adaptation, armor.
They watched as the trilobite crawls off and Chris, Martin, and Aviva followed it.
Trilobites are one of the first in a brand-new dynasty, the arthropods.
"Creatures had come a long way now." Chris said. "In these waters, 80% of creatures have a hard exoskeleton, and they are the arthropods."
"A suit of armor protecting the inside of the creature." Aviva said. "Fascinating."
They watched as the trilobite crawls up a rock and onto a flat section of seabed.
They've evolved an external skeleton, a shield-like shell that protects their soft insides.
"Trilobites are just the start of arthropods." Chris said. "In the future, they'll give rise to insects and spiders."
"And their tough armor is very good at protecting them." Martin said.
They watched as the trilobite crawls off and they followed it as the nearby seabed had a few other trilobites crawling.
And in these waters, they need it.
Close by, a sinister-looking creature rose from behind a rock and swims off. As this creature is proof of evolution being on the accelerator, and predators taking their first bite.
This is Anomalocaris.
The Anomalocaris swims over the seabed patrolling for any food.
A bizarre-looking animal, its name translates as "the abnormal shrimp." And in the tropical shallows 508 million years ago, it's the world's first apex predator.
And it wasn't long before Aviva spots the Anomalocaris.
"Yikes!" Aviva exclaimed tensely. "What is that?"
Chris and Martin soon saw it.
"No way." Chris said stunned. "An Anomalocaris."
"Earth's first super predator." Martin said. "And this guy owes his success in a monumental evolutionary landmark: eyes."
Aviva then noticed it's creepy-yet-interesting eyes.
"Hmm, they are rather odd." Aviva said.
"Yeah, they may look bizarre, but they're not unique." Chris said. "Many predators in the Cambrian seas have also evolved eyes."
"And so have their prey." Martin added.
The consequences have been explosive.
They watched as the trilobite crawls along the rocks as the Anomalocaris spots it as it crawls into a gap in the rocks as it swims off.
Despite the trilobite's armor, it makes sense to keep out of sight.
"Think we've seen something right here." Chris said. "Being able to see, and react to enemies has triggered an arm's race between hunter and hunted."
"This battle continues even in our time." Martin said.
"Guess that's why so many creatures right now are arthropods." Aviva said.
The Anomalocaris hovers not too far away as the trilobite begins to crawl out into the open on the seabed.
But away from the canyons, there's nowhere to hide...
The trilobite crawls off as the Anomalocaris begins it's approach.
because what makes this hunter so special... is its speed.
Chris, Martin, and Aviva watched as the Anomalocaris chases after the trilobite as it crawls alongside the seafloor as fast as it's legs could carry it. The trio watched the dramatic hunt as they were witnessing some of the hunts in history as the trilobite dodges the Anomalocaris making a grab.
Unlike jellyfish, Anomalocaris can swim with both direction and pace.
They watched as the trilobite made sharp turns just dodging the Anomalocaris' grasping arms.
But that isn't always enough...
The chase continues on as the trilobite caught to a wall of rock, but could climb up.
because when cornered, the trilobite's armor comes into its own.
The trilobite then turns and quickly tucks into a ball as the Anomalocaris snatches it in it's arms, and the Wild Kratts watched as the hunter tries open it's catch.
Rolling into a ball, it becomes completely impenetrable.
"Whoa, trilobites can roll into an armored ball." Chris said. "Making it impossible for the Anomalocaris to get around."
"Trilobite shell defense power is hard to beat." Aviva said.
Even for the abnormal shrimp.
The Anomalocaris soon drops the trilobite and turns and swims off, hoping to find an easier catch.
As soon as the trilobite senses the hunter was gone, unrolls itself.
With the coast clear, the trilobite continues on its merry way once more.
The trilobite then crawls off.
"Wow, trilobite armor made them so successful, that trilobites been around for over 300 million years." Martin said.
"That's a long time." Aviva said.
"Yeah, and evolved into 20,000 species we know of." Chris added.
They then followed the trilobite as it crawls along the seafloor.
It's searching for one of the ancient ocean's greatest sights...
A stirring moment occurred as the trilobite crawls on the rocky seabed as Chris, Martin, and Aviva followed it and soon saw a large gathering of trilobites, possibly thousands strong.
...the trilobite mating grounds, where thousands come together to breed.
"Whoa, that's a lot of trilobites." Aviva said amazed.
"Yeah, this must be the breeding season for them." Chris said.
They watched as their trilobite friend crawls to the gathering, wanting a chance to pass down genes to the next generation.
In the story of life, armor has been such a success that today, nearly 80% of all animals, including insects, spiders, and crabs, are related to this ancient arthropod.
Chris, Martin, and Aviva swam over the immense gathering as many trilobites crawled over one another.
But armor couldn't protect them from everything.
The sun shines through the clouds hovering over the ominous shallow seas of a new period of time called the Ordovician.
468 MILLION YEARS AGO
And Chris, Martin, and Aviva swam in the waters over a reef like the many around in their time.
Forty million years later, and a new era of life has begun, with more diversity than ever before.
Among the many corals and sea sponges, they soon spotted a species of Ordovician trilobite.
Here, trilobites are still in their prime, but their armor is even more robust...
They watched as another trilobite appeared.
"These trilobites are still looking tough." Aviva said.
"Yeah, these ones have tougher armor than their Cambrian relatives." Chris said.
because on this reef, danger comes from a new type of predator.
The trilobites crawled off as then they saw several large straight shells coming towards them slowly.
"Uh... what are those?" Aviva asked.
"Shells." Chris said. "Big too, and they look to be some kind of creature."
They watched as the large cone-shaped shells floated by them as one casted an eye similar to modern octopus.
Ancestors of today's octopus and squid, these tentacled giants are part of a dynasty known as the cephalopods.
Chris, Martin, and Aviva peeked by a rock as they saw the shell was attracted to a squid-like creature.
"Whoa, it's an orthocone." Chris said astonished.
"That is the biggest predator that the world has seen up in this time." Martin said.
They watched as the sinister orthocones gently swam by patrolling the seabed for prey.
The largest, with a shell eight meters long, are Cameroceras.
"These Cameroceras are huge, this is the top predator of this time." Martin said. "I mean, these guys are as long as a Killer Whale."
Close by, a trilobite crawls along the seabed.
The trilobite is dwarfed by this towering hunter.
The trilobite crawls off as a Cameroceras looks to have spotted it.
"Uh-oh, looks like he spotted the trilobite." Chris said.
"Now we've got a hunt." Martin said.
"I'd be nervous being chased by that big guy." Aviva said.
But it's not their size that makes them such a threat.
The trilobite crawls to a section of coral to hide and squeaks rushing under as the Cameroceras hovers right by it. And begins to use a new trick that predators have recently evolved using to catch food.
Cameroceras have evolved a new way to catch their prey...
Chris, Martin, and Aviva watched as the orthocone reaches it's tentacles out as they blindly follow the trilobite trying to get away.
even when they can't see it.
The trio swam over to a better look as the ominous tentacles reach further out as the trilobite tries to avoid them. And it soon crawls out of their reach.
"I think the Cameroceras is using a new skill to hunt other than sight." Chris said.
"Touch is just as important as sight when hunting." Martin said.
Because in these waters, they hunt using not just sight, but touch.
The trilobite crawls just out of the tentacles' reach and the Cameroceras moves over for a better angle and it's tentacles reach out as the trilobite crawls off.
All the trilobite can do is try to stay out of reach.
Then the Cameroceras swims off looking to have given up.
Back in it's hiding place, the trilobite remains still for a moment and the ominous atmosphere in the water fades as it crawls back. But then the Cameroceras tentacles shot from nowhere dramatically and snatching the helpless trilobite and pulls it back.
Chris, Martin, and Aviva watched as the hunter brings it's prize towards a horny beak hidden behind the tentacles.
With a scissor-like beak...
The Cameroceras' tentacles opens as a faint cloud of blood drifts by as it crunches through the trilobite. And the trio can heard crunching through the water and chillingly through them.
...able to slice through the toughest armor, Cameroceras dominate these seas.
"Wow, no wonder Cameroceras and other orthocones are the top predators out here." Chris said.
"Yeah, they even prey on the sea scorpions known as eurypterids that share these waters." Martin said.
Although, there is another important new arrival.
Hiding amongst the sponges, a small head with an opened mouth peeks out.
Graced with a look of permanent surprise, this is Arandaspis...
The Arandaspis then swims out of hiding and by Chris, Martin, and Aviva.
an early kind of fish.
"Is that a fish?" Aviva frowned.
The Arandaspis then turns to them.
"Whoa, it's an Arandaspis." Chris gasped. "An early type of fish in this time, around six inches long."
"What's with the surprised look?" Aviva frowned noticing the fish's expression.
"Arandaspis is a kind of jawless fish." Martin said. "But it does look rather surprised like that. I think I'll call him, Surprise."
They watched as Surprise around another Cameroceras feeding as several other Arandaspis swam around it's tentacles hoping for scraps of food.
It hasn't yet evolved a jaw, so can only suck up the scraps.
Chris, Martin, and Aviva watch close as Surprise and the other Arandaspis feed.
"So, how can Arandaspis feed if it doesn't have a moving jaw?" Aviva asked.
"Arandaspis actually uses suction to pull food to it's mouth." Martin explained.
They watched as Surprise and the other Arandaspis feed as they suck up any pieces of food small enough for their mouths.
"Are there jawless fish in our time?" Aviva said.
"Yeah, Hagfish, lampreys, 60 species of jawless fish in our home time." Chris said. "Not as much as compared to the other fish we know."
But what it has evolved will change the course of history.
"Arandaspis may not have a jaw, but it does have something special." Chris said.
"See how fast the Arandaspis are?" Martin said.
They watched as the Cameroceras lightly shoes the fish away.
"They're unique because instead of having armor on the outside, they're tough inside." Chris said and scans Surprise swimming by with his CreaturePod.
And a holographic screen was brought up and shows an internal structure within the fish.
"Is that a... backbone?" Aviva asked.
"Yeah, a primitive backbone, a notocord." Martin said. "It's the start of a spine."
It has a new internal skeleton that makes it both fast and agile.
Surprise and the other Arandaspis continue swimming around the Cameroceras as it then shoes them away with it's tentacles.
A backbone.
"And here's something interesting, fish are the first backbone animals." Chris said. "But the first ever fish is Haikouichthys." He works his CreaturePod and it shows a holographic screen of Haikouichthys from Walking with Monsters. "Only as big as our thumbnails, but an evolutionary giant. Our earliest known ancestor from the Cambrian."
"And the very first vertebrate." Martin said. "Forerunner of all future backboned animals, from the dinosaur, to the elephant, to us."
"Amazing." Aviva said astonished.
And while it may not look like much, fish like Arandaspis will one day give rise to all other vertebrates.
Surprise swims near the Cameroceras and then swims back around.
Amphibians, reptiles, mammals, and birds.
The Cameroceras then swings a tentacle as Surprise darts into some sponges.
But for now, vertebrates are only at the beginning of a very, very long journey.
Hidden by the sponges, Surprise then swims off.
Clouds hovered in the sky over the Ordovician ocean.
445 MILLION YEARS AGO
But a tense ambient atmosphere began to rise.
Twenty million years later, life faced one of its greatest challenges...
Storm clouds begin to gather with rumbling and howling wind.
As the climate suddenly began to cool...
The storm begins to grow as thunder rumbles, and underwater, trouble begins to brew.
...a development that was to have dire consequences.
The FishCam explores the darkens waters of the reef as then it spots a suspenseful moment of what looks like ice forming.
In the Tortuga, the Wild Kratts watched from the big screen seeing what was happening. As feather-like structures of ice forms all over the reef.
"Is that ice?" Jimmy asked.
"Yeah, water temperatures are dropping." Chris said.
They watched as more ice forms.
Little by little, the sea started to freeze.
Ice continues forming as the FishCam was force to retreat before it too will freeze over and shuts down.
For the inhabitants of Earth's once tropical waters, this was a catastrophe.
Many creatures were frozen within the layer of ice as the Wild Kratts watched the mournful moment and pieces of ice floated by.
The shallow seas became a frozen graveyard.
"It's so sad." Koki said.
"Yeah, and this is just the start of it." Chris said.
The world's first mass extinction.
"Over 80% of life soon followed with the cooling temperatures worldwide." Martin said. "Earth's first mass extinction."
"But what caused it?" Aviva said.
"Looking at the temperatures now, it seems that Earth had a sudden drop of carbon dioxide levels." Koki said looking at the readings on her computer.
On the continents, a layer of snow stood as snow flew in the wind.
The fatal freeze was caused by a 60% drop in carbon dioxide.
The wind carries bits of snow as it flew over the surface.
Without this greenhouse gas to warm it, the planet was plunged into an ice age.
The Tortuga flies over the frozen wasteland as Earth enters an ice age.
One that would last for 200,000 years.
"You know, the Ordovician extinction was a real mystery to us." Chris said. "At first, scientists thought it was caused by a gamma ray burst of an exploding star some 6,000 lightyears away."
"Really?" Aviva said.
"Yeah, but it wasn't until 2017 that a new theory suggest some volcanic eruptions." Martin said. "And eventually, the planet cooled in this ice age."
"So, this is an ice age before the one we know?" Jimmy frowned.
"Yeah, Earth surprisingly had many ice ages before." Chris explained. "In fact, almost 200 million years earlier, the Earth was actually a snowball planet."
"He's actually right." Koki said looking through her tablet. "630 million years B.C., and Earth was all white with a 10,000-foot layer of ice. And it wasn't until some volcanic eruptions that brought it to an end."
The Tortuga continues soaring over the ice landscape as a sorrowful atmosphere fills the air.
From space, most of Earth was completely white.
At its peak, almost half the world was covered in ice, causing the demise of 85% of all life, lost from our family tree forever.
In the ocean, there was no sign of life as it had an eerie silence.
With the tropical shallows gone, the few survivors were those who could head to deeper waters.
Chris and Martin swam around in the gloomy waters, seeing no signs of life, but then a familiar face in their home time was seen.
"A Nautilus." Martin gasped. "Some of the oldest animals, and one of the survivors."
"Let's follow it." Chris said.
Animals like the Nautilus, a smaller relative of the giant Cameroceras.
They followed the Nautilus around on the seabed.
It first evolved hundreds of millions of years ago, but still exists today.
"You know, it's amazing to think that this is a miniature relative of Cameroceras." Chris said.
"Really?" Aviva responded from Martin's CreaturePod.
"Yeah, they're both nautiloids." Martin said.
It owes its success to the deep ocean's unchanging nature.
They watched as the Nautilus hovers by the seafloor.
Below 600 meters, the temperature rarely fluctuates, making it a sanctuary of stability.
"Good thing that it's relatively safer down here than in the shallows for our shelled friend." Chris said.
"Yeah, the deeper parts of the ocean were less affected." Martin said. "It's one way how Nautilus are still around today."
When the Ice Age struck, all kinds of animals headed into the abyss. But it's the cephalopods who have thrived.
Chris and Martin watched as the Nautilus swims off and soon vanished into the black abyss.
Later, the Wild Kratts in the Amphi-Sub were in for a majestic light show seeing a deep-sea squid.
Today, many still haunt the deep sea...
Elsewhere in the black void, a deep-sea octopus hovers in the water with bluish transparent glow.
including octopus and squid.
The Wild Kratts then saw another squid giving off a a light blue glow.
"Wow, it's like the deep sea is ruled by the squid and octopus down here." Aviva said astonished.
"Sure is." Chris said. "The deep sea pressure doesn't even bother them."
Their gelatinous bodies are unaffected by the deep's immense pressure.
All around them, they saw other kinds of squid.
And super senses let them find their way in the dark. No longer constrained by shells, they evolved into almost every size and shape.
"It's amazing how many squid are here." Koki said.
"Yeah, cephalopods being free from shells allows squid to be in many forms and size." Chris said.
Further down, a deep-sea reef stood on the seafloor.
But this pitch-black world isn't theirs alone.
The Wild Kratts explore the reef as a pair of small deep-sea squid swam about, and even a small spider crab.
Arthropods, like this spider crab, live here too... feeling their way across the ocean floor.
"Wow, even this spider crab food safety down here." Chris said.
"Hey, even some fish." Martin said.
Close by, they saw a fish similar to the Chimera.
Alongside them, the vertebrates.
"That look likes a Chimera." Chris said.
"A what?" Jimmy frowned not catching it.
"Chimera." Martin said. "It's an ancient relative of sharks."
With little food on offer, down here, they're rare.
"In comparison, cephalopods are more common in the deep than fish are." Chris said.
Only around 10% of all fish today live in the deep.
The Chimera then swims off.
This is not a place they excel...
An eye of a squid peeks out from hiding.
unlike the cephalopods, who have became the deep's near-perfect predators.
"Hey, what's that?" Chris wondered.
They turn towards the hidden squid.
"It's an squid." Aviva said. "But what's it doing?"
"It must be hunting." Martin theorized.
Close by, a shrimp crawls along the sand.
Something this shrimp may soon discover.
The shrimp crawls about leaving little specks of blue as it then swims off. And the squid watches waiting for the right moment as the Wild Kratts watched in silence.
All around it, the water twinkles with bioluminescent plankton.
"Wow." Jimmy said softly. "What are these twinkle specks?"
"It's bioluminescent plankton." Martin said. "The shrimp's movements are what causing them to these small blue glimpses."
Any disturbance, and for the briefest of moments, they light up.
They watched as the shrimp swims around, and that the squid watches it's target come closer.
But the shrimp has company.
The squid watches waiting perfectly still.
A half-concealed squid is watching the show.
The shrimp fiddles around as the squid waits patiently for it to come closer.
Its large eyes allow it to see exceptionally well in the dark.
The Wild Kratts watched silently as the tense moment grows as the squid watches the shrimp fiddles around several inches from it. Stirring the plankton as it did.
Picking out the dots of light, it can follow every move the shrimp makes.
The group watches knowing the squid is waiting for the shrimp come ever closer.
All it needs is the right moment.
Things grew more tense as the shrimp continues fiddling around as the squid starts to make it's move, and then the squid lunges as the shrimps tries to make a break for it. But the squid has caught it as the Wild Kratts saw the whole thing.
The shrimp never saw it coming.
They watched as the squid feeds on it's catch, and soon it begins to conceal itself back in the sand for another waiting game.
With such extraordinary senses, perhaps it's no surprise that squid have mastered this cold, dark world.
The Wild Kratts watched as the squid uses it's tentacles to cover itself with sand.
But for those who lived back in the Ice Age, things were beginning to heat up.
Over a vast field of ice, many grooves covered it's surface with deep rumbling over a solemn atmosphere.
444 MILLIONS YEARS AGO
The Tortuga flies over the ice creaking.
200,000 years after the big freeze, there appeared in the ice a vein of blue.
The Tortuga flies over the majestic-looking field of ice as there were signs of the Ordovician Ice Age beginning to come to an end.
And amongst the many mazes of ice groove on the surface, a river of melted ice water flows.
Water.
"That flowing river on the ice is definitely encouraging." Chris said.
"Yeah, atmosphere is starting to regain carbon dioxide." Koki said reading her tablet.
Carbon dioxide levels had bounced back, causing global temperatures to rise.
The Tortuga hovers over the flowing river as it runs over the surface of the ice like a river through a canyon.
The great melt had begun.
They watched as the flowing water flows down through an opening leading into the ice.
Slow at first, the thaw rapidly gathered pace.
Eventually, they made it to the edge of the glacier as huge sections of ice breaks off and fell into the water.
Before long, glaciers hundreds of meters tall cascaded into the warming seas.
The Wild Kratts watched the rousing scene as massive chunks of ice break off the glacier wall and fell into the ocean.
Within a few millennia, almost half the planet's ice had melted. Within a few more, it had entirely gone.
Eventually, the sun shines over the ancient seas now completely free of ice as the Tortuga flies overhead.
A fin on a creature's undulates as it's mantle had a deep red striped pattern.
For those who had sought refuge in the deep, now was a chance to head back up.
The mysterious-looking creature swims by some coral revealing to be a modern-era Giant Cuttlefish.
Off the coast of modern-day Australia, this is a young Giant Cuttlefish.
The young cuttlefish swims about as Chris and Martin watch him after making a quick return to their home time.
"Wow, cuttlefish are quite something." Martin said.
"And to think his ancestors were giant shelled relatives once." Chris said.
Like his Ice Age ancestors, he's come to the shallows in search of a mate.
Chris and Martin followed the cuttlefish as they soon arrived to an area with several other cuttlefish.
But others have got here first...
"Whoa, that's a lot of cuttlefish." Martin said. "Looks like a breeding gathering."
"Could be a while before our friend gets a chance." Chris said.
A sinister moment fills the water as the cuttlefish watches as two males swam off as one large cuttlefish by with a blue color.
...including an alpha male...
Chris and Martin watched as the big male swims around and saw a female that he's shielding from the other males.
jealously protecting his chosen partner.
"Whoa, that guy is clearly guarding her from his rivals." Martin said.
And he does not intend to share.
The Brothers watched as the male chases off any rival that goes too close, and they saw that their friend isn't budging.
But the smaller male isn't deterred.
"Hmm, our friend sure isn't bothered by the big male." Chris said.
"Yeah, but, not way he'll get close enough without being spotted." Martin said.
Instead, he bides his time and watches as a new male enters the arena...
Chris and Martin watched as the youngster plays a waiting game as the big male confronts another trying his luck. And he displays an intimidating color.
and signals his intention... to challenge the alpha.
Things grew tense as both cuttlefish remained still as the Brothers watched.
With neither backing down, a fight is inevitable...
Then the two males dramatically begin to fish as each try to grab hold of one another with their tentacles. During the fight, the small male sees a chance.
...allowing the young male to make his move.
With the two males distracted, the whimsical youngster begins his approach as the Brothers watched him and the two dramatic males continue their fight as one squirts a cloud of ink.
And Chris and Martin watched as the young male begins to make his move.
As he approaches, he tucks in his tentacles and changes color... to perfectly mimic a female.
The young male begins his approach as the Brothers watched as the female seems to notice him.
"Interesting, he's mimicking a female to slip pass the other males." Chris observed.
"Smart." Martin said.
Using brain, not brawn, he sneaks straight in.
The whimsical male approaches the female as the alpha returns after driving off his rival, and chases off another approaching male. But doesn't take notice of the young male.
The alpha now thinks he's guarding not one female... but two.
"He's in." Chris said.
He's unaware that this sly young interloper is mating with his chosen partner.
The alpha cuttlefish continues guarding his partner as the Brothers see the disguised male having wrapped tentacles around her.
A tranquil moment fills the water the two continue mating as the alpha was still unaware, and soon both cuttlefish parted ways.
"Male animal sneaks are quite clever." Martin said.
Their exceptional intelligence and remarkable senses have helped cephalopods colonize every ocean on Earth.
One cuttlefish swims off as Chris and Martin followed and noticed as it swims under a rock and they saw egg sacs hanging as the next generation is now underway.
Yet, in the shallows, they are rarely the top predators their towering ancestors once were...
Many cuttlefish swam about as the Brothers watched them.
because in the ancient seas, there was to be a changing of the guard.
A suspenseful moment rose as the Wild Kratts in the Amphi-sub followed a large creature with several smaller ones behind it.
374 MILLION YEARS AGO
Seventy million years after the great melt, in a period known as the Devonian, the vertebrate made their move.
The creature glides through the water with strong, steady strokes of it's tail as it was a fish.
But the Kratt Brothers knew this was no ordinary fish as it was one of Earth's great sea monsters of the past. And the reason that the Devonian was the fifth most dangerous sea of all time.
And they watched as the sinister fish swam through the water.
This is Dunkleosteus...
The Wild Kratts watched as the Dunkleosteus swims by, and it's menacing and monstrous appearance would put a Great White Shark to shame.
a descendant of the tiny Arandaspis.
"That... is one scary fish." Jimmy quivered.
"Yeah, Dunkleosteus is really like a real Leviathan." Martin said. "So far, the biggest animal of this time in the history of life on Earth."
But at nine meters long, this fish is no underdog.
The Dunkleosteus continues swimming as the several youngsters followed.
Even its young, barely half its size, are fearsome predators.
"Wow, these young Dunkleosteus are big." Chris said. "Could easily challenge a Great White as well."
And then one juvenile peels off from them as the Wild Kratts followed it and Chris and Martin bravely got in the water despite of a 30-foot long, five ton predatory fish around.
"Where's he going?" Aviva wondered.
"Not sure." Chris said. "Must have seen something."
And this juvenile has spotted something out in the blue.
Up ahead, a group of smaller descendants of the giant Cameroceras swam about, unaware of the danger.
Ammonoids, close relatives of today's deep-sea Nautilus.
The tense atmosphere in the water grows as the young Dunkleosteus begins to stalk the ammonoids like a shark would. And the Wild Kratts watched as the ammonoids try to flee.
"Whoa, one of the ammonoids would make a snack for him." Chris said.
"If he can get pass the shell that is." Martin pointed out.
They watched as the young Dunkleosteus circles the ammonoids.
Being a vertebrate, Dunkleosteus has the pace to catch up with them.
The ammonoids flee as the young sinister Dunkleosteus chases after them.
But the ammonoids boast a trick of their own...
As the young hunter close in, most of the ammonoids escape as one quickly dodges the fish's jaws.
...jet propulsion.
"Whoa, jet propulsion just saved that ammonoid!" Chris exclaimed.
Just what it needs to outmaneuver the young fish.
The dramatic hunt continues as the youngster circles back around towards it's target.
As it starts to circle... the ammonoid does the same...
The Wild Kratts watched as the Dunkleosteus approaches the ammonoid it as starts circling trying to shield it's soft exposed head and tentacles with it's shell.
shielding its body with its shell.
The young Dunkleosteus circles it's prey almost with a growling-like look on it's appearance as it swims by the Wild Kratts. And Chris and Martin sticking close to the Amphi-Sub incase the youngster decides to try a taste in human flesh.
"Whoa, that is scary." Aviva said getting chills.
"And those teeth are brutal." Koki said.
"Actually, those aren't real teeth." Martin objected. "Their extensions of the jaw bone into these blade-like structures acting like scissors."
"And that armor plating on the head can be over two inches thick on an adult." Chris said. "And those jaws and open and snap shut in just 60 milliseconds."
"You're kidding me." Aviva said shocked. "That's faster than we can blink."
"Yeah, and so strong it creates a suction force that pulls the prey into it's mouth." Koki said.
Once upon a time, this defense would have worked. But Dunkleosteus has a weapon its tiny ancestors did not.
The young Dunkleosteus then snaps shut an evolutionary gift it's tiny ancestors lacked.
Jaws. It can bite down and crush its prey.
"Exactly, how strong are it's jaws?" Koki asked.
"Dunkleosteus have incredible jaw power." Chris said. "Able to bite with 11,000 pounds of force."
The young Dunkleosteus continues circling the ammonoid trying to shield itself.
As long as it can find the right angle.
Then things grew more suspenseful the young Dunkleosteus suddenly vanishes in the gloom.
"Uh, where'd it go?" Aviva asked looking around.
"I don't know." Chris said. "I can't see it."
Thinking that the hunter has given up, the ammonoid begins to swims off.
But it's never a good idea to let your guard down.
Suddenly, the young Dunkleosteus charges from below and snatches the ammonoid by it's shell. And the hunter shakes it trying to break through the protective shell.
Luckily for the ammonoid, the juvenile's jaws are not yet strong enough to break its shell.
The Wild Kratts watched as the Dunkleosteus' jaw blade tips clacked on the ammonoid's shell as it shook it trying to break through.
"It's jaws must not be strong enough to punch through yet." Chris said.
But the adult's are.
Suddenly an adult Dunkleosteus emerges from the blue as the youngster swims as Chris and Martin knew that adults are easily cannibals. And the adult Dunkleosteus snatches the ammonoid, and with three massive chomps, it crushes the shell with it's jaw structures and swallows it's prize.
And the Dunkleosteus swims right next to the Amphi-Sub as the Wild Kratts got a sinister look of it's jaws and armored head. And the sight alone gave them shivers down their spines as even a Great White Shark and Killer Whale would be wary of this prehistoric sea monster.
"That... is scary." Jimmy nervously said.
"Yeah, and Dunkleostus was the Devonian's apex predator for 20 million years." Chris said.
"And they and other Placoderm fish were around for 50 million years before disappearing." Martin said.
The pairing of backbones with jaws was to prove a winning combination.
The Wild Kratts watched as the Dunkleosteus glides off into the blue.
So perfect that, from this moment on, the vertebrates would never look back.
"You know, jaws actually evolved from gills." Chris said.
"Get outta here." Koki said unconvinced.
"No, it's true." Martin said. "Some jawless fish branched off and eventually formed muscles around the mouth where the first gill bars are." His CreaturePod showed an early fish with a gill structure. "That helped fish breathe through the gills and filter out food. But eventually, others started to use them for eating and later on developed teeth. Given rise to those that now catch food, and to the first sharks."
"Fascinating." Aviva said.
"Off goes, Chomp." Martin said.
"Chomp?" Koki frowned.
"The young Dunkleosteus." Martin said.
They watched in a rousing moment as Chomp catches up with the adult, most likely it's parent.
In modern-times, a shoal of fish swam around as bigger fish tried to snatch some.
Today, there are more than 30,000 species of fish.
The shoal swims around as a group of Trevally swam by a reef, and many others swam about as well, some with bright colors.
Forty times as many as the cephalopods.
Many fish swam around as an octopus tucked under a crevice in the rocks watched. A clownfish lies secured in it's anemone home, and a sea dragon gently swims by.
While their variety is remarkable...
A fish hovers by some coral, and an frogfish sits and waits for prey to come to it while a Moray Eel looms by it's hole.
each still has that perfect pairing.
A school of fish swam around a shoal of Mobula Rays swooped in catching any mouthful they can.
Backbones give them speed and power...
The shoal swiftly swam over the reef.
no matter the size.
In Californian waters of a kelp forest, a Sheephead Wrasse snatches an urchin.
While jaws give them bite.
Other Sheephead Wrasse snatched up urchins to help keep their numbers under control to prevent them from destroying the kelp forest.
But these is more to jaws than that.
Tucked in a burrow, a jawfish father keeps his clutch of eggs in his mouth.
Some fish use them to protect their eggs.
The eggs rest safely in their father's mouth in a serene moment as jawfish make one of nature's most devoted fathers.
In Africa's Lake Tanganyika, a male Callipterus Cichlid grabs an old snail shell.
Others to attract a mate.
The Callipterus Cichlid swims off with the shell and adds it to his pile of other shells.
In the ocean, the head of a fringehead fish pokes of hiding in a shell.
Then there's the Sarcastic Fringehead.
The fringehead begins to swim out of hiding as Chris, Martin, and Aviva watch as it approaches a small crab trying to snatch it.
He doesn't just use his to catch crabs.
"So, why is he called a Sarcastic Fringehead?" Aviva asked.
"See those floppy fronds that fall on the fish's eyes?" Chris inquired.
"Yeah." Aviva replied.
"His name refers to those." Martin said.
"And the term "sarcastic" is thought either describe the animal's sardonic closed-mouth expression." Chris added. "Or to derive from the Greek word sarkázein, which means "to tear flesh"."
"And here is one crazy thing about this particular species of fish." Martin said. "And how his jaws work."
He also uses them for one of the most intimidating displays in nature...
The fringehead then opens his jaws displaying a wide gape looking like a sea monster from a horror movie.
"Whoa!" Aviva exclaimed. "That's creepy."
to rid his patch of rivals.
"Fringeheads have that kind of display to intimidate rivals away." Martin said.
They watched as the fringehead then confronts another male as they display towards each trying to discourage one another.
For these fish, size is everything.
They watched as the confrontation continues as the atmosphere intensifies, and eventually the first fringehead manages to drive off the second fish as it swims off.
"Wow, fringeheads with big mouths truly mean business." Chris said.
Big jaws have let this fringehead rule his strip of seafloor, but they've also allowed a more infamous group of fish to rule the waves.
A fin of passing fish swims by as the fringehead looks out and noticed a familiar shape his kind has feared for countless generation. And Chris, Martin, and Aviva noticed the ominous shape heading off as well.
On the surface, a classic fin sails over the water.
They first appeared more than 400 million years ago and have been feared ever since.
The atmosphere around the water intensifies as the fish glides through the water.
They are the sharks.
A Copper Shark glides through the water as Chris, Martin, and Aviva watched it as a second Copper Shark swam alongside it. And they knew well that sharks are the ultimate ocean survivors.
To the winning combination of backbone and jaws, they've added senses so sharp they can detect prey from hundreds of meters away.
"Sharks are truly incredible." Chris said. "They've been around almost 200 million years before the first dinosaurs arrived."
"Talk about old." Aviva said.
"Yeah, and during that time, they came in all sizes and forms." Martin said. "And their cartilage skeletons truly helped out as well."
With many also boasting size and strength, they are as close to perfection as an ocean predator can get.
They watched as the Copper Shark attacks a shoal of fish as the tense wildlife moment continues.
In the sea off Western Australia, these fish are balled together for protection.
The large school of fish swim off as a Copper Shark follows them.
But the sharks hold back... because they have a special plan of attack.
The Copper Shark approaches the shoal as Chris, Martin, and Aviva watched as the fish looked to be getting corralled. And other Copper Sharks join in.
Appearing to work as a team, some of the sharks rise from below to trap the fish against the surface.
The trio watched as one shark swims through the shoal.
Others come in from the side, corralling the shoal away from the open ocean and into the shallows.
Chris, Martin, and Aviva followed the Copper Sharks as they corral the shoal into the shallow water. And from the air, many sharks have gathered for the hunt.
Now numbering in their hundreds, the sharks for time... as their prey get ever more tired.
"The fish in the shoal must be getting exhausted at this point." Chris said. "The sharks should attack any moment now."
In the air, many sharks were seen as the sinister scene in the water continues as they coral the shoal into a tight group to prevent escape.
It's a hunting technique that has been honed over millions of years.
One shark swims amongst the tight shoal sensing the moment of attack is upon them.
But the carnage starts in the blink of an eye.
The Copper Shark then makes a sharp turn as the dramatic hunt begins as the fish try to flee as the other sharks join in for the frenzy. Each snatching any mouthfuls of fish they can catch as several seagulls in the air join in, careful not to get in the shark's way. The hunt continues as many fish leap out trying to escape the jaws of death as the trio watched as the shoal slowly grew smaller after each mouthful.
And eventually the hunt was over as quickly as it began.
And one Copper Shark swims off.
Virtually changed since the great melt, sharks are one of the most successful dynasties in history.
"You know, seeing that hunt makes me realize how successful they were." Aviva said.
"Yeah, they even survived four of the five mass extinctions that Earth suffered in." Chris said.
But they owe their rise to the fall of their greatest rivals.
The Copper shark then swims off.
Clouds hover the Devonian ocean as the sun shines overhead.
360 MILLION YEARS AGO
But a mysterious atmosphere fills the air and the water below, a Dunkleosteus glides through the water.
But in the ancient seas, and Dunkleosteus had reigned for 20 million years.
The sinister Dunkleosteus swam through the water completely unchallenged as it swims by the Wild Kratts in the Amphi-Sub.
So vicious a predator that not even early sharks could compete.
"Wow, Dunkleosteus truly is unstoppable out here." Martin said.
"Yeah, and the sharks of this time are only prey for this monster fish." Chris said.
They watched as the Dunkleosteus swam off into the blue.
But Dunkleosteus was to suffer from a devastating quirk of fate...
"So... how exactly did Dunkleosteus die out, anyway?" Koki asked.
"Yeah, how?" Jimmy asked.
"Well, Dunkleosteus never had rivals except from another Dunkleosteus." Chris said. "But the answer is actually around us."
The Amphi-Sub then scans a section of water, and windshield showed a holographic image of plankton floating around.
...caused by plankton.
"Plankton?" Aviva frowned.
"Yeah." Martin said.
"But how can plankton be the end of Dunkleosteus?" Koki asked not understanding it. "Plankton looks harmless enough."
"Plankton is harmless normally, but not if it reaches a certain level." Chris said.
Billions of years earlier, plankton had been the catalyst for animal life.
The plankton floats around in the microworld of the ocean.
But now, they would almost bring it to an end.
The Tortuga eventually hovers over a section of ocean where it was green.
"Whoa, the ocean is all green." Jimmy said.
"Yeah, that's all plankton down here." Martin said. "There's been an increase in plankton numbers due to a surge in ocean nutrients."
A sudden surge in ocean nutrients caused the population of plankton to increase...
The Wild Kratts looked around seeing massive swathes of plankton staining the ocean green and even a greenish-yellow in some areas.
on an unprecedented scale.
The Wild Kratts looked around at the ominous sight of green ocean by plankton mass.
"Uh, this is bad, right?" Aviva asked.
"Plankton in this much mass, it is." Chris said.
Under the surface, even the water was all green.
As it spread through the sunlit shallows, this thick soup began to rot...
Rotten pieces of plankton sink down to the seabed.
causing the ocean's oxygen to plummet.
"Not only did the plankton create this mass thick soup, did the rotten pieces caused a drop in the ocean's oxygen levels." Martin said. "Bad news for any animal unfortunate enough to get caught in it."
The Tortuga lands on the water and submerges as they saw amongst the green water, an ammonoid swims through the rotten planktonic soup.
Without this critical ingredient for life, animals started to suffocate.
The mournful scene continues the Wild Kratts saw that the rotten plankton soup mass has already claimed it's victims after seeing several dead ammonoids.
Even a Dunkleosteus on it's back lies where it has sunken after meeting a suffocating end. The mightiest predator the world has ever seen in this time, defeated by the most important ocean factor.
For those unable to escape the sludge, there was only one possible outcome.
Extinction.
The Wild Kratts felt sorry for the massive predator that seem truly invincible.
Dunkleosteus was one of the many to be lost from our wild planet.
Leaving the ocean, the Tortuga flies over the shoreline where many fish corpses lie rotten away after becoming victims of the green plankton sludge themselves as the mournful scene continues. And no land animals exist just yet to scavenge and feast on this bounty.
Across the world, coastlines became littered with the dead.
The Wild Kratts saw countless fish lie dead on the beach.
Only the lucky few, including early sharks, were able to survive.
"Sure is so sad of seeing this." Aviva said remorsefully.
"Yeah, many ocean creatures suffered in this surge." Chris said. "This mass die-off caused the end of the Devonian."
From space, almost most of the ocean was green with few sections of blue free from the plankton plague.
In all, 80% of marine life was wiped out in this, the world's second mass extinction.
On the Earth's surface, the sun shines over a desert.
And yet this is only half the story.
Many dunes of sand stood over the desert, spreading as far as many miles across.
The nutrients that caused the plankton explosion didn't start out in the sea.
An uplifting moment fills the air as far inland, many stretches of rivers flowed.
They were carried there from the land...
Among the many rivers, water pours down from a waterfall.
...released by plants during one of the most amazing events of all time...
Above the waterfall, countless trees stood in one of the Earth's first ever forests. And the Tortuga flies over them.
...the greening of planet Earth.
"So this is the first forests?" Koki said astonished.
"Among the first, yeah." Chris said.
The Tortuga flies over the majestic forest.
What was once a volcanic wasteland was now overflowing with life.
The Tortuga flies over the forest as creatures were heard chirping below.
And this new world offered opportunity.
Layers of mist rest over the treetops as the Tortuga continues flying over them.
For where plants had paved the way, animals would follow.
"And the arrival of forests, trees started releasing more oxygen into the air." Martin said. "That opened the door for the first animals to venture onto land."
The chirping continues filling the forest's chorus.
And before long, the race to dominate the land would begin.
In the far future, a creature called a Gorgonopsid made a low growling as it patrols the dramatic landscape of the Permian.
And it growls and roars baring it's sharp canine teeth. A new improved weapon it evolved that it's descendants it one day use.
Author's Note:
My apologizes it took longer than expected, been a little busy with other things.
And saw the entire series of Life on Our Planet. And it was truly amazing, however, the only dislike was on episode 3 showing my less favorite: spiders. I seriously don't like spiders, especially close-up shots of their eyes. Jumping and Wolf Spiders in particular. Can't help but feel that scene may show me down a little when working on the next chapter.
Anyway, I did love that they showed Alamosaurus in the series.
The Dunkleosteus was quite something as well. Despite new studies showed it's now half that size now. How can that be?
And the young Dunkleosteus swimming alongside the adult, that seems very unlikely in real life. I think Dunkleosteus are pretty much on their own the second they are born.
But I did realized that the young being mention to be half the size of the adult, means they're likely 13 or 15 feet long, around the size of their new size estimate. How was it realized to be that size, anyway?
And curious question: has there been a fossil impression of a Dunkleosteus tail found yet? I'm just wondering if it truly had that same tailfin shape like most fish have today rather than early design like how the Chased by Sea Monsters Dunkleosteus had.
And, you know, Morgan Freeman sure is becoming quite good with narration. Though I do wish it was Attenborough who narrated the series.