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Documentary, Ancient Earth Season 1 - Permian Triassic Cretaceous
#PermianTriassic #AncientEarth #Cretaceous #Prehistoric ##Evolutionary
#PermianTriassic #AncientEarth #Cretaceous #Prehistoric ##Evolutionary
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AnimalsTranscript
00:01This is the story of the largest mass murder in world history.
00:10In the known universe for all we know.
00:14And these unassuming rocks are the most powerful pieces of forensic evidence a planet has ever seen.
00:23They convict, beyond a reasonable doubt, the killer of almost all life on Earth.
00:31Ninety-six percent of everything in the oceans.
00:37Seventy percent or more of everything on land.
00:41At a time full of bizarre and wondrous creatures.
00:46Sometimes a whole bunch of things go away all at once.
00:50That's what we call a mass extinction.
00:53And mass extinctions beg questions.
00:55It's called the Permian extinction, or the Great Dying.
01:00And it's by far the worst of the five major mass extinctions in our fossil record.
01:06Everything seems to die out in a very, very short period of time.
01:09And only recently have scientists found the smoking gun.
01:15A really smoky smoking gun that brought it all crashing down.
01:21The story of life on Earth is an epic saga of evolution and extinction.
01:36Turn back the clock several hundred million years, and we find many bizarre life forms thriving beneath vast ancient seas.
01:48But massive shifts in the Earth's crust, and a series of mysterious catastrophes, soon produce the first two of five major mass extinction events that wipe out more than 75% of all life on our planet.
02:04By the start of the Permian period, another massive change is taking shape.
02:15One that will finally allow life to thrive on land.
02:21In the Permian, the continents have all come together to form this gigantic supercontinent called Pangaea.
02:28So you can basically walk from Cape Town to Beijing to Boston, you know.
02:37Initially, most of the magic in the Permian isn't on land.
02:42Pangaea is surrounded by a single super ocean.
02:50Panthalassa.
02:51And though much of its depths remain a mystery, where the continental shelf creates shallows, fossils reveal a world where life runs riot.
03:02Reefs have finally recovered from the previous mass extinction that ended in the Devonian period.
03:09Coral and sponges are flourishing, as are Nautilus-type creatures called Ammonites.
03:16You would have just loved scuba diving in the Permian.
03:20There's corals, there's cephalopods.
03:22You still have trollobites that evolved back 540 million years ago.
03:30The lobed-finned fish that gave rise to us landlubbers have disappeared.
03:36From the seas, at least.
03:37They've walked onto land and into an amphibious lifestyle, like Tiktaalik.
03:49But new bony fish, rays and sharks, thrive.
03:53One almost unbelievable creature, the helicobrian, swims in search of prey.
04:04A shark with a circular saw of a mouth.
04:07It basically had this whirl of teeth mounted in its lower jaw, and it would slam into its upper jaw, and it was a slicing mechanism.
04:17It swam around in the sea and just chopped stuff in half, and then came back and ate it.
04:21One of the latest saw blade fossils found, called a tooth whorl, points to a creature that grew to 40 feet.
04:32It may be devoid of sea monsters, but on land, the cool, dry continent of Pangaea breeds life of its own.
04:51All the continents are together, right?
04:54And so what happens is that in the coastal part of the world, you have these swamps.
05:00And in the middle of Pangaea, because it's so far from the sea, it becomes quite dry.
05:08And so reptiles are favored because they seal in their body fluids, they lay their eggs on land, they bury them.
05:18It'll be a hundred million years before the first true mammals appear.
05:22But their surprisingly reptilian-like ancestors, like these pellicasaurus, with their flamboyant sails, have already begun to strut their stuff.
05:33What you've got are animals that look like a big iguana with a great big sail on its back.
05:45It's likely that these sails were for either impressing the other sex, or for moderating heat.
05:56Placid plant eaters, like Dicinodonts, rip through vegetation across Pangaea with bony beets.
06:08They come in dozens of species, from the size of rats to rhinos.
06:17But no doubt, many are on the meal plan for some of the day's largest predators.
06:30Like the world's first saber-toothed carnivore, the voracious Gorgonopsid, and Titanophonius, or Titanic murderer.
06:41At 15 feet long, one of the largest predators of its day.
06:50And so you had a food chain there, of plants, herbivores, predators, all living in the Permian, in relatively warm conditions on the globe at that time.
07:03Like their prey, these monsters were incredibly successful.
07:07Until they weren't.
07:19250 million years ago is the major, major mass extinction of all time.
07:24When you lose about 96% of the species of life on land, in the sea, animals, plants, forests, everything seems to die out.
07:32Again, in a very, very short period of time.
07:37The evidence for the Great Dying is rock solid.
07:41The fossil-rich layers of the Permian, chalk full of ammonites, snails and clams, end abruptly some 250 million years ago.
07:50Above, for millions of years, lie black, blank shale.
07:56A sign of empty, dead oceans.
08:00The cause of the dying has been a bit more controversial.
08:05Some people think that there was an impact of an asteroid or comet at that time.
08:16Some people think that it was volcanic eruptions that caused the climate to change.
08:22Other people think that it might be more mundane, things like sea level changing.
08:26Then, beginning in around 2008, things started to come into clearer focus.
08:34In a place called the Siberian Traps in modern-day Russia.
08:39That's where our infamous rocks come in.
08:44The result of perhaps the most devastating volcanic event ever.
08:49Where over 700,000 cubic miles of lava flowed from the center of the Earth.
08:57Enough to fill the Grand Canyon.
09:01Seven times.
09:04Tremendous amounts of lava coming out of fissures and cracks in the Earth.
09:10And spreading across a very wide area.
09:13Forming this huge plateau, thousands of feet thick.
09:15One lava flow on top of another.
09:18It may be in as short as 100,000 years or even less than that.
09:24Scientists already knew that these massive eruptions occurred around the time of the Great Dying.
09:30But have only recently pinpointed the dates.
09:34It's interesting.
09:36We know the time of the extinction event very, very accurately.
09:39Because there are volcanic ash layers right at the time of the mass extinction.
09:46Those have been dated very, very carefully.
09:49252 million years ago.
09:52And the date of the Siberian results turns out to be 252 million years.
09:57So, could it just be a coincidence that the biggest mass extinction happened at the same time as this huge outpouring of lava, which doesn't happen for tens of millions of years between events?
10:11I think it's too good to just be a coincidence.
10:14It's more like a smoking gun.
10:18Smoking gun.
10:20That one's easy.
10:21There's no evidence for any other trigger for this mass extinction.
10:25The dates line up.
10:27The volume of volcanic rock lines up with something.
10:31If you have that much volcanic rock coming out, there's going to be a problem.
10:34And the rocks themselves also hold clues as to just how bad it was.
10:43Trapped inside are bubbles of gas from the eruption.
10:47Traces of the trillions of tons of carbon dioxide that got belched out of the molten heart of the earth and into the atmosphere.
10:54If you put more carbon dioxide into the atmosphere, it's a greenhouse gas that warms the atmosphere, but it also causes the seeds to become more acidic.
11:06And that is going to make it very difficult for a creature that depends on calcite to make their shell because that will dissolve in low pH systems.
11:14It was a complete horror show.
11:1990% of all life wiped out.
11:25Nearly a factory reset for the earth.
11:32The world was not a pleasant place at that time.
11:36No.
11:39So, there were a lot of losers in the Permian Jurassic extinction.
11:42I mean, basically, a lot of our friends that have been with us for the entire Paleozoic, things like tralobites, the last tralobite goes.
11:52Lots of these earlier marine organisms that have survived through much of the earlier extinctions, can't make it through.
12:00But as always, life finds a way.
12:04Lots of major groups still survived.
12:06Cephalopods, reptiles, certain fishes, and trees all managed to survive the Great Dying.
12:15And the world they inherit is a very different place.
12:19It was a bad time, but thank goodness for the Permian extinction, because otherwise we wouldn't be here.
12:28I don't think we'd be able to compete with some of the things that were happily living there beforehand.
12:32In the next era, the Triassic, reptiles will expand their dominion to rule the air, sea, and land, along with the first true mammals.
12:44And for that, we should all be very grateful.
12:52I'm very grateful.
12:53I'm very grateful.
13:22I'm very grateful.
13:23I'm very grateful.
13:29When we think dinosaurs, we tend to think of the animals of the Cretaceous and Jurassic.
13:37Movie star dinos, like T-Rex.
13:42Velociraptor.
13:47Stegosaurus.
13:49But these creatures wouldn't have had a single cameo were it not for their forebears in the Triassic.
14:01When the first dinosaurs, plesiosaurs and pterosaurs,
14:08really cool ones, like this eudimorphodon, first appeared on planet Earth.
14:18The remarkable reptiles that took over the world during the Triassic,
14:26hung on by the skin of their terrifying teeth near its end,
14:31to give us the glorious giants to come.
14:34It begins 250 million years ago, in the aftermath of the Permian extinction,
14:53when violent volcanism nearly wiped out all life from the face of our planet.
14:58The Permian-Triassic extinction was the mother of all extinction.
15:05Life was back down to some of the simplest forms,
15:09and it took millions of years for it to recover.
15:11Until very recently, we thought the devastation was so complete,
15:16that little stirred on the charred Earth for the first 10 million years of the Triassic.
15:28But in 1998, scientists found this amazing creature.
15:32T. serophagus, in the fossil layers just above the Permian extinction.
15:42The size of a school bus, this dolphin-shaped reptile took to the seas in as little as 8 million years after the Permian disaster.
15:51As soon as the oceans began to take up oxygen again.
16:00It's a sign of things to come.
16:03The Triassic's time of tremendous innovation because the decks have been cleared so severely in the Permian-Triassic.
16:10So you basically wipe the slate not clean, but pretty clean.
16:15All the niches are open, all the ways of living, of making a living are there, and so it's like free lunch.
16:27If we spin the Earth back 247 million years to 5 million years after the Permian disaster,
16:35the subsiding smoke reveals a single supercontinent called Pangea,
16:44surrounded by a single mega-ocean called Penthalassa.
16:50T. serophagus hunts squid and bony fish here.
16:55As modern reef-forming corals and communities finally start flourishing and repopulating the seas.
17:07Ammonites, nearly wiped out, begin to proliferate and diversify.
17:14Sea urchins and sea stars appear for the first time.
17:18We had Pangea, and everything was great on Pangea for a long time.
17:28We had coral reefs that seemed to be doing okay.
17:32And just sort of a nice, hot, humid, high oxygen environment.
17:40On land, lumbering heavy armored herbivores thrive in lush conifer forests.
17:46My favorite terrestrial organisms in the Triassic are the animals called Aedosaurs.
17:54They look like a big, crocodile-sized lizard, but they have armored plates that look like football pads that are down the length of them.
18:03But their mouths are tiny and their teeth are tiny, so you have this animal that's armored itself up so you can walk around and nibble on vegetation.
18:11So they're all dressed up in the place they go.
18:12Bat armor comes in handy in the Triassic.
18:17When fending off speedy, agile predators like Coelophysis, one of the earliest known dinosaurs,
18:24seems to hunt in wolf-like packs, picking off young.
18:29See, the physis is cool. It's first discovered in Ghost Ranch in New Mexico, and they didn't find just one. They found a bone bed of dozens of them.
18:40The first pterosaurs, like Eudimorphodon, first take to the air in the Triassic.
18:47Though how they manage it, no one knows.
18:52Whether by air, land or sea, by the end of the Triassic, around 200 million years ago, life has radiated and repopulated the entire Earth.
18:59You had all these places to colonize, and then there was room to kind of make your place and put your roots down, literally or figuratively, and evolve and diversify. And they did.
19:13By the end of the Triassic, you've evolved the first dinosaurs, you've evolved the first mammals, and you start to see the hint of the modern world.
19:34But all good things must come to an end. And what happened then was the breakup of Pangaea.
19:44Toward the end of the Triassic, the same forces that crashed all the continents together are now conspiring to tear them apart.
19:56A rip in the fabric of our Earth pulls North America from Africa and Europe.
20:09So we find lava flows in New Jersey. We also find lava flows on the other side in Morocco.
20:16So Morocco and New Jersey were right next to each other, and that was one of the centers of these eruptions.
20:24Coming between them, a new body of water, the Atlantic Ocean.
20:31What I love is the fact that one day there was no Atlantic Ocean, and then some few years later, it was a narrow canal.
20:38And then you could jump across it, and then you couldn't jump across it.
20:43Then in a matter of just 40,000 years, the blink of an eye in geologic time, all hell breaks loose.
20:53Earth entered yet another period of extreme volcanism, spewing out its guts in waves of lava and gases.
21:06The larger creatures of the Triassic can run, swim, and fly faster than the violently widening New Sea.
21:16But they can't hide.
21:19The sudden release of carbon dioxide, sulfur, and methane creates runaway global warming, acid rain, and acidic oceans.
21:33Critical plants and animals at the bottom of the food chain die off.
21:38And the system collapses.
21:4175% of all species fade into the fossil record, the world's fourth mass extinction.
21:53So they're hit in the Permian, they're beginning to recover, they're recovering in the Triassic, and bam, they're hit again.
22:01But like all the previous mass extinctions, not everything is hit.
22:08The dinosaurs survived, the mammals survived, the turtles survived, the parasaur survived.
22:14So on land you have these lineages now that are often racing.
22:19Just under the scorched earth, some tiny shrew-like creatures, with their live-born young, hunker down.
22:30These first mammals, like Megazostradon, measured in ounces and inches, seem unlikely to inherit the earth.
22:40First, they'll have to survive yet another age under the feet of giant reptiles.
22:48Because the ones who managed to survive through the Triassic extinction are about to give rise to the most terrifying ancient creatures of all.
23:10It's the most famous line of mud in the world.
23:33Found in some 300 places all over the planet.
23:38From Gubbio, here in Italy, where it was discovered.
23:43To the Hell Creek formation in North Dakota.
23:47To the deserts of Western China.
23:51Like the many other geological layers deposited through the ages.
23:56It is not just a sediment line.
23:59It's a timeline.
24:03Only this one was laid down some 66 million years ago.
24:09And that makes it particularly special.
24:15It was like somebody dropped a newspaper in a fossil site 66 million years ago.
24:19And all you have to do is read the date off the newspaper.
24:22We can look below it and see what life was like before.
24:26And look above it and see what life was like after.
24:29Below, ancient sediments are full of dinosaur fossils.
24:34Tyrannosaurus to Triceratops.
24:37And everything in between.
24:39Above, in more recent layers, not a single dinosaur has been found.
24:45Something happened, very abrupt, which wiped out about 75% of the forms of life on the planet.
24:53And every dinosaur.
24:55It's the fifth mass extinction to strike our planet.
24:59And it takes out some of the most magnificent and terrifying creatures in the history of ancient Earth.
25:06The geological evidence found in 66 million year old rock across the planet.
25:23Tells a dark tale.
25:25Of worldwide wildfires.
25:28Choking sulfurous air.
25:31And scalding acid rain.
25:33But dip further into history.
25:37Back some 145 million years.
25:40To the beginning of the Cretaceous period.
25:43And our Earth is now starting to look positively modern.
25:49The continents are moving apart.
25:52The Atlantic Ocean is opening up.
25:54The climate is rather benign during the Cretaceous.
25:59You have sea level very, very high.
26:02Covering over large portions of the continents with interior seas.
26:08There are vast conifer forests.
26:12And vibrant flowering plants.
26:14If you actually landed in the Cretaceous period, let's say sometime around 100 million years ago and started walking around, you might not feel too out of place.
26:28You might see a snake and a turtle and a tree and flower.
26:32But this is also an ecosystem and a world dominated by giant dinosaurs.
26:37Herds of long-necked herbivores graze on an endless supply of vegetation.
26:49The biggest land animals that have ever lived.
26:51These gigantic sauropods.
26:53Some of them as much as 100 feet long, 20 feet tall, up to 88 tons.
27:01These massive, incredible animals.
27:03Flashy, crested Parasaurolophus trumpets its booming love songs through its magnificent headgear.
27:17So the herbivores get bigger, there's plenty of vegetation to feed on.
27:20And with ever larger creatures feeding on plants, come the animals that feed on other animals.
27:29There's an arms race.
27:34The meat eaters get bigger and bigger, and so you get larger and larger dinosaurs.
27:39The pteropods, like the bipedal, tiny-handed terror T-Rex, famously take the role of top predator on land.
27:47While the pterosaurs, the largest animals ever to fly, dominate the air.
28:04One of the largest, Quetzalcoatlus, has the wingspan of an F-16 fighter, and can glide the width of the continent in a single flight.
28:16The oceans have their own set of predators, like the long-necked Plesiosaurus.
28:28But by the end of the Cretaceous, their dominion has been challenged.
28:33In spectacular fashion.
28:37By the terrifying Mosasaurus.
28:4050 feet of hungry lizard.
28:4520 feet longer than T-Rex.
28:48But all of these outrageous displays of reptilian drama are doomed.
29:05A rock, six miles in diameter, and moving at some 45,000 miles an hour, is about to cross paths with the Earth.
29:22Moving at hypervelocity speeds, like seven times 100.
29:31Suddenly, in an instant, a blinding light, and you're dead.
29:37A comet explodes with the energy of a billion Hiroshima bombs.
29:46A billion going off at the same time in the same place.
29:50Vaporizing miles of the Earth's crust, and ejecting the superheated wreckage miles into the air.
29:59Air temperatures locally got to about three to five hundred degrees Celsius.
30:03So you probably would have been vaporized immediately if you were in the immediate vicinity.
30:08Animals, lucky enough to be out of the blast zone, are on the wing and on the run.
30:15In vain.
30:16As that flaming toxic debris rains back onto Earth.
30:21As it rains back in, it heats up, because it heats on re-entry.
30:26And the sky gets hot.
30:28The heat from the sky makes it to the ground and starts fires.
30:31So no matter where you are on Earth, within hours, you are feeling some serious hurt.
30:40Earthquakes rock the Earth, unleashing massive landslides, and causing sleeping volcanoes to erupt.
30:51Not even the great marine reptiles are protected.
30:54The explosion creates a tsunami a mile high, and moving at nearly the speed of sound.
31:09Massive wildfires, anywhere there was vegetation.
31:12And that is so terrifying.
31:14And then the other thing that was happening too, is that you heated up oceans locally so much,
31:19that you disrupted ocean currents, but also you developed these hurricanes that were so severe
31:24that they'd form these huge water spouts going up into the air called hypercanes.
31:29So you'd have these massive storms.
31:36Within days, death from the impact has encircled the Earth.
31:43There's smoke, there's dust, blocks out the sunlight.
31:47If you're a plant, there's no photosynthesis.
31:50If you were a big animal, if you survived the initial blast somewhere on Earth,
31:54there's probably nothing to eat.
31:58So the plant eaters die, the meat eaters die, food chains collapse.
32:04And the world saw its fifth mass extinction.
32:07The asteroid impact was an amazing thing because, unlike all the other extinctions that preceded it,
32:19this one was global and instant.
32:26Today, the impact still leaves a great wound in the Earth's crust.
32:30More than a 110-mile-wide, 20-mile-deep crater on the tip of Mexico's Yucatan Peninsula.
32:41Discovered in 1978, it dates precisely to 65 million years ago.
32:46We'd known for a long time that we had an impact of some sort that killed the dinosaurs.
32:54What we didn't know was, well, where did that impact happen?
32:57And then the Chicxulub crater was identified, and the age dates worked out that, okay, this must be it.
33:03All over the world, where Cretaceous rock is exposed, buried in that famous layer of mud, lies more telltale traces of the impact.
33:17We have more than 300 sites around the world where you can put your finger on the debris that was blown out of that asteroid impact crater.
33:24You find a lot of soot. You find a lot of dust. You find these little beads of glass, microtectites in that layer.
33:35Formed in an instant from the massive heat of the impact, these beads were ejected into the atmosphere before raining down around the world.
33:43Together with a spike in the trace element, iridium, exceedingly rare on Earth, but abundant in asteroids.
33:54These discoveries close the book on the mystery of Earth's most recent mass extinction.
34:01One that took out nearly 80% of all life on Earth.
34:05You wonder, you know, with something that bad, with that much energy released, you wonder how anything survived.
34:14But 25% of life did survive.
34:17All the pterosaurs and plesiosaurs died out, as did all of the dinosaurs, except some tiny feathered ones that weighed a pound or less.
34:27A few species of dinosaurs survived, and we know those today as birds.
34:35If you have birds, and I have chickens at home, and you see them in certain modes of growth, like when they go from the cute chick stage into the proper chicken stage, in that middle time they look really dinosaurish.
34:47And that's because they have a common ancestor with dinosaurs.
34:50And even smaller critters, which had been surviving under the feet of dinosaurs for as long as there had been dinosaurs.
35:00Well, now they too get their day in the sun.
35:07From these little mouse-like creatures that existed during the age of dinosaurs, they get up one morning, the dinosaurs are all gone, and the world is theirs for the taking.
35:18The age of mammals had gone.
35:24The yin and the yang of the planet. Life evolves, life goes extinct.
35:29And it's this whole process of evolution and extinction that has shaped the world that we have today.
35:35Sixty-six million years after the asteroid hit, many believe mammals and all the other lucky survivors of the fifth mass extinction on Earth are now in the midst of a sixth one.
35:49A recent report from the World Wildlife Fund estimates that more than two-thirds of all animal life could be wiped out by 2020.
36:00Only this time, the cause doesn't involve asteroids, volcanoes, earthquakes, or death rains.
36:08Oh yeah, we're absolutely in a period of extinction now. There's no question about it because we are actively causing extinction by direct things like hunting rhinos and killing orphans and chopping down forests.
36:22And the indirect impacts, we're putting fossil fuels in the atmosphere, we're carbonizing the atmosphere which acidifies the ocean.
36:30It's not as fast as an asteroid impact, but it's way faster than the lava flow.
36:36So the Earth, you know, this blue marble that we see from space is rather a fragile place in terms of life.
36:44Because although there are maybe 10 million or 20 million species alive today in the world, there are billions of species in the fossil record which are extinct.
36:54So extinction, extinction is the name of the game.
36:56And we should inform ourselves with the information about what we've learned from the past to help us ameliorate what we're doing at the present.
37:05Because at the end of the day, we don't want to live in a planet where we've actually caused a mass extinction.
37:26And we'll see you next time.
37:27We'll see you next time.
37:28Bye.
37:29Bye.
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