Permian-Triassic Extinction Event - The Great Dying

today's episode is brought to you by Squarespace the tool to use to make a website for your brand or business more about them in just a bit there was a time when Earth came perishly close to losing all life upon it this mass extinction event was so devastating and happened so far in the past 252 million years ago that isn't really impossible for us to contemplate the greatest disaster to ever hit earth happened long before humans existed indeed there were no mammals at all there was even many millions of years before the age of the dinosaurs yet we can understand what happened despite the utterly vast expanse of time involved the array of animals wiped out in massive numbers can seem tangible when we contemplate their fossilized skeletons and imagine how they must have looked roaming their ancient world some of those peculiar beasts though looked Nothing Like Us thankfully so were our ancestors throughout the many millions of years these animals lived and diversified a fascinating specimens came to roam the one giant continent at the time Pangea yet the vast majority of all the species alive on Earth by most accounts more than 90 of them did not survive this colossal disaster fortunately for us some plants and animals did survive and they evolved to become the life forms we know today including ourselves the great Extinction event is technically known as the Permian Extinction or sometimes the Permian Triassic Extinction as it marks the boundary between two geologic periods the Permian and the Triassic it's commonly also known as the great dying in the long back history of earth going back many millions of years there have been five major Extinction events the one that has got the most attention of course was the cataclysm which ended the age of the dinosaurs there are those who contend that we are in the midst of a sick major Extinction at present putting that terrifying Prospect aside for the time being the worldwide demise of the great lizards was the fifth and most recent Extinction event on Earth the one we're focusing on now was the third occurring 252 million years ago foreign ly deadly event from fossil evidence there are layers of fossils from before the great dying which are filled with a wide variety of plants and animal species the Permian period began as an ice age but the ice caps melted and Earth warmed by the end of the Permian just before the great dying the planet was Lush angry the plants and animals at the time could be considered primitive flowering plants would not appear for more than 100 billion years yet they had adapted to survive there were enormous forests of ferns and Seed ferns conifers and small shrubs existed seed plants began to dominate as plant species spread across Pangea insects that depended upon them for food flourished some insects at the time are even capable of flies in the oceans sharks and bony fishes had developed other forms of sea life included sponges corals and ammonites and they were widely dispersed brachiopods Marine invertebrates that live in shells such as the lingula which live in mud flats are fairly rare in the modern world but they were quite common in the Permian on land species from insects to large four-legged beasts ill seem to be hearing about some of our pre-mammalian ancestors roamed across Landscapes ranging from swamps to forests to arid deserts many of these species lived for millions of years yet evidence of their continued existence is absent in later there's a rock something profound happened to cause all these varied forms of life to just disappear from the fossil record it's widely accepted that an asteroid slamming into the Earth 66 million years ago doomed the dinosaurs when that was established it seemed possible that the mass extinction 186 million years earlier could have been caused by a similar event most artists now dismissed the idea that an asteroid was responsible for the great dying though the idea of a much earlier asteroid may seem like it would be a convenient way to explain the evidence in the fossil record but there simply isn't any evidence for an asteroid strike that would coincide with a mass extinction 252 million years ago there is compelling evidence for something else however and the generally accepted scientific theory for the cause of the Great dying is that it came not hurtling out of the sky but surging up from the core of the earth the earth would have looked very different 252 million years ago most of the land was pressed into one giant continent that we call Pangea and under that continent in a region that is present-day Siberia was a repository of magma that created enormous volcanoes the current consensus is that the great dying was caused by Massive and long long-lasting volcanic eruptions that led to Rising temperatures across the planet the volcanoes that created the conditions that made nearly all life unsustainable on Earth were what the scientists called the Siberian traps these were not the familiar cone-shaped mountains that come to mind when we think of volcanoes or the almost Majestic eruptions that we've seen and dramatic news footage they were not like any volcanoes that humans have ever witnessed but rather they were burning wounds in the Earth on a scale that's difficult to comprehend Fishers split the ground in networks miles long sending plumes of volcanic gases into the atmosphere the Siberian traps released gases into the Earth's atmosphere for a very long period of time some scientists believe the volcanic activity lasted for 300 000 years though others believe it went on even longer still others contend that the volcanic activity only lasted for about 60 000 years which is still an absurdly long time even if it's just a blip when discussing geologic events whatever the actual duration these sustain volcanic events polluted Earth's atmosphere to an extreme degree It is believed that enormous amounts of chemicals were pumped into the air the chemical infusion particularly the release of immense clouds of sulfur chlorine and fluorine caused acid rain the phenomenon of ordinary rainfall becoming acidic some scientists believe the acid rain during the eruptions of the Siberian traps would have made rainfall as acidic as undiluted lemon juice this would of course do tremendous damage to plant life compounding the problem for plants clouds of volcanic ash would soon have blocked out the sun with photosynthesis unable to occur plant life would have taken a devastating hit as plants died and the animals that depended on them would have also perished in yet another disaster to throw into the mix it is believed that gas is released into the atmosphere by the volcanic activity did enormous damage to the planet's ozone layer but oh would of course temperatures on Earth to rise it is possible that average temperatures across the planet Rose by as much as 10 degrees Celsius that would have raised the temperature of the Seas and it's estimated that oceans would have lost about 80 of their oxygen but the oceans turned in into massive dead zones unable to support life the entire food chain of the planet was put in Peril these cascading factors triggered by the massive volcanic eruptions caused Earth to lose more than 90 of its life now before we continue today I've got to tell you about a service you've probably never heard of before no I'm just joking you've definitely heard of it it's Squarespace look Squarespace is the best place to build a website in 2022. if you're thinking about doing it somewhere else just stop just go to Squarespace and get started and why should you do that because websites are ridiculously easy to make and feature Rich with Squarespace imagine this situation you know nothing about websites but you need a website and you've seen beautiful websites out there on the internet well all you've got to do is go over to Squarespace and they will allow you to build something like that and you don't need any 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goes back a few hundred years Scholars had been studying rocks Unearthed by Miners and it became apparent that layers of rock had been deposited during distinct time periods the study of these layers the strata is known as stratigraphy the man often credited as the father of stratigraphy was a British geologist named William Smith he was employed in the late 1700s and early 1800s by companies building canals throughout England his work required him to analyze the rock which would have to be cut through in order to dig the canals years of traveling about and looking at a vast amount of rock Portsmouth that layers of rock be identified by the fossils found in them strata found in different locations if they contained the same fossils must date to the same period he spent 15 years distilling his hard-earned knowledge into an astounding project his geological map of Britain which he published in 1815. Smith's map was detailed colorful and quite beautiful in its own peculiar way and it attracted a lot of attention Smith had been doing very practical work building canals that were the highways of the Industrial Revolution and he intended his map to be an aid to Industry by helping to determine where raw materials might be mined the amazing geological map as well as Smith's concept of using fossils to date layers of rock impressed the 19th century gentlemen Scholars who were attempting to make sense of ancient Life One such scientist always a geologist born in Scotland named Roderick Murchison he praised Smith's map and ideas which influenced his own work studying fossils Murchison who would eventually become the director of the British Geological Survey plays a role in our story today as he became instrumental in naming the Permian age the period of Earth's history just before the great dying the name Permian derives from perm an area of the Ural Mountains in Russia Murchison and other geologists explored there in the early 1840s their study of fossils found in the Rock layers of perm enabled them to date the material relative to other layers of rock Murchison determined the Permian Rock data to the end of the Paleozoic Era it was thus followed by the Triassic the beginning period of the Mesozoic Era thus the great dying is said to have marked the Permian Triassic boundary the great dying is not meaningful only because it was a disaster of enormous magnitude the slow recovery from it marked a true turning point in Earth's story the end of the Permian period also marks the end of the Paleozoic Era the long stretch of time when plants and animals had been diversifying in the strata there can be found a boundary line with new fossils above the Permian layer and then in a higher layer are the remains from the Mesozoic hero and life recovered and began to flourish again it is truly impressive that geologists in the 1800s embarked on fossil digging Expeditions and by exchanging letters with each other and Publishing papers created a system of geologic time which is still the basis for how we think about the Deep past however Smith and Murchison and their contemporaries didn't really have a handle on exactly how many years were involved they were thinking about millions of years but how many millions was utterly unclear was it a few million or was it hundreds of millions over the past Century the discovery and refinement of radiocarbon dating has given us some clarity and we now know the Permian is considered to have lasted from about 299 million to 252 million years ago and by studying the fossils found in the layers of rock known to be from the Permian we can determine how much life on Earth evolved through those roughly 50 million years we tend to care about endangered animals especially if the animals facing extinction are things we can relate to hey let's be honest we worry about the cute animals pandas hedgehogs only for baby rhinos get sympathy and yet there are some animals which may not be classically cute but we still respect them and we don't want to see them disappear sea turtles bison elephants gorillas daggers Eagles and so on but what was living in the Permian period that might have evoked some of our emotional energy well there were no animals or we would consider cute and cuddly the mammals anything warm and fuzzy would not begin to appear on Earth for at least another 70 million years at least you don't need to worry about adorable little hedgehogs and pandas struggling for air in the toxic smoke and acid rain many of the life forms that didn't survive were in the sea including some forms of coral one remarkable Oceanic animal that didn't make it through the great dying was the helicoprion which looked like a shark that wasn't properly assembled the helicoprion's distinctive feature was its jaw which resembled a buzzsaw the vertical structure in the middle of its normal mouth was lined with large teeth and it could slice its prey in half with one bite given the helicoprion's size up to eight meters in length it must have been an absolutely formidable Predator a lot of land animals that roamed during the Paleozoic would also look fairly unfamiliar to us there is however a notable example if you played with plastic dinosaurs as a child you probably remember handling one that looked a bit like a lizard with a big Sail on its back that would be a dimetrodon dimetrodon was not even a dinosaur despite generations of toy makers lumping them in with proper dinosaurs like triceratops and Brontosaurus dimetrodons lived on land more than 270 million years ago long before the dinosaurs appeared dimetrodon was an example of a synapse synapsids are terrestrial vertebrates they are a large group of animals and in fact you and I are synapsids as are all mammals remember the mammals would not come along until a very long time after the great dying but before the great dying there existed the non-mammalian synapses during in the Permian period terrestrial vertebrates of the palkisore family such as the dimetrodon faded away their evolutionary successes were the therapsids which included two well-known groups of creatures the gore gone upsids and the synodonts the gorgonopsids were Fizz and beasts some of them were larger than our present-day grizzly bears they were saber-toothed carnivores that walked on four feet some of them had long legs which presumably made them fast and deadly Hunters the gorgonopsids would have been the top predators on Earth at the time feasting on other animals they flourished during the Permian age but they did not survive the great dime their fossilized remains are found in layers known to be from before the extinction events such as in the Kuru desert of South Africa the synodonts were a group of premamelian animals that to our eyes might seem like a bizarre cross between a bear and a lizard more precisely their headset characteristics that would later be found in mammals yet their bodies seemed reptilian the cyanodons were a bearish group with some of them being quite small and that could be why some of the cyanodons Survived the Great dying and oh went on to evolve they became part of the progression that many millions of years later led to the rise of mammals those peculiar animals the size of rodents were better equipped to survive the chaos on Earth during the horrendous eruptions of the volcanoes they could survive on less food and they could borrow and hide the larger animals dump with big skulls with ornamented horns died out being large and flamboyant was no Advantage during disaster today's artists points to what's known as the Lilliput effect to explain what may have happened the phenomenon is named the fictional land of lillipop the island inhabited by tiny people in Gulliver's Travels the principle of the liliputupect is that the animals that survive a mass extinction event have a marked decrease in body size a cabelic beasts of evidence for this is that databases of fossils from the end of the Permian and the beginning of the following Triassic period show that large animals died out a large body was a disadvantage the small survived [Music] of the sign adults that survived the great dying a fascinating one is a small animal about the size of a cat called a thrinaxidon the littlestronaxadon is thought to have lived in boroughs its ability for Life underground may have helped it survive through the Bleak periods when the Earth was dark and Smoky as the Earth slowly recovered from the severe Extinction event it was thrinaxidon and other small animals that survived into the beginning of the Triassic period by topping it out hiding in Burrows and not needing much food to sustain itself scrappy little frenaxodons helped to ensure the future of life on Earth another Survivor at the late Permian period was the lystrosaurus an ugly beast about the size of a pig a lysosaurus had two long saber-like teeth and a horned beak similar to that of a turtle the leistrosaurus may absurvide the great dying because of its ability to dig burrows its name means shovel lizard and enter into a state similar to hibernation thus requiring less oxygen to survive however it managed to adapt and survive it flourished afterwards it spread across Pangea before the continents drifted heart and its Bones have been found in Africa India and Antarctica bones of lysosaurus are extremely common in Fossil Beds to the point where paleontologists become frustrated finding yet another one it is perhaps appropriate to pause for a moment and have a thought for the vast numbers of animals that were not able to adapt and survive had a fearsome animal like the gorgonopsid survived how might life had developed differently their absids that roamed across Pangea during the Permian with bizarrely haunt heads of the most part did not continue to evolve had they survived would their descendants be living among us today would they have out-competed us would we not be around today maybe maybe not but it's fascinating to consider how different life on Earth might have been if some of the peculiar Beasts of the Permian had not been quite literally stopped in their tracks foreign it took many millions of years but both survivors of the great dying would evolve into reptiles and mammals and give the Earth the age of the dinosaurs and of course it would lead to a time when mammals such as ourselves would become the dominant life forms The Saga of the most devastating Extinction event in the very long history of Earth is a fascinating tale it helps us understand how life evolved and it makes us consider how fragile life on Earth really is it also holds extra significance today as the idea of a warming planet is very much on the minds of people in the modern era and as mentioned earlier there are people who contend that we are in the middle of a sixth mass extinction event right now does the great dying really hold lessons for us today there's certainly no expectation that the events that brought about the extinction drama for many millions of years ago will ever be repeated we do not have one massive continent with a concentration of magma under it let its hope we're not drinking anything by declaring that gigantic cracks are not going to open in the earth and spew out plumes of toxic gases anytime soon however we do know that the planet has been damaged by the actions of mankind climate change is happening and the news is regularly filled with reports of severe weather events from massive tropical storms to severe droughts to shockingly intense heat waves if we are in the midst of an ongoing Extinction event it will play out very differently than what happened across earth 250 million years ago perhaps the lesson of the great dying is simply to remember that life on Earth is not a sure thing things can happen to endanger it and we are better off knowing that [Music]

Channel: Geographics

Views: 200,035

Keywords: permian-triassic extinction event, ordovician-silurian extinction event, permian mass extinction, the permian extinction, permian triassic, the great ordovician biodiversification event, late devonian extinctions, mass extinction, great dying, extinction, paleozoic era, permian, prehistory

Id: 8F_RcM9EY4E

Length: 19min 7sec (1147 seconds)

Published: Wed Nov 09 2022