It’s a lovely spring day  during the Cretaceous Period, and a massive Tyrannosaurus  rex sits on the bank of a river in what will one day be called Saskatchewan.

She’s a full-grown adult, twelve  meters long and several tons, and right now she’s enjoying her  favorite activity: snoozing in the sun. Birds chirp in the nearby trees, and  insects buzz around blooming flowers.

A pair of gar swim along the edge of the river, and a tiny mammal named  Cimolestes hunts for tasty bugs in a nearby pile of leaves. Eventually, it will be time  for our T. rex to go find food. But for now, her belly is full, and she has her favorite  napping spot all to herself.

One of the perks of being the  biggest, baddest beastie around is that you get to laze about  wherever and whenever you want. But although the sleepy queen doesn’t know it, this will be the last perfect  day of the Cretaceous Period. While our T. rex lazes and Cimolestes forages, there is a big bad rock from  space hurtling toward Earth.

It might have been an asteroid, or maybe a comet - scientists often simply call  it a bolide or an impactor. Whatever form it took, a huge chunk of space stuff was about to slam into our planet. But the mass extinction that  followed didn’t happen in a day.

That impact was just the first  step in a long and tragic process that brought the Age of Dinosaurs to a close. So let’s explore what really  happened in the hours, years, and millennia after the collision. [Intro music] Our little scene with the T. rex  might seem totally hypothetical, but we actually have a lot of fossil  evidence to help us reconstruct what was going on that day. Throughout this video, we’ll introduce you to several  dinosaurs and other species that we know experienced the catastrophe.

And the geological record tells us even more. We have pretty strong clues that  this event happened in the spring, for example; we think...(adlib)  but more on that later. It’s worth noting that  paleontologists and geologists didn’t know what killed off the dinosaurs for the entire first century  that we knew what dinosaurs were.

Researchers could tell that something big happened at the end of the Cretaceous Period. All over the world, whenever researchers  look at the layers dating to that time, they find this thin line of unusual clay. Since that clay layer occurs just before  the three quarters of life on Earth disappears from the fossil record, they had a suspicion that one might  have something to do with the other.

But what caused that clay layer to form  in the first place wasn’t all that clear. Some scientists hypothesized that  massive volcanic eruptions were to blame, and to this day, you’ll see  people make the association between dinosaurs and volcanoes in artwork. But the volcano idea wasn’t  the only one out there.

Other researchers suspected a global drought, which will sound familiar if  you’ve seen Disney’s Fantasia. It wasn’t until the 1980s that scientists  managed to get a much closer look at that layer of clay that  marks the end of the Cretaceous. Within that sediment, they found the tell-tale signs of  an extra-terrestrial collision.

The clay contained iridium, an element that’s rare on our planet  but is commonly found in asteroids. The clay was also full of  microscopic glass spheres, which formed when droplets of molten rock cooled while they soared through the air. There were also lots of shocked minerals, which are minerals that have been  deformed by intense heat and pressure.

These kinds of minerals are found  in asteroid impact craters … and today, nuclear testing sites! So with all this evidence, researchers have said goodbye to both  the volcanic and drought hypotheses for this mass extinction. Although, put a pin in the volcano thing.

Geologists soon realized that the signs of  this impact could be found all over the world … but they were most intense around Central America. Following the trail of debris,  they eventually found the crater. Located in the Yucatán Peninsula of Mexico, the Chicxulub crater is  roughly 200 kilometers wide, and it’s the best-preserved  large impact crater on Earth.

And yet you cannot see it from the surface. The crater is buried beneath  hundreds of meters of sediment that has built up over time. Scientists were only able to study the  crater using seismic imaging techniques, and by drilling up samples from deep underground.

All of this happened during my lifetime by the way We didn’t know this when I was born, Which makes me both feel excited  about how science works and old By gathering data from the crater and comparing it with observations of asteroid strikes  elsewhere in the solar system, researchers could finally put together  the story of how the Cretaceous ended. 66 million years ago, t he Earth was struck by a space  rock more than 10 kilometers wide - for comparison, that’s  bigger than Mount Everest. It blasted a hole in the  ground the size of Maryland and kicked off one of the worst  mass extinctions in Earth history. In a muggy floodplain in what’s now Brazil, the still water is so full of vegetation that you could easily miss the pair of  eyes peeking just above the surface.

The eyes belong to Pepesuchus. While he’s not technically a crocodile, he’s a close cousin to modern crocs, and the family resemblance is strong. A small, stripey pipe snake is slithering  across a floating chunk of wood nearby, and Pepesuchus is mulling over whether it’s worth the trouble to snap it up.

It wouldn’t be as satisfying  as a big fish or turtle, but a little snack might be nice. But before he can make a decision, the croc’s attention is diverted by a new arrival. From the nearby trees, there  emerges a reptilian head, followed by neck, neck, and more  neck, and finally an enormous body.

A titanosaur, Austroposeidon, 25 meters long and one of the largest  land animals in Earth’s history. Lucky for Pepesuchus, this  gigantic dinosaur is a plant-eater, and has merely come to the water to drink. But it’s also not the most perceptive of animals, and since Pepesuchus’ entire head could easily be crushed beneath one of its feet, the Pepesuchus decides it’s best to move along.

He slips quietly under the water, and therefore misses out on  a once-in-a-lifetime sight – a burst of blinding light that  fills the entire northern horizon. The apocalypse has begun. Asteroids that hit the Earth typically  travel around 20 kilometers per second, which is, like, really fast.

If there had been airplanes back then, the Chicxulub impactor could have  passed one at cruising altitude and then hit the ground only half a second later. An asteroid or comet hitting the Earth  isn’t like a baseball landing in the dirt. That much mass striking with that much speed created an immediate gigantic explosion.

And for Chicxulub, that meant a  few trillion tons of space rock, slamming into our planet at lightning speed. The blast instantly destroyed  the impactor itself a nd decimated the ground for a  hundred kilometers in all directions, leaving a 30 km deep crater in its wake. Any living thing in the vicinity would have  been obliterated in the blink of an eye.

And while that sounds awful, it might be preferable to what happened  to everything else that wasn’t wiped out. Scientific simulations of the  impact reveal what happened next. The explosion created a heat pulse that  started at several thousand degrees, which expanded outward for  thousands of kilometers, as far as the Canadian and Brazilian borders, toasting everything in its path.

Right after that came a shockwave powerful enough to flatten trees and knock even the  largest dinosaurs off their feet. And then came the debris. The explosion created an impact plume, a huge cloud of vaporized,  molten, and shattered rock.

Chunks of rock were launched from  the blast at such high speeds that some of them could have  escaped Earth’s atmosphere and floated away into space. Some of them are probably on the moon Bits of solid and molten rock  rained down from the plume for thousands of kilometers in all directions, depositing those glassy  spheres and shocked minerals that geologists would find  millions of years later. As heat, shockwaves, and  rocks blasted through the air, tremors from the impact  rippled through the ground, causing massive earthquakes.

At a site called Tanis in North Dakota, a good 3,000 kilometers away from the impact site, freshwater sturgeons and  paddlefish were mostly protected from the airborne dangers by  their watery surroundings. But mere minutes after the explosion, underground shockwaves tore across North America, causing violent sloshing of  the lake they called home, along with any other waterways in their path. The shockwaves churned up the mud, burying the fish in an instant, all while more bits of molten  rock fell from the sky.

Millions of years later, human paleontologists would discover the chaotic  piles of these fossilized fish, and find glassy spheres inside their gills, which they interpret to mean that these  fish died breathing in that debris as it filtered through their water. Those same fish fossils also give us  a clue to the timing of this event. Detailed examination of their bones has found that they seem to have died near the  beginning of their growing season, which suggests that they died during  spring in the Northern Hemisphere.

And, if they died so close  to the actual impact itself, that would mean the asteroid  landed in the spring, too. Just like these ill-fated fish, every living thing for  thousands of kilometers around would have heard, felt, or seen some  evidence of the Chicxulub event … and many didn’t live to tell about it. But the impact plume didn’t just  spread outward, it also spread upward.

Ash and dust were launched hundreds  of kilometers into the sky, high enough to reach the International Space  Station, if it had been there at the time. From up there, the giant cloud of  debris began to encircle the globe. But the immediate effects of the  blast only reached so far away.

At this point, most living things on Earth would  have no idea that anything unusual had happened. On the opposite side of the  world from the deadly explosion, life continues undisturbed for now. Someday, this landscape  will become the Gobi Desert, but right now it’s a vast floodplain crisscrossed with meandering rivers and twining tributaries.

In the dim light of the rising sun, a  family of Saurolophus eats their breakfast. This region is home to thousands  of these herbivorous dinosaurs, but there’s plenty of lush  green food to go around. A mother Saurolophus is splitting her time between grabbing mouthfuls of leaves in her bill and keeping watch on her surroundings, wary of danger as she stands guard  over her three newborn babies.

These little ones hatched just a few weeks ago. Eventually, they’ll grow into multi-ton adults, but if they’re going to put on all that weight, they’ll have to master the ability to find  and consume massive quantities of vegetation, every day. So far, their dining skills  are a work in progress.

Their breakfast is a messy struggle, with many frustrated squeaks and  the awkward clacking of tiny beaks. For this Saurolophus family,  it’s a peaceful morning. But by lunch time, something is… off.

As the sun reaches its highest point,  the sky above these dinosaurs is dim, as dark clouds cast ominous shadows on  the animals and on their leafy lunch. Simulations predict that it  only took four to five hours for the massive plume of ash and dust  to spread around the entire planet. And while that dark shroud  spread through the atmosphere, another danger was racing across the sea.

At the time of the impact, the Yucatán  Peninsula was covered in shallow ocean. Between the initial blast and the  resulting landslides and earthquakes, a lot of water was displaced. That displacement swept through the  ocean in the form of massive tsunamis.

Models predict that the tsunami  waves in the Gulf of Mexico were over 100 meters high, tall  enough to drown the Statue of Liberty. As the waves spread outward from the Americas, they reached coastlines all over the world, starting with the North Atlantic  and South Pacific Oceans. In the geologic record at  the end of the Cretaceous, coastal sites in these regions feature  chaotic deposits of rock and sediment, torn up and laid back down by  those powerful tsunami waves.

But in many places, there are no  end-Cretaceous sediments at all, since those layers of loose sediment  were wiped away by the 10-meter waves. Within 24 hours of the asteroid impact, the tsunami waves reached New Zealand, 12,000 kilometers across the ocean. By the end of that first day,  environments across the Americas were scorched, flattened, and buried in debris; coastlines around the world  were scoured by giant waves; and the entire globe was  shrouded in a dark cloud of dust.

But even as the immediate dangers  faded, destruction continued. Thanks to the initial heat pulse and  the burning debris falling from the sky, the impact ignited massive wildfires, leaving behind layers of soot  in the geological record. These might have continued burning for months, putting extra pressure on ecosystems that already had to suffer through the more  direct side-effects of the catastrophe.

But that’s not the only reason things got hotter. Remember how I said to put a  pin in the volcanoes thing? Well, some simulations of this entire event suggest that the tremors from  the impact could even have caused dormant volcanoes to erupt, although to be clear, there’s currently no direct evidence for this.

But, it does mean we don’t have to  throw away every piece of dino art with a volcano in the background. So it was a rough year. But it wasn’t  entirely apocalyptic everywhere.

The raining debris, the wildfires, the  tsunamis - these are devastating disasters, but they also have limited range. Deadly debris only spread so  far out from the impact site. Wildfires only burn through  certain flammable habitats.

And tsunamis are only a problem near the shore, and not even all shorelines - places like the Tethys Sea  in Europe were mostly safe. So, there would have been some habitats that were sheltered from these effects. Most animals in far-off environments or in underground or underwater habitats  probably avoided the worst of it.

Some critters might not even know  anything happened until much later. Nestled beneath the soil in what is now Patagonia, a small mammal named Groebertherium  curls up in a burrow. Springtime in the northern hemisphere means winter is fast approaching for the Southern Hemisphere, and this little fuzzball is  settling in for a long winter nap.

Tucked snugly underground, Groebertherium is completely protected  from the wildfires and debris raining down from above. But when our Groebertherium friend  awakens several months later, the catastrophe will be far from over. Things would only get worse in the  coming years of cold and darkness.

But before we get into that, a quick break Thanks to Brilliant for supporting this SciShow video! Brilliant has supported SciShow for years because, just like us, they’re all about science, learning, and making it all accessible. We all know cramming a bunch of formulas into your head doesn’t lead to lifelong knowledge.

So Brilliant lets you play around with concepts until they make sense. Whether you’re 10 or 110, you can learn with Brilliant. Like in their course on Coordinate Geometry that shows you how to derive Pythagoras’s Theorem from the coordinates and areas of shapes.

To learn for free with Brilliant for a full 30 days, go to brilliant.org/scishow scan the QR code onscreen, or click on the link in the description. They’re also giving you unlimited daily access to everything on Brilliant with 20% off an annual Premium subscription. Before the asteroid struck down,  the surface of the Yucatán Peninsula was covered in thick layers of evaporite rocks, which included large amounts  of a mineral called anhydrite, a form of calcium sulfate.

And once that asteroid struck down, all of those sulfate minerals  were vaporized into sulfate dust, which became part of the cloud that  quickly spread throughout the atmosphere. The cloud of sulfate dust and wildfire ash shielded the entire planet from the sun’s rays, meaning the Earth’s surface received  less light and heat from the sun. The planet fell into an impact winter.

Using climate models combined  with fossil evidence of changes in plant and plankton communities, scientists estimate that  global temperatures dropped at least 15 to 20 degrees Celsius  in the years following the impact. That means, in many places, summer  felt more like the beginning of winter, and winter felt even worse. And then there was the darkness.

Some models predict that the dust and  soot in the air blocked so much sunlight that for more than a year, plants  couldn’t even photosynthesize. With the combined loss of heat and sunlight, photosynthesizing plants and  plankton froze and starved. Without them around,  herbivores ran out of food too, and as the herbivores died off,  the carnivores starved next.

The wildfires, tsunamis, and deadly  debris definitely caused a lot of damage, disturbing or even destroying many habitats. Under more normal conditions, ecosystems are usually pretty good at  bouncing back after short-lived disasters. But the cold and darkness of this  impact winter was a different story.

These harsh conditions cracked the  foundations of ecosystems all over the world, plunging the planet into a global food crisis. Using climate models, scientists estimate that this impact  winter lasted at least a decade. It’s been several years since the impact, and the vast floodplains of Central Asia  are a lot less green than they used to be.

The lush vegetation has been  reduced to sparse patches of plants eking out an existence in the dark and cold. Plodding across this barren  landscape is a single Saurolophus, one of the awkward babies we  met before, now all grown up. Other than the first few  weeks when she knew sunshine, she has lived her entire life in this dark world.

Every meal she’s eaten has been a lucky break, and lack of food meant that  she never grew quite as big as her mother had been. But despite the odds, she grew up, found a mate, and even had offspring of her own. Only one of those babies is still  with her, trotting along at her feet, announcing his hunger with little squeaks.

As they make their way toward  the next anemic patch of shrubs, she holds her head high,  scanning the landscape for danger just as her mother once did. But she hasn’t seen a large  predator around for quite some time. There just isn’t enough food to keep them here.

Slow-growing plants suffered  immensely during the impact winter. Entire forests were wiped out, the trees unable to sustain  themselves with so little light. The lack of food at this time was one  of the main drivers of extinction.

Animals that were either strict herbivores  or carnivores had the worst time, especially large-bodied species  that needed lots of nourishment. If you only have a small  selection of things you can eat, that limits your odds of finding  food when times are lean. And the bigger your body, the  more calories it takes to fuel it, so the largest animals were most at risk.

Not only were ecosystems starved  of food, they were poisoned, too. That sulfur-rich dust would have reacted with  atmospheric gases to create sulfuric acids, which fell to the Earth as acid rain. Years of acidic precipitation would have disrupted the chemistry of soils and  water on the planet’s surface.

I got so bad that at some fossil sites, the remains of shelled  animals like snails and clams are completely missing from the fossil record. This might be a sign that acidic soils  had completely dissolved their shells before they could even fossilize, or worse, that the acidic water prevented  them from forming shells in the first place. One marine group that got hit  hard were the coccolithophores, a group of algae that were some of  the most important photosynthesizers of the Cretaceous seas.

More than 90% of these tiny organisms went  extinct in the aftermath of the asteroid impact. Those that survived were the ones who were  able to supplement their diet of sunlight by devouring other microbes. But not all species or habitats  suffered quite as badly.

There’s evidence to suggest that polar  ecosystems had better survival rates, probably because these  regions naturally experienced seasons of intense cold and darkness, so the local plants and  animals were better adapted to deal with the harsh  conditions of the impact winter. Likewise, river and lake ecosystems  also had a better survival rate, probably because freshwater  food webs receive nutrients from organic debris and dead stuff that washes into the water  from surrounding habitats. Whether through adaptation or sheer luck, some species managed to survive  even in this post-apocalyptic world.

A small stream in what’s now  Patagonia is clogged with debris. Many years ago, a sleepy  Groebertherium slept beneath this soil. Now, one of his close cousins wades  through the water searching for scraps.

This one is called Reigitherium, and right now it looks like a  waterlogged rat-wombat hybrid, poking his nose into piles of decaying vegetation. His relatively small size means he  doesn’t need much food to get by, and he’s not a very picky eater. Lucky for him, everything he likes  to eat is just as hardy as he is.

Ferns can thrive even in harsh conditions, and they grow fast and reproduce quickly, meaning a hungry little mammal can  always find some fronds to nibble. But at this moment, he’s finally  found another tasty treat: a mushroom cap, poking out of the soil. Fungi feed on decaying matter, and in  this world, there’s no shortage of that.

The soil beneath Reigitherium’s feet is  loaded with fungal spores and fern pollen, an unusual abundance that will  someday provide fossil evidence of which species fared the best at this time. And when food becomes scarce or  the cold becomes too much to bear, this mammal has another survival  trick up his furry sleeve. Like Groebertherium before him, we think that Reigitherium could shelter  underground and hibernate for a while, waiting out the worst of the surface conditions.

All around him, other species are  employing this same game plan. Turtles hide out underwater, sturdy seeds sit within the soil  awaiting the right conditions to grow, and many plankton enclose themselves  in cysts to enter a state of dormancy. For many species, surviving in this dust-shrouded world is a matter of making the most of the good  times and waiting out the rest.

Eventually, the skies cleared. The dust slowly fell out of  the sky and down to the Earth, depositing that famous iridium-rich layer of clay that marks the end of the Cretaceous Period. Sunlight and warmth returned to the  world, but even this wasn’t the end.

That terrible decade of dark winter was  followed by an age of heat and hardship. I mentioned earlier that the  rocks blown up by the asteroid were full of sulfur-rich minerals. Well, those rock layers also included  lots of carbonate rocks like limestone.

Carbonate rocks get their name  because they’re full of carbon. And when these rocks were vaporized in the blast, they released lots and lots of carbon dioxide. Climate models confirm that carbon dioxide lingers in the atmosphere a lot  longer than soot and sulfate dust.

And whereas that soot and dust reflected sunlight, carbon dioxide traps heat in the atmosphere. So, even after the dark clouds cleared, all that carbon dioxide lingered. And that brief period of global cooling was followed by a much longer  period of global warming.

Scientific simulations estimate  that the asteroid impact dumped around 1.5 trillion tons of carbon dioxide into the atmosphere. That’s just … so much carbon dioxide. Like, I don’t even have a fun comparison  to put that number into perspective.

And what that does to a planet… It’s just hard to wrap your brain around. But one of the ways that  researchers have tried to study all these impacts is through fossil plankton. Many plankton species construct these tiny shells, and their chemical structure can vary based  on the temperature of their environment.

Examining these plankton in the fossil record, paleontologists have found evidence that all that atmospheric  carbon swung global temperatures as much as 2 degrees Celsius warmer than  they had been before the asteroid impact. Which might not sound like much, but that kind of swing can  have massive global effects. So let’s not do that!

Carbon dioxide in the atmosphere  also seeps into the oceans, creating acidic water conditions. The chemistry of fossil  plankton also provides evidence for a slight drop in the pH of ocean water - that is to say, acidification of the ocean. Just as modern-day ocean acidification interferes with the formation of shells  and skeletons of marine animals, the acidic oceans of the post-impact  world would have been deadly for spiral-shelled ammonites, torpedo-shaped  belemnites, reef-building corals, and other ancient aquatic life.

These warmer conditions lasted  for tens of thousands of years. Entire species evolved, adapted, and  vanished again in the passing decades. The first real strides towards recovery had begun.

On a bright, warm night in  what’s now Saskatchewan, the moon shines down upon a massive  skull sitting on a river bank. Thousands of years ago, this  skull belonged to a tyrannosaur, a once unbeatable predator. These bones might have become fossils someday, had the flowing water of the  river not washed the soil away and returned them to the surface.

Eventually, the sunlight and the  wind will reduce these bones to dust. A tiny, furry face pokes  around the weathered jaws: it’s another Cimolestes, digging around the skull to find yummy  bugs that might be sheltering there. Long ago, tyrannosaurs were the  biggest carnivores in the land, but today, little mammals like  Cimolestes do most of the hunting, coming out at night to avoid the heat of the sun.

Nearby is a young broadleaf tree, part of a sparse forest that is slowly  reclaiming the habitat near the river. The leaves rustle at the passage of  another small mammal called Purgatorius. Purgatorius has flexible hands and a long tail that let it scamper quickly  through the branches of trees.

It’s on the hunt for the freshest leaves and – if it’s lucky – a juicy caterpillar. This was the state of the world  as the Cretaceous Period ended and the Paleogene Period began. Ecosystems all over the globe were in shambles.

Plants and plankton were severely diminished, there were no large land animals at all, and the species that persisted had to deal  with climbing temperatures and acidic oceans, not to mention food webs that  were barely holding together. Slowly, life on Earth began to recover. Plankton communities gradually  regained their former diversity.

In some parts of the world,  especially in northern oceans, this process took hundreds of thousands of years. In other parts of the ocean,  recovery was much faster, including - believe it or not  - inside the impact crater. Fossils excavated by drilling  into the Yucatán Peninsula reveal that a thriving microbial community became  re-established within just 30,000 years.

On land, mammal and plant  communities began to recover some diversity during the same period. Although they weren’t the same size. During the Cretaceous Period, the biggest mammals weighed as much as several kilograms,  about the size of a large housecat.

After the impact, mammal survivors remained  tiny for around 100,000 years before achieving housecat-size once again. It wasn’t until 300,000 years after impact that Earth’s ecosystems showed  signs they were bouncing back, with diverse communities of plankton  in the water and plants on land. Full plant recovery would take millions  of years, but the healing had begun.

By this time, large plants had become widespread, providing food for some of the first  large herbivores of the Paleogene Period, such as the mammal Carsioptychus,  which weighed more than 20 kilograms, about as big as a medium-sized dog. For comparison, 300,000 years  is about how long our species, Homo sapiens, has been around. That’s how long it took Earth’s ecosystems to truly begin to bounce back  after the cascade of catastrophes kicked off by the asteroid impact.

And even then, those earliest Paleogene ecosystems were a mere shadow of what had come before. There was a long, long way to go before life  on Earth looked anything like it does today. On the bank of a gently flowing river in  what’s now Colombia, there is a giant.

The coiled, massive body of a large Titanoboa, thirteen meters of giant snake, winds  through the shrubs that grow in this wetland. Above her head is a dense canopy of leaves, dripping with water from recent rain. These leaves grow on a diverse  assemblage of flowering plants and form the home for an abundance  of birds, mammals, insects, and more.

The impact, the wildfires, the devastating cold… Those events were five million years in the past. Now, this ecosystem thrives in one of the  world’s earliest tropical rainforests. Not far from the behemoth snake, there is a somewhat familiar  reptile resting on a floating log.

This slender-snouted, crocodile-like  reptile is called Acherontisuchus. With a total length of about five  meters, Acherontisuchus is a big reptile, but he’s clearly not the biggest one here. The Titanoboa doesn’t move as Acherontisuchus  lazily drifts by on a current.

Titanoboa’s diet is mostly fish, but  she’s eaten a croc or two over the years. Maybe she hasn’t noticed  the nearby Acherontisuchus, or maybe she just isn’t hungry enough  to leave her basking spot right now. Like we said before, one of the perks of  being the biggest, baddest beastie around is that you get to laze about  whenever and wherever you want.

It took several million years  after the asteroid impact for land plants to regain their former diversity. And many more before the first member of  familiar mammal groups like Primates appeared, or the early whales took to the seas  where giant marine reptiles once swam. And it was an astounding 25 million years  before herbivores got truly big again.

At the end of this so-called megaherbivore gap, large herbivorous mammals like  the rhino-shaped uintatheres became the first land animals since the  dinosaurs to grow heavier than one tonne. These were among the first steps in  the formation of our modern world, the Cenozoic Era, the Age of Mammals. Every organism alive today is a  descendant of some intrepid critter that somehow persisted through fire, darkness, and famine  at the end of the Cretaceous.

Thanks to some extraordinary fossil sites and  a rock record full of asteroid fingerprints, scientists have been able to put together an incredible amount of information  about the moments and millennia that followed the impact. But there’s still plenty that we don’t know. Scientists continue to investigate questions about the exact timing of events or the reasons why some species survived and others didn’t.

Studying environmental calamities of the past helps us understand how life  responds to catastrophe, what factors put which species at risk, and, hopefully, how to protect the world  around us from disasters of the future. The story of the Cretaceous mass extinction  is a tale of tragedy and resilience. It’s one of the most terrifying and incredible  stories in the history of our planet, and easy to talk about in grand, broad statements.

And yet, for the animals alive when it happened, the events unfolded minute by minute, day by day. The millions of years of recovery  were felt by living things, who did their best to stay  living through that chaos. They remind us that even  after disaster, life goes on. [ OUTRO ]