dinosaurs ruled the earth for 160 million years it seemed they would forever dominate the biosphere but one day their world was destroyed by a huge rock the size of everest falling from space this is the story of how the era of ancient reptiles came to an end [Music] the last day of dinosaurs earth 66 million years ago the end of the cretaceous period of the mesozoic era the parts of the pangaea supercontinent almost completely drifted apart the planet looked very similar to its modern state but not quite the same south and north america have finally split by the end of the cretaceous period africa australia and greenland have the same shape as today at the same time the outlines of europe and asia were just starting to form the mountain ranges of siberia mongolia the andes and the cordillera the continents were actively emerging the cretaceous period lasted 79 million years and became the longest period of the mesozoic era the planet's climate changed several times during this time it was relatively cool by the end of this period ice caps have formed at the poles winters have become harsher in some places the temperature dropped below minus 10 degrees celsius and as low as minus 45 degrees celsius in alaska but still the world was warmer than it is now lush vegetation covered the continent's surface it was during this period that flowering plants emerged conifers ginkgo and other trees from previous eras formed thick forests which also included modern looking walnuts ash and beech the sod produced by these trees made the top layer of soil more fertile for newly emerging herbs with the advent of flowering plants insects also had to evolve butterflies and bees started to fly spreading pollen seeded fruits developed from pollinated flowers providing food for many animal species including birds this was what drove the evolution of some herbivorous dinosaurs as well as many mammalian species the number of carnivores ungulates insectivores and primates increased under these favorable conditions admittedly they haven't yet become as large as they are now most mammals back then were small rodents and predators for example a fossilized head of a 20 centimeter long granopio dentiacudus was found in argentina this small mammal is called the saber-tooth squirrel because of its elongated muzzle with long facts presumably this species ate some insects but larger animals have already appeared in madagascar the remains of a huge ventana certici marmot were found this herbivorous mammal had a rather unusual appearance it had massive crests on either side of its skull for self-protection and an excellent sense of smell the animal weighed nine kilograms and was three times bigger than modern marmots however ropena mammoths was the real giant among the mammals of the cretaceous period it had a one meter body and weighed 12 to 14 kilograms outwardly ropano mammoths resembled the modern tasmanian devil or a squat dog this predator even hunted small or newly hatched dinosaurs [Music] and yet dinosaurs were the pinnacle of prehistoric evolution they were at the top of the mesozoic food chain a great number of dinosaur species of various sizes populated all continents the smallest were ogdentavis congress the head of this miniature reptile was no longer than 14 millimeters beak included unfortunately paleontologists haven't yet found the bones of the torso but given its head size this dinosaur wasn't bigger than a modern hummingbird [Music] according to some estimates the largest animal that has ever lived on earth is alamosaurus these dinosaurs were 29 meters tall weighed 38 tons and had a 12 meter long tail five hours till the impact the day terrestrial life was changed completely all animals young and old were going about their day as usual doing some foraging and hunting a herd of 50 alamosauruses went to the yucatan peninsula looking for some fresh greenery these giants were herbivores they had to consume up to a ton of vegetation per day to stay in shape it could take them a few days to eat leaves from an entire forest which made them lead a nomadic lifestyle a middle-aged predatory tarbosaurus living on the territory of present-day mongolia and china was also looking for food this 14-meter long species is considered the largest among the predatory dinosaurs of the cretaceous period our tarbosaurus set out to hunt for prey in the floodplain medium-sized animals and small dinosaurs would often come there for a drink so the hunt was going to be a success like any tarbosaurus this reptile walked on two hind legs its two-fingered forelimbs were disproportionately small relative to the rest of the body and yet they were very helpful in holding the prey or catching fish with long claws tarbosaurus main weapon though was about six dozen of long sharp teeth reaching up to 85 millimeters [Music] three hours till the impact meanwhile one adult pachycephalosaurus was also going about his day in north america this 4. 5 meter long dinosaur weighed about 450 kilograms and looked quite formidable its skull was protected by a 25 centimeter thick bone dome that surely softened the blows when the great reptile fought its enemies the back of the dome had bony projections and short spikes protruding upwards from its muzzle pachycephalosaurus was primarily herbivorous it crushed leaves seeds and fruits with its relatively small sharp teeth however it appears this dinosaur also included meat in its diet it ate small amphibians shellless animals mammals perhaps even newly hatched dinosaurs on this day our pachycephalosaurus got closer to the ocean where it found many trees with nutritious seeds it could also eat plenty of huge ammonite mollusks lizards and other critters in small lagoons meanwhile a female ankylosaurus went into the forest to grab some lunch in western north america she was guiding four newly hatched cubs this reptile looked like a nightmarish chimera it reached the size of a rhinoceros or even an adult african elephant the body of this tetrapetal monster was covered in powerful bone armor and it had a massive club-like knob on its tail but despite its intimidating appearance ankylosaurus was a harmless herbivore the mother with the cubs didn't seek to kill anyone with her club the tale served to protect against predators and cannibal reptiles and so being protected by their mother's formidable tail the family went into a thick forest near the newly formed rocky mountains two hours till the impact meanwhile young reptiles had a real massacre in north america hundreds of kilometers away from the site of impending disaster some absent-minded carnotaurus wandered into the territory of the tyrannosaurus rex and didn't notice the owner in time at the speed of up to 50 kilometers per hour carnotaurus could easily run away from its opponent who can only run at 40 kilometers per hour but the t-rex came into view too unexpectedly the intruder smell gave it away a while ago t-rex had an excellent sense of smell compared to other dinosaurs and in terms of eyesight precision even a hawk might be jealous of this predator in addition the reptile's vision was binocular its eyes could look in different directions and then the input from each eye was combined to create a single visual image this enabled the dinosaur to accurately determine the distance to its prey and so the t-rex furiously attacked the enemy to protect its territory and get a delicious meal at the same time you see this dinosaur never missed a chance to enjoy the flesh of its own kind it was up to carnotaurus now to fight back if we saw this fight and had to take a bet everyone would put their money on the t-rex the carnotaurus had no chance the weight difference was huge tyrannosaurus weighed up to 6. 8 tons and outweighed carnotaurus by almost 5 tons its muscle mass and therefore strength was multiple times greater even with its horn-like projections above the eyes the carnotaurus had no chance to fight off the t-rex's super-powerful jaws tyrannosaurus quickly tore the opponent to pieces and began its feast right away it was a great stroke of luck for the reptile according to some estimates t-rex needed up to 100 kilograms of meat per day this is equivalent to daily intake of three or four lions as it was preoccupied with lunch the reptile didn't care to look up and so it missed the bright light in the sky that was growing bigger by the second ten minutes till the impact a huge asteroid was approaching the planet in a few minutes it will kill 75 of all living creatures causing the cretaceous paleogene extinction event in 1980 scientists proposed a hypothesis that it was the asteroid impact that led to this disaster they found far more iridium in 66 million year old clays around the world than in layers above and below this is a very rare substance on earth but there's a lot of it in some types of asteroids which is why iridium is sometimes dubbed a space metal scientists suggested that the metal was probably brought by an asteroid in a collision event ten years later another team of researchers determined the exact site of the impact a crater with a diameter of 180 kilometers was discovered in the yucatan peninsula and was named chixula its age coincides with the dinosaur extinction chicxulub has a large amount of iridium and as you move away from the crater's center less and less metal is found in addition 25 000 animal fossil fragments were recently found in new jersey quarries these creatures died on the same day at the end of the cretaceous period this was another evidence of the mass extinction that followed the asteroid impact two minutes till the impact while our tyrannosaurus was enjoying its lunch a 10 kilometer rock weighing several trillion tons flew into the atmosphere the gravity's pull was becoming exceedingly stronger accelerating the object to a fantastic 20 kilometer per second speed like a piston the asteroid squashed one 20-kilometer air column after another along with friction this process heated the giant rock to tens of thousands of degrees celsius making it much brighter than the sun at the same time the tyrannosaurus was having a little break from its lunch it lifted its head up and was blinded by the light of the blazing sky the dinosaur quickly lowered its head closing its eyes but the light was burning them even through closed islands the heat incinerated the reptile skin set fire to the trees and grass around it a second later the asteroid disappeared over the horizon leaving the glowing sky behind tyrannosaurus rex got a little break but only for a moment nothing was happening for a few seconds but then the sky got blindingly bright the asteroid crashed into the gulf of mexico near the northern coast of the yucatan peninsula the energy released by the impact was approximately equivalent to 10 billion hiroshima atomic bombs in a second the asteroid penetrated about 20 kilometers into the earth's crust the whole globe was shuttering like a thousand bells from the impact [Music] to put this into perspective a relatively recent krakatoa volcano eruption caused half of a crew member's eardrums to rupture on one of the ships 70 kilometers away the asteroid's impact was a million times more powerful furthermore shock waves rushed in all directions faster than the speed of sound right after the collision they were so strong that they skinned animals alive lifted them up into the air swirled them around and crushed everything even hundreds of kilometers away from the crater the heaviest dinosaurs flew like balloons the t-rex sustained a severe concussion and died in an instant immediately the shockwave lifted its body up into the air for several seconds the wave continued to spread going a few times around the globe but even before killing the t-rex the asteroid destroyed the herd of alamosauruses that we saw previously animals were grazing right next to where the infernal rock fell dinosaurs couldn't escape the unthinkable heat it burned everything to the ground turning animal bones to ashes meanwhile the female ankylosaurus with her four babies was peacefully eating leaves in the forest they were hundreds of kilometers away from the impact site however they died even before the alamosauruses the red-hot asteroid caused huge fires while passing through the atmosphere one of them broke out where a family of ankylosaurus were grazing the fire instantly incinerated the forest leaving the reptiles no chance to survive the asteroid also knocked out 15 trillion tons of rock from the planet and sent it high into the sky a small portion flew into outer space while the remaining parts including house-sized boulders began to fall back from orbit at the same time glass rain started it was raining hot 5 millimeter rock falls the stone hail and the scorching rain have killed innumerable animals however the pachycephalosaurus who was hunting near the ocean in north america was lucky it didn't die from fires and boulders falling from the sky but a bit later when a gigantic 100 meter tsunami rose from the ocean to get some idea about its scale consider the devastating tsunami in japan of 2011.
those waves were barely 10 meters high nonetheless almost the entire island state incurred losses but the giant tsunami caused by the asteroid impact went thousands of kilometers deep into the land it flooded almost the entire territory of the future usa wave traces have even been found in north dakota one of these waves took the pachycephalosaurus under dragged its body into the ocean and buried it in the abyss the area of modern mongolia just then an elderly tarbosaurus was looking for a prey here kilometers from the explosion epicenter hundreds of dinosaur species still roamed wooded areas meanwhile the disaster was getting closer by the minute the asteroid impact triggered a series of terrible earthquakes measuring up to 11. 2 points the tremors were about 50 times stronger than any earthquake known to humanity the most powerful great chilean earthquake of 1960 had a 9.
