Plot
In the Pacific Northwest, a Quetzalcoatlus is soaring above the valley during a rainstorm when it spots an unguarded Tyrannosaurus nest. The pterosaur then flies down and consumes several young babies. Meanwhile, the father Tyrannosaurus is hunting for prey in the forest when his acute sense of smell alerts him to the intruder and runs back to the nest. The pterosaur is forced to flee when the enraged father arrives, trying to take off but its huge wings prevent it from flying in the forest. The Tyrannosaurus repeatedly lunges and tries to kill it. It finally takes off just as the father bites its foot, though the pterosaur manages to break free of his jaws by pecking at his eye and then flying away. Only one hatchling survives the attack.
A male Triceratops loses a fight for mating rights against another male Triceratops. Two Tyrannosaurus hear the commotion and close in to attack the loser. Working together, they bring down the Triceratops and eat it together.
Meanwhile, in Mexico, a herd of Alamosaurus, relatives of the French sauropod Hypselosaurus , are roaming the plains in search of food. A female lays a clutch of eggs as an asteroid enters the atmosphere. The asteroid hits the Earth in Mexico, causing a big explosion and sending debris shooting through the air. The explosion heats the air temperature near the site to hundreds of degrees. Hundreds of alamosaurs are burned alive. Moments later, burning debris comes raining down from the sky, crushing many Alamosaurus. Afterwards, an earthquake cripples the rest of the herd before the blast arrives and finishes off the last of the Alamosaurus. Most of the alamosaur eggs are destroyed but some survive, buried under the soil.
In what is now Mongolia, a herd of Charonosaurus , relatives of Hypacrosaurus and Parasaurolophus , reside by a watering hole, where the females lay their eggs. A Saurornithoides, an Asian relative to the Troodon , steals an egg from one of the nests, but is soon confronted by the enraged mother Charonosaurus. A second Saurornithoides appears however, which forces the Charonosaurus to flee. The two predators chase their prey and eventually manage to bring her down.
The impact has caused a searing hot ejecta cloud to begin engulfing the planet. As it approaches the pacific northwest, the earthquake from Mexico arrives and begins to decimate the area. A pair of Triceratops flee up the mountain slopes whilst a mated pair of Quetzalcoatlus try to escape their nest by flying away, but are quickly caught in the approaching cloud, which is showering burning debris. The debris burn holes in the Quetzalcoatlus wings, and the male's wings eventually lose their ability to keep him in the air, and he falls to his death, his mate eventually having to land to avoid the same fate. The pair of Triceratops make it up into the mountains, only to be engulfed by the ejecta cloud, which scorches them alive.
The intense heat from the ejecta cloud ignites fires around the world, including in the pacific northwest. This causes a firestorm to form that reaches speeds of 9mph. All large dinosaurs, including a feeding T. rex, a group of Triceratops and an Ankylosaurus, a related cousin of Hylaeosaurus , are forced to flee whilst smaller animals hide underground. The female Quetzalcoatlus, who was mourning her mate, is also forced to fly away as the firestorm consumes the forest.
In Mongolia, forty-five minutes since the impact, the ejecta cloud rolls in from the east, increasing the temperature around Mongolia by several degrees every second until it reaches 300°, causing three Charonosaurus and a pair of Saurornithoides to use the cave for shelter. The temperatures return to normal after five hours, and as the pair of Saurornithoides run outside to feast on the corpse of a nearby Charonosaurus, while two of the surviving Charonosaurus travel to the watering hole. The third stays put. However, the dramatic shift in temperature causes a gargantuan sandstorm. The Saurornithoides survive by hiding behind their prey, while the third Charonosaurus remains in the cave. The two other Charonosaurus however get caught in the storm and quickly suffocate. The storm eventually passes, and the last Charonosaurus heads to the watering hole on her own, with the surviving Saurornithoides making their way there too, where they find the Charonosaurus taking a drink. They are desperately hungry, yet they are too weak from their ordeal. One of them recklessly attacks the Charonosaurus, but after a quick struggle, the hadrosaur collapses on top of it, killing it. The remaining Saurornithoides resorts to cannibalizing the corpse of its companion.
Four days since impact, food is in short supply across the entire planet. In the Pacific Northwest, four Triceratops head towards an island untouched by a firestorm in search of food. The cause of the island forms a huge megatsunami, but also causes the water to recede and form a bridge to the ocean. Three of the Triceratops cross the land bridge to the island. The remaining female Quetzalcoatlus lands, where she eats a stranded fish, just as the wave builds and races towards shore. She attempts to take off but is caught into the 300-foot wave and drowns, with the wave drowning three Triceratops as well.
Ten days have passed since impact, only a few dinosaurs remain. In Mongolia, the Charonosaurus stays close to the watering hole, but collapses and dies from inhaling gas that rose up from the hole's basin. The Saurornithoides runs up to the dead Charonosaurus, but it too is killed by the toxic gas.
Back in the Pacific Northwest, a small number of dinosaurs patrol the grey wasteland. A starving Ankylosaurus finds a small bush, and almost faces off with a Triceratops over it, until a T. rex arrives. Attacking the Triceratops first, the T. rex loses an eye to his prey's right horn, but he then manages to break off its left horn and kills it by lunging and biting down on its neck. The T. rex then turns his attention to the Ankylosaurus and after being struck in the leg, flips it onto its back and bites its throat. He then heads back to the dead Triceratops, but trips over the Ankylosaurus and has his neck impaled on the Triceratops's remaining right horn. Back in Mexico, an Alamosaurus egg, sheltered safely under the ground, hatches as the last remaining dinosaurs across the world try to repopulate. However, crippled by inbreeding and disease, their tiny population eventually disappears, ending the dynasty of the dinosaurs.
Life on Earth was not completely destroyed, however. Insects and other arthropods took shelter underground, as well as small reptiles. Crocodilians, amphibians and fish hid beneath the water, and birds flew or swam away from disasters. One group of animals, mammals, hid in burrows beneath the ground. With their ability to adapt better and reproduce quicker, they were able to outlast the apocalypse. As the ejecta cloud cleared and sunlight returned to the Earth, plants began to flourish once more, especially ferns. Over the 65 million years after the dinosaurs disappeared, mammals grew to dominate the planet, leading to the evolution of humans, which now rule the Earth, just as the dinosaurs once had.
