In the Middle Triassic, the first primitive dinosaurs appear, small and swift bipedal reptiles.
A large-scale extinction wave removes many competing reptile species, allowing dinosaurs to become the dominant land animals.
Enormous herbivorous sauropods such as Diplodocus and Brachiosaurus dominate the landscapes of the Jurassic.
Archaeopteryx, a transitional form between dinosaurs and birds, develops in the Late Jurassic.
In the early Cretaceous, the first angiosperms appear, drastically changing vegetation and ecosystems.
Species such as Tyrannosaurus rex, Triceratops and Ankylosaurus dominate a rich and diverse ecosystem.
A massive asteroid strikes near what is now the Yucatán Peninsula, causing worldwide devastation.
Most dinosaur species become extinct as a result of the climatic effects of the asteroid impact.
A small group of feathered dinosaurs survives the mass extinction and evolves further into modern birds.
These immense four-legged plant eaters developed long necks to reach high vegetation and lived in herds on vast plains of ferns and conifers. Their enormous size, some up to 30 metres long, made them the largest land animals ever to have existed. Predators such as Allosaurus hunted young or weak specimens of these colossi.