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.
The impact, with a force equal to billions of atomic bombs, caused tsunamis, earthquakes, and a global dust cloud that blocked out the sun. This led to a drastic drop in temperature and the collapse of photosynthesis-dependent food chains. The crater, more than 150 kilometres in diameter, is still visible in geological data beneath the Gulf of Mexico region.