Dinosaurs first appeared about 230 million years ago. They dominated the Earth for about 135 million years until an extinction event wiped out all but bird-like dinosaurs 65 million years ago.
Dinosaurs had different shape and size ;they have been the biggest land animals of all time. They spread out on lands, seas and skies. Some were herbivorous, others carnivorous. While dinosaurs were ancestrally bipedal, many extinct groups included quadrupedal species, and some were able to shift between these stances.