Dinosaurs have lived on the earth for about 65.438+0.65 billion years, and they are representative and symbolic species of Mesozoic. Dinosaurs only appeared in the Middle Triassic about 230 million years ago. After Mesozoic Jurassic and Cretaceous, it was not extinct until 65 million years ago. Lived together on earth for 165 million years.

The Mesozoic began in Triassic about 240 million years ago and ended in the end of Cretaceous about 65 million years ago, with a time of about 65.438+75 million years. But in the early Triassic of Mesozoic, only primitive reptiles and dinosaurs did not appear.