1, Triassic: About 250 million to 200 million years ago, serrated reptiles slowly developed into the earliest dinosaurs. By the late Triassic, dinosaurs were already a variety of ethnic groups and were called "the dawn of dinosaurs". Triassic ended with an extinction event, which made many Serrati animals extinct, but it provided great opportunities for dinosaurs to develop.
2. Jurassic: about 65.438+99.6 million years BC (with an error of 600,000 years) to 65.438+45.5 million years BC (with an error of 4 million years). In the early Jurassic, because of extinction, all kinds of animals and plants were very scarce (in the stage of recuperation), but dinosaurs stood out and waited for opportunities to dominate the land. After the middle and late Jurassic, dinosaurs ruled the earth for 65.438+0.5 billion years.
3. Cretaceous: It started 6.5438+45 million years ago and ended 66 million years ago. The species of dinosaurs reached its peak in Cretaceous, and the most famous one was Tyrannosaurus Rex. At the end of Cretaceous, a large number of dominant reptiles disappeared on the surface, dinosaurs were completely extinct, mammals survived the crisis, occupied the ecological environment where reptiles such as dinosaurs withdrew, and quickly evolved into new rulers.
Extended data
The discovery of dinosaurs
Dinosaurs are a kind of reptiles that appeared in Mesozoic. The vigorous limbs, long tail and huge body are the portrayal of most dinosaurs. They mainly inhabit woodland or open areas in lakeshore plains (or coastal plains). There are many kinds of dinosaurs, and their shapes and habits are very different. The largest fragile double-chambered dragon may be more than 50 meters, while the smallest hummingbird may be less than 10 cm.
It was not until the19th century that people knew that dinosaurs once existed on the earth. The first person to find dinosaur fossils was gideon algernon, a British doctor, and Chad Owen, a British paleontologist, coined the term dinosaur.
Baidu encyclopedia-Triassic
Baidu encyclopedia-Jurassic
Baidu encyclopedia-Cretaceous