1 climate change. Because 65 million years ago, the earth's temperature dropped sharply, resulting in a sharp drop in the oxygen content in the air, and dinosaurs were cold-blooded animals, which were difficult to adapt to the earth's temperature and led to extinction.

The volcano erupted. Due to volcanic eruption, the content of carbon dioxide rises, which leads to the greenhouse effect on the earth. A lot of food died, and dinosaurs starved to death because they couldn't find food.

3 orogeny. Because plants changed 65 million years ago, and dinosaurs were herbivores, when they didn't eat enough food, they would become extinct.

The ocean is ebbing. Because of the low tide of the ocean, many creatures on the earth are connected with each other. In addition to the relationship between eating and being eaten, there are also diseases and parasitic infections, which led to the extinction of dinosaurs.

5 species aging. Because dinosaurs have multiplied for hundreds of millions of years, their bodies are aging and life is inconvenient, which eventually leads to the extinction of dinosaurs.