The sudden disappearance of dinosaurs at the end of Cretaceous 65 million years ago became a mystery in the evolutionary history of life on earth. This mystery has not been solved so far. In the past, all living things on the earth were recorded in fossils. Many dinosaur fossils have been found in Mesozoic strata. A large number of bones or various shapes can be seen in it.

However, in the subsequent Cenozoic strata, there were no fossils of non-bird dinosaurs at all, thus inferring that non-bird dinosaurs died out together in Mesozoic, and now only birds are left. Most scientists agree that "birds belong to dinosaurs".

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. As far as eating habits are concerned, there are docile herbivores and fierce carnivores, as well as omnivorous dinosaurs who are both vegetarian and vegetarian. Ruled the earth for about 80 million years.

Second, physical characteristics

Dinosaurs as a whole are very big. According to dinosaur standards, lizard's foot is one of the behemoths. In the long dinosaur era, even the smallest sauropods were larger than other animals in their habitats, while the largest sauropods were several grades larger than any animals that appeared on the surface.

Most dinosaurs were much smaller than large sauropods. The estimated weight of dinosaurs is mostly between 1 and 10 metric tons. A study by the National Museum of Natural History in London pointed out that the average weight of dinosaurs was about 100 kg, while the average weight of new generation mammals was between 2 and 5 kg.

The disappearance of extended information dinosaurs

Dinosaurs first appeared in the late Triassic period about 235 million years ago and died out in the late Cretaceous period about 65 million years ago.

In the Mesozoic era more than 200 million years ago, some dinosaur fossils became turtles, crocodiles, snakes, lizards today, and some evolved into mammals all over the world today. Dinosaurs are the largest of all land reptiles.

So dinosaurs ruled the earth for more than 100 million years, but for some reason, they suddenly became extinct in a short time 65 million years ago. What people see today is only a large number of dinosaur fossils left at that time.

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