Dinosaurs

There are many kinds of dinosaurs, such as pterosaurs, Tyrannosaurus Rex and Stegosaurus. What is a dinosaur? It was a long time ago that there lived a huge family on our earth. Their offspring hatched from eggs, and their skin was covered with scales and impermeable. They ruled the ocean, land and sky, and all other animals could not compete with them. They were veritable overlords. This is the dinosaur. Dinosaurs ruled the earth for 16 million years from their appearance to their extinction.

dinosaurs generally lived in three periods in the history of the earth: Triassic, Jurassic and Cretaceous. Different kinds of dinosaurs survived and died out in these three periods. Each dinosaur may only have lived for 2-3 million years. At that time, the climate of the earth was warm and humid, and there were dense forests everywhere. There were all kinds of animals living in the forests. Therefore, no matter whether dinosaurs ate plants or animals, they all enjoyed endless food. Because of such a good environment, dinosaurs generally grew huge. It is speculated that the largest dinosaur is 3 meters long and weighs more than 5 tons, which can't be pulled by the largest bus now. Of course, there are also smaller dinosaurs, such as Palatosaurus, which is only 6 cm long and weighs 3 kg, which is similar to the chicken we see. Dinosaurs generally reproduce in the same way as living reptiles. Dinosaur egg in China is extremely rich, which is of great significance to the classification of dinosaurs and the division and comparison of strata. Dinosaur eggs are often produced in nests, with up to 2-3 eggs in a nest, overlapping several layers and arranged in concentric circles. The bigger the egg is, the closer it is to the center of the circle. Eggs are round or oval in shape, with a small diameter of only 5-6 mm and a large diameter of more than 5 mm.