A long time ago, about 200 to 70 million years ago, there is a huge family on our planet that rules the ocean, the land, and the sky. No other animal can fight them. They are the name is the overlord, this is the dinosaur.
At that time, the earth's climate was warm and humid, and there were dense forests everywhere. The forest was home to a variety of animals. Therefore, whether it is a plant or an animal dinosaur, there are endless foods.
Because of such a good environment, dinosaurs are generally huge. It is assumed that the largest dinosaurs are 30 meters long and weigh 40 to 50 tons. They can't pull them with the biggest bus now. Of course, there are also smaller dinosaurs, like the fine dragon, which is only 60 cm long and weighs 3 kilograms, which is similar to the chicken we have seen.
However, such a huge family suddenly disappeared from the earth very quickly. The time of disappearing is at the end of what scientists call the "Cretaceous". Why did dinosaurs disappear so cleanly at once? This is a scientific mystery. People have speculated for many years, but there has never been a positive answer.
Fortunately, some dead dinosaurs have not completely disappeared, their bones have become fossils and have been preserved by nature so that we know today that there are such animals in the past, and according to these skeletons, they are drawn to look like them. If you are interested in dinosaurs, you may wish to try to see if you can solve this mystery.
The study of dinosaurs is very meaningful. It not only helps us understand the evolution of the Earth's biology, but also allows us to understand the changes in the Earth's climate, the state of geological activities, the relationship between ourselves and the environment, and even the Every aspect of the cosmic celestial body.
There are many types of dinosaurs. According to the shape of their bone fossils, scientists divide them into two categories, one is called a dragon and the other is a lizard. According to their tooth fossils, it can also be inferred whether it is carnivorous or herbivorous. This is only a rough classification.
According to the restoration of dinosaur bone fossils, we found that there are not only many types of dinosaurs, but their shapes are nothing more than strange. These dinosaurs are flying in the sky, swimming in the water, and climbing on the land. Let's get to know them about it.
Pterodactyls lived in the Cretaceous and their bones were found in Europe. The pterodactyl is not very large, its wings are only about 22 cm. But the wing of the Aeolus stegosaurus is as long as 12 meters, as big as a bus. American scientists have discovered stegosauri with wings that are more than 15 meters long. If we can see it today, we might think that the plane is flying in the sky. Many flying dragons are somewhat like today's bats. They seem to use their hands to prop up huge wings. Therefore, the wings and the claws become a major feature. Some people think that the later birds evolved from them.
How did the huge stegosaurus fly to the sky? Scientists have different understandings about this. Some people think that the giant pterosaurs will not fly at all. They can't shake their wings like birds, but they can climb to the heights first and open the huge wings in the wind so that they can use the updraft. I glide in the air.
Others believe that the membrane on the stegosauri's wings is very stiff and that the outside of the wings are connected like a frame-like bone, so they can flap their wings like a bird. Because their wings are very large, you can get a huge reaction force and make yourself fly. Which of these two viewpoints is correct, there is no conclusion yet, and you may be able to crack it in the near future.
When the dinosaurs ruled the land, the ocean was also occupied by some giant reptiles. They are close relatives of dinosaurs on land and pterosaurs in the air. They also use the lungs to breathe the air and generally lay eggs. They are the hegemony of the ocean, some with sharp teeth, in order to prey on other fish.
These reptiles grow more or less like today's fish, some people think they are fish, and some people think that today's fish is what they change. There are also many kinds of monsters in the sea, like the crickets, turtles, snakes, crocodiles, etc. we have today, and there are similar types in the past. Such as dragons, such as the snake neck dragon and so on. The thin plate dragon is the longest plesiosaur with a total length of up to 15 meters. Its neck is about twice the size of the torso.
The dragon is a kind of plesiosaur, and their fossils have been found in Japan. They are measured to be about 7 or 8 meters long. And they have sharp teeth.
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