Prehistoric animals that humans have never seen, how did they depict what animals looked like?

The only way to understand ancient earth life is through fossils, there are several kinds of fossils, one of which is a huge creature, because of gravity, a large creature must have a structure that is hard enough to support the body shape, that is, the skeletal system, there are more inorganic substances in the bones themselves, and fossils are formed after complex physical and chemical reactions underground; Others are fossils of small animals, and the body tissues of mollusks are more difficult to form fossils, so many mollusk fossils are just fossils left by their imprints after death.

Fossils are more difficult to form, and those that can form obvious fossils are mostly larger organisms, while smaller organisms without hard structures are more likely to form fossils. Moreover, large fossils are easier to find, and small biological fossils or imprinted fossils need to be carefully investigated, and the probability of discovery is lower. A variety of factors lead people to have the illusion that prehistoric animals were relatively large, when in fact the largest animals in the age of dinosaurs and modern creatures are about the same size, but there is one obvious difference, that is, the evolution of the size of animals on land.

There have been dinosaurs on land that are roughly the same size as blue whales, and there have been insects up to several meters long, and some scientists have believed that the difference in body size is the difference in the oxygen content of the earth's atmosphere at that time, but in biological research, raising insects in an environment with high oxygen content, the size of insects can be increased, but it is also limited, and it cannot grow indefinitely, and it is good to increase the size by 30%.

Geological research has found that the atmospheric oxygen content of the Carboniferous period is about 35%, there were many large insects at that time, but the age of dinosaurs did not come, and in the later Permian, the atmospheric oxygen content decreased to about 15%, but the era of megafauna came, and many large dinosaurs appeared, which shows that the body size is not affected by the oxygen content alone. The most important is probably the earth's environmental factors, the earth's environment as a whole is constantly changing, but in some historical periods, it will remain relatively stable, in the history of several large animal concentration period, are the long-term more stable environment period, the earth's land plants can provide sufficient food for animals, animals can reproduce and grow recklessly, due to the factors of survival competition, those who are larger are relatively easier to survive, so the size of animals is roughly in this direction.

Today's land animals are all left over after the mass extinction event 65 million years ago, and some animals are getting bigger and bigger, giraffes and other mammals have this trend, but they have not been able to reproduce the size of dinosaurs, and some mammals have returned to the ocean and evolved into the largest animal on the modern earth - whales.

Humans excavate a large number of fossil specimens of prehistoric animals, and then use modern technology, such as computer scanning technology and computer 3D imaging technology, to simulate these specimens in computers.

Although prehistoric animals have not been seen by humans, the size and appearance of prehistoric animals can be deduced from the fossils and modern 3D simulation technology based on excavated fossils, and the simulation can be carried out.

Humans have never seen prehistoric animals, so all the portraits of prehistoric animals are all guessed based on bones, and they are not real.

The history of the earth is at least 4.6 billion years, and the history of human beings is only a small part of it, so what animals were there on the earth in the prehistoric period before the emergence of human beings? Why did the trilobites, which once dominated the oceans, suddenly disappear? Why did the dinosaurs that once dominated the land suddenly go extinct?

Let's think together and swim in the ocean of knowledge. It lived in the early Triassic period of geohistory about 200 million years ago, and it is also considered by many scientists to be the ancestor of all mammals on earth, so it is also considered the ancestor of humans.

Stoneclawed lived 12 million years ago, and its body size was similar to that of a modern horse, with claws on its feet and shaped like stones, so it was called Stoneclaw.