稍迁至栘中厩监:关于恐龙（英文的）

I AM NOT A KONG LONG

Death of dinosaurs
In the Mesozoic period which wa about 70 million years ago to 20 million years ago was a flourishing time for creeping animals. They were the emperors of the earth., reigning the sea, the land and the sky. We call this kind of animal " dinosaur".
There are many types of dinosaurs. We can divide them into two kinds, bird dinosaur and lizard dinosaur according to their pelvises, and divide them into meat-eating kinds and grazer kinds according to the food they ate. There were big-sized dinosaurs and small-sized. It is presumed that the heaviest dinosaur was about 80 meters in length, 40~50 tons in weight, while the slim crocodile dinosaur was only about 60cm in length, 3kg in weight, almost like hens. Dinosaurs had different living spaces, some flying in the sky like bats, some swimming in the water like dolphins, some living on the land upright.. Such a big dinosaur family suddenly disappeared 65 million years ago. Some sea creeping animals, flying creeping animals, some fishes and other living animals, etc., accompanied those dinosaurs to death. Their death still is a big mystery to the scientists.

There is an acceptable saying that groups of dead dinosaurs have some relationship with the move of the earth. During the Mesozoic period, many hills took the place of swamps. The climate also changed, cold seasons and warm seasons began to appear by turns. So the cold-blooded dinosaurs could not adapt themselves to such cold weather, their body temperature began to fall with the decline of temperature, then they died. On the other hand, their breath organ could only stand wet and hot air, not dry and hot air. Due to the changes of the climate, the flourishing plants, such as some fern began to disappear, everything withered, and dinosaurs began to face the disaster of hunger. Since dinosaurs' body structure had defined itself after a long evolution, they could not adapt themselves to such a sudden change. Death was the only way for them to go. Only some dormient snakes, dinosaurs of lizard kind, some small mammals with furs on their body which could hide themselves in caves avoiding coldness and some birds were left alive. There was a theory similar to the above theory to say that the death of dinosaurs was directly caused by the continental shift. When dinosaurs appeared on the old mainland, there might have been a dinosaurs' heaven. Until Jurassic, the old mainland came to crack into small pieces and began to float in all directions. Due to the move of the land, climate went worse, temperature went down, huge changes happened on the dinosaurs' environment by the end of the Cretaceous period. They didn't have any cold-resistant supplies or any physical energy to avoid such coldness, so all of them went to death.
There is also an academic opinion in the science world, they thought that the death of dinosaurs was due to the impacts of meteorites. This was called meteorites sciences. Some scientists presumed that some small planet fell into the sea, speeding at 40 kilometers / second from the sky, forming a deep hole within 4 seconds, with high-temperature smoke poles reaching to a height of 40 kilometers and surfs 5 kilometers high and its gasified dust attacking the earth. At this time, snow on the icy earth began to melt away, the plants began to die, dinosaurs were covered under the earth. Of course, this meteorite might have fallen on the mainland, that would have aroused more serious destruction. Until now, there is no clear evidence which could prove such a presumption. If such a thing happened on the earth, we should find a big meteorite hole on the surface of the earth. Some scientists presumed that such a meteorites' fall on the earth was not in one piece, but in thousands like heavy rain. Though they were small, the power of every meteorite was more than several A-bombs. Falling on the land together would result in entire destroy.
Some astronomers forwarded a theory of a supernova explosion. These supernova are some shining star bodies which could perish suddenly. Due to the temperature and the density of the star nucleurs overstepping the ambit of the star body itself, a burst resulted, emitting strong visible light, cosmic rays and X-rays. This was called a supernova explosion. The X-rays emanated from the burst would carry high energy, the same energy as 10 suns, raising the earth's surface temperature. Big typhoons and strong storms appeared on the surface of the earth, the high-temperature air formed into icy clouds and hid the sun. Since the dinosaurs had adapted themselves to warm weather, such a sudden cold weather brought them to death.
Some biologists considered that dinosaurs died out because of food poisoning. The food dinosaurs ate, such as fern, cycad, gingko, pines, etc. are plants with no flowers, they would do no harm to dinosaurs. But some plants with flowers appeared afterwards, their flowers contained much alkaloid with much poisons. Dinosaurs ate many such plants which resulted in their death.
Many dinosaur fossils were discovered in the ZiGong area in China, which was called "Dinosaurs' home", many foreigners admired the Chinese and called them "rich men with dinosaurs". After scientists analyzed these dinosaur fossils using spore powder, sediment, spectral analysis, etc., they discovered that the arsenic in these fossils was over 100PPM., so they thought that these poisonous plants caused the death of dinosaurs.
Except this, scientists also made all kinds of presumptions on the dinosaurs' death.. Some people thought that mammals were shrewd with agile action at that time, so they often robbed dinosaurs' food, which made ponderous and stupid dinosaurs hungry to death. They also stole dinosaurs' eggs to eat so that dinosaurs lost their offspring.
Some people presumed that volcanoes broke out frequently at that time. Eruption polluted air and hid the sun, so the whole environment changed suddenly. Devoid of oxygen and rain, swamps and mountains dried up, so plants went to death. In such a bad situation, dinosaurs had to disappear from this world.
A French scientist named Daditeur forwarded his unique idea on the extinction of dinosaurs. He thinks that dinosaur broke wind a lot and released a lot of methane into the air. Because they were in such a great number, the wind they released destroyed the ozonosphere and formed a destructive climate.
There was an abroad research team having a 20 years' study on dinosaurs and drew a conclusion that visitors from another planet destroyed the dinosaurs. An ancient anthropologist from the former Soviet Union said: "Visitors from another planet began to hunt dinosaurs 60 million years ago, and destroyed this animal within thousands of years." Dinosaurs has some intimate relationship with birds. To these visitors, dinosaurs were just like delicious chickens. They hunted tons of dinosaurs meat every year. Four years ago, a dinosaurs tomb was discovered in Arctic Pole, which proved his viewpoint. In that tomb, thousands of dinosaurs were discovered, on some of their brain bones laser cut marks had remained. There is some hint that visitors from another planet brought dinosaurs to their planet as their domestic animals, maybe they had sensed that dinosaurs would disappear from the earth some day.
Other ancient anthropologists agreed with his scientific report. An English expert said: "We have some actions in common with those visitors from another planet, such as overhunting, leading animals to extinction. So his idea sounds reasonable.". Some ancient anthropologists decided to look for a slaughterhouse in Arctic Island.
Which is the most reasonable explanation or the truth? We believe this mystery will surely be uncovered some day.