One day in 1 20xx, I was already a researcher in the Dinosaur Department of Chinese Academy of Sciences. One day, I took a time machine with several other researchers to the end of Cretaceous to see how the dinosaurs that ruled the earth for centuries became extinct.
When I got off the time machine, I saw a lot of cigarettes piled up on the ground, followed by a thick smell of smoke. I don't know what prompted us to go straight ahead with the smell of smoke. We came to a clearing where many dinosaurs smoked in twos and threes: Lei Long, Liang Long ... and even pterosaurs flew in the sky, as if possessed. Dinosaurs, large and small, smoked one by one with a cigarette in each mouth. How come, as people say, the extinction of dinosaurs has nothing to do with tobacco?
I checked the dangers of smoking with a pocket computer: there are hundreds of harmful substances in cigarettes. These harmful substances first play a great role in destroying the disease prevention function of respiratory system; Harmful substances in smoke can directly drive bronchioles and alveoli, paralyzing cilia on respiratory mucosa; Tobacco contains nicotine, which can also cause arteriosclerosis, heart disease and high blood pressure. There is also carbon monoxide in the smoke, which will also affect the ability of hemoglobin to carry oxygen, reduce the oxygen content in the blood, and the oxygen content in the brain is insufficient, which will affect memory and brain sensitivity ... and even lead to death.
I turned off the computer and walked forward with everyone. The scene before us is: dinosaur bodies are everywhere along the way, and some dinosaurs have a cigarette in their mouth; Someone has a cigarette in his hand, and half-smoked cigarette butts are everywhere on the ground. What a smoky world, a smoky ocean.
We didn't want to see it anymore, so we took the time machine back to the present. I pondered for a long time: the harm of smoking is so great that even dinosaurs can't resist it, so why do we humans smoke?
Speaking of dinosaurs, it's really mysterious and desirable! Dinosaurs lived in the Mesozoic from 23 million to 65 million years ago, which was divided into three periods, namely Triassic, Jurassic and Cretaceous. And how did such a huge prehistoric creature become extinct? Today, we will discuss it without taking precautions.
There are many opinions about the extinction of dinosaurs, so the controversy is overlapping, and I also have many ideas about the extinction of dinosaurs. Some people say: "In 65 million years, an asteroid hit the earth, causing the earth's crust to shake, leading to volcanic eruption. The fiery magma began to produce a fire, covering the sun all over the world. Plants died, and herbivorous dinosaurs cut off their sources and died like this. Carnivorous dinosaurs died without food. " Some people say: "Global warming, I don't know what the reason is, a highly toxic plant has grown on the earth. Some herbivorous dinosaurs who didn't know energy ate it and died. The weaker dinosaurs couldn't find food, so they ate the body of the poisoned dinosaur and died. So, when the news spread, the dinosaurs became extinct. " Others said, "A global earthquake plunged dinosaurs into the ground, because dinosaur fossils were dug out of the ground ..."
How did dinosaurs die out? Still waiting for us humans to think and discover. ...
Composition 3 Dinosaur Extinction One day, I went to the library and read a book about dinosaurs.
After reading it, I have been thinking, how did dinosaurs become extinct? Thinking, thinking, I was lost in thought ... It is said that dinosaurs died because an asteroid hit the earth, but I think that before the asteroid hit the earth, carnivorous dinosaurs preyed on herbivorous dinosaurs in large quantities, and herbivorous dinosaurs ate a lot of grass, which led to the destruction of the natural environment. Then, thieves began to steal the eggs of other dinosaurs.
And dinosaurs have been killing each other, and the air is filled with thick blood smell. Later, due to the crustal movement and volcanic eruption, the earth was full of volcanic ash and hot lava flows spewing out. It was dark, like purgatory on earth, and many dinosaurs became extinct. Later, the magma slowly walked into the forest, devouring one towering tree after another with its amazing flame, and slowly, the earth returned to calm. The herbivorous dinosaurs burned all the grass and leaves because of magma, and they all became extinct without food.
Carnivorous dinosaurs starved to death one after another because they had no food, and the only ones left fell into a deep quagmire. Suddenly, the volcano erupted again, the weather changed greatly, and magma spewed out of the ground. Dinosaurs were swallowed up by magma again and again. After volcanic eruption again and again and drought year after year in ........................................................................................................................................., dinosaurs died out slowly. I can't help but take a deep breath at the thought of this. At that time, dinosaurs wantonly destroyed the environment, leading to their own extinction, showing how much impact the destruction of the natural environment would have.
Therefore, none of us can destroy the environment! Moreover, being kind to the earth is being kind to yourself!
How dinosaurs became extinct has been puzzling people for many years. I didn't know until the 30 th century.
In the 30 th century, scientists invented the time machine and found that it can travel through time and space, and it has been widely used since then. At that time, most people reached the age of dinosaurs. The home where dinosaurs lived had to be divided into two halves with humans.
At first, humans just didn't disturb dinosaurs. They slowly caught them in zoos for the public to watch. Later, someone did kill dinosaurs. Later, more and more people hunted dinosaurs, and fewer and fewer dinosaurs. Because they are all eaten or kept as pets.
Finally, dinosaurs could not adapt to the present environment and gradually became extinct.
Man, wake up, don't be so greedy, your desire will never be satisfied.
There are no dinosaurs in the world because they are extinct, but how did they become extinct?
The first is the tsunami. Because there were more and more dinosaurs, the ground fell lower than the sea surface, so there was a tsunami. The second is the earthquake. The continent of the dinosaur era is not far away. If there is an earthquake in one place, if all places are shaken, dinosaurs will become extinct. The third is the volcano. There are volcanoes everywhere. The global temperature rises, volcanoes erupt together, and dinosaurs are scalded to death. The fourth is a meteorite. When the meteorite hit, the dinosaurs couldn't stand the impact and all died.
But I think there are too many carnivorous dinosaurs, and all the herbivorous dinosaurs have been eaten up. Carnivorous dinosaurs killed each other and died countless times. The last surviving dinosaur also starved to death.
The composition of dinosaur extinction 6 There were many kinds of reptiles in Mesozoic in the history of the earth. It is such a huge animal group that ruled the earth for 65.438+0.6 billion years and once flourished. At the end of Cretaceous, it was suddenly destroyed, which wrote a puzzling chapter in the history of biology. I think the reason why dinosaurs died out was that asteroids hit the earth.
I think this view is quite convincing. In recent years, among hundreds of protoceratops and Ankylosaurus fossils unearthed in Bayin Mandu Lake stratum in Inner Mongolia, a large number of dinosaur complete bones are piled together in groups. Judging from the burial posture of the remains, they died in extreme pain. Among them, there are two nests of Ankylosaurus cubs, who huddle together and snuggle up and look up. Obviously, something terrible happened when they died. On the Gobi desert in Mongolia, there is a fossil of a carnivorous dinosaur that hatched its eggs before it died. Its hind legs are separated, and its front paws are extended to the rear, showing that it is protecting its eggs. There are fifteen dinosaur eggs in its nest. These scenes of instantaneous death clearly show that they are catastrophic collective deaths, and the bodies are quickly buried on the spot after death. Many dinosaur fossils in other parts of the world have similar death characteristics. At the same time, it is found that the local fossil-bearing strata are brick-red silty strata, while dinosaur fossils are generally produced in sandstone strata. This sedimentary rock formed by a large amount of volcanic ash is the best environment for fossil formation. If there are no special circumstances, animal carcasses will soon be buried in situ, and so many complete individual fossils will not be preserved. If animals are exposed to the ground after death and cannot be buried quickly, the remains will be destroyed by external forces such as weathering and running water. Even if fossils are formed, they can only be residual limbs and broken arms.
We can speculate that the process of environmental upheaval is quite sudden and short-lived. Because, if the earth's environment changes gradually over a long period of time, the dinosaur population will gradually become extinct, and their burden will certainly be greatly affected, so many dinosaur eggs and the whole nest of dinosaur baby fossils will not be left behind. Therefore, most dinosaurs should have died in large numbers because of sudden devastating disasters when their living environment was basically normal.
Some small dinosaurs survived the disaster. Because of their advantages in survival, such as easy to hide to avoid changes in the external environment, eating less and hungry, and some' originally insignificant' animals that evolved into primitive birds and mammals as early as Jurassic, they followed the natural law of natural selection and survival of the fittest. In a relatively harsh environment, after 70 million years of continuous evolution, most species have changed their original forms. From cold-blooded animals with variable temperature to cold-resistant warm-blooded animals with adjustable body temperature-birds, mammals and humans-they gradually occupy the vast space on the earth's surface. Because of the origin of mammals and reptiles, dinosaurs can be seen on them, such as rhinoceros and ceratosaurus, platypus and platypus.
Although many people are skeptical about this asteroid impact theory, the fact is that frogs, crocodiles and many other temperature-sensitive animals survived the Cretaceous. This theory can't explain why only dinosaurs died. But so far, there is no obvious evidence that the mass extinction of dinosaurs was caused by the impact of asteroids and other influences from outer space.
Students, do you know that we humans have lived on the earth for two or three million years? Will you be surprised by this? But I tell you, compared with the survival history of dinosaurs, this is only a short moment. 450 words recommended for reading the mystery of dinosaur extinction.
For us humans, the earth used to be a world dominated by dinosaurs. Dinosaur is a very mysterious animal. During the long Mesozoic period from about 230 million years ago to nearly 1 100 million years ago, it lived on the earth and ruled the earth for 65.438+600 million years. After reading it, I feel that the recommended composition of Reading the Mystery of Dinosaur Extinction is about 450 words. In the late Triassic, they were born; Jurassic, dinosaurs ushered in its heyday; However, in the late Cretaceous, this creature suddenly disappeared, leaving us only fossils and endless mysteries. Students must really want to solve this mystery, so read The Mystery of Dinosaur Extinction (Color Picture Collector's Edition) edited by Baiyun as soon as possible.
This book not only leads us into the unknown dinosaur world, but also tells the story behind the phenomenon and reveals the truth behind the mystery. Moreover, the book directly attacks these unsolved mysteries through a large number of precious pictures, which shows students a broader cognitive vision and imagination space. As long as you open this book once, the interesting mystery tour will immediately appear in front of your eyes. Let's take a look at this magical world together!
The composition of dinosaur extinction 8 visited the VR Science and Technology Museum today. There are many novel discoveries in the VR Science and Technology Museum, and the most impressive one is that I saw the reasons and hypotheses of dinosaur extinction through VR technology.
The first hypothesis is the food poisoning hypothesis. Herbivorous dinosaurs ate a poisonous grass. After eating this grass, herbivorous dinosaurs had small creatures in their bellies, which poisoned them and killed them. Those carnivorous dinosaurs ate the bodies of the dead herbivorous dinosaurs and poisoned them. This repeated evolution led to the final death and extinction of dinosaurs.
The second hypothesis is that mammals prey on young. Many dinosaurs laid eggs. When they went out to look for food, small mammals ate dinosaur eggs, which led to the death of endangered dinosaurs. Finally, this led to the aging of dinosaurs, which made them extinct.
The third is the hypothesis that an asteroid hit the earth. In this hypothesis, an asteroid hit the earth, and then a lot of tiny dust was scattered into the air. Dark clouds covered the sun, and the day turned into a long night, making plants lose sunlight and unable to carry out photosynthesis. In the end, plants could not grow, which made most herbivorous dinosaurs extinct, which led to the lack of food for carnivorous dinosaurs, and eventually both carnivorous dinosaurs and herbivorous dinosaurs became extinct.
Today, I saw the extinction of dinosaurs, and learned that we humans should protect the ecological environment and abide by the rules of biological survival, otherwise we humans are in danger of extinction.
In the sky, groups of pterosaurs are flying around.
On the ground, countless dinosaurs are living and walking.
In the water, plesiosaurs are growling.
Yes, this is the end of Mesozoic.
A team of dinosaurs waded along forests and rivers. The leader is an old dinosaur, the elder of this team. It's going to a place with more fertile land. The sky is blue, the sun is shining and white clouds are fluttering. The jungle is lush, and many small dinosaurs are jumping around in it. Suddenly, the old dinosaur heard a long whistle and stopped. The dinosaurs behind saw the leader stop, so did they.
What is this? It doesn't know either. It saw all the "birds" living in the forest flying, and it felt the earth tremble slightly. The sound is getting closer and closer, and the regular vibration makes it immediately aware of the danger! It gave a cry and ran as fast as it could, and the dinosaur behind it immediately followed. It heard a terrible whistling again. Looking back, I was shocked: a Tyrannosaurus rex appeared at the edge of the forest-this behemoth was forty meters high. Dinosaurs became more and more afraid and tried to escape. But Tyrannosaurus Rex immediately caught up with them. After all, other dinosaurs took a dozen steps, and it could catch up in a step or two. It's ready.-start its killing.
But it stopped, and so did the other dinosaurs, as if they saw something that scared them. But this does not seem to be a terrible thing. A big meteor flashed by with its long tail. But this is not an ordinary meteor, it is so big that you can even see the fiery flame generated by friction when it passes through the atmosphere. It's approaching.
The dinosaurs just stood there, but they soon discovered the fatal problem. They scattered and fled, even the majestic Tyrannosaurus Rex at ordinary times was no exception. It's a pity that it's too late, and a huge fire group has approached them. Those old and frail dinosaurs had to stand and wait for death. Mother dinosaur picked up the little dinosaurs and threw them far away. The fire is just around the corner.
"Bang" a loud noise, suddenly flames, the sky was dyed in a mess. The meteor was impartial and landed in the middle of the burning forest. Because of the impact of this meteor, the ground was wrinkled, but there were more cracks. Unfortunately, those dinosaurs didn't know how they died when they died. High-temperature lava spewed out from the cracks, and the raised dust wrapped the earth tightly like a roll of paper. The earth is full of dead dinosaurs, and many plants are either burned or withered because they can't get sunlight. Many herbivorous dinosaurs became extinct, and carnivorous dinosaurs could not eat food, so they also became extinct. The flying dust blocked the sun.
The earth turned to ashes and the dinosaurs became extinct. A new period has begun.
The composition of dinosaur extinction 10 In that period when wind and rain turned into flowers and energy was evaporated by years, there lived a group of familiar and unfamiliar creatures-dinosaurs.
I walked into the stream of time and listened to their stories. Dinosaurs are creatures from unknown planets. They came to wake up the earth. After the first dinosaur landed in the wind, its cry made the earth's streams sing crisp songs; Every step it takes, there is grass watching it under its feet, and flowers nodding to it frequently; It lies on the grass, and there will be lush trees to shelter it from the summer sun. It happily returned to the planet, but forgot to close the door to the earth. Dinosaurs used this once-in-a-lifetime opportunity to come to the outside world-the earth. They have lived on the earth for hundreds of millions of years and acted recklessly. Although their leaders are fierce in appearance, they are like Lei Feng at heart. He sent messengers to spread the news and called the dinosaurs home. At this time, the asteroid hit the earth, causing volcanic eruption, thick rocks boiling, dense forests turning into a sea of fire, and the hot airflow caused the climate to be dry and nothing to grow. The dinosaurs lost their homes and disappeared from now on.
With the development of social economy and the improvement of scientific level, serious energy shortage and environmental pollution have appeared in energy utilization. Reducing automobile exhaust and industrial waste gas has become a top priority. If human beings continue to act recklessly, various pollutants will enter the earth's atmosphere; If all kinds of pollutants enter the earth's atmosphere, the atmosphere may be destroyed and fragmented; If there is no clean atmosphere, the earth will become dark and cold. Silent world, all creatures will leave this poetic world! Humans will be as miserable as dinosaurs, because the environment is deteriorating and resources are scarce, and they will go extinct. There is nothing delicious; There is no sweet clear water; Without that brilliant sunshine ..... Man will not be the master of the earth, but will just disappear in the long river of history like a dinosaur! Protecting the environment is urgent! Flowers expect the breeze to blow themselves more beautifully; Grass expects green to make its decoration dazzling; The brook expects the fish to play hide-and-seek with it; The earth expects human beings to join hands with themselves to protect this beautiful ecosystem.
Clouds pour into summer, another summer! The story of dinosaurs haunts me again. ......