This research is still going on about the reasons for the extinction of dinosaurs. For a long time, the most authoritative view was that the extinction of dinosaurs 65 million years ago was a huge meteorite. According to research, when an asteroid with a diameter of 7-1 kilometers landed on the earth's surface, it caused a big explosion, and the dust cloud formed by the atmosphere and clouds threw out a lot of dust, which led to the temporary cessation of the photosynthesis of plants and the extinction of dinosaurs.
The asteroid impact theory quickly gained the support of many scientists. In 1991, a long period of time was found in a crater in Mexico's Yucatan Peninsula, which further confirmed this statement. Today, this view seems a foregone conclusion.
But many people are skeptical about this asteroid impact theory, because the fact is: frogs, crocodiles, many people are very sensitive, and animals with temperature resisted Cretaceous survival. This theory can't explain why only dinosaurs died. So far, scientists have put forward the reasons for the extinction of dinosaurs. There should be more than a dozen exciting and dramatic meteorite collisions, but one.
In addition, according to the theory of meteorite collision, there are the following main viewpoints about the extinction of dinosaurs:
Climate change. 65 million years ago, the earth's climate changed suddenly, and the temperature dropped, which led to the decrease of oxygen content in the atmosphere, and dinosaurs could not survive. Some people think that dinosaurs were cold-blooded animals, but without hair or warm organs, they could not adapt to the temperature drop of the earth and froze to death.
species struggle. At the end of the dinosaur era, the first small mammals, which were rodent carnivores, probably ate dinosaur eggs. Due to the lack of natural enemies of this small animal, more and more people eventually eat dinosaur eggs.
/> Continental drift Geological research has proved that the only continent existed in the dinosaur era, and there is only one earth, namely "Pangea". A continental division occurred in Jurassic and drift phenomenon, due to crustal changes, which eventually led to changes in the environment and climate, and the danger of dinosaur extinction.
geomagnetic variation theory. Modern biology has proved that the death magnetic field of some organisms. The changes of magnetic field sensitive organisms in the earth's magnetic field may lead to extinction. It is inferred that the extinction of dinosaurs may be related to the changes in the earth's magnetic field.
5 angiosperm poisoning. At the end of the dinosaur era, gymnosperms gradually died out, replacing a large number of angiosperms. Gymnosperms did not have the toxins in these plants, and the huge dinosaurs had a strange appetite. Ingesting angiosperms led to the accumulation of toxins in the body and eventually they were poisoned from the body.
6 acid rain. During the late Cretaceous, there may be strong acid rain, trace elements, in which strontium dissolved in the soil, and dinosaurs, directly or indirectly, ingested strontium through drinking water and food, were acutely or chronically poisoned, and the last batch died.
Hypothetically, more than a few dinosaurs died out. However, these are several assumptions that have more supporters in the scientific community. Of course, the above method is imperfect. For example, "climate change" does not clarify the causes of climate change. After the inspection, some small dinosaurs, Osteoporosaurus, were competitive enough to fight against the early species of small mammals, saying that there were loopholes. Modern geology, continental drift theory "itself is still a hypothesis." Angiosperm poisoning "and" acid rain theory "also lack sufficient evidence. Therefore, the real reason for the extinction of dinosaurs remains to be further explored.
On our planet, many species have appeared and then disappeared in the history of biological evolution, which is a necessary stage. However, why such a huge dinosaur-dominated family suddenly disappeared from the earth has aroused our speculations. Scientists have been arguing about what happened at the end of the Cretaceous period 65 million years ago and what caused all dinosaurs and other creatures to die in large numbers. Some people say that the geological orogeny of the earth happened at that time, because many high mountains have grown to the plains, and the reduction of swamp wetlands has become less humid and warm to the climate. Breathing dinosaurs couldn't adapt to cold, dry, hot, dry air, and a dinosaur with winter food, so we went to a dead end. Some people say that it caused a strong supernova in the earth's climate change, and the temperature suddenly rose and then fell very low. It was dinosaurs that ate a lot of flowering plants, and many toxins in these flowers were eaten by dinosaurs, so they were poisoned. The evidence is that when flowering plants. Other wisdom says that it is because dinosaurs, a huge animal, kept farting and released a lot of methane gas into the air because they ate too much. Because they are too long, the survival time, the destruction of the earth's ozone layer destructive climate. Some people even said that as a result, aliens went to the earth to look for it because they thought dinosaur meat was particularly delicious. The evidence is the dinosaur bones they found in the North Pole, such as laser cutting marks. All kinds of miracles. However, it is widely recognized that a meteorite impact theory.
in the process of frequent conflicts in socialist modernization, developing countries are developing their economies and protecting the environment. Our economic development and the need to protect the environment.
first of all, we need to protect the environment, and economic development is the essential requirement of economic development. Economic development to improve their living standards. Economic development in China is the need to solve the people's growing material and cultural life. The country was born out of a semi-colonial and semi-feudal agricultural country. Weak economic foundation, industrialization, extensive contradictions, low level of economic development, protecting the environment in the process of economic development. Environmental protection, including the protection of people's living environment and natural environment. Urban economic development, especially industrial development, has a negative impact on residents living in rural areas, which is the destruction of the problematic natural environment and ecological environment. The purpose of economic development is to improve people's living standards and affect people's lives in the process of development, because it destroys the environment and goes against the original intention of economic development.
second, economic development must take environmental protection as the requirement of sustainable development strategy. We live in an environment where our children and grandchildren live. Our economic development and environmental damage, some of which are irreparable, are crimes against future generations. All countries in the world attach great importance to the strategy of sustainable development and develop green industries and pollution-free industries. China is a big country with a long history and civilization. In the process of economic development, we should pay more attention to environmental protection and leave a beautiful living space for future generations.
to meet the needs of economic development, protecting the environment is the requirement of natural laws. In the process of economic development, the natural environment is seriously damaged, so we will be severely punished. The loss caused by major floods is the inevitable result to the environment. The fear of human, material and financial resources consumed in the flood exceeds the fruits of economic development at the expense of the environment. The law of nature is ruthless, and whoever violates it will be retaliated by it. We must attach great importance to the protection of natural and social environment in the process of economic development.
the fundamental solution lies in the further economic development, the contradiction between economic development and environmental protection. Development is the last word. We can't afford to lose sight of environmental protection, economic development, and hold back on the ground to protect the environment. The way out is to develop the economy. To strengthen the awareness of environmental protection, use their brains. Economic development and environmental protection are not inevitable contradictions. On the contrary, economic development should promote environmental protection. With one more high-level science and technology, pollution-free green industry has a wide range of development. In a country with economic development and prosperity, conquering nature and transforming nature will naturally further strengthen the ability level and improve the development of productive people. People not only have the ability to protect the environment, but also can change it. The transformed desert turned into fertile farmland. Developing economy is the way to protect the environment.
the whole society should pay attention to economic development and environmental protection. In many places, many departments are sacrificing environment and economic development there. Historical and practical reasons, but from the perspective of development, people will have a deeper understanding of the importance of protecting the environment. In the process of economic development, leaders at all levels should establish environmental awareness, develop awareness of economic and environmental protection issues from a high-level strategic perspective, and vigorously develop the economy according to a global, integrated, while protecting the environment and improving people's living standards.
in a word, there is no contradiction between protecting the environment and developing the economy. We must pay attention to protecting the environment in the process of economic development.
of course, because of the harm of pollution. The earth is a circular world. In fact, there is no absolute waste on earth. Everything can be recycled. Human intervention, this cycle has been wrong, things that cannot be recycled. For example, the foam lunch box in earlier years. If this is the case, then it is a vicious circle. Therefore, the earth's resources will be consumed. Then, the earth is very dangerous. Protection measures should be as close as possible to the earth's cycle. We should do more "farsightedness" in prevention, instead of always focusing on economic goals. From the point of view of man and nature < P > It is estimated that scientists believe that dinosaurs have been discovered, and there are about 9 kinds of dinosaurs about dinosaurs. 12/4。
Extremely Stegosaurus, Whale, Dragon Lei, Longliang, Long Qi, Long Qi, Long Yu, Long Chong Long
Qilong Tulong Sui Longhua Yanglong Sliding Toothed Dragon, Megalodon of Odontosaurus, Kunming Dragon Side Defender, Atherosaur Bird, Dragon Plate Foot, Archaeosaurus Diplodocus, Chiroptera, Domesticated Dragon, Dragon Tuojiang Dragon Bat
appleton Tulong Eye Dragon Dragon, Fabres Dragon Building, Gas Dragon, Mamenxi Dragon, Su's Smart Dragon br/&
The single-spined dragon Yang Mamen Xilong in the Temple of General Ailavro Qutanlong.