In Greek, Mesozoic means "middle"+"creature". Mesozoic is between Paleozoic and Cenozoic. Because the dominant animals in this period are reptiles, especially dinosaurs, it is also called the reptile era.
Mesozoic is also an era of great changes in plate, climate and biological evolution. At the beginning of Mesozoic, the continents were connected as a supercontinent-Pangea. Pangea was later divided into two parts: North America and Eurasia, and South America, Africa, India and Madagascar, Australia and Antarctica. Only Australia was not completely divided from Antarctica. The Mesozoic climate was very warm, which had an impact on the evolution of animals. At the end of Mesozoic, the embryonic form of modern biota has been seen.
The Mesozoic era ranged from 252 million years ago to 66 million years ago, starting with the Permian-Triassic extinction event and ending with the Cretaceous-Tertiary extinction event, spanning10.80 billion years. Mesozoic can be divided into the following three periods:
Triassic: 250 million years ago to 200 million years ago Jurassic: 200 million years ago to145 million years ago Cretaceous:145 million years ago to 66 million years ago.
The lower limit of Mesozoic is the Permian-Triassic extinction event, which wiped out 90% to 96% of marine organisms and 70% of terrestrial organisms at that time, and was also the most serious extinction event in the history of biological evolution.
The upper limit of Mesozoic is the Cretaceous-Tertiary extinction event, which may have been caused by the Hicksulubo collision event in the Yucatan Peninsula. This extinction event caused 50% species to disappear at that time, including all non-bird dinosaurs.
Basic introduction Chinese name: Mesozoic mbth: Mesozoic Era alias: dinosaur era time: about 250 million to 65 million years. Name origin: Geologist J. Phillips put forward the main famous animals in 184 1 year: dinosaurs and ichthyosaurs. Pterosaurs, etc. Presented by J. Phillips: introduction of time: 184 1 year, environment, plants, geology, plates, animals, climate, major events, mass extinction, biological evolution, introduction In Greek, Mesozoic means "intermediate"+"biological". Mesozoic is between Paleozoic and Cenozoic. Because the dominant animals in this period are reptiles, especially dinosaurs, it is also called the reptile era. Mesozoic is also an era of great changes in plate, climate and biological evolution. At the beginning of Mesozoic, the continents were connected as a supercontinent-Pangea. Pangea was later divided into two parts: North America and Eurasia, and South America, Africa, India and Madagascar, Australia and Antarctica. Only Australia was not completely divided from Antarctica. The Mesozoic climate was very warm, which had an impact on the evolution of animals. At the end of Mesozoic, the embryonic form of modern life has been seen. The Mesozoic era ranged from 2.5 1 100 million years ago to 66 million years ago, beginning with the Permian-Triassic extinction event and ending with the Cretaceous-Tertiary extinction event, spanning10.800 billion years. Mesozoic can be divided into the following three periods: Triassic: 252.2 million years ago to 200 million 1 300,000 years ago, Jurassic: 200 million 1 300,000 years ago to Cretaceous:145 million years ago, and the upper limit of Mesozoic is Permian. The lower limit of Mesozoic is the Cretaceous-Tertiary extinction event, which may have been caused by the Hicksulubo collision event in the Yucatan Peninsula. This extinction event caused 50% species to disappear at that time, including all non-bird dinosaurs. Environmental plants Mesozoic plants, true ferns and gymnosperms are the most prosperous. By the end of Mesozoic, angiosperms had developed greatly, while gymnosperms still occupied an important position. At the end of Mesozoic, famous extinction events occurred, especially the extinction of dinosaurs and ammonites. Some people think that the extinction event is related to the impact of extraterrestrial small objects on the earth, but the real reason needs further study and determination. Mesozoic pteridophyte geology In the middle and late Mesozoic, the plates drifted faster, subducted and squeezed on the contact zone between the ocean and continental crust with subduction zone, which led to the famous Yanshan Movement (or Pacific Movement), forming a large-scale circum-Pacific magmatic belt, terrane accretion belt and various endogenetic metal and nonmetal mineral belts. The climate of Mesozoic was generally warm, and there were usually only differences between tropical, subtropical and temperate zones. The continental position of the plate in the late Paleozoic is quite unclear, and scientists have been able to roughly calculate the continental positions in Mesozoic. At the beginning of Mesozoic, the continents were connected as a supercontinent-Pangea. Pangu was later divided into two parts, namely, Lauea in the north and Gondwana in the south. The division of continents forms a passive continental margin along the Atlantic coast, such as the eastern coast of the United States. During the Mesozoic, the continents gradually moved to their present positions. Lauea is divided into North America and Eurasia, Gondwana in the south is divided into South America, Africa, India and Madagascar, Australia and Antarctica, and only Australia is not completely divided from Antarctica. India collided and converged with Eurasia in the Cenozoic era, forming the Himalayas. Animal dinosaurs were not "completely extinct". As early as Jurassic, some dinosaurs flew into the blue sky, and their body structure changed significantly, avoiding the extinction. They are all kinds of birds today, and birds are the direct descendants of dinosaurs. Reptiles are not completely extinct. A considerable number of reptiles escaped the catastrophe because of their small size and easy hiding, and their strong adaptability to the environment, and have survived to this day. Today, these reptiles still live on our earth. They are chameleons, the camouflage masters in the dense jungle, small lizard subjects that inhabit the walls and ceilings of our bedrooms-geckos, chilling snakes and crocodiles, slow-moving turtles and so on. Mesozoic Mammals and Their Fossil Climate The Triassic global climate was relatively dry and varied greatly seasonally, especially in the interior of Pangea. Since the late Carboniferous, the global climate has gradually become dry. The low sea level during this period may have contributed to extreme temperatures. Because of the high specific heat of water, large-volume water bodies can stabilize the temperature, especially the ocean, while the land temperature adjacent to large-scale water bodies changes little. Because the inland areas of Pangea are far away from the ocean, the temperature in these areas varies greatly, and there may be vast deserts. A large number of red beds and evaporites (such as salt) support this theory. During the Jurassic period, the sea level began to rise, probably because of the acceleration of submarine expansion. The newly formed marine crust has raised the sea level to about 200 meters above sea level today. In addition, Pangea began to split and formed Tethys Ocean. The temperature gradually rises and stabilizes. Because the continents are adjacent to the ocean, the desert shrinks and the humidity in the atmosphere increases. The climate of Cretaceous is uncertain and controversial. The high content of carbon dioxide in the atmosphere makes the temperature gradient between the tropics and the polar regions smoother, and there is little difference between the temperatures in different regions. The average temperature is about 10℃ higher than today. In the middle Cretaceous, the ocean bottom temperature in the equatorial region was about 20℃, which may be too warm for many marine life, and the land adjacent to the equatorial ocean turned into a desert. The oxygen circulation system in the lower ocean may be slow and interrupted. Therefore, a large number of biological organisms can not be decomposed smoothly, and then a large number of accumulation, and finally deposited into oil shale. Mesozoic reptiles However, not all existing data can support the above hypothesis. Even if the global climate is warm, the polar ice caps and glaciers still cause the most temperature changes; However, there is no evidence of the existence of ice caps and glaciers in Cretaceous. The quantitative model may not be able to reconstruct the flat temperature gradient of Cretaceous. During the Mesozoic, the oxygen content in the atmosphere was about 12%~ 15%, which was lower than the present 20%~2 1%. Some scientists even put forward the oxygen content of 12%, because this is the lowest oxygen concentration for natural combustion. However, a study in 2008 considered that the minimum oxygen concentration for natural combustion was 15%. The major event extinction The Cretaceous extinction event that occurred at the end of Mesozoic resulted in the extinction of 50% creatures, including all dinosaurs. Most scholars believe that a comet hit the earth, causing great climate change, and many animals, especially cold-blooded animals, could not adapt to the low temperature and became extinct. But why cold-blooded animals such as crocodiles survived at that time is still unanswered. Biological evolution in the early and middle Mesozoic was dominated by reptiles on land, but at this time, primitive mammals and primitive birds appeared, and prosperous angiosperms also developed at this time. In the middle and late Jurassic, a large number of feathered dinosaurs, early birds, ancestor groups of modern insects and angiosperms appeared, indicating that this period was an important period of change. However, the extinction at the end of Cretaceous in the late Mesozoic made the once prosperous reptiles decline, and new species began to occupy the niche left by reptiles, thus a new era-Cenozoic was born. The Triassic extinction event of the Paleozoic trilobite occurred at the end of Permian, which wiped out most of the creatures on the earth at that time and made many creatures begin to adapt to radiation after the event. Millions of years after the extinction event at the end of Permian, large-scale main dragon reptiles became the dominant terrestrial animals in Mesozoic, including: dinosaurs and pterosaurs; Reptiles in the water are: ichthyosaurs, pterosaurs, and sea dragons. Time and space traveled to Triassic, when the earth had entered Mesozoic. Compared with the past (Paleozoic Permian), it was full of vitality. In the ancient ocean, the ferocious carnivorous Sastre ichthyosaur was preying on other marine prey. For it, the Triassic ocean became its "free restaurant". It has been playing an important role in the ocean for most of the Mesozoic, accounting for about 70%. There are no four oceans at this time. The land is a complete joint ancient land which is connected and integrated by all the seven continents in the world today. Gasmatosaurus (living in the early Triassic, a huge amphibious animal that ate meat and was the earliest ancestor of modern crocodiles and American crocodiles). In the northern part of this pan-continent, a huge group of hoses is slowly migrating south. This is a kind of mammal-like reptile. They look like dinosaurs that appeared 30 million years later, but unlike dinosaurs, these early mammal-like reptiles are closer to our immediate ancestors-mammals, but they are not so close to lizards and crocodiles. Of course, it is a direct blood relative of modern mammals, including humans, and evolved from the Permian cave animal Bidentata. During the Permian extinction, it escaped the disaster and survived because of its small size and tenacious vitality and its forelimbs being good at digging holes. Deep in the forest, it seems that an unremarkable species is destined to completely change the face of life on the earth in the future, and open a new era of reptiles, laying the foundation stone for the birth of the most powerful "empire" in history. This time is about 240 million years ago. In today's South Africa, there is a vast jungle, which is a paradise for carnivores and herbivores. Here, a small carnivorous crocodile, New Bus Crocodile, which is less than one foot tall, can stand on its hind legs and run with agility, and specializes in killing insects, is busy and active in every corner of the jungle. Its developed hip bones make it have super jumping ability, which can not only accurately and effectively catch dragonflies or other insects in flight, but also easily avoid the threat of predatory natural enemies at lightning speed. Because of its small body and extraordinary "skill", it has become an unparalleled predator champion in the jungle. However, no one would have thought that the little guys who were running around in this early Triassic jungle would dominate the whole world in the next 37 million years, and dominate the land, sky and ocean of the earth. They are the Mesozoic earth overlords that we are familiar with today-dinosaurs (meaning scary lizards). Tyrannosaurus Rex, the ace killer in the dinosaur family in later generations, as well as Liang Long, Brachiosaurus, and various large sauropods all evolved from the new bus crocodile, an elf who was less than a foot tall. It is the same ancestor of dinosaurs and crocodiles. Jurassic time then continued through Triassic and entered the early Jurassic about 200 million years ago. Since then, the era of "dragon running the world" has begun. From the early Jurassic to the late Cretaceous,10.40 billion years (which is almost 150 times the time of human existence on the earth), the earth has always been "the world of dragons". Reptiles ruled the land, the sky and the sea. They walked freely like nobody's business, because they were the overlord of the world at that time. Just like our status on the earth today, we belong to the favored son of the earth and the king of the earth. In addition to a major natural disaster, it is almost impossible to let it quit the earth stage, and there is no chance that a species can replace it. This period is called the golden age of reptiles, also known as the age of dinosaurs. In that "dragon world", there is no room for the development of any other species. Early mammals can only live in caves for their own safety, and often sneak out to find food at night. In the Jurassic of Mesozoic, the climate of the earth was extremely warm and humid, and there was no concept of four seasons in a year, only dry season and rainy season. The ancient continental plate had gradually split and drifted from the super-large ancient land that had been pieced together at the beginning, and formed the embryonic form of the original four oceans. The climatic conditions in Mesozoic were especially suitable for plant growth. In the middle and late Jurassic, the earth was widely covered with extremely lush gymnosperms and ferns. This is also a rich food paradise for vegetarian dinosaurs. Every year before the rainy season, the beak-billed pterodactyl, which lives in South America today, flies across the Atlantic Ocean to the west coast of France today to find its opposite sex to mate with. At this time, the Atlantic Ocean was only 300 kilometers wide. On the way across the ocean, male pterosaurs would come close to the sea from time to time to peck at the fish jumping in the sea to supplement their physical strength, and there was always the danger of being swallowed by the terrible marine killer Serpentodon. By the time they reached their destination, the pterodactyl was exhausted. It often takes more than a week to rest before looking for your spouse. The Cretaceous period has passed for nearly 70 million years. When the earth reached the Cretaceous period, the "law of the jungle" was still being staged on the land. At this time, two ferocious Tyrannosaurus Rex were fighting for each other to bite a pseudo-Junsaurus. This is the Cretaceous cold-blooded killer that people are most familiar with today. Because of its huge size and sharp teeth of powerful jaws, the food it bites in one bite is equivalent to the volume of a whole strong boar. However, not all herbivorous dinosaurs will become the "Chinese food" of Tyrannosaurus rex, and Tyrannosaurus rex can't help Ankylosaurus. The earth's climate in the late Cretaceous was worse than before, and a large number of plants died because of long-term drought. The number of herbivorous dinosaurs decreased sharply because they could not find enough food to satisfy their hunger. With the mass extinction of vegetarian dinosaurs, natural carnivorous dinosaurs also cut off their food sources. However, "when the water is full, it will overflow, and when the moon is full, it will lose money." Once everything in the world reaches its peak, it will go downhill. The dinosaur family has come to an end at this time. The earth seems to indicate that a "Holocaust" at the end of Permian will be repeated in a certain period in the future. About 65 million years ago, an asteroid named Yucatan with a diameter of about 1 km crashed into today's Mexico. Tens of thousands of nuclear bullets exploded in an instant. This "collision between heaven and earth" destroyed many lives on the earth and ended the dinosaur era. At the end of Mesozoic, there was a Cretaceous extinction event, and 50% of the creatures were extinct, including all dinosaurs. Climate change in the late Jurassic and Cretaceous caused another radiation adaptation. The diversity of sauropods reached its peak in Jurassic period, and birds and placental mammals also began to appear and develop. Angiosperms also began to develop in the early Cretaceous, and began to appear in the tropics. The global temperature in the Cretaceous allowed angiosperms to distribute to the polar regions. At the end of Cretaceous, angiosperms have become large dominant plants in many areas. If calculated by biomass, the dominant plants in various places are still cycads and ferns until the end of Cretaceous. Some scientists believe that some organs of insects are quite suitable for angiosperms, especially mouthparts, and that insects and angiosperms begin to diversify at the same time. However, the appearance time of insect mouthparts is earlier than angiosperms, and also earlier than the time when insects began to diversify, so insect mouthparts evolved for other reasons. In the process of Mesozoic, the early large animals gradually decreased, while the number of small animals gradually increased, including lizards, snakes, and possibly the ancestors of mammals and primates. At the end of Cretaceous, the extinction event aggravated this tendency. Large main dragons disappeared, while birds and mammals continued to survive to this day.