It is said that a dragonfly was 70 centimeters long in the Carboniferous period, why did they grow s

The earliest life originated from the seabed, so the earliest ancestors of insects in the Carboniferous period were also ** on the seabed, and later with the formation of the atmosphere, it was able to block most of the ultraviolet rays and solar wind, and the early life came to land from the ocean. The marine creatures basically breathe with their gills, so after these marine creatures evolved into insects, they did not use lungs to breathe because they did not have lungs, so they formed tiny traches through the bones, and injected oxygen into them through the trachea, and dragonflies still use trachea to breathe. During the Carboniferous period, the oxygen content in the air reached a historical peak of 35% due to the abundance of plants, while the oxygen content of the Earth we live on now is only 21%.

With the help of this respiration, as well as the abundant oxygen content in the air, these creatures are conditioned to move towards a larger body.

Evolution has no purpose, and while such conditions can make them larger, organisms don't necessarily move in that direction either. However, the environment will eliminate a group of evolutionary directions that are not adapted to the environment, and this environment is largely the relationship between predation and food. The Carboniferous sky overlord, feeding on small insects and micro-amphibians, was at the top of the food chain at the time, similar to that of today's eagles.

Since the moment life is born, life has followed the law of "big fish eat small fish, small fish eat shrimp", but survival is the instinct of living beings, and in order to continue their lives, each living thing has evolved its own coping strategy.

Some creatures try to make themselves poisonous and avoid predators beating their minds. Some organisms live with the population to avoid being eaten by predators when they are alone. Some creatures, on the other hand, make themselves bigger so that they don't eat them.

Moreover, getting bigger can also make it easier for you to hunt for yourself, so that you can continue your life. The evolution of life does not follow one direction, and each creature has its own coping strategy when competing for survival, and the giant vein dragonfly is called the sky overlord of the Carboniferous period by making itself bigger.

At that time, the climate was very warm and humid, the plants were at their peak, and the oxygen content in the air was higher than it is now, and in the environment of sufficient food and oxygen, dragonflies would grow very large.

Because the oxygen content in the Earth's atmosphere was very high in the Carboniferous Period, the plants at that time grew very large, and the animals did not lack nutrients and could grow without restrictions, so dragonflies of 70 cm appeared.

Because oxygen is abundant at that time, and the place where the dragonfly absorbs oxygen is the exoskeleton, that is, its shell, the larger it grows, the easier it is to absorb oxygen.

Carboniferous. Known as the Age of the Giant Bugs.

Because there were a lot of huge bugs at that time. The oxygen content of the earth's atmosphere reached 35% in the Carboniferous period, and the high oxygen content indicates that the plants are luxuriant, there is enough food for animals, and the environment is more suitable for growth.

The energy flow in nature starts from plants, which fix nitrogen and carbon in the atmosphere, collect energy from sunlight, synthesize organic matter, and become the first energy level in nature.

Animals have enough food, and the abundance of food brings a huge number of certain organisms that can be raised, and evolution is based on the population, and the larger the population will produce more variation, and in the competition for survival, the larger organisms have a certain advantage. On the other hand, insects and vertebrates.

They breathe with an open and closed breath located in the abdominal valve trachea, and the higher the concentration of oxygen in the air, the better it is for them to breathe, supporting a larger body size.

In the competition for survival and the constant changes in the environment, the size of insects gradually increases. However, for insects, large size is both an advantage and a disadvantage, although large size can avoid the attacks of some small animals, for contemporaneous dinosaurs and other creatures, they are just an appetizer, and the wing structure like a dragonfly, supporting the flight of a large body is not good. In the Cretaceous period, hundreds of millions of years ago.

There was also a sudden increase in atmospheric oxygen content, but the size of insects has shrunk, and at that time there were already some large vertebrates that could fly, and later the appearance of birds, insects had more natural predators, and the size was too dazzling, and the competition for survival made their size decline.

The body size of the organism is the result of multiple factors, the most basic is the gene mutation, the body size of the existing related genes can be increased, but environmental factors, survival competition may make the body shape of the organism become a factor that is not conducive to survival, under the action of a variety of factors, the body size of the organism is constantly changing.

When the oxygen content in the environment is high, abundant and abundant, the metabolic capacity of the insects will be enhanced, so the insects are very large.

These animals were created because of the changes in the environment that led to genetic changes, because the environment at that time was suitable for the growth of large animals.

Because during the Carboniferous period, the earth was very rich in resources, so the insects at that time were very large.

I think this is mainly because the oxygen content in the air was very large at that time in the Carboniferous period, which could support the evolution of organisms to such a large size, so the insects at that time were relatively large.

Because the vegetation coverage on the earth was very high at that time, the oxygen content on the earth's surface was much higher than now, which could support the development of animal size in a larger direction.

The Carboniferous period refers to the period from 100 million years ago to 100 million years ago, when the earth's carbon and oxygen were quite sufficient, so many huge insects were born.

The giant dragonfly has a certain connection with the current ordinary dragonfly, but it is much larger, its wings can reach 75 centimeters wide, it is also the largest insect among the ten terrifying creatures of the Carboniferous period, and its main food is insects and some smaller animals.

Generally about 20 centimeters long, the forest lizard has a slender body and tail, and during the Carboniferous period, it relied on its incredible agility and dexterity to evade attacks.

The lung scorpion is a relatively large scorpion, its original form is a sea scorpion, which later became extinct due to lack of oxygen, and its main food is giant spiders for life.

With a body length of more than 2 meters, the newt is a relatively large carnivorous amphibian, and it is an extinct species, unlike all amphibians today.

With a body length of about 6-7 meters and a weight of more than 2 tons, the Hissa has terrifying teeth, which feel a little similar to the teeth of the spirodont among the ten most terrifying animals of the ancient period, and it is quite a powerful character among the ten terrifying creatures of the Carboniferous period.

The arthropodal centipede and the current centipede millipede have a certain relationship, its body length is between meters, mainly distributed in North America and Scotland, although it is called centipede, but the difference between centipede and centipede is still very big.

The three-eyed dinosaur shrimp is a creature that still exists today, which is equivalent to a living fossil, and many Japanese people even keep it as a pet, of course, it is also very magical and interesting to look at.

The horseshoe crab is the oldest and largest spider ever discovered, having been successfully discovered in 1970 and unearthed in Argentina as a specimen of the order of spiders.

Archaeopteryx lived mainly about 306 million years ago, during the Late Carboniferous period, and is one of the oldest known synchotomycetes.

The aspinous crocodile is a giant crocodile, and although only the skull has been found, paleontologists have speculated that its body should be more than 10 meters long and weigh about 6 tons.

During the Carboniferous period, 300 million years ago, giant insects lived on Earth, with a wingspan of nearly one meter. Through the fossil record, scientists have found that before the dinosaurs, there were huge species on the earth, which were giant arthropods from the Carboniferous period 300 million years ago, including oversized mayflies, insects, and scorpions; spiders the size of spider plants; And 5-foot-long millipedes, and so on. One of the most amazing is the giant dragonfly, which can reach a wingspan of two and a half feet (nearly one meter), the size of an eagle, and the largest insect ever seen on Earth.

Ancient dragonflies. Giant dragonflies.

With a wingspan of about a foot (hem) and a living mainly by catching other small insects and small animals that had changed from aquatic to amphibious in the early days, it was the largest flying insect ever seen on Earth.

Ancient centipede. The ancient centipede insect was a foot (about a meter) wide (from the left foot to the right foot in the same row) and lived mainly by devouring plants and small animals.

Ancient scorpions. The largest ancient scorpion species ever discovered is the broad-winged abyssal sea scorpion shown in the picture above. This deep-sea scorpion lived hundreds of millions to hundreds of millions of years ago, is about 8 feet (about a meter) long, and has a ferocious nature, and was the dominant force of the sea in ancient times.

This sea scorpion, also known as "Jack", is believed to have lived hundreds of millions of years ago, and given that this claw is about half a meter long, it is estimated that this scorpion is about half a meter long, almost half a meter longer than previously estimated. This giant fossilized scorpion claw proves that ancient arthropods, including arthropods, with their segmented trunks, connected limbs, and a hard shell of spiders, insects, and crabs, were much larger than previously thought.

Why were insects so huge in ancient times? Scientists speculate that this may have something to do with the amount of oxygen in the atmosphere at the time, when the Earth's atmosphere contained far more oxygen than today's standards, and insects "breathed" through a system of stomata on their bodies. The stomata are connected to the trachea, and from top to bottom, more layers of smaller and smaller stomata are attached to carry oxygen throughout the body.

At today's oxygen levels, the total length of the stomatal system has reached its limit; Beyond this limit, oxygen levels become insufficient. Therefore, this structure can effectively determine the size of the insect.

The wingspan of the current dragonfly is definitely not more than 20 centimeters, so how big can the ancient dragonfly be? About 300 million years ago, in the Carboniferous period, there lived an arthropod with a wingspan of more than 1 meter, the ancient dragonfly, which was the largest insect in history. The appearance of the ancient dragonfly was almost the same as that of the current dragonfly, except that it was a few sizes larger.

Can a dragonfly of this size fly? At first, scientists thought that such a giant dragonfly would be impossible to fly, and at best it would only glide briefly in the air.

However, professional aeronautical engineers concluded after argumentation - they can fly! Wings that can swing, bend and twist at will allow them to climb and advance in the air at will, but not as fast as they can fly. In fact, in addition to these insects, the Carboniferous was also home to many large insects, including oversized snails, meter-long centipedes, and spider-plant-sized spiders.

The high concentrations of oxygen in ancient times made all of this possible, and the Carboniferous air contained more than 35% of the oxygen, and the tiny blood vessels that dotted the muscles helped them to absorb oxygen and guide them to become larger. The reduction in oxygen levels is no longer suitable for the survival of large organisms, and they have to live forever in the past.

The researchers noted in the report that the concentration of oxygen in the Earth's atmosphere was as high as 35% during the Carboniferous period, much higher than the current 21%. Many arthropods absorb oxygen directly through the tiny tracheas that dot their bodies, rather than indirectly through the blood, so high oxygen levels can encourage insects to evolve in the direction of larger size.

These insights are based on the study of the flight mechanism of ancient dragonflies.

Scientists have long believed that such a giant dragonfly could only glide and could not fly. Aeronautical engineer Roy Bekmeyer noted: "Obviously, they can fly.

One of the key conditions is that their wings can swing, bend, and twist. Modern dragonflies rise and move forward by bending and twisting their wings.

Fossil data show that the wings of ancient dragonflies have a folded structure similar to that of modern dragonflies, modern dragonflies can twist their outer wings, and ancient dragonflies can slowly twist all their wings, so they may not fly too fast, but they can still fly.

Because dragonflies nowadays don't need a one-meter wingspan to survive.

Because the oxygen content was high at that time, it was large.

The environment was suitable for them to grow, and the oxygen content was greater, but now it can't make them grow that big.

In order to better adapt to the current natural environment.

Because the current environment does not allow him to have such a large body structure.

In order to adapt to nature, but also to avoid being discovered by natural predators.

The evolution of the outside of living things is to adapt to the environment and change.

At that time, the earth had a lot of oxygen, and many animals were large.

Now that the times have changed, he has become smaller in the process of continuous evolution.

The reduction in oxygen levels is no longer suitable for the survival of large organisms.