Running dinosaurs

After printing fossils, Alexander judged that many large four-legged sauropods were really slow-moving "idiots", and their walking speed was only about 1 meter per second, which was similar to the walking speed of human beings. The footprints of large two-legged dinosaurs showed that their walking speed was generally less than 2.2 meters per second, which was similar to the speed when human beings walked quickly. Those smaller ones, The footprints of bipedal dinosaurs weighing about 5 kilograms (similar to the size of a horse race) show that they can run at a speed of 12 meters per second, which has exceeded the highest speed of human 1-meter race champions (11 meters per second), but it is still much lower than the running speed of horse races (about 15 to 17 meters per second).

Chiropters

Chiropters lived in Cretaceous, and their bones were destroyed in Europe. Its wings are only about 22 centimeters long. But the wings of Fengshen pterosaur are as long as 12 meters, which is as big as a bus. American scientists once found a pterosaur with wings more than 15 meters long. If we can see it today, we might think it is an airplane flying in the sky. Many flying birds and dragons are somewhat like bats today. They seem to hold up huge wings with one hand, so, Having wings and claws has become a major feature of them. Some people think that later birds evolved from them.

Scientists have different understandings about how pterosaurs flew into the sky.

Some people think that those giant pterosaurs can't fly at all. They can't vibrate their wings like birds, but they can climb to high places first and spread their huge wings against the wind, so that they can use the updraft. Some people think that pterosaurs can flap their wings like birds because the membrane on their wings is very hard, and the bones and muscles on the outside of their wings are connected like a frame. Because their wings are very big, they can get a huge reaction force by flapping them a little, and make themselves fly.

Eel dragon

Eel dragon is a kind of plesiosaur, and their fossils have been found in Japan. After measurement, their fossils have been found. 8 meters. And they have sharp teeth.

Triceratops

Triceratops is a kind of ceratosaurus. It has a horn on its nose, like a rhinoceros, and two horns on its eyes, like a cow. These three horns are all 1 meter long, which is a powerful weapon for them to fight.

Lei Long

Lei Long is the largest dinosaur, and some of them are more than 3 meters long. It is as high as six stories. They are all herbivores or leaves. Most of the dinosaur fossils we saw in the museum are this kind of dinosaur.

Allosaurus

Allosaurus is a fierce and terrible carnivorous dinosaur. Its big mouth can swallow a pig at once. Its teeth are all bent inward. If the prey is bitten by it, it can't escape.

Data

Dinosaur _ _ _ _ _ _ The scene of the dinosaur era

Dinosaurs lived on the earth for 15 million years. During such a long time, the environment of the earth has also undergone many changes. The Pangu continent, which was originally connected as a whole, gradually drifted and split into the form we know now. After these landmasses drifted around the world, Coupled with climate change, the plant species on the earth have undergone tremendous changes. However, because these changes were gradually formed in a very long time, the animals that grew in them can still adapt well. In the early dinosaur era, the dwarf shrubs composed of ferns were the main vegetation on the earth. Later, tall coniferous forests and low cycad jungles replaced ferns and became the main plant landscape on the earth. Soon after, The first batch of flowering plants appeared, which greatly changed the plant landscape on the earth. Many plants and flowers that dinosaurs lived on at that time still exist on the earth today.

Dinosaurs

Carnivores

Carnivorous dinosaurs are large dinosaurs with large heads, powerful hind legs and short forelimbs. They all belong to theropod, and are often called carnivorous dragons or carnivorous lizards. Carnivorous dinosaurs walk on hind legs; Because their hind legs have to bear the weight of their huge bodies, they may not move very fast. Their heads are very big, their jaws are very long, and the whole row of huge curved teeth on their jawbones look like the serrations on the edge of steak knife. Carnivorous dinosaurs mainly feed on other dinosaurs, and sometimes they also eat animal carcasses. They may kill prey with their claws on their hind legs first, and then with the help of their teeth and claws on their forelimbs. Tear off the meat of the prey and eat it. Osteosaurus is also a carnivorous dinosaur, but they are completely different from ordinary carnivorous dinosaurs. Osteosaurus is light and agile, with a pair of long arms and palms that are easy to grab, and long and narrow jawbones. They run very fast and hunt down small mammals and insects. In addition, Osteosaurus often eats after large carnivorous dinosaurs are full. Pick up the leftovers and eat them.

Dinosaurs

Vegetarians

Many dinosaurs are herbivorous, including the largest sauropod dinosaur and all the birds and buttocks dinosaurs. In fact, it is much more troublesome for dinosaurs to eat plants than meat, because plants are made of cellulose and lignin, and these tough substances must be decomposed before they can be digested by the stomach. To solve this problem, herbivorous dinosaurs For example, sauropods don't chew at all, but directly swallow the food they have bitten into their stomachs, allowing bacteria in their stomachs to ferment the food or letting them deliberately eat pebbles to grind the food. Hadrosaurs dinosaurs have special teeth, so they can bite and grind the food first; Dinosaurs of the suborder Ceratosaurus tore up tough plants with exceptionally strong jawbones and sharp teeth.

Extinction of dinosaurs

What happened at the end of the Cretaceous period 65 million years ago, which caused dinosaurs and a large number of other creatures to die, scientists have been arguing endlessly. Some say that there was a geological orogeny on the earth at that time, because many mountains grew on the flat land, and the swamp was reduced. The climate has also become less humid and warm. The respiratory organs of dinosaurs can't adapt to the dry, cold and dry air, and in winter, dinosaurs run out of food, so they are on a blind alley. Some say that the supernova explosion caused a strong change in the earth's climate, and the temperature suddenly rose and then dropped very low. Others say that dinosaurs ate a lot of flowering plants, which contained a lot of toxins, and dinosaurs ate a lot. So he died of poisoning. The evidence is that flowering plants began to appear at that time. Others ingeniously said that it was because dinosaurs, a huge animal, ate too much and farted constantly, releasing a lot of methane gas into the air. Because of their too many numbers and long survival time, they destroyed the ozone layer of the earth and caused a devastating climate. Some even said that it was the result of aliens coming to the earth to hunt. Because they think dinosaur meat is particularly delicious. The evidence is that the dinosaur bone fossils they found in the Arctic have traces of being cut by laser. In short, they are all kinds and wonders. However, it is generally recognized by everyone that the meteorite impact theory.

_ _ In 198, American scientists found high concentration of iridium in the strata 65 million years ago, and its content was dozens or even hundreds of times higher than the normal content. Therefore, scientists have linked it to the extinction of dinosaurs. According to the iridium content, it is also calculated that the impact object is an asteroid with a diameter of 1 kilometers. It is absolutely an unparalleled blow for such a large meteorite to hit the earth. Calculated by the intensity of the earthquake, it is about 1 on the Richter scale, and the diameter of the crater produced by the impact will exceed 1 kilometers. It took scientists 1 years to finally get the preliminary results. They found this big pit in the stratum of the Yucatun Peninsula in Central America. According to the calculation, the diameter of this pit is between 18 km and 3 km. Now, scientists are still making further research on this big pit.

___ Scientists began to describe the heroic scene 65 million years ago for us. One day, dinosaurs were still eating and drinking carefree in the earth paradise, and suddenly there was a piercing white light in the sky. A boulder with a diameter of 1 kilometers, which is equivalent to the size of a medium-sized city, fell from the sky. It was an asteroid. It crashed into the sea at a speed of 4 kilometers per second, creating a huge pit on the seabed. The seawater was rapidly gasified, and the steam was sprayed into the sky for tens of thousands of meters. Then the tsunami was as high as 5 kilometers, and it spread at an extremely fast speed. The raging water swept everything on the landing ground, and the surging waves swept across the surface of the earth and then merged at the back end of the impact point. There, the huge sea power triggered a strong volcanic eruption in Deccan Plateau, and at the same time changed the movement direction of the earth plate. What a terrible disaster it was. Meteorites hit the earth and produced overwhelming dust, polar snow melted, plants were destroyed, and volcanic ash filled the sky. For a time, the temperature plummeted, heavy rain, flash floods and mudslides swept away dinosaurs and buried them. In the next few months or even years. The sky is still dusty and covered with dark clouds. The earth has entered a low temperature because it has not seen sunlight all the year round, and the vast land is silent for a while. An era in the history of biology has thus ended.

Dinosaurs

Strange heads

Some dinosaurs have very strange heads, such as strange protrusions or bony protrusions on their heads-they may appear as small pieces, lumps, new moons, spines or helmets. These are weird. Like the special structures or bright colored spots on birds or mammals, they have the function of attracting eyes. Their striking shapes may be used to attract the opposite sex, scare off enemies or express their good or bad mood. In addition, the bony protrusions on the head are also defense or attack weapons, which can be used as natural safety helmets or hard collision tools. Among many grotesque skulls, the most unique one is the head of the duck-billed dragon. The duck-billed dragon has a wide flat toothless face. Named after the duckbill-like beak.

At the end of the dinosaur era

At the end of the Cretaceous period, dinosaurs became less and less, and finally all disappeared. At the same time, the landscape of the earth changed. Pangea was divided into several pieces because of the expansion of the seabed. The sea level rose, making the low-lying areas where many dinosaurs lived become Wang Yang. Many kinds of marine animals also became extinct. In addition, the warm climate was originally all year round. Now it's changing, or seasonal. The species of plants have also changed, and flowering plants have become more and more important. The extinction of dinosaurs just made another group of creatures on the earth, mammals, take the opportunity to rise.

Double-crowned Dragon:

___ 6 meters long, with two protruding ridges on its head, eating carrion. Its forelimbs were short and good at running. The carnivorous dinosaur in the early Jurassic period was 6 meters long. When standing, the head is about 2.4 meters high. There are two large bone crowns on the top of the head, so it is named Shuangguanlong. The front end of the nose and mouth is particularly narrow, soft and flexible, and you can take out those tiny lizards or other small animals from the bushes or cracks in the stones and eat them. Compared with the later large carnivorous dinosaurs, Shuangguanlong's body looks "slim", so it moves quickly. Its mouth is full of teeth, and it can also kill some big herbivorous dinosaurs. However, Some scientists also doubt its tooth function, saying that it is just a dinosaur that eats carrion.

Legend of dragon phobia

A long time ago, about 2 million to 7 million years ago today, there lived a huge family on our earth. They ruled the ocean, land and sky, and all other animals could not compete with them. They were veritable overlords, and this is the dinosaur.

There are dense forests everywhere, and there are all kinds of animals living in the forests. Therefore, no matter whether dinosaurs eat plants or animals, they can enjoy endless food. Because of such a good environment, dinosaurs generally grow enormous. It is speculated that the largest dinosaur is 3 meters long and weighs 4 to 5 tons, even the largest public car can't pull them. Of course, there are also some. Weighing 3 kilograms, it is almost the same as the chicken we saw.

However, such a huge family suddenly disappeared from the earth. The disappearance time was at the end of what scientists called the Cretaceous period. Why dinosaurs disappeared so cleanly at once is a scientific mystery. People have speculated for many years, but there has never been a definite answer. Fortunately, some dead dinosaurs did not disappear completely. Their bones turned into fossils and were preserved by nature, which made us know that some animals existed in the past, and described their appearance according to these bones. If you are interested in dinosaurs, you might as well try and see if you can solve this eternal mystery.

The study of dinosaurs is very meaningful, which can not only help us understand the evolution process of life on earth, but also help us understand the changes of climate and geological activities on earth. Our relationship with the environment, and so on, even involves all aspects of the celestial bodies in the universe. How about it? It's very interesting. Let's look down with us. But because there are many beautiful pictures, the speed may be slower. Don't worry.

Dinosaurs

__ _ Dinosaurs are the best

_ _ When you walk through the shop window, Do you feel strange or curious because of the extra-large music bottle or the petite cartoon doll? Do you want to know what the smallest dinosaur is and the longest? The largest one. The smallest dinosaur

___ Among the known dinosaur types, the smallest one is the fine jawed dinosaur, but it is the size of a chicken. Some species are only about one meter and forty centimeters long; Some are only seventy centimeters! Although it is a little bigger than a chicken, some dinosaurs, including the long tail, may be smaller than the fine jawed dragon, but they are only obtained from sporadic fossils, such as the sauropod, a carnivorous animal with sharp claws as big as a cat. Smaller than the fine jawed dragon and the sauropod are the larvae of some dinosaurs: the parrot-billed dragon is only 25 cm long, while the newly hatched sauropod is only 2 cm long, which is not much larger than the robin. A paleontologist guessed that the adult could be as long as six meters. But until the adult of the real mouse dragon was discovered, it was just speculation! _

2. The ugliest dinosaur

__ I think the pachydantosaurus is the ugliest among those ugly dinosaurs. The pachydantosaurus belongs to that kind of dinosaur with a protruding top. Its skull is covered with an arc-shaped bone plate, which is about 23 centimeters thick. Around this protrusion, rows of small tumors and mucro are decorated around the smooth hill, which is like a tumor. Its front edge looks like a bone disease that is unspeakable. It is also full of tumor-like protrusions and spines. These surrounding tumor-like thorns and spines make the protruding part of the head look like a shaved head. Compared with the pachydantosaurus, the second ugliest guy may be a thick-nosed dragon. It is also a ceratosaurus, with short and raised ornaments above its nose, which looks like the trunk left by sawing left on its skull. _

III. The longest dinosaur

_ _