What is a Dinosaur?

Dinosaur (English name: Dinosaur) is a class of reptiles that have survived in the Mesozoic (Triassic, Jurassic, and Cretaceous) to this day (but only birds exist, and non-bird dinosaurs have all been extinct 65 million years ago) ) ^[1-2] collectively, the robust limbs, long tail and huge body are the portrayal of most dinosaurs. They mainly inhabit forested or open areas on the lakeshore plain (or coastal plain). In 1841, when British scientist Richard Irving ^[3] studied a few fossils that looked like lizard bones, they thought they were left by some prehistoric animals and named them dinosaurs, which means "horrible lizards".

Chinese Dinosaur Chine

Human discovery

Non-bird dinosaurs have lived on the earth for 160 million years, and a branch of theropod dinosaurs differentiated into birds, but at the end of the Cretaceous they suddenly disappeared all over the world. The extinction of non-bird dinosaurs is a major unsolved case in the history of life on Earth. Since the 1970s, various theories and hypotheses about the extinction of non-bird dinosaurs have been introduced, and an unprecedented scale of debate has been launched. ^[14]

Historical mass extinction

Event name	time	possible reason	as a result of
Ordovician species extinction	438 million years ago	climate change	50% of species are extinct, mainly marine life
Devonian species extinction	360 million years ago	Gamma ray radiation	40% of species are extinct
Permian species extinction	245 million years ago	Volcanic activity, etc.	More than 95% of species are extinct
Cretaceous species extinction	66 million years ago	Meteorite impact	45% of species are extinct

Carnivorous (Theropod) Dinosaurs (20 photos)

Li Yang, a paleontologist and physicist from China, published a 2009 paper at Yale University that caused a sensation in the international paleontology community. He and his Chinese team were in the K-T formation of the Hicksulub crater 65,653,800 years ago. A high concentration of iridium was found, and its content exceeded the normal content by 232 times. Such a high concentration of iridium can only be found in meteorites in space, and the earth itself cannot exist. According to the accurate determination of the iridium content around the Gulf of Mexico, the material of an asteroid with a mass equivalent to Mount Everest at the time not only hit the Earth's Central America region, but also broke the crust, and then a major earthquake never occurred on Earth . The impact caused the slurry to be thrown to a height of several kilometers, followed by a stream of fire that lasted for tens of days. High temperatures may not be the most deadly. Tens of millions of tons of dust and toxic substances spread throughout the world in the following month. ^[15]

In the following four months, the sun was just a fuzzy shadow, the plants stopped growing, the herbivorous animals decreased, and the dirty dinosaurs, food shortages, wanton diseases, etc., all destroyed the surviving dinosaurs. Due to the cover of dust, the earth is facing a cold attack. But cold doesn't seem to be the most serious problem, but keep in mind that the sex of some animals is determined by temperature, and dinosaurs are one of them. Caused this biological extinction. ^[14]

In the past, the academic community discussed the alien celestial impact theory separately from the volcanic eruption theory, but these two academics have considerable flaws. The foreign celestial body said that the impact alone is not enough to affect it so severely, for a long time, and so far ( Global), and the volcano said that the volcanic activity on the earth itself is very intense, but not enough to cause such large extinctions, including the Yellowstone super volcano. Because of the long-standing doubts of the international paleontological community, the combination of the two can cause such a major extinction of the earth's biology. ^[14]

2000 Dinosaur 2000 Theory

Theropod dinosaurs (20 photos)

German scientists have suggested that the extinction of dinosaurs was caused by the bad "space weather" of the time, that is, a strong particle flow from the universe broke into the earth's atmosphere and caused drastic changes in the earth's climate, which led to the extinction of dinosaurs. ^[14]

The hypothesis that an asteroid hit the earth proposed by American physicist Louis Alvarez has attracted much attention. When he studied the upper sticky layer in the Late Cretaceous strata in Gubbio, Italy, he found that the content of the trace element date and iridium increased sharply by 30-160 times compared with strata in other periods. Afterwards, people took samples from many locations around the world to test the same. It is concluded that the abnormally high iridium content in the formation in the late Cretaceous is indeed universal. So Alvarez thought that at the end of the Cretaceous period, an asteroid with a diameter of about 10 kilometers hit the earth, and the dust generated by the sky covered the sky. Caused great changes in the surface climate and environment, leading to the demise of dinosaurs. ^[14]

Scientists believe that it is the explosion of cosmic particle flow that has caused drastic changes in the Earth's climate, and dinosaurs that cannot adapt to this kind of climate change have also become extinct in a short time. ^[14]

Swollen-headed dragon dinosaurs (14 photos)

We know that the thermonuclear reaction inside the earth will continuously accumulate huge energy. Once the crust cannot bear it, the internal pressure will burst through the crust and release suddenly to form a big explosion. Iridium jujube, an element mainly present in the earth's core, was brought from the depths of the earth to the surface of the earth's crust through a lava eruption during the big eruption, and the clay layer, which is considered to mark the end of the Cretaceous, was formed by a large accumulation of volcanic dust. Therefore, the general increase of the iridium content in the strata in the late Cretaceous period proves that there was a general severe eruption at that time. ^[14]

The fossil archives tell us that the time of death of most dinosaurs and the production of most dinosaur egg fossils were at the end of the Cretaceous. All the dinosaurs and dinosaur egg fossils found have been preserved in the stratum below the thin clay layer rich in iridium. This coincides with the time when a series of global crustal structures, such as the large-scale orogenic movement of the late Cretaceous period, recognized by the geological community. ^[14]

Among the hundreds of protoceratops and ankylosaurian fossils unearthed in the strata of the end of the Cretaceous in Bayin Mandu, Inner Mongolia, a large number of complete dinosaur skeletons were stacked in groups. From the burial position of the remains, they were in extreme pain. In the dead, there are a whole group of dinosaur cubs. This scenario shows that they were catastrophic collective deaths. ^[14]

Theropods (20 photos)

A large number of fossils of animals and plants reflecting the characteristics of the earth's environment at that time show that before the end of the Cretaceous, the density and thickness of the earth's atmosphere far exceeded 2000, the ground was relatively flat, and the world was a very warm and humid climate. At that time, there was a small temperature difference between the polar and the equator. In the 1980s, Canadian geologists found a fossil forest dominated by metasequoia in Ellesmere Island in the Arctic Circle, and there were animal fossils such as crocodiles in the forest. The polar region used to have a tropical climate. ^[14]

Some have evolved into primitive birds, mammals as early as the Jurassic Period, following the rules of natural selection and survival of the fittest in a relatively harsh environment. After 70 million years of continuous evolution, most species have changed. The original form. Of course, after each large-scale species evolution, some species will always remain intact. For example, after the fish evolved into amphibians, the fish continued to survive. There are also very few reptiles (crocodile, lizard, etc.) that still maintain 7000 to this day. Original form ten thousand years ago. ^[14]

The biological remains in the earth's rock formations reveal that in the history of biological evolution, a species extinction occurs every certain period of time. The extinction of dinosaurs in the late Cretaceous period is not the only disaster in the history of biological evolution. Most of them occurred in earlier times. The "Cambrian Life Explosion" phenomenon that invertebrates suddenly appeared in a short time. Just like the evolution of organisms from single cells to multi-cells and reptiles to mammals, they need an evolutionary process (as evidenced by the fossil group in Chengjiang, Yunnan, China, discovered in 1984). ^[14]

Mesozoic birds (birds are a special dinosaur) (19 photos)

The fact that the geological structure inside the earth continues to change frequently shows that the environmental "catastrophic" caused by periodic crustal structure changes has always played a leading role in biological evolution. Of course, the gradual evolution of small-scale species also runs through the evolution of life. process. Periodic celestial body bursts (such as nova bursts) are an indispensable link in the evolution of all planets, including Earth. The fossils of marine life and seabed minerals in those mountains are the best explanation for the end of the dinosaur era due to drastic changes in the crust. We know that the extinction time of dinosaurs was about 65 million years ago, and the geological age is the end of the Mesozoic Cretaceous or the beginning of the Cenozoic Tertiary. And at that time, not only all the dinosaurs that had ruled the earth for more than 100 million years were all extinct, but the same tragic fate came to many other creatures on the earth at the same time. Also extinct in this disaster are reptiles such as ichthyosaurs and snake-necked dragons, flying reptiles such as pterosaurs, terrestrial reptiles like dinosaurs and other dinosaurs, and oceans such as chrysanthemums and arrows. Miniature phytoplankton, calcareous foraminifera and calcareous microphytoplankton in the invertebrate ocean have also been almost swept away. After this catastrophe, about 50% of the biological genus and almost 75% of the biological species on the earth disappeared from the earth forever. ^[14]

This mass extinction caused a radical change in the appearance of the biological world on Earth around 65 million years ago. This mass extinction marked the end of the Mesozoic, and the geological history of the earth has entered a new era-the Cenozoic. ^[14]

Here, only some of the more well-known statements are described as follows: starvation, killing each other, etc., but the statements are increasing, but Chinese scientists have verified that dinosaurs have survived about 2 million years after the meteorite impact. ^[14]

Dinosaur Meteor Impact

The whole process of dinosaur extinction (meteorite impact) (24 photos)

In 1980, the American scientist Afrazi and his son discovered high concentrations of iridium in the formation 65 million years ago, the content of which is tens or even hundreds of times higher than the normal content. This concentration of iridium can be found in meteorites, so scientists have linked it to the extinction of dinosaurs. According to the content of iridium, it is also calculated that the impact object is an asteroid with a diameter of about 10 kilometers. Such a large meteorite hits the earth. It is an unbeatable shock. Based on the intensity of the earthquake, it is about 10 on the Richter scale. The resulting crater will exceed 100 kilometers in diameter. It took 10 years for scientists to get preliminary results, and they found the crater in the strata of the Yucatan Peninsula in Central America, Mexico. It is estimated that the diameter of this pit is between 180-300 kilometers. In 2000, scientists were still doing further research on this big pit. ^[14]

Now that the crater has been found and scientists have some relevant evidence, it seems that the mystery of the dinosaur extinction can be settled. ^[14]

Dinosaur Climate Change Theory

As the plates move, ocean currents change, and they also cause dramatic changes in climate. Frigid and dry climates have killed plants, and dinosaurs have fallen short of food. ^[14]

Dinosaur Ocean Low Tide

According to Robert Buck, the oceans are ebb, and when the land borders, the creatures come into contact with each other, causing some kind of biological extinction. Kangaroo, for example, can survive on an island continent such as Oceania, but when it encounters another species on the South American continent, it is declared dead. In addition to this relationship between eating and being eaten, there are also problems of infection and transmission of diseases and parasites. ^[14]

Dinosaur volcanic eruption

Because of the volcanic eruption, a large amount of carbon dioxide was emitted, causing the earth's rapid greenhouse effect and causing plants to die. In addition, the volcanic eruption caused a large amount of salinity to be released, the ozone layer was broken, and harmful ultraviolet rays irradiated the earth's surface, causing the destruction of life. But this doctrine has a premise that volcanoes erupted on a large scale. ^[14]

The famous Italian physicist Antonio Zikiki proposed that the cause of the dinosaur extinction is likely to be a large-scale underwater volcanic eruption. Professor Zikiki believes that at the end of the Cretaceous period, a series of large-scale volcanic eruptions occurred on the earth under the ocean, which affected the thermal balance of seawater, and then caused changes in the terrestrial climate, thus affecting those who need a lot of food to survive. The survival of animals such as dinosaurs. ^[14]

Dinosaur Orogeny

Asteroid hits the earth

The orogenic movement that occurred in the late Cretaceous period dried up the swamp, and many dinosaurs who lived in the swamp could no longer live. Because of climate change, plants have also changed, herbivorous dinosaurs cannot adapt to new foods, and have become extinct. The extinction of herbivorous dinosaurs has also lost their dependence on carnivorous dinosaurs and has become extinct. This extinction process lasted 10-20 million years. By the end of the Cretaceous, dinosaurs were extinct on Earth. ^[14]

Dinosaur warm-blooded animal says

In the past, all scientists thought that dinosaurs were cold-blooded or warm-blooded like other reptiles, but as the amount of fossil data continues to increase, people's understanding has also changed. Some people have suggested that some dinosaurs may be warm-blooded. First of all, they think that some dinosaurs are extremely agile, and instead of crawling on the ground like snakes, they run on the ground with their hind legs, and their speed can reach more than 20 to 90 kilometers per hour. This requires a strong heart and a high metabolism, which obviously cannot be done by cold-blooded animals. Secondly, the dinosaurs' diets are quite large. It is speculated that a 30-ton sauropod dinosaur may eat nearly 2 tons of food every day. Only warm-blooded animals need so much energy. From the point of view that carnivorous dinosaurs are far less than herbivorous dinosaurs, this is also reasonable. In addition, there are some smaller dinosaurs, which are covered with a layer of feathers or hair, which is also to prevent the loss of body temperature. Other aspects, such as skeletal studies, have also shown that some dinosaurs are warm-blooded. The idea of a warm-blooded dinosaur was criticized as soon as it was put forward, but it is still difficult to determine what the conclusion is. ^[14]

Some people think that dinosaurs are warm-blooded animals because

Antarctic Dragon (28 photos)

This may not be able to withstand the cold weather of the late Cretaceous and lead to inability to survive. Because even though dinosaurs are warm-blooded, their body temperature is still not high, which may be similar to that of living sloths. To maintain such body temperature, they can only survive in tropical climates. At the same time, the respiratory organs of dinosaurs were incomplete and could not provide sufficient oxygen. The difference between warm-blooded animals and cold-blooded animals is that if the body temperature drops below a certain range, it will consume physical energy to raise the body temperature, and the body will soon become weak. They are too bulky to drive into the cave to avoid the cold, so if the cold days last for a few days, they may be destined to be frozen to death due to exhaustion of physical strength. However, there is a doubt about this theory, that is, dinosaurs are not all huge, and they are not necessarily unable to hide in caves, so this theory has some imperfections. ^[14]

Dinosaur breastfeeding evolution theory

In the second half of the Mesozoic era, there were already ancestors of mammals. According to fossil records, the mammals were very small and limited in number at that time, and they did not increase rapidly until the late Cretaceous. It is speculated that they are omnivorous with insects as the main food. After discovering dinosaur eggs, these small mammals continue to eat them, eventually leading to the dinosaur's fertility crisis and dinosaur extinction. ^[14]

Dinosaur abrupt change theory

According to data obtained from deep-sea geological drilling, some scientists believe that the Earth s climate changed abnormally 65 million years ago and the temperature suddenly increased. This change makes dinosaurs and other weaker heat-dissipating animals unable to adapt well to the environment, causing disturbances in the endocrine system of their bodies, and especially causing severe damage to the male reproductive system. As a result, the dinosaurs were unable to breed offspring, leading to their ultimate extinction. ^[14]

There is another theory, although it is also believed that the climatic change caused the extinction of dinosaurs, but the process of speculation is different. This school of scholars believes that about 70 million years ago, the Arctic Ocean was completely separated from other oceans by land, and in the last days, the salty seawater gradually became fresh water due to various factors. . 65 million years ago, the "bank" separating the Arctic Ocean from other oceans suddenly broke. A large amount of water from the Arctic Ocean that has been lightened by desalination flows into other oceans. Because the water temperature of the Arctic Ocean is very low, these "spilled" cold water forms a layer of cold current, which rapidly reduces the temperature of the sea water of the earth's ocean by about 20 degrees. The drop in ocean temperature has severely affected the climate of the continent, making the air above the continent colder. At the same time, the water vapor content in the air also rapidly decreased, causing widespread drought on land. ^[14]

One possible way that a sudden climate change caused dinosaurs to become extinct is to seriously affect the eggs of dinosaurs. Some scientists have found that the egg shells of dinosaur eggs tended to thin before the end of the Cretaceous before the dinosaurs became extinct, indicating that there were effects caused by drastic climate changes before the dinosaurs became extinct. Some paleontologists in China have also found that in dinosaur eggs produced in some fossil sites, there are fewer stomata in the egg shells of dinosaur eggs near extinction than in other periods. Related to the climate becoming cold and dry. ^[14]

Dinosaur species evolution theory

It is believed that the dinosaur's flesh was too giant due to its 160 million years of prosperity. In addition, horns and other bones also develop abnormally, which causes great inconvenience in life and eventually leads to extinction. ^[14]

The most representative confusing dragon among dinosaurs is 25 meters in length and 30 tons in weight. Due to its large size, it slows down and loses its ability to live. In addition, Triceratops, etc., are becoming self-destructed due to the abnormally developed three horns and the bones that protect the head. ^[14]

Dinosaur frustration theory

Egg fossils of ancient reptiles have been found in many places in the world, especially egg fossils of dinosaurs. According to the morphological structure, dinosaur eggs can be divided into short round eggs, oval eggs and long eggs. The size of dinosaur eggs varies widely. There are different differences in egg shell thickness and its internal and external "decorations", egg shell structure, and the ratio of the vertebral and columnar layers in the shell. In order to conduct in-depth research on the internal characteristics of dinosaur eggs, scientists have adopted very new technologies and various methods, such as scanning tunneling microscopes, x-ray diffractometers, polarizing microscopes, CT scanners, and so on. Chinese scientists used CT technology for the first time to study the internal structural characteristics of dinosaur egg fossils unearthed in Laiyang, Shandong, and found that some dinosaur egg fossils in Laiyang, Shandong had dinosaur embryos that could not be observed by other methods. Some scientists think. The deformation and dislocation of dinosaur embryos may cause the dinosaur eggs to fail to hatch normally, which will cause the dinosaurs to weaken and eventually die out. ^[14]

Dinosaur Change Theory

The extinction of dinosaurs in the late Cretaceous period is a mystery in biological history. Scientists have proposed one theory after another to try to explain the reason, but so far no conclusion is acceptable to everyone. The more popular argument is that the disaster caused by the asteroid impact on the earth caused the extinction of dinosaurs, but this theory is not perfect. Because dinosaurs were the most successful animals on the earth at the time, their rich diversity was even more diverse in size, shape, and lifestyle. ^[14]

Modern scientific analysis has taught us that in the distant era when the earth was just formed, there was basically no oxygen in the air, but the content of carbon dioxide was very high. Later, with the advent of autotrophic organisms, photosynthesis began the process of consuming carbon dioxide and producing oxygen, thereby changing the atmospheric environment on the earth. At the same time, carbon dioxide is deposited in the formation by coal and petroleum on the one hand through biological fixation, and it is also deposited in the form of various carbonates through organic or inorganic processes. This deposition is ongoing. ^[14]

There is evidence that the Mesozoic carbon dioxide concentration of dinosaurs was high, while the subsequent Cenozoic carbon dioxide concentration was low. ^[14]

As we all know, every living thing needs to be in the right environment to live normally. Changes in the environment can often lead to the rise and fall of a species. When the environment is good for this species, it will thrive and vice versa, and it will decline or even become extinct. Environmental factors include factors such as temperature and water, as well as the composition of the atmosphere. So, will the changes in atmospheric composition affect the lives of living things? The answer is yes. ^[14]

In the Mesozoic era of dinosaurs, the atmospheric carbon dioxide content was high, indicating that dinosaurs are very suitable for atmospheric environments with high carbon dioxide concentrations. Maybe they can only live well in that atmospheric environment. At that time, although mammals have also appeared, they have not been greatly developed. Maybe this is because the atmospheric composition and other environments are not very beneficial to them, so they have been in a weak position in the Mesozoic and developed slowly. With the passage of time, at the end of the Cretaceous period, the atmospheric environment has undergone tremendous changes, the content of carbon dioxide has decreased, and the content of oxygen has increased. This unfavorable environment for dinosaurs may be reflected in two aspects: 1. The body of the dinosaurs has occurred Ill, in the new environment, it is easy to get sick, and the disease will spread like a plague. 2. The new atmospheric environment is more suitable for the survival of mammals, and mammals have become more advanced and more adaptable competitors. Under these two factors, the dinosaurs eventually became extinct. Those relics are the few reptile species that can adapt to the old environment as well as the new environment. ^[14]

There are two starting points for the theory that the change of atmospheric composition caused the extinction of dinosaurs. One is that the atmospheric composition of the Mesozoic is different from that of modern times, and the other is that each organism needs a suitable atmospheric environment to survive. In ancient times, there was almost no oxygen in the atmosphere, and carbon dioxide was very high. Later, due to the emergence of organisms, the process of gradually reducing the amount of carbon dioxide in the atmosphere and increasing the content of oxygen under photosynthesis may explain many phenomena in the history of biological evolution. For example, the Cambrian explosion of life is also a difficult mystery in the history of evolution. Changes in atmospheric composition can also explain this, because animals cannot directly use inorganic substances for photosynthesis, its origin lags behind the origin of plants, and must occur when the oxygen content in the atmosphere reaches a considerable degree. Therefore, the Cambrian life explosion must be guaranteed that the oxygen content in the atmosphere has reached a certain level, and this has been scientifically proven. ^[14]

In addition to the 12 well-known ones, there are many lesser-known ones (such as sunspot bursts, electromagnetic disturbances, changes in the Earth's magnetic field direction and strength). ^[14]

But no matter what happens, one thing that cannot be questioned is that dinosaurs are unable to adapt to the impact or change caused by the events that occur. ^[14]

Dinosaur latest findings

The latest research by scientists shows that 65 million years ago, when asteroids collided with the earth, the dinosaurs might not have died out sooner or later. The real reason for the extinction was that dinosaurs were in a relatively fragile ecosystem at that time, and environmental changes could easily lead to extinction. ^[14]

Before the asteroid hit the earth 65 million years ago, dinosaurs were affected by environmental changes, and a large number of volcanic activities and temperature changes made the dinosaur ecosystem vulnerable. If asteroids collide with the earth millions of years earlier, a large number of dinosaur species and a more stable food chain will allow dinosaurs to survive; if asteroids collide with the earth millions of years later, dinosaurs will have the opportunity to improve evolution and better Adapting to harsh environmental conditions may escape extinction. ^[14]

About 65 million years ago, when an asteroid with a diameter of 10 kilometers collided in today's Mexico, the world of dinosaurs suffered severe environmental changes, putting them in a vulnerable state. The latest study was led by an international research team led by paleontologists at the University of Edinburgh, UK, who analyzed and analyzed a large number of dinosaur fossil specimens, most of which were excavated from North America. ^[14]

The research team found that widespread volcanic activity, sea level changes, and temperature fluctuations led to a crisis in the dinosaur food chain. At this time, an asteroid with a diameter of 10 kilometers collided with the earth, which worsened the extinction of dinosaurs. ^[14]

The latest research report was published in the recently published Journal of Biological Review. When asteroids collide with the earth, it will cause tsunami, earthquakes, wildfires, sudden changes in temperature, and other environmental factors, which will bring a fatal blow to the originally fragile dinosaur ecosystem and make dinosaur species extinct. Surviving airborne dinosaur species, they gradually evolved into today's birds. Dr. Steve Brussatt, of the University of Edinburgh s School of Geological Sciences, said: "Dinosaurs were the victims of 'bad luck'. The Earth was hit by a huge asteroid when the dinosaur ecosystem was at its worst. Vulnerable to attack. This latest study helps clarify the mystery of dinosaur extinction. " ^[14]

The culprit for the disappearance of dinosaurs is the moon

The disappearance of dinosaurs on the earth is caused by the change of the global climate environment. The climate environment during the dinosaur period and the climate environment after the disappearance of dinosaurs are two different climate environments. Who has so much energy to control the climate environment of the entire planet? In the origin of the moon, there is a capture saying that the Earth captured the moon at the end of the Cretaceous, and the capture time coincided with the time when the dinosaurs disappeared on the earth. And scientists have proven that the earth is caused by the moon all year round. The earth in the dinosaur period did not have all seasons. At that time, the equator and the Arctic were forests and dinosaurs, and 65 million years later the Arctic was a cold world. The plants and animals of the dinosaur period were larger than the same plants and animals now? The reason is caused by different climates. During the dinosaur period, the earth was like spring all year round. After the dinosaurs disappeared, the earth had all seasons. The capture theory also mentioned that orogenic movement and continental drift, and the hypothesis of dinosaur "extinction" also has some coincidence. At that time, orogenic movement and drift occurred on the earth. ^[14]

If the dinosaurs disappeared due to a sudden disaster, then after the disaster, why hasn't the earth recovered to the climate environment of the original dinosaur period? Sudden disasters will make the size of the earth s plants suddenly smaller. Sudden disasters will also cause a great change in the distribution of plants throughout the earth. But the scientists' discovery of this fossil did not coincide with the sudden disaster. Scientists' discovery of plant fossils is a slow process, not a sudden change. ^[14]

If the moon entered its current position at the end of the Cretaceous period, analyze the reason for the disappearance of dinosaurs from the change of environment. It is more reasonable to explain what happened on the earth at that time. ^[14]

Dinosaur hatching eggs

On May 16, 2018, a research team from the University of Nagoya in Japan published scientific research results in the British Science Journal, stating that large dinosaurs may "incubate eggs" by placing them without crushing the eggs. The results of this research may provide important clues for understanding the breeding methods of large dinosaurs. ^[14]