Dinosaurs disappeared from the earth about a year ago.

Dinosaurs first appeared in the Triassic period about 240 million years ago and died out in the Cretaceous period about 65 million years ago during the late Cretaceous mass extinction event of the Mesozoic Era. The dinosaurs eventually became extinct 63 million years ago, in the Cenozoic, Tertiary and Paleocene epochs.

About 65 million years ago, at the very end of the Cretaceous period, the dinosaurs went extinct. For millions of years or so, dinosaurs had become smaller, but all of these animals and many others had suddenly died.

Dinosaurs disappeared from the earth about a year ago.

Multiple extinctions on Earth are inevitable in the evolution of the solar system's environment.

In the long process of evolution, the solar system has given birth to life, and at the same time, it has also continuously eliminated some that cannot adapt.

Species of the solar system's environment changes. To this day, mankind has not determined the rest of the solar system except for the Earth.

Whether life also exists on the stars.

The extinction of the dinosaurs is indeed a natural mystery of great interest to mankind. This is because dinosaurs were once on Earth.

Their extinction is indeed a sign of a dramatic change in the Earth's environment.

Let's analyze the basic conditions for biological extinction:

1) Changes in temperature and environment.

2) Changes in the radiation environment.

3) Changes in the gravitational environment.

4) Breakage of the food chain.

Alterations in (1), (2), and (3) may lead to a break in the food chain.

Therefore, species extinction is usually a tendency for parts of the food chain to disappear.

Those animals that crossed the food chain were able to survive and evolve into species that were more adapted to the environment at the time.

First of all, the era when dinosaurs lived, the earth's climate was hot. Due to the initial cooling of the climate, a large number of organisms are not adapted to the cold.

Extinct. Dinosaurs were most likely to become extinct due to temperature changes. It's just that the time scale of extinction is too short, people hypothetical.

An asteroid hitting the Earth also caused the Earth's climate to cool suddenly, and it was impossible to return to the state it was in before the impact.

However, it is not excluded that the Earth's climate will change a lot due to changes in the brightness of the sun.

In fact, conceived on Earth.

In the course of life, it must have been after the massive impact of an asteroid on Earth. Otherwise, the earth's environment will not be very stable and life will evolve.

The route can be difficult to determine due to the drastic changes in the environment. In the age of the dinosaurs, it was certainly not a regular occurrence for asteroids to hit the Earth.

At that time, the probability of an unexpected event on the Sun was higher than that of an asteroid impact on the Earth. Solar Emergencies.

Not only will it cause changes in the temperature environment, but also sudden changes in the Earth's radiation environment, so a large number of species will inevitably be eliminated. Biological tests.

These suggest that changes in the radiation environment can cause rapid extinction or mutation of species.

Gravitational environmental changes are related to the density distribution of matter in the solar system.

And the changes in the overall gravitational environment of the solar system may be related to the Sun in the Milky Way.

location. The evolutionary timescale in this area is very long and difficult to determine.

Anyone can put forward the hypothesis of the extinction of the dinosaurs. But it's the hypothesis that tests the most important thing.

The only way to test the hypothesis is to obtain concrete evidence through the archaeology of the solar system (including the Earth). Therefore, it is easy to come up with a hypothesis.

The search for archaeological evidence is difficult and exciting.

Exploring the mystery of the extinction of the dinosaurs is essentially exploring the mystery of the evolution of the solar system. This is by no means an isolated incident.

Dinosaurs appeared about 100 million years ago in the mid-to-late Triassic period of the Mesozoic Era.

The earliest and most primitive dinosaur found in the world is the archaeopterator, which lived 100 million years ago and the fossils were found in Argentina, South America.

Archaeraptor lived for a longer time than the Achilisaurus 100 million years ago, the fossil was found in Africa, when South America and Africa were still connected, this Achilisaurus is not a dinosaur in the real sense, it is a dinosaur form of a reptile, Achilisaurus is like a dinosaur, the skeletal structure is very similar to the dinosaur, but it is by no means a dinosaur, so it cannot be the ancestor of the dinosaur. The only possibility is Archaeraptor, whether from the structural structure of the pelvis, or from the analysis of its birthplace and living habits, Archaeraptor is a real dinosaur.

Archaeraptor has a body length of 1 meter, weighs 10 kilograms, has strong and powerful hind limbs, relies on three toes to support its weight, can run quickly, short forelimbs, sharp claws, can hunt prey, because its hind teeth have grooves and serrations, which is a typical carnivorous dinosaur teeth, the front teeth are leaf-shaped, with obvious herbivorous dinosaur teeth, so it is speculated that Archaeraptor was an omnivorous dinosaur, Archaeopterac has the characteristics of both later sauropods and later theropods, Archaeopterosaurus was probably the common ancestor of sauropods and theropods, and indeed all dinosaurs, so it was also the most primitive dinosaur.

The dinosaurs became extinct at the end of the Cretaceous period of the Mesozoic Era, about 65 million years ago.

The cause of the extinction of the dinosaurs is still being studied. For a long time, the most authoritative opinion was that the extinction of the dinosaurs was related to a large meteorite 65 million years ago. According to research, there was an asteroid with a diameter of 7-10 kilometers that fell on the surface of the earth, causing a large **, throwing a large amount of dust into the atmosphere, forming a dust fog that obscured the sky and the sun, causing the photosynthesis of plants to temporarily stop, and the dinosaurs became extinct.

The asteroid impact theory quickly gained support from many scientists. This view was further confirmed by the discovery in 1991 of a meteorite impact crater in Mexico's Yucatan Peninsula and the discovery of a very thin layer of iridium in strata of the same geological period (iridium is found in very small quantities on Earth). Today, that view seems to be a foregone conclusion.

About 100 million years ago in the middle and late Triassic period, extinct in about 6500 years ago, at the end of the Cretaceous period in the Mesozoic Era.

Dinosaurs existed on Earth for about 160 million years.

Dinosaurs are a general term for a class of reptiles that appeared in the Mesozoic era, and most dinosaurs are portrayed by their orthopedic limbs, long tails, and large bodies. They mainly inhabit woodlands or open areas on lakeshore plains.

The term "dinosaur" refers to the dinosaur, the terrifying lizard, which was translated as "dinosaur" by Japanese paleontologists and later became popular in China. The ancient Greek word lizard refers to a group of large, lizard-like reptiles with limbs, tails, or wings.

The dinosaurs disappeared at the end of the Cretaceous period 65 million years ago, becoming a mystery in the history of the evolution of life on Earth, which is still unsolved. All of the earth's past creatures are recorded in fossils. In the strata of the Mesozoic era, many dinosaur fossils have been found.

A large number of bones can be seen in a variety of shapes. In the Cenozoic stratigraphic feast that followed, there were no fossils of non-avian dinosaurs, and now only birds remain, and most scientists agree that "birds belong to dinosaurs".

There are many types of dinosaurs, and their body shape and habits also vary greatly, with the largest fragile dinosaur being more than 50 meters long, while the smallest hummingbird may be less than 10 centimeters. In terms of eating habits, there are docile herbivores and ferocious meat eaters, as well as omnivorous dinosaurs that eat both meat and vegetables.

The first dinosaurs appeared about 100 million years ago, and for ease of study, dinosaurs can be divided into avian and non-avian dinosaurs. Among them, non-avian dinosaurs lived only in the Mesozoic era (Triassic, Jurassic and Cretaceous) and were all extinct 65 million years ago.

The discovery of dinosaur fossils has a long history, and long before the Mantels discovered avian dragons, Europeans knew that there were many huge fossilized bones buried in the ground. However, at the time, people did not know their exact attribution, so they were always mistaken for "the remains of giants".

Dinosaurs lived on Earth for about 100 million years and were a representative and iconic species of the Mesozoic Era.

Dinosaurs only appeared in the middle of the Triassic period, about 100 million years ago. After the Jurassic and Cretaceous periods of the Mesozoic Era, it did not become extinct until 65 million years ago. Lived together on Earth for 165 million years.

The Mesozoic Era began in the Triassic period about 100 million years ago and ended at the end of the Cretaceous period 65 million years ago. But in the early Triassic period of the Mesozoic Era, there were only primitive reptiles, and dinosaurs had not yet appeared.

The Earth has been born for 4.6 billion years, and in these 4.6 billion years, the Earth has experienced five mass extinctions, the most recent of which was the extinction of the dinosaurs 65 million years ago. Then it took countless more years for the birth of humanity.

It took about 3 million years for human beings to evolve from primitive life to intelligent life, which is too short for the evolution of a life, and it has to be said that human beings have created a miracle of life.

Dinosaurs were the overlords of the earth 65 million years ago, it relied on a huge and robust physique to stand at the top of the food chain, and dinosaurs lived on the earth for hundreds of millions of years, such a long time, did not dinosaurs evolve into intelligent life, did not develop into civilization? I'm afraid no one can do this question.

Less than 200 million years, about 100 million years.

Dinosaurs appeared in the late Triassic period of the Mesozoic Era, about 100 million years ago. After the Jurassic and Cretaceous periods, it became extinct 65 million years ago and coexisted on the earth for about 100 million years.