When did the dinosaurs go out and when did the dinosaurs go out?

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 65 million years ago when an asteroid hit the Earth.

Dinosaurs were a group of animals that lived between 235 million and 65 million years ago, and were able to walk upright with some hind limbs, and dominated the world's terrestrial ecosystems for more than 160 million years. Most of the dinosaurs have gone extinct, but the descendants of the dinosaurs, the birds, have survived and survived to this day.

More than 200 million years ago, during the Mesozoic Era, many reptiles lived on land, so the Mesozoic Era is also known as the "Reptile Age". They continue to diverge into a variety of different species of reptiles, some of which have become today's turtles, some of which have become today's crocodiles, some of which have become today's snakes and lizards, and one of which has evolved into today's mammals that pervade the world.

About 65 million years ago, at the very end of the Cretaceous period, the dinosaurs went extinct. Millions of years before that, dinosaurs had grown in size, but all of these animals and many others had died suddenly.

A: The dinosaurs died out between 7,000 and 100 million years ago.

Unprecedented mass extinction Dinosaurs have successfully lived on Earth for hundreds of millions of years and have been the masters and powerful rulers of the planet. However, 65 million years ago, at the end of the Cretaceous period, they suddenly disappeared from all parts of the world. Along with the dinosaurs, a large number of other phyla and animals of different ecological conditions were extinct.

On land, crocodiles, lizards, etc. died on a large scale, and higher plants had 1 3 genera extinct. There are also many dead creatures in the ocean, prominent ones such as ammonites, arrowstones, foraminifera, corals, and supermicroorganisms. Famous relatives of dinosaurs, pterodactyls, plesiosaurs, ichthyosaurs, etc., also went with the dinosaurs.

Some scientists counted the number of genera of various phyla at the end of the Cretaceous and the beginning of the Tertiary period, and there were 2868 genera at the end of the Cretaceous period, and only 1502 genera in the early Tertiary period, accounting for 52%, indicating that about half of the organisms were extinct. If we look at the taxonomic units of organisms at the species level, the extinct species of organisms reach 75%, that is to say, about 2 3 organisms are extinct! Fossil data show that the extinction event at the end of the Cretaceous was global and occurred in a short period of time.

Among the extinct animals are those who walk on the ground, those that fly in the sky, and those that swim in the water, and there are not only large animals (such as dinosaurs), but also very small animals. In addition, there are plants. An unprecedented extinction!

It was not only the dinosaurs that disappeared in the extinction event 65 million years ago, but also a large number of other animals and plants, why did reptiles such as crocodiles, lizards, snakes, and turtles survive and continue to thrive until now? And the dinosaurs left only a few fossils? The extinction of dinosaurs is considered one of the top ten scientific mysteries of our time, and it is one of the major unsolved cases in the history of life on Earth.

Since the 70s of the last century, various theories and hypotheses about the great extinction have been promulgated, and there has been an unprecedented controversy. What kind of catastrophe happened that led to such an unprecedented extinction?

1. Dinosaurs died out in the late Cretaceous period, about 65 million years ago.

2. Introduction. Dinosaurs were diverse dominant terrestrial vertebrates that appeared in the Mesozoic. The word "dinosaur" is a translation of the English dinosauria or "terrifying lizard" by biologists, not the "dragon" in traditional Chinese culture. Dinosaurs dominated the world's terrestrial ecosystems for more than 160 million years.

Dinosaurs first appeared in the Late Triassic 230 million years ago and emerged from the mass extinction, which occurred at the end of the Cretaceous period about 65 million years ago, during the Late Cretaceous period. The Archaeopteryx fossil found in 1861 is very similar to the Eugenesaurus fossil, except that the Archaeopteryx fossil has traces of feathers, suggesting that the bird may have been descended from dinosaurs.

3. Causes of extinction.

The cause of the extinction of dinosaurs has not yet been determined, and the latest research by scientists believes that when an asteroid collided with the earth hundreds of millions of years ago, it was a period when the dinosaur ecosystem was relatively fragile, and the dinosaurs went extinct after hundreds of millions of years of life.

Simple question, the dinosaurs became extinct in the late Cretaceous period, about 65 million years ago.

This has been debated in the scientific community for a long time. According to the West **April 20**, British scientists have put forward a new speculation, that if the physiological structure of dinosaurs is similar to today's reptiles, then 65 million years ago, due to the great changes in the earth's environment, the sex of dinosaur offspring was greatly affected by temperature, and there was strict.

The major mass extinction of dinosaurs occurred 65 million years ago, and a few species did not become extinct until tens of thousands of years later.

Some say that it was caused by a comet hitting the earth; Some say that it is caused by the sun; And so on and so forth, but none of this is very accurate. In fact, no one can say how the dinosaurs became extinct, and can only be inferred from various reasons. Now, scientists have deduced one of the most powerful theories about the extinction of the dinosaurs

Dinosaurs died because of environmental changes. Dinosaurs liked to eat ancient plants, but at some point in the life of dinosaurs, the earth began to bloom with flowers, and more and more flowers were more and more than the ancient plants that dinosaurs could eat. Dinosaurs have no food, they can only eat flowers, and there is a harmful substance in flowers, called alkaloids, dinosaurs will be poisoned and die after eating too much, and dinosaurs do not know, they have been eating, and finally, many dinosaurs have been poisoned and died.

At this time, the competitiveness of flowers has far exceeded the ancient plants that dinosaurs could eat, and in the end, dinosaurs withdrew from the stage of history because they could not adapt to environmental changes.

Of course, this statement is not the most accurate, but it is the most powerful explanation of the cause of the extinction of the dinosaurs. Because the time spent on the earth coincides with the time of the extinction of the dinosaurs, the extinction of the dinosaurs is about 65 million years ago, and the time spent on the earth is also 65 million years ago, which shows that the dinosaurs are caused by the lack of adaptation to the environment.

It is also said that the extinction of the dinosaurs was caused by a comet hitting the earth, but if this is the case, the extinction of the dinosaurs should have been sudden, and the actual extinction of the dinosaurs was gradual over 10 million years. Therefore, the best explanation for the extinction of the dinosaurs is caused by the appearance of flowers.

How did the dinosaur become extinct and obscure?