When did the dinosaurs become extinct? 20

As a large family of animals, dinosaurs ruled the world for more than 100 million years. However, within the dinosaur family, not all of the different species lived together, with some species occurring only in the Triassic, some only in the Jurassic, and some only in the Cretaceous. For some "long-lived" taxa, it can only cross the boundaries of time, and no dinosaur can live from the late Triassic period 140 million years ago to the end of the Cretaceous period 65 million years ago.

Triceratops That is, in the history of the dinosaur family, they themselves have undergone a process of constant evolutionary development. Some dinosaurs appeared first, others later; Similarly, some dinosaurs went extinct first, and some dinosaurs became extinct later.

So, which were the last dinosaurs to go extinct? Obviously, the dinosaurs that lived until the "last moment" before the extinction 65 million years ago were the last dinosaurs to become extinct. They include many species.

Among them, vegetarian dinosaurs include Triceratops, Swollen-headed Dragon, Edmontosaurus and so on; Carnivorous dinosaurs include Tyrannosaurus rex and Serratosaurus, among others.

An 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?

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.

The more common theory is that it became extinct at the end of the Cretaceous period 6,500 years ago, but there are many different theories about how it became extinct! ~!

The time of death is the time of extinction.

About 70 million years ago.

About 70 million years ago.

About 70 million years ago.

About 70 million years ago.

About 70 million years ago.

I'm a student of bioscience, and our book says that it was extinct at the end of the Mesozoic Era.

65 million years ago.

But now there are a lot of dinosaurs.

When an asteroid collided with the Earth 100 million years ago, it was a fragile period for the dinosaur ecosystem, and the dinosaurs went extinct after living for hundreds of millions of years due to the great changes in the environment caused by the asteroid collision.

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.

Since the 70s of the 20th century, many studies have pointed out that modern birds are most likely direct descendants of theropod dinosaurs. Most scientists regard birds as the only dinosaurs that have survived to this day, while a few even argue that they should be grouped within the same class.

Crocodiles are modern relatives of another group of dinosaurs, but they are more closely related to dinosaurs than birds. Dinosaurs, birds, and crocodiles all belong to the main clade of reptiles, which first appeared in the late Permian and became the dominant amphibian group in the middle Triassic.

Dinosaurs (excluding birds) were the dominant group of land-dwelling reptiles, with their limbs erect under their bodies rather than spread out on either side. Many prehistoric reptiles are often informally identified as dinosaurs, such as pterosaurs, ichthyosaurs, plesiosaurs, cangosaurs, and disodontosaurs (heterodontosaurs and gyaloptyls), but from a scientific point of view, these are not dinosaurs.