Studies caused by the asteroids and other units caused by the asteroids and other units found that dinosaurs may be extinct.

Hubei Daily News (Reporter Zhang Ye, correspondent Wang Junfang, Chen Huawen) Dinosaurs are one of the most well -known paleonts on the planet. Why dinosaurs suddenly disappeared 66 million years ago, the "Asteroid impact hypothesis" has always been the mainstream view. Recently, Chinese scientists have put forward a new point of view based on the progress of research.

In 1980, Alvarez's father and son proposed the "Asteroid impact hypothesis", that is, a "nuclear winter" caused by a small asteroid of about 10 kilometers in diameter was the main reason for the sudden extinction of dinosaurs. In 1991, the Hick Surubo meteor pit discovered on the Yicatan Peninsula Mexico Peninsula provided direct evidence for this hypothesis. Since then, the "asteroid impact hypothesis" has gradually become the mainstream view of the cause of dinosaurs.

Recently, the scientific research teams from the Chinese University of Geosciences (Wuhan) (hereinafter referred to as Earth Dacheng), the research team of ancient vertebrates and ancient human research institutes and the Institute of Geosure of the Chinese Academy of Sciences have achieved new progress. They found that dinosaurs' diversity was reduced in the late white world, which may be another important reason for dinosaurs.

"Before the asteroid hits the earth, the diversity of the dinosaur group has been very low, and the impact of the asteroid has given them the last blow." Said Dr. Han Fei, the first author of the paper, Dr. Earth Magnetic and Planet Magnetic Laboratory.

Beginning in 2013, researchers inspected Luonan, Lingbao, Lingchuan, Shanyang, Puxi, and Puyang in the east of the Qinling Mountains in my country. Among them, during the research on the Shaanxi Shanyang Basin, the 44 -layer continuously distributed dinosaur bones and dinosaur egg fossils were found, and more than 1,000 fossil samples were collected for research.

The age measurement method based on the law of radioactive element decay is a commonly used method for determining geological age. However, the stratigraphy of the dinosaur fossils in the Shanyang Basin is a red sandstone, and the annual mineral that can represent the age of the strata.

In order to obtain the accurate age of 44 fossil layers, the team has collected nearly 10,000 rock samples to comprehensively use biological stratigraphy, magnetic stratigraphy, and rotation of stratigraphy, and continuously segmented the age of the stratigraphy, giving the resolution "100,000 years 100,000 years "Time frame.

"Millions of years" is the basic age unit in geological research. Under a high -resolution time framework, the research team discovered the clue of dinosaur diversity -

72 million years ago, dinosaurs such as Chilong, bird dragons, egg stolen dragons, Avara Ci Longs, Tyrannosaurus, duck bilies, and armored dragons all existed in the east of the Qinling Mountains, and while By 68.24 million years ago, only a small amount of dinosaurs such as egg dragon, tyrannosaurus, and duckbill dragons lived here, and continued until 66.38 million years ago.

Research has further discovered that dinosaurs in Nanxiong and other places in Guangdong also have similar characteristics, which means that around 72 million years ago, the dinosaur diversity of my country has a significant reduction trend. This is similar to the characteristics of dinosaur fossil distribution in western North America.

It is speculated that the decrease in dinosaurs' diversity in late White Bai Shi is likely to be a global phenomenon. This makes the dinosaur group cannot survive and recover from the environmental drama caused by major disaster events such as the planet or the outbreak of volcanic eruptions, thereby going for extinction.

The study was jointly funded by the National Natural Science Foundation of China and the leadership of the Chinese Academy of Sciences. The research results were published as cover articles on the International Journal of the National Academy of Sciences (PNAS). The author of the communications was Wang Qiang, an associate researcher at the Institute of Ancient Human Research Institute of the Chinese Academy of Sciences.

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