Mass Extinctions On The Earth

INTRODUCTION: Some 65 million years ago, several phenomena caused mass extinction of land and sea, and as a result they became the basis of the geology between the older Mesozoic (commonly known as "reptile era") and the modern Cenozoic Defined. At the border, finer scale than "age of mammals", extinction defines the boundary between the Cretaceous (geological symbol, "K") and Tertiary ("T") period. This mass extinction is often called KT extinction.

These mass extinctions are fatal, but opened up the earth to create new forms of life. Dinosaurs appeared after the greatest extinction on the planet and the extinction of the Permian - Triassic was about 250 million years ago. The extinction of the largest species studied between the Cretaceous and the Paleogene three centuries ago about 65 million years killed the dinosaurs and provided mammals with space for rapid diversification and evolution. Scientists narrowed down some of the most likely sources of mass extinction. Events of flood basalt (volcanic eruption), asteroid collision, sea-level descent are the most likely cause of mass extinction, but other known events may also contribute. When the Earth's ocean loses oxygen - these include global warming, global cooling, methane eruption and anoxic cases

In billions of years, the mass extinction of many large species occurred. Many people believe that the earth is experiencing another mass extinction case, the "serendipitous extinction case", and the arrival and spread of humans on a global scale is related to the current case believe. Unlike the extinction of large species so far, the extinction of the present species is obviously not simply due to the power of nature. People have the ability to choose how to influence the future of other species on the planet and can choose to reduce species diversity or protect biodiversity.

Probably the most famous mass extinction case is a case of destroying all the dinosaurs on the earth. This is the fifth mass extinction incident known as Cretaceous - Tertiary extinction, or simply K - T annihilation. The mass extinction of the Permian age (also called "extinction") is much more extinct species, but the KT extinction is known for the reason that the general public is interested in dinosaurs. . The extinction of K - T is the borderline between the Mesozoic and Tertiary that began during the Cretaceous, which was the new generation (the age we are still alive). The extinction of K - T occurred about 65 million years ago, estimated to account for 75% of all species on Earth.