Examining the Cretaceous: Paleogene Extinction Event

Some paleontologists believe that before the last blow, global ecosystems are already in recession and asteroids have destroyed most of life on Earth. Continental drift and seabed expansion may have changed the circular pattern of the ocean, resulting in dramatic changes in the climate of the sea and the earth. In addition, many volcanic eruptions were discovered in the late Cretaceous period before K - Pg; it was thought that dust and gas release caused a large environmental change. However, when Chicxulub asteroid collided with Earth to release energy "one billion times higher than atomic bomb that destroyed Hiroshima and Nagasaki", an important point occurred (Choi, 2013).

Cretaceous - Paleogene extinction event (end of Cretaceous, K-Pg annihilation, or previous K-T annihilation): 66 Ma - transition zone of the Cretaceous Dania era (Maastricht). The event formerly known as Cretaceous - Tertiary or K - T extinction or K - T boundary is now called Cretaceous - Current (or K - Pg) extinction event. About 17% of families, 50% of all genera and 75% of species are extinct. In the sea, ammonite, Presiosaurus, moss all disappeared and the proportion of adherent animals (immovable animals) decreased to about 33%. In the meantime, all the dinosaurs except birds have become extinct. Boundary events are serious, there is a big difference in annihilation rate between different clades. Mammals and birds, the latter from the animal dinosaur dinosaurs, became the predominant large terrestrial animal

Cretaceous - Quaternary extinction does not mean that all dinosaurs are extinct. Birds evolved from Jurassic small feather beasts, and most dinosaur strains were cut off at the end of the Cretaceous, but some birds survived. Therefore, dinosaurs are part of modern fauna. Mammals did not evolve from modern reptile populations, but instead mammals and reptiles evolved from a common ancestor. Immediately after the first reptile - like animals appeared, they were divided into two branches, a lizard and a synapse. The line leading to mammals (synapse) is separated from the line leading to the modern reptile line (lizard) in the middle of the coal era about 320 million years ago. For the first time in the late Carboniferous or early Permian, contemporary reptiles (Lepidoptera, Tortoise and Crocodile) opposed. Mammals themselves are the only survivors of the synaptic system.

Abbreviation of KT extinction, Cretaceous - Tertiary extinction. K - Pg means extinction or Cretaceous - Paleogene extinction, involved in the elimination of the Cretaceous, very close to Cretaceous and the border. Approximately 80% of animal species. During the Paleogene, about 66 million years ago. The extinction of K - T is characterized by the elimination of many important elements of the Mesozoic (252.2 to 66 million years ago) including almost all dinosaurs and many marine invertebrates. The name of this event comes from the German Kreide meaning "chalk" and the word Tertiary which was traditionally used to describe the period from the Paleogene to the New Era. The extinction of KT was ranked third in the scale of five major extinction cases, which broke the scope of geological time.