The Five Major Extinctions of the Phanerozoic.Describe the five major extinctions in the Phanerozoic and suggest possible causes for each.

The Five Major Extinctions of the Phanerozoic

Throughout the history of Earth, there have been five major extinction events in the Phanerozoic era. This era began 541 million years ago and continues to the present day. These five mass extinctions have been identified as the Ordovician, Devonian, Permian, Triassic, and Cretaceous. Each event was marked by the disappearance of numerous species of plants and animals from the planet, some of which were never recovered. While there is still much debate about the exact causes of each event, there are some potential explanations for their occurrence. The first mass extinction event in the Phanerozoic era is the Ordovician, which occurred around 444 million years ago. It is thought to be the second-largest extinction event in the history of the planet, with up to 85% of species becoming extinct. It is believed that a large-scale glaciation event may have caused the extinction, as well as an increase in ocean acidification due to increased volcanic activity (“Ordovician Extinction”). The Devonian extinction, which occurred around 374 million years ago, is the third-largest mass extinction event ever recorded. It is thought that the extinction was caused by a combination of an increase in sea level and anoxia, which refers to the depletion of oxygen levels in the ocean (“Devonian Extinction”). The Permian extinction, which occurred around 252 million years ago, is the largest and most devastating extinction event in the history of the planet. It is believed that a combination of volcanic eruptions, a decrease in sea level, and climate change may have caused the extinction (“Permian Extinction”). Cont…