What Cataclysmic Events Have Occurred in Earth's History?
According to National Geographic, the Earth began with a cataclysmic event called the big bang. The BBC states that there have been five major cataclysmic events that caused mass extinctions in the recorded history of the Earth.
About 450 million years ago, the Ordovician-Silurian event caused the death of approximately 85 percent of the life in the Earth's oceans. The BBC states that nearly all life on Earth lived in oceans during this time period. The second cataclysmic event occurred 359 million years ago during the Devonian period. The Devonian mass extinctions are thought to have occurred over the course of millions of years and included several mass extinction events. This event also mostly affected seas and sea life.
According to Wikipedia, the next mass extinction is thought to have killed approximately 96 percent of life on Earth during the Permian mass extinctions, which occurred over the course of millions of years. The Triassic-Jurassic extinctions affected marine life, birds and reptiles, and caused about 50 percent of land and sea animals to become extinct. The dinosaur extinctions occurred during the fifth cataclysmic event on record. During the Cretaceous-Tertiary event, the fifth cataclysm, the Earth was affected by many events that caused extinctions to occur. The final event that prompted mass dinosaur and sea life extinctions was a meteor that hit southern Mexico.