Cretaceous Extinction EventCauses, evidence and effects on biodiversityThe most important event of the Cretaceous era occurred at its end. Nearly 65 million years ago, the second most severe mass extinction in Earth's history occurred. This resulted in the loss of around 80% of the species living at the time. Although nowhere near as severe as the end-Permian mass extinction, the end-Cretaceous extinction is the best-known mass extinction event. This is due to the violent event that caused its extinction, as well as the chapter in Earth's history that it closed: the dinosaurs. The Cretaceous Event (often shortened to the KT Event) Among the animals that were killed off were the flying reptiles (pterosaurs) and the later mosasaurs and plesiosaurs, both early marine reptiles. Many molluscs and microscopic plankton species were killed. Land plants also experienced mass extinction. Nearly 60% of land plants have been lost. This led to high extinction rates among insect populations, especially insects highly specialized to feed on only a few types of plants that were most affected. It took about 9 million years for global insect populations to recover from the Cretaceous extinction. Immediately after the extinction, Earth experienced an explosion of short-term species that respond well to fire or other external disturbances. Evidence of the disaster comes from a thin layer of rock deposited around the world immediately after the impact. It is dominated by fossil plants whose descendants recover quickly after fires from other disturbances, such as Fire Weed in Alaska. The causes of the Cretaceous extinction are still debated by paleontologists. Scientists agree that the main cause of the extinction was a...... middle of paper ... that lasted about a million years. The eruption was not violent compared to others, but it could have sent ash up to the stratosphere. Another theory is that shifting tectonic plates caused the Deccan Traps to erupt, causing the release of massive amounts of carbon dioxide out of the Earth's crust. This then created a global greenhouse effect that cooked the planet. This, combined with climate change due to continental drift, could have caused the KT event. Paleontologist Richard Cowen believes that the evidence for an asteroid impact is so strong that it is unnecessary to explain this evidence by volcanic effects alone. We should focus on the fact that the KT border coincided with two different, but very dramatic events. Works Cited Cowen, Richard. A story of life. 2nd ed. Flight. 1. Massachusetts: Cambridge, 1999. Print.