Sea level decline wiped out the dinosaurs

Another event that occurred during this period was sea level decline. The direct cause is that the submarine rift entered the quiet period, the oceanic crust stopped moving and slowly sank into the mantle, the sea water above also sank. On land, the coastline recedes. Within 100,000 years, much of what was once an ocean had become land.

Marine retreats affect both marine and terrestrial life. On the one hand, great changes have taken place in the terrestrial environment, such as the drying up of formerly humid areas, the reduction of precipitation, the drying up of lakes, the withering of forests, and the death of animals. That would mean the extinction of many terrestrial species. On the other hand, creatures that live offshore, such as corals, have died out without a hitch. At the same time, the ocean’s depth, temperature and oxygen content have changed dramatically, resulting in a large number of phytoplankton in the sea water death. Phytoplankton are at the bottom of the ocean food chain, and their destruction creates domino effect throughout the ocean food chain. It is conceivable that eventually large marine reptiles, such as the mosasaurs, would become extinct.

Therefore, the cretaceous-paleogene mass extinction event was caused by many factors. Many Cretaceous species were extinct before the impact. Imagine if there had been no meteorite impact, would the dinosaurs still be extinct? If some of the dinosaurs had survived, what would the world look like today?