Why did dinosaurs become extinct ?
During the cretaceous-tertiary period, about sixty-five million years ago, all dinosaurs went extinct; expect some that eventually evolved into modern birds. In the extinction, all animals died except some of those animals smaller than a cat. The extinction caused the sky black out for a long period, killing microbes and plants, which is the main source of food of the species. In the boundaries of North America alone, almost half of the plants decomposed. Paleontologists called it “K-T boundaries”, after the layers of rocks corresponding to this extinction.
Even in the modern days, we do not have a concrete knowledge regarding what caused this immense extinction. One theory by Luis Alvarez that paleontologist relied upon involved a six-mile asteroid that hit the Earth, causing a meteor shower with an impact compared to two million atomic bombs. This asteroid caused a rain of molten magma killing everything on its path.
There are two facts that back up Alvarez’s theory of extinction. The First is the enormous crater found in Mexico’s Yucatan peninsula dated back in the K-T boundary. The second fact is the large amount of iridium found in the rock from the K-T boundary, which found in all parts of the world as well. This substance can rarely be found on earth but present in most asteroids. These facts suggested that the impact was so huge, it scattered the rocks all over the world. A substance called Gypsum is also present in the rocks found in the crater. Research proved that this substance could create a sulfur dioxide clouds, causing acid rain that could kill all creatures.
The asteroid’s impact and its after effect caused extreme heat that killed over ninety-nine percent of the dinosaurs within hours. Even if certain species survived the incident, they would die in the following years due to the completely unraveling of the ecosystem drying up their food source.
