There have been many different theories of how the dinosaurs went extinct. These theories were the asteroid theory, the volcanic theory, and the marine regression theory. The marine regression theory does not exclude the existence of an asteroid impact, but the impact is determined to be extinction to an already decreasing ecosystem. The volcanic theory suggests that the iridium surplus found in the Yucatan Peninsula might have come from intense volcanic activity. This theory believes …showed first 75 words of 1042 total…

…showed last 75 words of 1042 total…caused the dinosaurs to become extinct. Also, the large crater supports that it was probably the site of the asteroid collision. The rare elements found in the area of the asteroid collision aid that they came from another planet, and collided with the Earth leaving these elements behind in plentiful amounts, in the K-T layer. This strong evidence was proven by many different facts and concludes that the dinosaurs were killed by an asteroid collision.