Many of us have seen the movie Jurassic Park or heard of the famous dinosaur “Sue” whose bones were found near Faith, South Dakota. Even though dinosaurs have been extinct for 65 million years, their lives have intrigued the world of science. Why did the dinosaurs die out? These are three main theories that have been formed that include asteroids, disease, and volcanoes.
The first and probably the most famous theory is the asteroid theory. In the first few hours after a giant asteroid crashed into the coast of Mexico, nearly 65 million years ago, Earth’s atmosphere became so hot that it quickly incinerated any unprotected life on land (Ascravala 1). That would be enough to wipe out anything anywhere. But, to the Bulletin of the Geological Society of America, they think that this contradicts the widely accepted theory that dinosaurs died out over a period of months or years after the asteroid impact. The asteroid landed in Chicxulub, Mexico, 180 kilometers in diameter. The climate changes that the asteroid would’ve caused would be tremendous. The dust from the impact would’ve blocked the sun’s rays and started a “nuclear winter”. But some say that before the winter effect could have caused any damage, the dinosaurs would have died right away. “We think the nuclear winter was still important, but we think that a lot of life would have died immediately (Ascravala 1). Besides the nuclear winter, the heat from the impact and the Co2 and nitrogen would have elevated the temperature to extreme highs.
Volcanoes come in second among the famous theories, and for a good reason. Volcanic activity was a lot during the Cretaceous era. The Deccan Traps in western India and areas in the Pacific Basin are likely sites for increased volcanic activity at this time (Drake 1). As a lot of children around the world have seen the, “Land before Time” movies, where baby dinosaurs explore their world as its decaying. The main theory in those movies, volcanoes, is causing the dinosaurs to migrate to the “Great Land”. But, it still doesn’t explain what volcanoes could do to the greatest surface dwelling monsters ever known. As result of volcanic eruptions, the air between the ground and the ozone layer would become so hot; it would incinerate anything in a few minutes. The high lever of volcanic activity would also have emitted large volumes of greenhouse gases such as Co2 and methane, increasing the Earth’s temperature and drastically changing the planet’s climate (Drake 1). Ashes from the explosion would linger in the air for months; causing acid rain, unbearable temperatures, and in some locations, nuclear winter. The biggest problem caused by volcanic eruptions; the acid rain. The rain would pollute any bodies of water and suffocate marine life. And this would be happening all around the world. Nothing could run from the fate chosen by the volcanoes.
Disease is another suggestion for the extinction of the dinosaurs. It is difficult to see however how one disease could be so prevalent as to wipe out large swathes of the animal population, travel vast distances and kill off land and marine species as well as plant life (Drake 1). But the diseases 65 million years ago could have been way different then what we have today. Scientist’s don’t know if dinosaurs had immune systems or natural defense. If that was the case, any deadly disease could have caused high numbers of deaths among dinosaurs. Like a domino effect, they would eventually all fall; one after another.
