The end of the dinosaurs is one of the greatest mysteries of paleontology. The leading theory of their extinction involves a massive meteor impact, possibly the one that created the Chicxulub crater in Mexico. Alternative theories include multiple global impacts, a sudden change in the sea level and a worldwide increase in volcanic activity that drastically altered the atmosphere and global climate.Continue Reading
According to the Alvarez Hypothesis, the extinction of the dinosaurs occurred as a result of a massive comet or meteor impact. One of the major pieces of evidence that supports this hypothesis is a layer of iridium found in clay that marks the boundary between the Cretaceous and Paleogene periods, which is when the dinosaurs went extinct. In the 1990s, geologists discovered a 112-mile-wide crater just off the Yucatan peninsula that provided evidence of just such a massive impact occurring around the same time as the extinction.
A few questions remain unanswered, however. A single impact would have had devastating effects on the environment, but most of the dangerous changes, such as an increase in acid rain, would only last a decade or two after the event. The dinosaurs' extinction occurred over a more extended period of time, bringing up the possibility that multiple impacts, possibly including the one that caused the Shiva crater in India, may have contributed to the extinction.Learn more about Dinosaurs