Introduction to Mass Extinction

The Cretaceous-Paleogene (K-Pg) event, occurring approximately 66 million years ago, marks one of Earth's most significant mass extinctions, eradicating nearly 75% of all species.

The prevailing theory suggests a colossal asteroid impact caused the extinction. Evidence includes a worldwide layer of iridium, a metal rare on Earth's crust but common in asteroids.

The Chicxulub crater, buried under the Yucatán Peninsula in Mexico, is the impact site. At 150 kilometers wide, it provides physical evidence correlating with the extinction timeline.

Some scientists argue that massive volcanic activity in the Deccan Traps released climate-altering gases, exacerbating the extinction event, possibly predating the asteroid collision.

Post-extinction, reduced sunlight from impact ejecta affected photosynthesis, collapsing food chains. It took ecosystems several million years to recover, allowing mammals to rise.

The K-Pg event famously caused the demise of non-avian dinosaurs. This allowed mammals and birds to evolve into vacant ecological niches, reshaping life on Earth.

Remarkably, some species like crocodiles and turtles survived. Their survival is attributed to factors such as semi-aquatic lifestyles, slower metabolisms, and hibernation-like states.