The K-Pg Boundary

The K-Pg boundary marks a global geological marker about 66 million years ago, signaling the end of the dinosaurs’ dominance. It’s identified by a layer of clay enriched with iridium, a rare metal often associated with asteroids, indicating a massive impact event. This impact caused widespread environmental changes, such as fires, a “nuclear winter,” and disruptions in ecosystems, leading to the extinction of about 75% of species, including the dinosaurs. The boundary is a key point in Earth's history, highlighting how a single event can dramatically reshape life on our planet.