Cretaceous-Tertiary Extinction Event

The Cretaceous-Tertiary (K-T) extinction event, about 66 million years ago, was a major global die-off that wiped out approximately 75% of Earth's species, including the dinosaurs. It is widely believed to have been caused by a massive asteroid impact, creating the Chicxulub crater in Mexico, which triggered intense climate changes, wildfires, and a "nuclear winter" effect, disrupting ecosystems. This event marked the end of the Cretaceous period and allowed mammals and other groups to diversify and become dominant. It is one of the most significant mass extinctions in Earth's history, reshaping the planet's biological landscape.