When did the Cretaceous-Paleogene mass extinction occur?

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Cretaceous paleogeography — Cretaceous Period Distribution of landmasses, mountainous regions, shallow seas, and deep ocean basins during the late Cretaceous Period. Included in the paleogeographic reconstruction are the locations of the interval's subduction zones.

The Cretaceous-Paleogene (K-Pg) mass extinction, also historically referred to as the Cretaceous-Tertiary (K-T) boundary event, occurred approximately 66 million years ago.123

This cataclysmic event marked the end of the Cretaceous Period and resulted in the disappearance of approximately 75 to 80 percent of all species on Earth, including the dinosaurs. While the exact duration of the extinction process remains a subject of scientific study, it is widely associated with the impact of a massive asteroid near the Yucatán Peninsula in present-day Mexico, which triggered severe global environmental changes.431