THE FIFTH GREAT EXTINCTION. EXTINTION AT THE END OF CRETACEOUS. K-PG BOUNDARY. 66 Ma

Extinction rate: 75% of the species.

Affected lifeforms: extinction of dinosaurs, pterosaurs, rudists and ammonites.

Main causes and consequences: the impact of a meteorite between 10 and 15 kilometers in diameter in the Yucatan Peninsula, Mexico, caused clouds of dust and ash and a nuclear winter.