When did pteranodons become extinct?

Pterosaurs died out 65.5 million years ago during the K-T Extinction Event. The K-T Extinction Event not only wiped out the pterosaurs, but all non-avian dinosaurs, the plesiOSaurs and mosasaurs, and many types of plants and animals that are not as well known today. In fact, it is believed that 75% of species went extinct.