白垩 (bái'è) literally means 'white chalk' — the period was named after the chalk deposits formed from microscopic plankton in the Cretaceous seas (cf. the White Cliffs of Dover). Latin Cretaceous is from creta = chalk, and Chinese mirrors that meaning exactly. The Cretaceous ended with the K–Pg extinction (the asteroid impact that wiped out non-avian dinosaurs).
