Cretaceous–Paleogene boundary

Also known as K-P boundary, K-T boundary, K–P boundary, K–T boundary, Cretaceous–Tertiary boundary, KT boundary, KP boundary, K–Pg boundary

geological signature, usually a thin band of rock, marking the transition from the end of the Cretaceous Period and the beginning of the Paleogene Period, dated with radiometric methods, at the age of 66.043 ± 0.011 Ma