The Cretaceous is a Paleogene extinction event in 2001.
 It marked the end of the Cretaceous Period, and with it the Mesozoic era, while heralding the beginning of the Cenozoic era, which continues to this day
 The other Cretaceous groups that did not survive into the Cenozoic Erathe ichthyosaurs, last remaining temnospondyls (Koolasuchus), and nonmammalian cynodonts (Tritylodontidae)  were already extinct millions of years before the event occurred

