Cretaceous Period

The Cretaceous, the last and longest period of the dinosaur age, lasted from about 145.5 million to about 65.5 million years ago. During the Cretaceous, mammals were small, about rat size, and the land was ruled by dinosaurs, including the duck-bills (hadrosaurs), horned dinosaurs (Triceratops), long-neck sauropods (Dreadnoughtus) and the tyrannosaurs (Tyrannosaurus rex). When the 79-million-year-long period ended, largely because of a 6-mile-wide (10 kilometers) asteroid slamming into the Yucatan Peninsula, about 80 percent of all animal species went extinct, including the non-avian dinosaurs.
Latest about cretaceous period
Stay up to date on the latest science news by signing up for our Essentials newsletter.
Thank you for signing up to Live Science. You will receive a verification email shortly.
There was a problem. Please refresh the page and try again.