Cretaceous period: Animals, plants and extinction event
Michael Dhar
(Image credit: USGS) Cretaceous period plants One hallmark of the Cretaceous period was the development and radiation of flowering plants, or angiosperms, which rapidly diversified, according to the National Park Service. Duck-billed dinosaurs were the most common type of ornithischians, a group of mostly herbivorous dinosaurs with bird-like hips, according to the Cal Poly Humboldt Natural History Museum (opens in new tab). How did the Cretaceous period end? This crater dates to within 33,000 years of the K-Pg event, Live Science previously reported. Illustration of the K-Pg extinction event at the end of the Cretaceous Period.