Stegosaurus

Ankylosaurus, an ankylosaurian is in the order of Ornithischia. Are saurischian dinosaurs extinct? At the end of the Cretaceous Period, all saurischians except the birds became extinct in the course of the Cretaceous–Paleogene extinction event. Birds, as direct descendants of one group of theropod dinosaurs, are a sub-clade of saurischianRead More →