The Early Cretaceous Period was a time in which the Earth was undergoing a process of change. Learn more about some common and not so common Early Cretaceous dinosaurs, including the Iguanodon, Muttaburrasaurus, and Sauropelta.
Discovered in Outer Mongolia in 1922, Psittacosaurus was one of the smallest and most primitive members of the Ceratopsia. Two of the specimens were juveniles, smaller than a robin. Learn about these tiny dinosaurs.