hadrosaur: any of numerous large bipedal ornithischian dinosaurs having a horny duck-like bill and webbed feet; may have been partly aquatic
ornithischian: herbivorous dinosaur with a pelvis like that of a bird
rockers: originally a British youth subculture that evolved out of the teddy boys in the 1960s; wore black leather jackets and jeans and boots; had greased hair and rode motorcycles and listened to rock'n'roll; were largely unskilled manual laborers