Upper Cretaceous Period, 70-80 million years BP. A hadrosaur tooth from the Hell Creek Formation, Montana, USA, in a display case. 1.32 grams, 17mm without case (1/2"). From an old Bristol paleontological collection; acquired 1950s-1960s. Hadrosaurids, or duck-billed dinosaurs, are members of the ornithischian family Hadrosauridae. This group is known as the duck-billed dinosaurs for the flat duck-bill appearance of the bones in their snouts. [No Reserve] Fine condition.