12.7" Fossil Hadrosaur (Edmontosaur) Jaw Section - North Dakota
This is a 12.7" fossil hadrosaur (Edmontosaur) dentary (lower jaw), from the Hell Creek Formation near Bowman, North Dakota. It is in very good condition with repaired cracks on the ramus, the part of the lower jaw that engages the skull and filled cracks on the body of the bone. It shows "sockets" for ten teeth and is from the left side of the skull.
Hadrosaursare frequently referred to as duck-billed dinosaurs and are members of the ornithischian family Hadrosauridae They were fairly common herbivores which roamed Asia, Europe and North America during the Upper Cretaceous Period. Many species of hardrosaurs had distinct crests on their head, some of which had air filed chambers that may have produced a distinct sound. These crests may have been used for both audio and visual display purposes.
Because of its age and sedimentary composition composition, the Hell Creek Formation has become one of the most paleontological studied areas in the world. 158 genera of animals and 64 genera of plants are known from the formation and new discoveries are made frequently. In addition to Tyrannosaurs, Ceratopsids, and hadrosaurs, the formation has yielded remains of amphibians, reptiles, including lizards, snakes and turtles, fish and sharks, avian and non-avian dinosaurs, and mammals. The Hell Creek Formation gives the most complete understanding of the environment just before the Cretaceous-Paleogene extinction.