10" Hadrosaur (Edmontosaurus) Spinous Process - South Dakota

Hadrosaurs are frequently referred to as duck-billed dinosaurs and are members of the Ornithischian family Hadrosauridae. They were fairly common herbivores that roamed Asia, Europe, and North America during the Upper Cretaceous Period. Many species of Hadrosaurs had distinctive crests on their heads, some of which had air-filled chambers that may have produced a distinct sound. These crests may have been used for both audio and visual display purposes.

The Hell Creek Formation

Renowned for both its age and rich sedimentary layers, the Hell Creek Formation is one of the most intensively studied fossil-bearing regions on Earth. To date, scientists have documented 158 genera of animals and 64 genera of plants from its rocks, with new finds emerging regularly. Beyond iconic dinosaurs such as tyrannosaurs, ceratopsians, and hadrosaurs, the formation has produced an extraordinary array of life, including amphibians, reptiles, lizards, snakes, turtles, fish, sharks, birds, and early mammals. Together, these fossils provide the most complete picture of the ecosystems that thrived just before the Cretaceous–Paleogene extinction event.