This is a 5.4" Hadrosaur (Hypacrosaur) Metatarsal (foot bone) from the Two Medicine Formation Montana. It is in excellent condition with two repaired cracks and minor filling. This is the first metatarsal from the third toe (outside) of the right foot.
Hypacrosaurus is a very large, Lambeosaurini Hadrsosaur that would have been almost as large as the Tyrannosaurs that it lived alongside. Like Corythosaurus, it had a tall, hollow rounded crest, although not as large and straight. It is known from the remains of two species that spanned 75 to 67 million years ago, in the Late Cretaceous of Alberta, Canada, and Montana, United States, and is the latest hollow-crested duckbill known from good remains in North America. It is estimated to have been around 9.1 meters (30 feet) long and to have weighed up to 4-5 tons.
Hypacrosaurus drawing by wikipedia user debivort. Creative Commons License
are 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.