7.9" Fossil Hadrosaur (Brachylophosaur) Metacarpal on Stand - Montana

The Judith River Formation is one of the most prolific sources of Late Cretaceous vertebrate fossils. At least sixteen Orders containing more than forty Genera are known from the formation. These include fish, amphibians, mammals, and insects in addition to the reptiles, avian and non-avian dinosaurs (birds). Among the more interesting specimens is Leonardo, a mummified and fossilized Brachylophosaurus. This is a Hadrosaur, a duck-billed dinosaur with amazing preservation of the soft tissues of the body. The pattern in the skin of the feet is even preserved. In addition to Leonardo, the Judith River Formation contains the remains of the theropod Hesperornis, the only known freshwater Hespernorthid, a penguin like bird.

Hadrosaurs 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 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.