Age: Campanian Cretaceous, 80-74 million years old. This is an authentic Fossil Maiasaura Paroccipital Skull Bone from the Two Medicine Formation of Montana. Hadrosaur bones generally cannot be confidently assigned to a particular species, as many species of hadrosaur are found in most formations, and isolated bones are not diagnostic in most cases. But in this case, the bone comes from a bonebed where the hadrosaur material found has all been identified as Maiasaura thus far, making this a piece that can be confidently ID'ed.
Other species of hadrosaur in the Two Medicine Formation include Gryposaurus, Prosaurolophus, Acristavus, and Hypacrosaurus.