This is a complete fossil tooth of the dinosaur Edmontosaurus annectens, the predominant hadrosaur species that can be found in the Lance Formation of Wyoming, U.S.A.. The tooth is a superb quality example that is UNBROKEN but only showing NATURAL feeding wear on the tip just emerged in the jaw.
These kind of teeth are far more rare than more prevalent "spit" teeth that are worn, used-up teeth ejected from the jaws continuously over the life of the dinosaur. Hadrosaurs were an important part of the food chain as these herbivores were a primary food source for the meat-eating dinosaurs in the same region, namely Tyrannosaurus rex, Nanotyrannus and Dromaeosaurs. No fossil tooth collection should be without at least one nice complete example tooth to display alongside fossils of the very dinosaurs that terrorized these peaceful beasts of the Late Cretaceous.