List of North American dinosaurs
Finally, in the long Upper Cretaceous, the greatest abundance and diversity of dinosaurs of all time lived in North America. During the early part of the Upper Cretaceous, the therizinosaur Nothronychus and the ceratopsian Zuniceratops lived. During the Campanian stage (83.672 mya), an enormous diversity of dinosaurs is known. Theropods included the tyrannosaurs Albertosaurus, Gorgosaurus, Daspletosaurus, Appalachiosaurus, and Dryptosaurus, and the dromaeosaurids Dromaeosaurus, Saurornitholestes, Atrociraptor, and Bambiraptor. Ceratopsians, such as Pachyrhinosaurus, Styracosaurus, Centrosaurus, Monoclonius, Brachyceratops, Pentaceratops, and Leptoceratops also existed. Among hadrosaurs, Parasaurolophus, Corythosaurus, Lambeosaurus, Saurolophus, and Prosaurolophus existed.