During the latest Cretaceous, the Maastrichtian stage (7265.5 mya), the diversity of dinosaurs wasn't as great as the preceding Campanian stage. North American herbivorous dinosaurs then included the titanosaur sauropod "Alamosaurus", the ceratopsians "Triceratops" and "Torosaurus", the pachycephalosaurs "Pachycephalosaurus", "Stygimoloch", "Dracorex", and "Stegoceras", the hadrosaurs "Edmontosaurus" and "Anatotitan". Predatory dinosaurs from this time period included "Tyrannosaurus" and "Nanotyrannus" (which may just be a juvenile of the former), and the troodontid "Troodon".