North American herbivorous dinosaurs from this time period include the titanosaur sauropod `` Alamosaurus '' , the ceratopsians `` Triceratops '' and `` Torosaurus '' , the pachycephalosaurs `` Pachycephalosaurus '' , `` Stygimoloch '' , `` Dracorex '' , and `` Stegoceras '' , and the hadrosaur `` Edmontosaurus '' .
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 '' .