The taxonomic history of the Ceratopsia began in 1876 with the description of Monoclonius crassus Cope followed in 1889 by Triceratops horridus Marsh. After a peak of discovery and description in the 1910s and 1920s resulting from the Canadian dinosaur rush in the province of Alberta and the Central Asiatic Expeditions to Mongolia of the American Museum of Natural History, the study of ceratopsians declined to a low level until the 1990s, when discoveries in China, Montana, Utah, Alberta, and elsewhere, abetted by increased biostratigraphic and phylogenetic precision, led to an unprecedented resurgence of activity. Even Richard C. Fox, along with colleagues from Peking University, joined in the activity, by naming Psittacosaurus lujiatunensis. To place the activity in historical perspective, half of all known ceratopsians have been described since 2003. Despite important finds of basal ceratopsians in China, Mongolia, and Korea, North America continues to dominate ceratopsian, especially ceratopsid, diversity.