Centrosaurine

Biogeography

Centrosaurine fossils have mostly been found in Western North America (Alberta, Montana, and Alaska). In the United States, two taxa, Diabloceratops and Machairoceratops, have been found as far south as Utah. Yehuecauhceratops, a nasutoceratopsin from Coahuila, Mexico, is the southernmost occurrence of a centrosaurine in North America. No centrosaurine fossils had been uncovered outside Western North America until the 2010 discovery of Sinoceratops in the Shandong Province of China. However, some authors question the placement of Sinoceratops within Centrosaurinae. All other Late Cretaceous dinosaur groups from North America have also been found in Asia, so the initial absence of Asian centrosaurines had been surprising. The current evidence suggests that Centrosaurinae originated in Laramidia 90-80 million years ago, with the discovery of the oldest known centrosaurine, Menefeeceratops further proving this. This means Sinoceratops would have migrated to China from North America. Some hypothesize that centrosaurines originated in southern Laramidia and later radiated north.