cladogram follows Longrich (2014), who named a new species of Pentaceratops, and included nearly all chasmosaurine species. Longrich stated that the holotype and referred specimen of P. aquilonius fall within the diagnosis of Pentaceratops, and were recovered very close to the type species in the phylogeny. He noted that the placement of Utahceratops does not make the genus paraphyletic, as there is no requirement that genera are monophyletic. The Williams Fork chasmosaur differs from the Pentaceratops and Utahceratops species, and might require a new specific or generic name. Paleobiology Pentaceratops, like all ceratopsians, was an herbivore. During the Cretaceous, flowering plants were "geographically limited on the landscape" and so it is likely that this dinosaur fed on the predominant plants of the era: ferns, cycads and conifers. It would have used its sharp ceratopsian beak to bite off the branches which were then shredded - leaves, needles and all - by the tooth batteries, providing a self-sharpening continuous cutting edge in both upper and lower jaws. Ultimately the plant material was digested by the large gut. Paleoecology Pentaceratops lived around 76–73 million years ago, its remains having been mostly found in the Kirtland Formation in the San Juan Basin in New Mexico. Other dinosaurs that shared its habitat include Parasaurolophus cyrtocristatus, the pachycephalosaur Sphaerotholus, the armored dinosaur Nodocephalosaurus and the tyrannosauroid Bistahieversor. See also Timeline of ceratopsian research Ah-Shi-Sle-Pah Wilderness Study Area, the type locality for Pentaceratops fenestratus References Sources Lehman, T. M., 2001, Late Cretaceous dinosaur provinciality: In: Mesozoic Vertebrate Life, edited by Tanke, D. H., and Carpenter, K., Indiana University Press, pp. 310–328. Sullivan, R.M., and Lucas, S.G. 2006. "The Kirtlandian land-vertebrate "age" – faunal composition, temporal position and biostratigraphic correlation in the nonmarine Upper Cretaceous of western North America." New Mexico Museum of Natural History and Science, Bulletin 35:7-29. Lucas, S.G., Sullivan, R.M., Hunt, A.P., 2006, Re-evaluation of Pentaceratops and Chasmosaurus (Ornithischia, Ceratopsidae) in the Upper Cretaceous of the Western Interior: New Mexico Museum of Natural History and Science, Bulletin 35 External links Chasmosaurines Late Cretaceous dinosaurs of North America Fossil taxa described in 1923 Taxa named by Henry Fairfield Osborn Kirtland fauna Paleontology in New Mexico Campanian genus first appearances Campanian genus extinctions Ornithischian genera