position. A phylogenetic analysis performed by Sampson et al. (2013) found Nasutoceratops to be the sister taxon of Avaceratops. According to this study, the existence of Nasutoceratops would support the hypothesis of faunal separation between the north and south of Laramidia. Its clade would differ from the northern centrosaurines in the retention of long brow horns and a short nose horn, combined with developing, convergent with the Chasmosaurinae, low epiparietals. In 2016, this clade was named Nasutoceratopsini; it contains Nasutoceratops as well as ANSP 15800 (the holotype of Avaceratops), MOR 692 (previously treated as an adult specimen of Avaceratops), the newly described CMN 8804 from the Oldman Formation, and another undescribed ceratopsian found in Malta, Montana. The cladogram presented below follows a phylogenetic analysis of the Centrosaurinae by Chiba et al. (2017), which included a systematic re-evaluation of Medusaceratops lokii: Paleoecology The only known specimen of Nasutoceratops was recovered at the Kaiparowits Formation, in southern Utah. Argon-argon radiometric dating indicates that the Kaiparowits Formation was deposited between 76.1 and 74.0 million years ago, during the Campanian stage of the Late Cretaceous period. During the Late Cretaceous period, the site of the Kaiparowits Formation was located near the western shore of the Western Interior Seaway, a large inland sea that split North America into two landmasses, Laramidia to the west and Appalachia to the east. The plateau where dinosaurs lived was an ancient floodplain dominated by large channels and abundant wetland peat swamps, ponds and lakes, and was bordered by highlands. The climate was wet and humid, and supported an abundant and diverse range of organisms. This formation contains one of the best and most continuous records of Late Cretaceous terrestrial life in the world. Nasutoceratops shared its paleoenvironment with theropods such as dromaeosaurids, the troodontid Talos sampsoni, ornithomimids like Ornithomimus velox, tyrannosaurids like Teratophoneus, armored ankylosaurids, the duckbilled hadrosaurs Parasaurolophus cyrtocristatus and Gryposaurus monumentensis, the ceratopsians Utahceratops gettyi and Kosmoceratops richardsoni and the oviraptorosaurian Hagryphus giganteus. Paleofauna present in the Kaiparowits Formation included chondrichthyans (sharks and rays), frogs, salamanders, turtles, lizards and crocodilians. A variety of early mammals were present including multituberculates, marsupials, and insectivorans. See also Timeline of ceratopsian research References External links Image Centrosaurines Late Cretaceous dinosaurs of North America Fossil taxa described in 2013 Taxa named by Scott D. Sampson Paleontology in Utah Kaiparowits Formation Campanian genus first appearances Campanian genus extinctions Ornithischian genera