page_title: Anchiceratops
section_title: Classification
hierarchical_section_title: Anchiceratops / Classification
caption_attribution_description: Anchiceratops specimen ROM 802. Exhibit in the Royal Ontario Museum, Toronto, Ontario, Canada. This exhibit is old enough so that it is in the public domain, and photography was permitted in the museum. I took this photograph and release it into the public domain.
context_page_description: Anchiceratops is an extinct genus of chasmosaurine ceratopsid dinosaur that lived approximately 72 to 71 million years ago during the latter part of the Cretaceous Period in what is now Alberta, Canada.
  Anchiceratops was a medium-sized, heavily built, ground-dwelling, quadrupedal herbivore that could grow up to an estimated 5 m long. Its skull featured two long brow horns and a short horn on the nose. The skull frill was elongated and rectangular, its edges adorned by coarse triangular projections. About a dozen skulls of the genus have been found.
context_section_description: Brown in 1914 assigned Anchiceratops to the Ceratopsia. In 1915, William Diller Matthew refined this to the Ceratopsidae. In the same year Lawrence Lambe assigned this genus to a new taxon that he erected, "eoceratopsinae", which included "Eoceratops" (now Chasmosaurus), "Diceratops" (now Nedoceratops) and Triceratops. "Eoceratopsinae" however soon fell into disuse as a taxon. Ironically, in the same study Lambe erected Chasmosaurinae, the taxon that Anchiceratops is assigned to currently. Over the decades Lull (1933), Romer (1956), Russell and Chamney (1967), Molnar (1980) agreed with the assignment to Ceratopsidae.
   
  In 1990, Peter Dodson and Phil Currie placed it in the Chasmosaurinae. The phylogenetic analysis conducted by Ryan et al. (2010) confirmed this assignment. Modern cladistic analyses usually recover Anchiceratops in a more advanced position within the Chasmosaurinae, closer to Arrhinoceratops than to Chasmosaurus.  Mallon's study of 2012 concluded however, that Anchiceratops was more closely related to Chasmosaurus than to Triceratops, suggesting that this genus was less derived than previously thought.
  C.M. Sternberg had originally designated a smaller skull as the type specimen for a new species Anchiceratops longirostris, because of its size and its horns which are significantly more slender and point forward instead of upward.  Later however, paleontologists had concluded that the size and form of this skull falls within the expected range of variation seen in A. ornatus and that it was probably a member of that species.
  In 2010 Mallon removed specimen NMC 8547 from the fossil material of Anchiceratops because of the few frill elements associated with it and because it could not be determined with certainty whether the material belonged to this taxon. The related Arrhinoceratops is known from the same formation, and has a comparable frill surface structure. According to Mallon, in 1925 C.M. Sternberg had referred the material to Anchiceratops because he had been unaware that Arrhinoceratops had been described in March of that year. If correct, this would mean that no unequivocal postcrania (all skeletal elements posterior to the skull) of Anchiceratops are known.
caption: ROM 802, a skull in the Royal Ontario Museum
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