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Temporal range: Late Cretaceous, 80.1–77 Ma
Reconstructed skull
Scientific classification e
Kingdom: Animalia
Phylum: Chordata
Clade: Dinosauria
Order: Ornithischia
Family: Ceratopsidae
Subfamily: Centrosaurinae
Genus: Machairoceratops
Lund et al., 2016
Type species
Machairoceratops cronusi
Lund et al., 2016

Machairoceratops is an extinct genus of centrosaurine ceratopsian dinosaur known from the Late Cretaceous Wahweap Formation (late Campanian stage) of Grand Staircase-Escalante National Monument, southern Utah, United States.[1]


It contains a single species, M. cronusi, first described and named in 2016 by Eric K. Lund, Patrick M. O’Connor, Mark A. Loewen and Zubair A. Jinnah. The generic name is derived from Greek machairis, meaning "bent sword", in reference to its unique frill ornamentation showing two forward curving horns on the frill's uppermost part, and Latinized Greek ceratops, meaning "horned-face", which is a common suffix for ceratopsian genera names. The specific name cronusi refers to Cronus, a Greek god who deposed his father Uranus by castrating him with a sickle or scythe based on the mythology, and as such is shown carrying a curved bladed weapon. Machairoceratops is known solely from the holotype UMNH VP 20550, found in 2006, which is housed at the Natural History Museum of Utah. It is represented by a partial skull including two curved and elongate eyesocket horncores, the left jugal bone, a nearly complete but slightly deformed braincase, the left squamosal bone, and a parietal bone complex and its unique horn ornamentation, all collected in association.[1]


Lund et al. (2016) tested the position of Machairoceratops within Centrosaurinae by performing maximum parsimony and Bayesian phylogenetic species level analyses. The maximum parsimony analysis yielded a large polytomy at the base of Centrosaurinae, with only Centrosaurini, most of Pachyrhinosaurini (Einiosaurus, Wendiceratops and Pachyrostra), and a clade formed by Avaceratops and Nasutoceratops being resolved. The Bayesian analysis yielded a fully resolved topology which is shown below.[1]




Machairoceratops cronusi

Albertaceratops nesmoi

Diabloceratops eatoni

Avaceratops lammersi

Nasutoceratops titusi


Rubeosaurus ovatus

Styracosaurus albertensis

Spinops sternbergorum

Centrosaurus apertus

Coronosaurus brinkmani


Xenoceratops foremostensis

Sinoceratops zhuchengensis

Wendiceratops pinhornensis


Einiosaurus procurvicornis

Achelousaurus horneri

Pachyrhinosaurus canadensis

Pachyrhinosaurus lakustai

Pachyrhinosaurus perotorum


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