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. Machairoceratops meaning "bent sword horned face" as a reference to the two horns projecting from the top of the frill.
Discovery and Naming[]
The species Machairoceratops cronusi is named after greek titan Cronus, who deposed his father Uranus by castrating him with a sickle or scythe. Machairoceratops was found in 2006 and was officially declared a new genus in 2016 by Eric K. Lund, Patrick M O'Connor, Mark A. Loewen, and Zubair A. Jinnah. Prior to receiving its genus name, the specimen found was referred to as "Wahweap centrosaurine B".
Description[]
Machairoceratops was a large quadruped, its frill covering its neck. The parietal bone (the back of the skull) of the genus has a single long pair of curved spikes, measuring at approximately 44 cm in length. The frill of the genus also lacks the epiparietales found in other centrosaurines, which is presumed to be a unique feature to the genus. Said frill covered the neck of the animal, much like other ceratopsians. Machairoceratops itself measured approximately 20-25 feet and weighed 1-2 tons.
Classification[]
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.