... analysis of ceratopsids, which is the first to include Medusaceratops , indicates that M . lokii is a unique, early centrosaurine ceratopsid taxon that is more closely related to Centrosaurini and Pachyrhinosaurini than Nasutoceratopsini. No unequivocal chasmosaurine bones or diagnostic material from any...

... ) of the newly defined Centrosaurini . This stem-based clade is composed of centrosaurine ceratopsids with well-adorned parietosquamosal frills and short postorbital horncores that are more closely related to Centrosaurus apertus than Pachyrhinosaurus canadensis . The rarity of nasutoceratopsins in the well...