Arrhinoceratops [SEP] parent taxon
herbivorous dinosaurs with parrot-like beaks which thrived in North America and Asia during the Cretaceous Period, which ended roughly 66 million years ago. In 1930 Lori Russell refined this to the Ceratopsidae. Tyson concluded it was closely related to "Torosaurus", probably even its direct ancestor.
Modern research indicates that "Arrhinoceratops" is a member of the Chasmosaurinae. Cladistic analyses recover it close to "Anchiceratops".
The following cladogram shows the phylogeny of "Arrhinoceratops" according to a study by Scott Sampson e.a. in
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.
Paleobiology.
"Anchiceratops" is rare compared