Name: »bramble or thornbush horned face«
Length: 5 – 6 m
Height: 2 m
Weight: 2 – 3 tons
Time: Cretaceous (75 MYA)
Location: North America
Rubeosaurus (meaning “bramble or thornbush horned face”) is a genus of ceratopsian dinosaur which lived in what is now North America. Rubeosaurus fossils have been recovered from strata of the upper Two Medicine Formation of the Upper Cretaceous of Montana, dating to between 75 and 74 million years ago. The holotype specimen, USNM 11869, is composed of a partial parietal and was discovered by George F. Sternberg in 1928. A second specimen, MOR 429, is composed of a partial skull including a partial left premaxilla, co-ossified left and right nasals with horncore, partial left postorbital with horncore, and a nearly complete right parietal with two spikes. It was discovered in 1986.
This genus was named by Andrew T. McDonald and John R. Horner in 2010, and the type species is Rubeosaurus ovatus. Formerly this species was assigned to Styracosaurus. It is found as the sister taxon to Einiosaurus. It is notable for its large broadâ€“based nasal horn and the ornamentation of its bony frill: there were one or two pairs of straight spikes on the edge, with the two spikes closest to the midline pointing so that they converged. Immature specimens referred to a separate genus, called Brachyceratops, may be juvenile Rubeosaurus.
Species: R. ovatus (Gilmore, 1930 [originally Styracosaurus])