Reptilia - Dinosauria - Ceratopsidae

Alternative combination: Ceratops horridus

Synonyms: Diceratops hatcheri Lull 1905, Diceratus hatcheri Lull 1905, Nedoceratops hatcheri Lull 1905, Sterrholophus flabellatus Marsh 1889, Triceratops albertensis Sternberg 1949, Triceratops brevicornis Hatcher and Lull 1905, Triceratops brevicornus Hatcher and Lull 1905, Triceratops calicornis Marsh 1898, Triceratops elatus Marsh 1891, Triceratops eurycephalus Schlaikjer 1935, Triceratops fabellatus Marsh 1889, Triceratops flabellatus Marsh 1889, Triceratops hatcheri Lull 1905, Triceratops obtusus Marsh 1898, Triceratops serratus Marsh 1890

Full reference: O. C. Marsh. 1889. Notice of gigantic horned Dinosauria from the Cretaceous. American Journal of Science 38:173-175

Belongs to Triceratops according to N. R. Longrich and D. J. Field 2012

Sister taxon: Triceratops prorsus

Type specimens:

• Triceratops horridus: YPM 1820, a skull. Its type locality is Buck Creek, Johnson Brothers Ranch (YPM), which is in a Maastrichtian fluvial-lacustrine sandstone/shale in the Laramie Formation of Wyoming.
• Nedoceratops hatcheri: USNM 2412, a skull. Its type locality is 3 miles southwest of Lightning Creek, which is in a Maastrichtian terrestrial sandstone in the Laramie Formation of Wyoming.
• Triceratops albertensis: NMC 8862, a skull. Its type locality is T. albertensis type, Red Deer River (NMC), which is in a Maastrichtian terrestrial claystone/sandstone in the Scollard Formation of Canada.
• Triceratops brevicornus: YPM 1834, a skull. Its type locality is Lightning Creek (YPM 1834), which is in a Maastrichtian terrestrial sandstone in the Lance Formation of Wyoming.
• Triceratops calicornis: YPM, a skull. Its type locality is east of Lance Creek, which is in a Maastrichtian terrestrial horizon in the Lance Formation of Wyoming.
• Triceratops elatus: YPM 1201. Its type locality is Lance Creek, near mouth of Lightning Creek, which is in a Maastrichtian terrestrial shale in the Laramie Formation of Wyoming.
• Triceratops eurycephalus: MCZ 1102. Its type locality is Horse Creek, Lance Fauna, which is in a Maastrichtian terrestrial horizon in the Lance Formation of Wyoming.
• Triceratops flabellatus: YPM 1821, a skull. Its type locality is Buck & Lance Creeks (YPM 1821), which is in a Maastrichtian terrestrial marl in the Lance Formation of Wyoming.
• Triceratops obtusus: YPM, a skull. Its type locality is U-L Ranch, Lance Creek (USNM 4720), which is in a Maastrichtian terrestrial horizon in the Lance Formation of Wyoming.
• Triceratops serratus: Its type locality is Middle Fork, Dry Creek (YPM), which is in a Maastrichtian terrestrial sandstone in the Laramie Formation of Wyoming.

Average measurements (in mm): femur length 950.0, fibula length 630.0, humerus length 800.0, radius length 400.0, tibia length 610.0, ulna length 635.0

Estimated body mass: 3.62 tons based on femur length