Diabloceratops eatoni

Diabloceratops eatoni lived in southern Utah early in the Campanian, about 81.3 million years ago. It is one of the oldest well-diagnosed members of Centrosaurinae and helps show that this branch of horned dinosaurs had already developed elaborate skull ornamentation before later forms such as Centrosaurus and Styracosaurus appeared. Its deep face, small nasal ornament, long brow horns and pair of large curved spikes at the back of the frill create an unusual mixture of features. Almost everything distinctive about the species comes from one skull, so the body shown in reconstructions is inferred from related ceratopsids.

Its fossils occur between approximately 81.42 and 81.01 million years ago. Values shown here are approximate and reflect the current curated seed dataset.

The approximately 1.4-metre skull was short and deep at the snout. A low paired ornament sat over the nose, while substantial brow horncores projected above the eyes. The frill narrowed toward its rear and carried many small marginal ornaments plus two very long, curved spikes. Broad cheek horns projected sideways. The toothless beak and rows of continually replaced cheek teeth identify it as a plant eater. No complete body skeleton is known; a four-legged, heavy-bodied reconstruction follows other ceratopsids rather than direct Diabloceratops evidence.

• Deep, short face with a strongly rounded nasal region
• Low paired ornament above the nose
• Long brow horncores extending over the snout
• Short frill narrowing toward its rear edge
• Pair of very long, curved spikes at the back of the frill
• Numerous smaller horn-covered ornaments around the frill margin
• Broad, blade-like cheek horns

Utah Geological Survey palaeontologist Donald DeBlieux found the holotype skull, UMNH VP 16699, near Last Chance Creek in Grand Staircase–Escalante National Monument in 2002. Preparation took more than 800 hours because much of the skull remained embedded in sandstone. James Kirkland and DeBlieux named Diabloceratops eatoni in 2010, honouring palaeontologist Jeffrey Eaton. Another partial Wahweap skull, UMNH VP 16704, was initially referred to the genus but may represent a more derived centrosaurine, so this profile counts only the holotype as secure.

Discovery credit: Donald D. DeBlieux.

Naming authors: James I. Kirkland, Donald D. DeBlieux.

The Wahweap Formation records rivers, floodplains, lakes and coal-forming wetlands on southern Laramidia, west of the Western Interior Seaway. The climate was warm and seasonally wet, and flowering plants were becoming increasingly diverse alongside conifers, ferns and other vegetation. Diabloceratops shared the wider formation with hadrosauroids, armoured dinosaurs, small theropods and large tyrannosaurids. Not every Wahweap animal occurs at exactly the same level as the holotype.

Its beak cropped plants and its dental batteries sliced vegetation before swallowing. The striking horns and frill may have combined visual display, recognition, defence and physical interaction, but one skull cannot reveal which role was most important. No bonebed, trackway or nesting site securely assigned to Diabloceratops documents herd size, combat or parental care.

• The two great frill spikes inspired a name meaning “devil-horned face.”
• Its skull took more than 800 hours to prepare from the surrounding sandstone.
• The secure fossil is about 81.3 million years old, making Diabloceratops one of the earliest well-known centrosaurines.
• A cast of the skull is displayed at the Natural History Museum of Utah.

A research repository is not necessarily a public exhibit. Loan and display status can change, so check with the institution before visiting.

1. 01
   New basal centrosaurine ceratopsian skulls from the Wahweap Formation (Middle Campanian), Grand Staircase–Escalante National Monument, southern Utah

   James I. Kirkland, Donald D. DeBlieux · New Perspectives on Horned Dinosaurs: The Royal Tyrrell Museum Ceratopsian Symposium · 2010

   Open source
2. 02
   Refined geochronology and revised stratigraphic nomenclature of the Upper Cretaceous Wahweap Formation, Utah, U.S.A. and the age of early Campanian vertebrates from southern Laramidia

   Palaeogeography, Palaeoclimatology, Palaeoecology · 2022

   Open source
3. 03
   Diabloceratops eatoni

   Natural History Museum of Utah

   Open source
4. 04
   Diabloceratops

   Utah Geological Survey

   Open source