Eotriceratops
"dawn three-horned face"
Type species Eotriceratops xerinsularis
- Lived
- 72 to 66 million years ago, Late Cretaceous
- Diet
- Herbivore
- Group
- Ceratopsians, Ceratopsidae
- Found in
- Canada
- Named by
- Wu et al. 2007
Where its fossils were found
The evidence
Today
70 million years ago
Habitat
Rivers and wetlands spread across the plains recorded by the Horseshoe Canyon Formation, with ferns, conifers and flowering plants. Edmontosaurus, Saurolophus and Albertosaurus also occur in these rocks.
Field notes
About Eotriceratops
What it was like
Eotriceratops was a huge horned dinosaur and one of the closest known relatives of Triceratops. It had long horns over its eyes and a big frill, and its skull ranks among the largest of any land animal, although only one partial skull has been found.
Its world
It lived about 72 to 66 million years ago, in the Late Cretaceous, in what is now Alberta, Canada. Its bones come from the Horseshoe Canyon Formation, where it shared the land with the duck-billed Edmontosaurus and Saurolophus, the horned Pachyrhinosaurus, the ostrich-like Ornithomimus and the tyrannosaur Albertosaurus.
How it was found
Wu and colleagues named Eotriceratops xerinsularis in 2007. The fossil is older than Triceratops, which is why it was named the "dawn" Triceratops.
Field gallery
More views of Eotriceratops
Scenes reconstructed from the available fossil evidence.
1 of 3
Lived alongside
Found in the same rock formations
A rock formation can hold fossils laid down millions of years apart, so not every animal here met Eotriceratops.
The evidence
The science behind Eotriceratops
Which parts of the picture come from its own bones, and which come from its relatives.
From its own fossils
- A partial skull preserves the beak, nose horn, long brow horns and parts of the frill.
- The brow horn bones curve forward, and the cheeks carry pointed bony projections.
- Slender, elongated bony ornaments lie along the side edge of the frill.
Borrowed from relatives
- The missing lower jaw, body, limbs and tail are inferred from Triceratops and other close horned relatives.
- Triceratops provides a comparison for the compact hands and their weight-bearing inner fingers.
Still unknown
- The complete outline of the back of its frill.
- Its full body size and proportions.
- Its color and how its appearance changed as it grew.
Often drawn wrong
- A crown of giant spikes replaces the slender ornaments preserved along the side of its frill.
Discovery timeline
- 2007Named itWu et al.
- 2009Close relativeFujiwara
- 2012PostureFujiwara & Hutchinson
Key papers
The research behind what we know of Eotriceratops
Named it
Named a large horned dinosaur from a partial skull and neck bones, identifying distinctive features of its face and frill.
A new ceratopsid dinosaur (Ornithischia) from the uppermost Horseshoe Canyon Formation (upper Maastrichtian), Alberta, Canada. Canadian Journal of Earth Sciences 44: 1243-1265
Read the paper : A new ceratopsid dinosaur (Ornithischia) from the uppermost Horseshoe Canyon Formation (upper Maastrichtian), Alberta, Canada (opens in a new tab)Close relative
Reconstructed the compact hand of Triceratops, providing a comparison for the missing forefeet of Eotriceratops.
A reevaluation of the manus structure inTriceratops(Ceratopsia: Ceratopsidae). Journal of Vertebrate Paleontology 29: 1136-1147
Read the paper : A reevaluation of the manus structure inTriceratops(Ceratopsia: Ceratopsidae) (opens in a new tab)Posture
Used elbow muscle mechanics to support an upright walking posture in Triceratops, offering a comparison for its horned relatives.
Elbow joint adductor moment arm as an indicator of forelimb posture in extinct quadrupedal tetrapods. Proceedings of the Royal Society B: Biological Sciences 279: 2561-2570
Read the paper : Elbow joint adductor moment arm as an indicator of forelimb posture in extinct quadrupedal tetrapods (opens in a new tab)
Close relatives
Other members of Ceratopsidae
Sources: Wikidata