# Triceratops horridus

> A large three-horned chasmosaurine ceratopsid from the very end of the Cretaceous of western North America, living alongside Tyrannosaurus rex in the Hell Creek and Lance formations.

- Classification: Dinosauria (clade) > Ornithischia (clade) > Ceratopsia (clade) > Ceratopsidae (family) > Chasmosaurinae (subfamily) > Triceratops (genus) > Triceratops horridus (species)
- Length: 8–9 m
- Hip height: 2.4–3 m
- Mass: 6–10 t
- Age: 68–66 million years ago (Late Cretaceous)
- Fossils found in: Hell Creek Formation (Montana); Lance Formation (Wyoming); South Dakota; North Dakota
- Diet: herbivore
- Described: Othniel Charles Marsh, 1889
- In films: Jurassic Park (1993), The Lost World: Jurassic Park (1997), Jurassic Park III (2001), Jurassic World (2015), Jurassic World: Fallen Kingdom (2018), Jurassic World Dominion (2022)

Canonical page: https://dinodex.club/dinosaurs/triceratops-horridus
Last updated: 2026-09-27

## Overview

Triceratops horridus lived in western North America during the Maastrichtian, the last age of the Cretaceous. O. C. Marsh first described it in 1889 as Ceratops horridus from a skull (YPM 1820) collected by John Bell Hatcher in the Lance Formation of Wyoming, and moved it to the new genus Triceratops later that year.

It was a heavy, four-legged plant eater with a short nose horn, two long brow horns and a solid bony frill. Its fossils are among the most common dinosaur remains in the Hell Creek and Lance formations, where it shared its world with Tyrannosaurus rex.

Complete skeletons are rare, so body size is less certain than the many skulls suggest. The figures below are given as ranges with their source.

## Name meaning

From Greek tri- ("three"), keras ("horn") and ops ("face"): "three-horned face"; Latin horridus means "rough" or "bristling" (Marsh 1889).

## Sources

1. Cohen, K. M., Harper, D. A. T., Gibbard, P. L. & Car, N. (2023). International Chronostratigraphic Chart (v2023/09). International Commission on Stratigraphy. https://stratigraphy.org/ICSchart/ChronostratChart2023-09.pdf
2. Fowler, D. W. (2017). Revised geochronology, correlation, and dinosaur stratigraphic ranges of the Santonian-Maastrichtian (Late Cretaceous) formations of the Western Interior of North America. PLoS ONE 12(11): e0188426. https://doi.org/10.1371/journal.pone.0188426
3. Marsh, O. C. (1889). Notice of gigantic horned Dinosauria from the Cretaceous. American Journal of Science (series 3) 38: 173-175.
4. Paul, G. S. (2010). The Princeton Field Guide to Dinosaurs. Princeton University Press.
5. Paul, G. S. (2016). The Princeton Field Guide to Dinosaurs (2nd edition). Princeton University Press.

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Cite as: "Triceratops horridus". DinoDex. https://dinodex.club/dinosaurs/triceratops-horridus (updated 2026-09-27).