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Grey three-horned dinosaur with a solid frill walking in side view
Life reconstruction of Triceratops horridus based on specimen P 256878.Image credit: Connor Ashbridge, CC BY-SA 4.0, via Wikimedia Commons (unmodified except resizing)CC BY-SA 4.0 (unmodified)Source (opens in a new tab)

Triceratops horridus

Pronounced try-SER-ah-tops HOR-ih-dus

Ceratopsia · Ceratopsidae

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.

  • Horned
  • Quadrupedal
  • Giant
  • Skin impressions known
  • Movie icon
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Period
Cretaceous· Maastrichtian
Diet
Herbivore
Length
8–9 m
Mass
6,000–10,000 kg
Location
Montana, Wyoming, South Dakota, North Dakota

Quick answers

How big was Triceratops horridus?
Triceratops horridus was about 8–9 m long. It stood about 2.4–3 m tall at the hips. It weighed about 6–10 t. (Paul 2010; Paul 2016)
When did Triceratops horridus live?
Triceratops horridus lived during the Late Cretaceous, about 68–66 million years ago. (Cohen et al. 2023; Fowler 2017)
Where have Triceratops horridus fossils been found?
Fossils of Triceratops horridus have been found in Hell Creek Formation (Montana), Lance Formation (Wyoming), South Dakota, and North Dakota. (Marsh 1889; Paul 2010)
What did Triceratops horridus eat?
Triceratops horridus was a herbivore. (Marsh 1889; Paul 2010)
Who named Triceratops horridus, and when?
Triceratops horridus was described by Othniel Charles Marsh in 1889. (Marsh 1889)
Was Triceratops horridus in Jurassic Park?
Yes. Triceratops horridus appears in Jurassic Park (1993), The Lost World: Jurassic Park (1997), Jurassic Park III (2001), Jurassic World (2015), Jurassic World: Fallen Kingdom (2018), and Jurassic World Dominion (2022). A sick Triceratops is the park's gentle patient in the first film; later films show it in herds and in fights. The anatomy is broadly faithful. Healed horn wounds on skulls suggest Triceratops really did lock horns with each other. (Wikipedia: Dinosaurs in Jurassic Park 2026; Farke et al. 2009)

On this page

try-SER-ah-tops HOR-ih-dus

Period
Cretaceous68–66 Ma
Diet
Herbivore
Length
8–9 m
Mass
6–10 t
Classification
Ceratopsia · Ceratopsidae
Described
1889, Othniel Charles Marsh

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).

Biology & evidence

What scientists think about how this animal lived, and how strong the evidence for each idea is.

Skin & covering

  • Triceratops was covered in large, non-overlapping scales.

    Evidence level: Moderate evidence

    A nearly complete Triceratops in Houston preserves skin with large polygonal scales. The skin has been shown and discussed but not yet fully published, so the details may change.

    Evidence for / against · 1
    Evidence for

    • Skin impression · Triceratops skin impression (Lane specimen)

      Large patches of skin with big polygonal scales, some with a central bump, from a nearly complete Triceratops in Houston.

Growth

  • Torosaurus is the fully adult form of Triceratops.

    Evidence level: Disputed

    Scannella and Horner argued that the frill of Triceratops opened up with age until it looked like Torosaurus. Others found immature Torosaurus and no clear transitional skulls. Most researchers still keep them as separate genera.

    Evidence for / against · 2
    Evidence for

    • Specimen · Triceratops skull growth series

      A series of skulls from juvenile to large adult showing the frill thinning, lengthening and opening holes with age.

    Evidence against

    • Comparative anatomy · Torosaurus specimens with mature bone but no Triceratops transition

      Torosaurus specimens that are not fully mature and lack the transitional features predicted if they were old Triceratops.

Behavior

  • Triceratops used its horns to fight other Triceratops.

    Evidence level: Moderate evidence

    Many Triceratops skulls carry healed wounds on the frill and cheeks that fit the horns of another Triceratops, much more often than in related horned dinosaurs. This points to horn-locking fights, like those of modern antelope.

    Evidence for / against · 1
    Evidence for

    • Specimen · Healed horn and frill lesions in Triceratops

      Healed wounds on squamosals (frill bones) of Triceratops are far more frequent than in Centrosaurus and match the shape of Triceratops horn tips.

Fossil skin impression of Triceratops at the Houston Museum of Natural Science, showing large polygonal scales.Image credit: TheUltimateGrass, CC0, via Wikimedia Commons, Houston Museum of Natural ScienceCC0 1.0Source (opens in a new tab)

Size

Length
8–9 m

(29.5 ft)

Height
2.7 mpublished range 2.4–3 m

(8.9 ft)

Based on composite mounts (e.g. USNM 4842 "Hatcher")

Mass
6,000–10,000 kg
Triceratops horridus was about 9 m (29.5 ft) long, roughly 5 times the height of a 1.8 m adult human.

Timeline

Lived from about 68 to 66 million years ago (Ma), within the Mesozoic era (252–66 Ma).

Periods: Maastrichtian (72.1–66 Ma), Late Cretaceous (100.5–66 Ma)

endAgeMa 66.0 = end of the Maastrichtian (ICS 2023/09). startAgeMa left empty: no primary source verified for the first appearance.

Location

Formations

Map data: Natural Earth (public domain). Modern positions, not where the continents were then.

These are the places where fossils have been found, not the full area where the animal lived.

Ecosystem

Lived in: Hell Creek

68–66 million years ago · floodplain, river system, forest, coastal plain

Warm, humid coastal lowlands and river floodplains west of the retreating Western Interior Seaway at the very end of the Cretaceous, with forests of conifers and flowering plants. The ecosystem ends at the Cretaceous-Paleogene extinction.

Same ecosystem

Tyrannosaurus rex

Cretaceous· MaastrichtianCarnivore

Same ecosystem

Ankylosaurus magniventris

Cretaceous· MaastrichtianHerbivore

Same ecosystem

Pachycephalosaurus wyomingensis

Cretaceous· MaastrichtianHerbivore

Same ecosystem

Edmontosaurus annectens

Cretaceous· MaastrichtianHerbivore

Classification

  1. cladeDinosauria
  2. cladeOrnithischia
  3. cladeCeratopsia
  4. familyCeratopsidae
  5. subfamilyChasmosaurinae
  6. genusTriceratops
  7. speciesTriceratops horridus

Taxonomic status: Valid

Fossil record

Triceratops skeleton at the Cleveland Museum of Natural History.Image credit: Erik Drost, CC BY 2.0, via Wikimedia Commons, Cleveland Museum of Natural HistoryCC BY 2.0Source (opens in a new tab)
Specimens
Catalog numberStatusInstitutionFound
YPM 1820HolotypeYale Peabody Museum (YPM)1888
USNM 4842 “Hatcher”Referred specimenNational Museum of Natural History, Smithsonian Institution (USNM)—

What has been found

Holotype: YPM 1820

  • Preserved
  • Partial
  • Reconstructed
  • Unknown / not recorded

Holotype: YPM 1820

Region by region (table)
Skeleton regions of Holotype: YPM 1820
RegionState
SkullPartial · Horn cores and partial skull.
MandibleUnknown / not recorded
TeethUnknown / not recorded
Cervical vertebraeUnknown / not recorded
Dorsal vertebraeUnknown / not recorded
SacrumUnknown / not recorded
Caudal vertebraeUnknown / not recorded
RibsUnknown / not recorded
GastraliaUnknown / not recorded
Scapula / shoulder girdleUnknown / not recorded
HumerusUnknown / not recorded
Forearm (radius / ulna)Unknown / not recorded
Hand (manus)Unknown / not recorded
PelvisUnknown / not recorded
FemurUnknown / not recorded
Tibia / fibulaUnknown / not recorded
Foot (pes)Unknown / not recorded

Referred specimen: USNM 4842 “Hatcher”

Region by region (table)
Skeleton regions of Referred specimen: USNM 4842 “Hatcher”
RegionState
SkullReconstructed
MandibleUnknown / not recorded
TeethUnknown / not recorded
Cervical vertebraeUnknown / not recorded
Dorsal vertebraePartial
SacrumUnknown / not recorded
Caudal vertebraeUnknown / not recorded
RibsUnknown / not recorded
GastraliaUnknown / not recorded
Scapula / shoulder girdleUnknown / not recorded
HumerusUnknown / not recorded
Forearm (radius / ulna)Unknown / not recorded
Hand (manus)Unknown / not recorded
PelvisPartial
FemurPreserved
Tibia / fibulaUnknown / not recorded
Foot (pes)Unknown / not recorded
Triceratops skull P12003 on display at the Field Museum of Natural History, Chicago.Image credit: Evolutionnumber9, CC BY-SA 4.0, via Wikimedia Commons (unmodified except resizing), Field Museum of Natural HistoryCC BY-SA 4.0 (unmodified)Source (opens in a new tab)

All specimens

Discovery

Year described
1889
Described by
Othniel Charles Marsh
Type specimen
YPM 1820 (holotype of Ceratops horridus)
The Triceratops horridus type skull YPM 1820, as figured in The Ceratopsia (Hatcher, Marsh & Lull 1907).Image credit: J. B. Hatcher, O. C. Marsh and R. S. Lull, Public domain, via Wikimedia CommonsPublic domainSource (opens in a new tab)

Discovery timeline

  1. 1887 · First material found

    Horn cores found near Denver named Bison alticornis

    Marsh first mistakes a pair of horn cores from Colorado for those of a giant bison; they were later recognised as Triceratops.

    People: Othniel Charles Marsh

  2. 1889 · Formally described

    Marsh names Ceratops horridus, then Triceratops

    Marsh names Ceratops horridus from Hatcher's skull and, later in 1889, the new genus Triceratops.

    People: Othniel Charles Marsh, John Bell Hatcher

  3. 2010 · Revision

    Torosaurus proposed as adult Triceratops

    Scannella and Horner propose that Torosaurus is the mature form of Triceratops; the idea is contested.

In Jurassic Park & Jurassic World

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)

On screen

A sick Triceratops is the park's gentle patient in the first film; later films show it in herds and in fights.

Film vs fossils

  • The anatomy is broadly faithful. Healed horn wounds on skulls suggest Triceratops really did lock horns with each other.

Film titles are used for identification only. DinoDex is not affiliated with or endorsed by the Jurassic Park / Jurassic World franchise. All dinosaurs seen in the films

Sources

  1. (2026). Wikipedia: Dinosaurs in Jurassic Park. Wikipedia. https://en.wikipedia.org/wiki/Dinosaurs_in_Jurassic_Park (opens in a new tab)
  2. 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 (opens in a new tab)
  3. Farke, A. A., Wolff, E. D. S. & Tanke, D. H. (2009). Evidence of combat in Triceratops. PLoS ONE 4(1): e4252. doi:10.1371/journal.pone.0004252 (opens in a new tab)
  4. 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. doi:10.1371/journal.pone.0188426 (opens in a new tab)
  5. Marsh, O. C. (1889). Notice of gigantic horned Dinosauria from the Cretaceous. American Journal of Science (series 3) 38: 173-175.
  6. Paul, G. S. (2010). The Princeton Field Guide to Dinosaurs. Princeton University Press.
  7. Paul, G. S. (2016). The Princeton Field Guide to Dinosaurs (2nd edition). Princeton University Press.
  8. Shay, D. & Duncan, J. (1993). The Making of Jurassic Park. Ballantine Books.