Dino profile
Triceratops
the dinosaur with three horns
Triceratops was a big dinosaur that ate plants. You can spot it by its three horns and the wide bony frill behind its head.
Its ID card
- When
- At the very end of the Cretaceous, about 69 to 66 million years ago. It was one of the last dinosaurs before they disappeared. [1][2][4]
- Where
- In western North America: mostly in the United States (Montana, Wyoming, Colorado), and also in Canada. [1][2][4]
- Its family
- The ceratopsians, the horned dinosaurs. [1]
Three horns and a frill
It had two long horns above its eyes and a shorter one on its nose. Behind its head, a wide bony frill, solid and without holes, covered the top of its neck. [2][4]
Its skull was huge: the biggest one we know of is about 2.5 meters long, almost a third of the animal's length. [2]
What were its horns and frill for? Maybe for defending itself, for getting noticed, or for recognizing other Triceratops. Scientists don't agree. [1][2][3][4]
At birth, the baby was roughly the size of a bulldog. Its horns were short and straight. They became long and curved in the adult, which was bigger than a rhinoceros. [3]
A big plant eater
It had a pointed beak and rows of tightly packed teeth: between about 432 and 800 teeth. They were replaced all the time, as they wore down. [1][2]
It walked on four legs, a bit like a rhinoceros. But it is not part of the rhinoceros family at all: they just happen to look alike. [1][2]
Its skin was covered in big rounded scales, like pebbles. [1][2]
Its fossils are most often found alone: maybe it lived on its own. [1][4]
Its discovery
In 1887, George Lyman Cannon finds two horns near Denver, Colorado. Paleontologist Othniel Charles Marsh first thinks they come from a giant bison. [1][2]
In 1888, John Bell Hatcher digs out a skull in Wyoming. A third horn is discovered on it, on the nose: in 1889, Marsh gives it the name Triceratops. [1][2]
In 1905, the Smithsonian's National Museum of Natural History, in the United States, puts a Triceratops skeleton on display. Since nobody had a complete skeleton, it was made with the bones of ten different animals. [5]
It is one of the dinosaurs with the most fossils found. Today, two species are recognized: Triceratops horridus and Triceratops prorsus. [1][4]
Sources
The information on this page comes from these sources:
- Triceratops, Dino Directory, Natural History Museum, London (accessed November 5, 2026).
- Triceratops, Wikipedia (English), and the publications it cites: Marsh 1887, 1888 and 1889, Paul 2010, Scannella & Horner 2010, Fujiwara 2009 (accessed November 5, 2026).
- Learning a little more about little Triceratops, Burke Museum, University of Washington, March 7, 2017 (accessed November 5, 2026).
- Why Triceratops, a prehistoric herbivore, looked so fierce, Amy McKeever, National Geographic (accessed November 5, 2026).
- About the Cast, CU Museum of Natural History, University of Colorado Boulder (accessed November 5, 2026).