Triceratops: Facts About the Three-Horned Dinosaur

Triceratops, with its three horns and bony frill around the back of its head, is one of the more recognizable dinosaurs. Its name is a combination of Greek syllables tri-, meaning "three," kéras, meaning "horn," and ops, meaning "face."

Artwork by Scott Hartman reveals the bone structure of Triceratops.
Artwork by Scott Hartman reveals the bone structure of Triceratops.
Credit: © Scott Hartman / All rights reserved

Triceratops roamed North America about 68 million to 65 million years ago, toward the end of the Cretaceous Period. There were several species in the genus Triceratops, most notably T. horridus and T. prorsus. There is some debate about whether Torosaurus was a separate genus or a Triceratops in its mature form. There was also a two-horned dinosaur named Diceratops, which some paleontologists think was another species of Triceratops.

About 50 Triceratops skulls and partial skeletons have been found, so paleontologists have a lot of material available to help them get a clear picture of the dinosaur.

Triceratops was about 26 feet to 29.5 feet (7.9 meters to 9 meters) long; 9.5 feet to 9.8 feet (2.9 meters to 3 meters) high and weighed 13,000 pounds to 26,000 pounds (5,909 kilograms to 11,818 kilograms).

It had strong limbs to move its massive body. The forelimbs, which were shorter than the rear ones, each had five toes; the rear limbs had four toes each. The first three toes, or hooves, on the front limbs bore the animal's weight while the other were vestigial, lacking any obvious purpose. Recent studies have suggested that Triceratops' posture was upright like an elephant's rather than a sprawling, elbows-out posture like a lizard's. 

Mounted version of one of the juvenile Triceratops skulls from Hell Creek Formation in Montana.

The head of Triceratops was huge, some making up one-third of the entire length of the dinosaur's body. The largest skull specimen is calculated to have been about 8.2 feet (2.5 meters) long when complete, making it the largest known skull of all land animals at that time. Its eyes were set to the sides of the skull to provide a better view of potential predators.

Two massive horns, which were about 3 feet (1 meter) long, were above each eye and a smaller one was on the snout. Paleontologists say it's likely that the horns were used in combat against other horned dinosaurs, mating and establishing a pecking order in a herd. However, paleontologists do not believe Triceratops was confrontational — charging like a bull; there is stronger evidence that the horns were used more as a protective tool, especially when its young were endangered.

Because of its large size, Triceratops could only move at 10 mph (16 kph). Being a prime target for Tyrannosauruses looking for a meal, it had to battle its enemies rather than try to outrun them. Some scientists think the frill — also known as a flounce — acted as a type of body armor. It also may have played a role in regulating body temperature. While other prehistoric animals had frills, Triceratops is the only known species to have such an adornment that was supported by bones.

The skin of Triceratops was believed to be covered in bristle-like formations, which is unique and not seen on other dinosaurs. This indicates that Triceratops may at one point have had feathers, which would have helped regulate body temperature.

What did Triceratops eat?

Triceratops was an herbivore, existing mostly on shrubs and other plant life. Its beak-like mouth was well-suited for crunching on tougher plants and trees avoided by other herbivores, providing it with a wealth of food. It also likely used its horns to tip over taller trees.

It had up to 800 teeth that were constantly being replenished. To fit all of those teeth in its mouth, they were in groups called batteries — with each battery having 36 to 40 teeth stacked in three to five columns.

Fossil discoveries

In 1887, the first bones of a Triceratops were discovered in Denver and were sent to Othniel Charles Marsh. At first, Marsh believed it was a bison. It wasn't until more Triceratops bones were found in 1888 that Marsh gave the beast the name Triceratops.

While no complete skeleton has been unearthed, partial skeletons have been found in Montana, South Dakota, Colorado and Wyoming, as well as in Canada in the Saskatchewan and Alberta areas. Triceratops was confined to North America because the continent had already split from Europe and, along with South America, had begun to drift across the ocean. [Tiny & Old: Images of Triceratops Ancestors]

Specimens representing life stages from hatchling to adult have been unearthed. Triceratops fossils have generally been found in coastal lowland sediments.

Although Triceratopses are commonly portrayed as herding animals, there is currently little evidence that they lived in herds. Bone beds of other species of horned dinosaurs have been discovered with bones from hundreds or thousands of animals. To date, there is only one documented Triceratops bone bed.

In 1997, a baby Triceratops skull, along with a few vertebrae, teeth and bony tendons, were discovered in the Montana portion of the Hell Creek Formation by amateur fossil hunter Harley Garbani.

From 2000 to 2010 alone, more than 40 complete or partial skulls were discovered in the Hell Creek Formation, an area covering the Eastern Badlands of Montana, Southwestern South Dakota, and Southwestern North Dakota.

Learn about the horns, bones, habitat and other secrets of Triceratops.
Learn about the horns, bones, habitat and other secrets of Triceratops.
Credit: Ross Toro, Livescience contributor


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Kim Ann Zimmermann

Kim Ann Zimmermann is a contributor to Live Science. She holds a bachelor’s degree in communications from Glassboro State College.
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