Triceratops (TRI-sair-ah-tops) was a ceratopsid herbivorous dinosaur genus, from the Late Cretaceous Period (from around 70-65 million years ago) of what is now North America. It lived at around the same time and place as Tyrannosaurus, Ankylosaurus and another well-known ceratopsid, Torosaurus.

Although no complete skeleton has been found, it has been estimated that Triceratops was about 9 metres (30 ft) long, 3 metres (10 ft) tall, and weighed around 5,400 kg (12,000 lb).

The sturdy nature of the animal's skull has ensured that many examples have been preserved as fossils, allowing variations between species and individuals to be studied.

Triceratops remains have subsequently been found in Montana, South Dakota, and Wyoming, in the USA and in Saskatchewan and Alberta, in Canada.

Triceratops was a rhinoceros-like dinosaur. It walked on four sturdy legs and had three horns on its face along with a large bony plate projecting from the back of its skull (a frill). One short horn above its parrot-like beak and two longer horns (over 3 feet or 1 metre long) above its eyes probably provided protection from predators.

The horns were possibly used in mating rivalry and rituals. It had a large skull, up to 10 feet (3 metres) long, one of the largest skulls of any land animal ever discovered. Its head was nearly one-third as long as its body. Triceratops hatched from eggs.

Triceratops was probably a herding animal, like the other Ceratopsians. This hypothesis is supported by the finding of bone beds, large deposits of bones of the same species in an area.

When threatened by predators, Triceratops probably charged into its enemy like the modern-day rhinoceros does. This was probably a very effective defense.

It probably ate cycads and other low-lying plants with its tough beak. Triceratops could chew well with its cheek teeth (like other Ceratopsians, but unlike most other dinosaurs).