Triceratops

Triceratops was a large plant-eating dinosaur that lived in western North America about 68 to 66 million years ago. Its name means "three-horned face" in Greek. Triceratops had two long horns above its eyes and a shorter horn on its nose. It also had a big bony shield, called a frill, that stuck up behind its head. Triceratops was one of the last dinosaurs to live on Earth before the great extinction.

An adult Triceratops was about 30 feet long from nose to tail. That is about as long as a school bus. It weighed between 6 and 12 tons, heavier than a modern elephant. It walked on four thick legs and carried its heavy head low to the ground. Its long eye horns could grow to more than three feet long.

Triceratops ate only plants. Its mouth ended in a sharp beak, a bit like a parrot's beak but much bigger. Behind the beak were rows and rows of teeth packed together into one strong grinding surface. When a tooth wore out, a new one grew in below to replace it. A single Triceratops had hundreds of teeth in its mouth at once. It used them to chop up tough plants like ferns and palm fronds.

The frill and horns are a puzzle that scientists still argue about. For a long time, people thought the frill was mostly armor to protect the neck from predators. Some fossils show bite marks from Tyrannosaurus rex on Triceratops frills, so the frill did sometimes block attacks. But the frill was also thin in places, which would have made it weak armor. Many scientists now think the horns and frill were mainly used for showing off to other Triceratops, for attracting mates, or for fighting each other. Fossils have been found with horn-shaped holes in their frills, which suggests they jabbed one another in duels.

Triceratops lived at the same time and place as Tyrannosaurus rex. The two dinosaurs were neighbors, and sometimes enemies. Scientists have found Triceratops bones with T. rex tooth marks on them. A fight between a healthy adult Triceratops and a T. rex would have been fierce on both sides.

Triceratops died out about 66 million years ago, when a huge asteroid hit Earth near what is now Mexico. The crash changed the climate and killed off most dinosaurs. Today, Triceratops lives on in museums, in movies, and as one of the favorite dinosaurs of kids everywhere.