Triceratops: The Cretaceous plant-eater with three horns and a frill

Triceratops is one of the most photogenic dinosaurs in the museum: three horns on its face and a broad frill sweeping back from its head. It lived during the Late Cretaceous and was a plant-eating dinosaur. Let's meet this "grand three-horned knight".

Its body

Triceratops was a ceratopsian dinosaur. Its huge head ended in a mouth shaped like a bird's beak, ideal for cropping plants, while rows of teeth behind the beak ground up the plant material. The most striking feature is its three horns: two long horns above the eyes and a shorter one on the snout. Behind the head stretched a broad, scalloped bony frill.

Exactly what the horns and frill were for is still debated. They may have been used for display, for recognising members of the same species, for courtship, for contests between rivals, or for defence against predators. The frill may even have changed as the animal grew, so it probably served more than one purpose.

Where it lived and what it ate

Triceratops lived in open, well-watered areas, cropping low ferns and shrubs and perhaps reaching into taller plants. It may have lived in herds, using its horns and frill to tell other individuals apart. It shared its land and time with Tyrannosaurus rex, one of its predators.

Where its fossils were found

Triceratops fossils are mainly found in North America, in rocks of the United States and Canada. It was very common in the late Late Cretaceous, roaming the plains like a kind of "cow of the Cretaceous".

What the fossils tell us — and what they do not

Fossils reveal the shape and size of its skull, horns and frill, but the colour of the horns, the pattern on the frill and whether the horns were for defence or display have to be inferred. So the colours and pose on the stage are evidence-informed reconstructions.

A note for grown-ups

You could count horns with a child: "How many horns does it have?" Then notice how they differ in length and together guess what each might be for. Counting is a start — going from "how many" to "what for" is a great observation exercise.