Triceratops is a genus of ceratopsian dinosaurs that lived during the late Cretaceous. These large herbivores ate low growing plants and are known for their recognizable frill and hors. An individual Triceratops could have reached 8-9 meters in length and weighed up to 12 tonnes. The three horns (one of which is modelled above) were used primarily as a display of sexual maturity but could also have been important for defence from predators. Not a lot of dinosaurs would have messed with someone with horns that big!