A triceratops was a massive plant-eating dinosaur that lived about 68 to 66 million years ago, during the very last period of the age of dinosaurs. The name means “three-horned face,” and one look at a triceratops skull makes it obvious why: two long horns jutted forward above its eyes, while a shorter horn sat on its nose like a rhinoceros. Behind its head, a massive bony frill extended backward like a shield.

Triceratops could grow to 30 feet long and weigh as much as 12 tons, roughly the weight of three large elephants. Despite their fearsome appearance, these dinosaurs were herbivores, using their powerful beaks to slice through tough prehistoric plants. Scientists believe they traveled in herds across ancient North America, and their horns and frills likely helped them defend against predators like Tyrannosaurus rex.

Triceratops fossils are among the most commonly found dinosaur remains in North America, which has helped paleontologists understand them better than many other dinosaurs. Their distinctive three-horned skulls have made them one of the most recognizable and beloved dinosaurs in museums, books, and movies.