The 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 m 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 m) 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 about 30 feet long (9 m), 10 feet tall (3 m), and weighed up to 6-12 tons. It had a short, pointed tail, a bulky body, column-like legs with hoof-like claws, and a bony neck frill rimmed with bony bumps. It had a parrot-like beak, many cheek teeth, and powerful jaws. Triceratops lived in the late Cretaceous Period, about 72 to 65 million years ago, toward the end of the Mesozoic, the Age of Reptiles. It was among the last of the dinosaur species to evolve before the Cretaceous-Tertiary extinction 65 million years ago. Among the contemporaries of Triceratops were T. Rex (which probably preyed upon Triceratops), Ankylosaurus (an armored herbivore), Corythosaurus (a crested dinosaur), and Dryptosaurus (a meat-eating dinosaur). The 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. No one knows how Triceratops reproduced or raised their young, except that they probably hatched from eggs. Triceratops was a ceratopsian, whose intelligence (as measured by its relative brain to body weight, or EQ) was intermediate among the dinosaurs. Cool!