Triceratops horridus was a large herbivorous dinosaur that lived during the late Cretaceous period, around 68 to 66 million years ago. It is known for its three distinctive facial horns and a large bony frill at the back of its head. This dinosaur could grow up to 30 feet long and weigh over 12 tons, making it one of the largest ceratopsians. Triceratops primarily fed on low-lying vegetation, using its beak-like mouth to clip plants. Fossils have been found mainly in North America, particularly in the Hell Creek Formation. Its unique features likely served as defense against predators like Tyrannosaurus rex and may have played a role in mating displays.