When famed paleontologist Othniel Charles Marsh first discovered a Triceratops fossil in 1887, he mistakenly identified it as a type of bison. Another Triceratops fossil was discovered a year later by John Bell Hatcher, and in 1889, Marsh, realizing his mistake, finally named this dinosaur. Triceratops, which is believed to have lived in herds much like modern buffalo, had three distinctive horns -- one on its snout and two more above the eyes. Along with the bony frill that protected the rear of its skull, these horns provided a natural defense against the attacks of other dinosaurs, but the Triceratops was himself an herbivore, feeding on plants and shrubbery with his sharp beak.