Triceratops were herbivorous and probably ate low-growing plants because of their short necks and low heads. They may have eaten bushes, small trees and grasses. They may have been able to eat taller plants by knocking them down with their horns and beaks.
Triceratops had anywhere from 432 to 800 teeth arranged in columns of 36 to 40 and stacked three to five teeth high. This is because the dinosaur ate massive amounts of plant matter with shearing vertical force, causing its teeth to wear down quickly. With so many teeth in its jaw, triceratops could replace teeth continuously throughout its lifetime.