Among the following, Tyrannosaurus rex was the biggest land dinosaur. One of the largest fossils of this species measures up to 42 feet with a weight of about 14−15 metric tons. Stegosaurus was a herbivorous dinosaur that measured around 23−40 feet in length and weighed around 5−7 metric tons. Triceratops were also herbivorous dinosaurs that measured around 26 to 30 feet in length and weighed around 6 - 12 metric tons.