Diplodocus longus is a species of sauropod dinosaur from the Late Jurassic of North America. Diplodocus is one of the most abundant sauropods (long-necked dinosaurs) in the Morrison Formation. Its pencil-like teeth were only in the front of the jaws and were used to strip leaves off of low-growing plants. It could get up to 92 ft (28 m) in length and traveled in small herds. Despite its length, it was lightly built, weighing a mere 15 tons.