Dinosaurs are descendanst of the most recent ancestor of modern birds and the Triceratops. In fact, you can trace their behavior with that of the birds, especially when they sleep. “Dinosauria” came from the descendants of the recent ancestors of the Iguanodon and Megalosaurus. This also includes the Sauropodomorphs (huge herbivorous quadrupeds), Theropods (bipedal carnivores), Ankylosaurians (armored types of herbivorous quadrupeds), Stegosaurians (plated types of herbivorous quadrupeds), Ceratopsians horned and frilled herbivorous quadrupeds) and the Ornithopods (quadrupedal or bipedal herbivores).

Here are some of the largest plant-eating dinosaurs that existed.

Ankylosaurus

This is the last and biggest “armored” dinosaurs that evolved. This plant-eating dinosaur lived through the latter part of the Cretaceous Period, approximately 70 to 65 million years back.

It eats loads of low-lying plant materials to sustain itself. It has a large gut, and produces phenomenal amounts of gas.

It is a huge armored reptile that measures approximately 25 to 35 feet long, 4 feet tall and 6 feet wide. It weighs about 4.4 tons. Its oval and thick plates embedded on its upper leathery skin, the spikes and tails all protect it from predators or carnivores. The only un-plated part is its underbelly, which means, you can only wound it if you flip it over.

This dinosaur got its name in the year 1908 from Barnum Brown. Its fossils were found along Alberta, Canada and Montana, US. 3 partial skeletons (armor and tail) and 2 skulls were uncovered. Trackways were even found in South America (Sucre, Bolivia).

Alamosaurus

This plant-eating quadrupedal dinosaur lived through the latter part of the Cretaceous Period. This period was approximately 73 up to 65 million years back. It is both a Titanosaurid and Sauropod which means it has some body armor.

Being a whip-tailed and long-necked dinosaur, it grows to 69 feet long and weighs 33 tons. Fossils such as fragmentary skeletons (no skulls) of the Alamosaurus were discovered in Utah, New Mexico and Texas. Its name means “Ojo Alamo Lizard.”

Apatosaurus

The Apatosaurus was formerly known as the Brontosaurus. It is among the largest animals that existed on land. It lived through the latter part of the Jurassic Period, approximately 157 up to 146 millions of years back.

It is a whip-tailed, long-necked dinosaur, measuring roughly 70 up to 90 ft. long and 15 feet tall around the hips. Its head is not more than 2 ft. long with a very small brain and long skull. The long neck consists of 15 vertebrae and hollow backbones. Its long “whip-like” tail is approximately 50 feet long. It also has “peg-like” teeth in the frontal part of its jaws. It has 4 “column-like” massive legs, with the hind legs being larger than the ones in front. The nostrils are on the upper part of its head.

Fossils of the Apatosaurus were discovered in Oklahoma, Colorado, Wyoming and Utah. It was Othniel C. Marsh, an American paleontologist, who named and described the Apatosaurus in 1877. In 1879, he named and described another fossil, the Brontosaurus. Further studies have proven that both the Apatosaurus and Brontosaurus came are from a similar genus. It was the former name, Apatosaurus that was adopted.