Plant-eating dinosaurs made up a large portion of the prehistoric world. This is the group that Little Foot from Land Before Time and Arlo from The Good Dinosaur belong to.
Scientists have studied the skulls of these creatures and found that they ate a variety of plants. These herbivore dinosaurs could digest cellulose, which helps break down tough materials like tree bark.
Long-necked herbivores
During the Jurassic Period, long-necked herbivores like the Diplodocus and Brachiosaurus roamed the Earth. These massive dinosaurs were the largest land animals ever to have lived. Their heads were small and their necks were extremely long — comparable to a giraffe’s. In some cases, a Diplodocus’s neck reached over 26 feet! This allowed them to graze on vegetation that would have been difficult for other dinosaurs to access.
Aside from their long necks, sauropods were also very large. These giant herbivores often had herds to help protect them from fierce carnivorous dinosaurs, such as the Tyrannosaurus rex. Moreover, fossil evidence shows that sauropods were good at walking on all fours. They usually walked in groups and moved slowly as they ate grass, plants, and tree branches.
One of the most famous sauropods is the Brontosaurus. This colossal beast measured over 100 feet in length and weighed over 80 tons. The Museum’s specimen of this gigantic creature is on display in the Wallach Orientation Center.
Although the Brontosaurus was a meat eater, its large digestive system allowed it to digest plants as well. The teeth of this king of the herbivores were shaped as combs, which helped it strip leaves from trees with ease.
The Anchisaurus is another example of a long-necked herbivore. During the late Jurassic Period, this species thrived in North America. Unlike some sauropods, the Anchisaurus was capable of walking on two legs. Fossils of the Anchisaurus have been discovered in Nova Scotia, Connecticut, and Arizona. Like other sauropods, the Anchisaurus primarily ate plants and occasionally eat some meat.
As a group, long-necked herbivores shared many similar characteristics. Their long, flexible necks allowed them to reach vegetation that would be difficult for other dinosaurs to obtain. Moreover, these dinosaurs had a long tail that provided balance while they were eating.
The shape of an animal’s teeth can reveal a lot about its diet and lifestyle. The banana-sized teeth of the Tyrannosaurus rex are suited for ripping flesh, while the simple and flat teeth of herbivores have a specific purpose: grinding up fibrous plant material.
Short-necked herbivores
The long necks of sauropod dinosaurs are the stuff of legends, evoking a sense of wonder and awe in people of all ages. These gentle giants were some of the most massive and tall animals to ever roam Earth, with many specimens of their fossilized bodies having been found on every continent. The Museum has several of these stupendous sauropod species on display, including the famous Apatosaurus and Diplodocus.
Like giraffes, sauropods used their necks to reach high into the trees for vegetation. Sauropod necks were extremely flexible and could be moved in a wide range of positions, enabling these creatures to access a variety of plant life. However, this also meant that they could be vulnerable to carnivorous predators.
As a result, sauropods developed a number of features that were designed to protect their heads from being crushed or snapped off by rapacious carnivores. These features included a robust skull, small teeth that were rod-shaped, and cervical ribs, which added strength to the neck but made it laborious to turn.
In addition to protecting their heads, sauropods also evolved a special type of vertebra that was more resilient and stronger than regular vertebrae. This was called the jugular notch, and it was formed from an arch that ran back from the base of the neck to the rear of the skull.
Unlike most tetrapods, sauropods did not have any neck flexion muscles, so they were unable to make their necks as long and stiff as those of giraffes. Nevertheless, the flexibility of their necks allowed these giants to feed on a variety of plants and to maintain the stability of their heads while eating.
One of the most remarkable things about sauropod necks is how wildly they vary in size, shape and posture. While some, such as Diplodocus, had a neck that was remarkably slender and curved, others, such as the legendary Brachiosaurus, had a neck that was incredibly broad and straight. These differences probably reflected the different habitats and plant life that sauropods inhabited. Other clades of large herbivores that did not evolve long necks either opted for a compromise with a smaller head on a shorter neck (ceratopsians, proboscideans, and tyrannosaurs) or developed extensive oral processing of their food, which required massive dentition and huge heads.
Bipedal herbivores
A number of herbivorous dinosaurs were bipedal. These included the horned dinosaurs like Pachycephalosaurus and Triceratops. They also included the long-necked dinosaurs, such as Hadrosauridae.
These herbivorous dinosaurs typically walked with their heads held high, which allowed them to see where they were going. They also had very long arms for grazing and pruning plants. Their teeth were shaped for crushing, and they swallowed stones (called gastroliths) to help them crush and grind their food. Some had a special gland that acted as a natural stomach acid to help digest their meals.
Herbivorous dinosaurs were generally very hardy, which allowed them to survive harsh environments. They could withstand prolonged drought, freezing temperatures, and even volcanic eruptions. Some had even developed special adaptations for water conservation. For example, a group of small herbivores called the ornithopods had a respiratory system that enabled them to take in water from the air.
Herbalians were a diverse group of dinosaurs that varied in size and body type, but they all shared certain characteristics. One of the most important is their ability to eat large quantities of grass, which was essential for their survival. Another important characteristic was their ability to chew efficiently. This was made possible by a complex system of bones in their skulls that formed an arched palate, allowing them to bite into and shred the leaves, seeds, and fruits they consumed.
In general, the herbalians were able to consume a wide variety of foods, which meant that they had many different niches within their ecosystems. The herbivorous dinosaur assemblage preserved in the late Campanian-aged Dinosaur Park Formation (DPF) of Alberta preserves a diverse collection of herbivores, including several species that were bipedal.
Herbivory has evolved multiple times independently in phylogenetically disparate dinosaur clades. The occurrence of convergent craniodental traits in herbivorous clades such as the basal sauropodomorphs, stegosaurs, and therizinosaurs suggests that plant consumption was a major driving force behind dinosaur evolution.
Armoured herbivores
The armored herbivores were a group of heavy, heavily-built dinosaurs that were a fearsome sight. They had a tank-like appearance and many of them had sharp horns, clubs, or spikes to defend themselves against carnivorous dinosaurs. They also had a very thick coat of armour to protect them.
A remarkably well-preserved fossil of the small herbivore Nodosaurus was found in 2017. Its bones, skin, and even possible food remnants were preserved along with it. This is the first time that armoured dinosaurs have been preserved with such a high degree of detail.
This dinosaur is similar to the Ankylosaurus in that it had lots of plates on its body. However, unlike Ankylosaurus, this herbivore’s plates were not aligned in a straight row down its back. The plates were much smaller and were likely located on the neck, hips, and tail. Its teeth were long and were set like batteries, with rows of replacement teeth ready to take over if the front ones got worn down.
Another armored herbivore is the Gargoylesaurus, a relative of the Ankylosaurus. Its arms had huge spines, but these weren’t as prominent as those of the Ankylosaurus. In fact, Live Science shared a study by paleontologists that showed that the spines of this dinosaur were more useful for defending it against Tyrannosaurus rex than attacking other dinosaurs.
The Scutellosaurus is another armored herbivore that lived in the early Jurassic period. It was only 3.9 feet long, but it was one of the earliest armored dinosaurs to appear on the scene. It was a member of the Thyreophora family and was likely a biped, rather than a quadruped like the more evolved Ankylosaurus or stegosaurs.
Despite its intimidating appearance, this herbivore was actually quite peaceful and ate only plants. Its skull was designed for chewing and it may have had a beak like that of the Triceratops. Its jaws were also a bit shorter than that of Triceratops, making it easier for this herbivore to bite into a plant.
Jakapil, the newest member of the armored herbivores, is a missing link between early thyreophoran dinosaurs and the more diverse groups of ankylosaurs and stegosaurids. Its skeleton has been discovered in the US and it has many characteristics that make it similar to its relatives. But it also has some unusual features such as small, backwardly-directed bony projections (like ossified tendons) along its backbone to help support its back muscles.