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How dinosaurs lived

How dinosaurs fed

Plant-eaters and meat-eaters of the JurassicPlant-eaters and meat-eaters of the Jurassic Dinosaurs can be divided into plant-eaters or meat-eaters, although some may have been omnivores: they ate both animals and plants. The shape of a dinosaur’s jaws or teeth is often the first clue that reveals to which group it belonged and how it obtained its food. We know from the fossil record what food was available at a certain time. In some fossils, the stomach contents have also been preserved, providing vital clues about diet. We can also work out how dinosaurs fed simply by studying modern animals’ eating habits.

Gastroliths found in fossil remainsGastroliths found in fossil remains


The sauropods’ sheer size meant they would have needed immense amounts of food in the form of plant matter to nourish them. Yet their teeth were small, few in number and incapable of chewing. How could they digest their colossal meals?
The presence of pebbles in some fossil remains provides the answer. Known as gastroliths, these polished, rounded pebbles were a vital part of the digestive system.

From studying how birds—the dinosaurs’ modern relatives—eat, we know that they swallow grit or small stones to fill their gizzard, a part of their stomach. Muscular movements inside the gizzard cause the stones to grind the food into a paste, which can then be digested in the intestines. Sauropods such as Apatosaurus could digest their vast daily intake of unchewed vegetation with the help of gastroliths in the same way.A large herd of Apatosaurus feedingA large herd of Apatosaurus feeding
Saurolophus skullSaurolophus skull


One unusual group of dinosaurs, the heterodontosaurs, had teeth for eating both plants and flesh in their jaws. Their cheek teeth were good for grinding tough plant material, while the pointed fangs at the front of their jaws, along with the sharp, curved claws on their arms, suggest they were predators, too.

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