Scientists determine a dinosaur’s diet by studying fossilized remains, called coprolites. These fossils can reveal bones, skin, and even food remnants!
Plant-eating dinosaurs like the Triceratops had wide teeth with ridges and mash up vegetation in their mouths. Other herbivores gulped down their veggies whole, a strategy similar to living tortoises and birds that use gizzard stones to help with digestion.
Sauropods were the largest herbivore dinosaurs ever to exist and are known for their long necks and massive bodies. They had small heads and four very strong legs with five toes on each foot. These dinosaurs are the only group to have reached almost the maximum size possible on land.
The biggest sauropods like the Edmontosaurus had hundreds of tough teeth packed together in their upper and lower jaws. The teeth worked like coarse files to cut rather than chew plants. This would help make it easier for the plant-eating dinosaur to digest their food. It is also thought that this helped them conserve energy as chewing takes a lot of effort and could actually reduce the amount of nutrition obtained from food.
These gigantic herbivores lived during the late Triassic, Jurassic and Cretaceous periods which witnessed dramatic changes in world geography (the break-up of Pangea) and world ecosystems – as well as the advent of flowering plants and the major change from gymnosperm to angiosperm-dominated environments. The latter were typically arid and seasonally dry, leading to a drop in the quality of available food.
Whether the arid environment of herds of sauropods helped them get more nutrition from their food remains unclear as they were likely to have to migrate during the dry season to find fresh greenery. But, studies of modern mammalian herbivores have found that larger animals are able to survive on a wider range of low-quality vegetation than smaller ones. This is due to the fact that the digestive system of large mammals can keep plant material in it for longer, which increases its nutritional value and allows animals to live off poorer quality foods.
But if this is true, why did not all herbivores become as big as sauropods? A study led by Dr. Mary D’Emic suggests that different animal groups achieve their own sizes according to the ecological niches they occupy and this can appear random. The large sauropods probably used their size to outcompete other herbivores in a struggle for the most abundant and nutritious leafy plants. Horsetail plants were the most prevalent in the Jurassic period and provided an abundance of nutrients that allowed the largest sauropods to grow.
Like all sauropods, Apatosaurus was extremely large. It weighed up to 33 t (32 long tons; 36 short tons) when fully grown. This made it an effective countermeasure against predators, and it also served to insure that it would be able to reach food, which it did by using its massive neck. However, despite its great weight, fossils indicate that this dinosaur could walk on four legs without having to hunch over or crawl.
Fossil evidence suggests that Apatosaurus ate mostly conifers, other tree leaves, and ferns. It was a non-selective browser that probably also ate cycadeoids, pteridophytes, and algae. The skull was small in proportion to its overall size, and the jaws were lined with spatulate teeth that resembled chisels, which were well-suited to a herbivorous diet.
It swallowed whole plants, a practice known as “herbivory” that allowed for the efficient digestion of tough vegetation. Like modern reptiles, Apatosaurus had gastroliths, which were stomach stones that helped it digest its food. It was the largest herbivore in its ecosystem, and it created a small temporary ecosystem around itself when eating, which included all manner of detritivores, insects, and even birds that took advantage of dung and carcasses.
In addition, it was a scavenger and was able to eat the remains of its own deceased members, which helped reduce disease. Its dung and carcasses also fertilized the soil.
Like other sauropods, Apatosaurus lived in herds, which was beneficial for protection and social interaction. It was a peaceful dinosaur that largely avoided combat with other herds, but it did fight other large herbivores such as Triceratops.
The herds in Jurassic World Evolution move about their habitat in search of forested areas and graze together to ensure that enough food is available for everyone. This herd behavior has been observed in natural herds of sauropods in North America. Herds of sauropods have also been seen in Europe, including at Dinosaur Park in northern Italy. Herds in the parks are much larger, but this is because they were raised from eggs, so they reached maturity earlier. This allows them to breed more often, and this can help the animals cope with stress and injury.
Diplodocus is a genus of sauropod dinosaur that is the longest dinosaur known from a complete skeleton. It was a plant-eater that traveled in herds and reproduced by laying eggs. Its long neck enabled it to graze on low-lying plants and, with its laterally and dorsoventrally flexible neck, may have been able to rear up on its hind limbs and browse the tops of trees. Its tail, whose underside was adorned with chevron-shaped bones giving it the appearance of a double beam, is also thought to have been useful for supporting the animal as it grazed. Its name comes from the Greek words diploos (double) and dokos (beam), in reference to these double-beamed chevron bones found on the underside of its tail.
The fossilized skeletons of Diplodocus are remarkably complete and have a number of interesting features. For example, the front “feet” of Diplodocus were highly modified compared to other sauropods. These “feet” had a vertical column of finger and hand bones, horseshoe-shaped in cross section, which was detached from the bones of its hands, creating an unusually specialized claw. This claw was able to strip branches from trees, and it has been suggested that Diplodocus used this ability to feed on low-lying trees and shrubs.
In contrast to earlier thinking, it is now believed that Diplodocus had a warm-blooded metabolism and could not have held its neck high off the ground for extended periods of time (this would have put enormous stress on its heart). Instead, scientists believe that it may have moved from side to side while grazing on low-lying plants with its long neck in a more horizontal position.
A more recent theory about Diplodocus’s tail is that it was used as a whip to defend itself against predators and create a sonic boom similar to cracking a whip to scare off prey. Fossilized skin impressions have been found that show Diplodocus had thin, keratinous spikes along its back and on the end of its tail.
In addition, it has been argued that Diplodocus had a sex organ that differentiated male and female specimens. The presence of small ventral scales has been observed in male and female Diplodocus, but more research is needed to understand their function.
The Triceratops was one of the most distinctive dinosaurs of the Late Cretaceous period. Its head was adorned with three prominent horns and a large frilled head crest. It also sported smaller hornlike projections on its jugal bones (cheekbones) and a hornlike beak. At its maximum size, the Triceratops was nearly 3 metres (about 10 feet) long. It weighed more than the largest elephant and may have been one of the most imposing predators of its time.
Like most ceratopsian dinosaurs, the Triceratops was primarily herbivorous. Its narrow, beak-tipped mouth and low-set head imply that it preferred to pluck fibrous plants with its sharp, narrow bill rather than gnaw them. Its powerful chewing muscles and 432-800 teeth could have handled tougher plant material, such as ferns, palms and cycads. Triceratops probably grazed in herds, although its herding behavior is unclear.
While most fossils of the Triceratops are primarily skulls, fragmentary remains of other body parts have been recovered as well. From these, paleontologists know that its hind limbs were longer than its fore legs and that the dinosaur’s short toes terminated in hooves. The Triceratops’s neck and limbs were adapted for a digitigrade stance, in which the weight of the animal was distributed to the small toes rather than the whole foot.
Fossil evidence indicates that the Triceratops primarily occupied floodplains and wetlands close to rivers and streams. It probably stayed in wet areas throughout the day, grazing on grasses and other low-growing vegetation while lounging in pools or mud wallows to cool off. The Triceratops coexisted with a variety of other herbivorous dinosaurs, including the hadrosaurus and the ostrich-like theropod Pachycephalosaurus.