What was a dinosaur’s anatomy (its insides) like? Was there a difference in the digestive systems of meat-eaters and plant-eaters? Remarkably, thanks to fossil evidence, we have an idea of what the insides of various dinosaurs would have looked like, as these models show.
Euoplocephalus lived on tough plants and needed a digestive system that could help break these plants down. This dinosaur could not chew, so instead it mashed its food using small, leaf-shaped cheek teeth, before swallowing. The plant matter went into a gizzard, a churning, muscular stomach, where the plant fibers were broken down. Many modern-day birds and reptiles have a gizzard.
A meat-eater’s digestive system, like the one of this Carnotaurus, was similar to that of reptiles we know today, such as crocodiles. Compared to those of a plant eater, the intestines are small, while the liver is large. The heart and lungs are also large, because the dinosaur would have needed extra oxygen to run after its prey.
Carnotaurus fossils show that many meat-eating dinosaurs had hollows in their bones, which may have been air spaces. These might have allowed an increased oxygen flow to the lungs, helping these dinosaurs to be active.