Most dinosaurs held their heads up, with a few exceptions. Sauropods, such as the Diplodocus and Brachiosaurus, were massive, long-necked dinosaurs that held their heads up to reach leaves and branches in trees. Theropods, such as the Tyrannosaurus Rex and Velociraptor, also held their heads up, as they were bipedal and needed to see clearly to hunt.

Some dinosaurs, however, did not hold their heads up. Ceratopsians, such as the Triceratops and Styracosaurus, had large frills on the back of their skulls that would have made it difficult to hold their heads up for long periods. Instead, they likely spent most of their time with their heads down, grazing on plants.

Ankylosaurus, such as the Ankylosaurus and Euoplocephalus, also had low-slung heads. Their skulls were covered in thick bone, and they had small eyes and nostrils. This suggests that they spent most of their time on the ground, using their armored skulls to protect themselves from predators.