Dinosaurs had relatively lightweight, flexible skulls with lots of holes. These holes had several purposes. They cut down on the weight of the skulls so that they were not too heavy, and they helped carnivores keep bones from breaking while eating a squirming meal. Ceratopsians, like Triceratops, are the exception; they had very large solidly built skulls. Their complex, lightweight construction makes it extremely hard to find complete dinosaur skulls now. They break up easily during the fossilization process.