Not all dinosaur nests looked alike. Many were simple pits dug into the soil or sand; others were more complicated, including deep, mud-rimmed nests lined with vegetation. Some dinosaurs even had a certain way of laying their eggs. For example, the Maiasaura, a herbivore, would arrange its eggs in a spiral, making sure to allow enough space between hatchlings to aid them in escape from predators. Protoceratops also apparently laid eggs in a spiral fashion.