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How dinosaurs lived

Dinosaur nests

A baby Megalosaurus inside its eggA baby Megalosaurus inside its eggThe discovery of fossilized dinosaur eggs, the nests that they were hatched in and even the baby dinosaurs inside the eggs, has given palaeontologists a great deal of information about how dinosaurs brought up their young. A 1979 find of fossil eggshells and babies of Maiasaura was particularly revealing. Taken together with study of nesting habits in modern birds and reptiles helps us to build up a picture of the dinosaurs’ parenting behaviour.

Nesting colony

A nesting colony of MamenchisaurusA nesting colony of MamenchisaurusClose examination of fossilized nesting colonies tells us both about how the nests were constructed and the early years of the hatchlings. Some dinosaurs built their nests in colonies on high ground to avoid flooding and predators—a similar strategy to sea birds, such as albatrosses. The nests were packed together with the gap between them just sufficient to allow the parents to visit their nests without disturbing their neighbours’.

Parasaurolophus with its egg moundParasaurolophus with its egg moundUsing their feet, the mother dinosaurs gouged out hollows in the ground in which they laid their eggs. Then, using their teeth, they built up the soil around them and covered the eggs with a blanket of rotting vegetation to keep the eggs warm. Afterwards, they stood guard to keep predators away. The eggs were incubated by heat coming from rotting vegetation piled on top of them, rather than a parent sitting on the nest—although some smaller dinosaurs, for example, Citipati, did brood their eggs. 

Some dinosaurs nested in huge colonies, like gannets and other birds do today. They probably did this for protection against predators, who would have found it more difficult to seize eggs or young with so many adults around.

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