MEET MAIASAURA

Discovery and name The name Maiasaura means ‘good mother lizard’ in Greek, after the apparent care given from adults to their young.

Maiasaura was named by the famous palaeontologists Robert Makela and John Horner in 1979.

Lived where and when? Maiasaura lived in the Late Cretaceous (approximately 74 million years ago) in North America. Many skeletons of Maiasaura have been found from Montana.

Size Maiasaura was a medium sized member of the duck-billed Family Hadrosauridae, measuring seven to nine metres long, three metres high and weighing two 2 tonnes.

Diet The mouth of Maiasaura were covered with a keratinous, horny beak at the front, which helped nip off woody vegetation. Behind this were thousands of tightly-packed teeth in large dental batteries. These teeth were replaced continuously throughout life and were used to chew, a special feature of duck-billed dinosaurs.

Palaeontologists have discovered probable Maiasaura poo which contains large pieces of conifer branches. The poo of duck-billed dinosaurs are sometimes found in unusual shapes, as they were often trampled by members of the same herd.

Herding and parental care Thousands of specimens of Maiasaura are known - from adults, juveniles and nests with eggs. Many Maiasaura nests have been found built on top of each other, indicating that herds returned to the same sites every year to lay eggs and take care of their young. Nests were made of stones and mud, and lined with rotting vegetation to incubate the eggs.

Baby Maiasaura were between 40–150cm long and doubled in size before leaving the nest. This suggests that Maiasaura grew quickly and were probably warm-blooded, like birds.

Trampled eggshells and underdeveloped legs indicate that babies could not walk and did not leave the nest for some time. Babies were probably brought food by their parents. Nests contained 25 eggs and were around seven meters apart, enough space for adult Maiasaura to move between.

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