Maiasaura
Mary Evans Picture Library/Deagostini Editore
Maiasaura ('good mother lizard') was a large duck-billed dinosaur that lived in very large herds of around 10,000 creatures about 74 million years ago. It was a herbivore, and walked on either two or four legs. Maiasaura was the first dinosaur to be found with its young, eggs, and nests - hence its name of 'good mother'.