Maiasaura

Maiasaura is a genus of herbivorous hadrosaurid dinosaur that lived in what is now Montana during the Late Cretaceous period, around 80 million years ago. It was first described by paleontologist Jack Horner in 1979, based on a partial skeleton found in the Two Medicine Formation. The name Maiasaura means 'good mother lizard', in reference to the discovery of nests of eggs, some with the remains of hatchlings, indicating that Maiasaura engaged in parental care.

Maiasaura is characterized by its large size, with adults reaching lengths of up to 30 feet and weighing around 4-5 tons. It had a broad, flat snout and a mouth filled with hundreds of small, peg-like teeth, adapted for grinding up vegetation. Like other hadrosaurs, it also had a distinctive 'sail' on its back, formed by the elongated neural spines on its vertebrae. Maiasaura is thought to have lived in herds and primarily fed on low-lying plants, possibly using its broad snout to sweep across the ground and gather food.