Maiasaura Facts
| Diet | Herbivore |
| Height | 3m |
| Length | 9m |
| Weight | 4 tonnes |
| Speed | 25 km/h |
| Environment | Land |
| Era | Cretaceous |
| Period | Late Cretaceous |
| Type | Ornithopod |
| Location | North America |

| Diet | Herbivore |
| Height | 3m |
| Length | 9m |
| Weight | 4 tonnes |
| Speed | 25 km/h |
| Environment | Land |
| Era | Cretaceous |
| Period | Late Cretaceous |
| Type | Ornithopod |
| Location | North America |
Maiasaura was a large ornithopod dinosaur that lived in what is now Montana and Alberta between 86.3 and 70.6 million years ago during the Late Cretaceous period. This remarkable duck-billed dinosaur earned its name 'Good Mother Lizard' after scientists discovered extraordinary evidence of parental care at nesting sites in Montana.
Measuring approximately 9 metres in length and standing 3 metres tall at the hip, Maiasaura was a substantial herbivore that could move on both two and four legs. Like other ornithopods, it possessed a distinctive duck-like bill perfect for cropping vegetation, along with hundreds of small grinding teeth arranged in dental batteries for processing tough plant material. Its body was built for efficient plant processing, with a long tail for balance and powerful hind legs.
Maiasaura lived in herds and demonstrated sophisticated nesting behaviour, building large communal nesting grounds where multiple families would raise their young together. The discovery of fossilised nests, eggs, and juveniles of various ages provided unprecedented insights into dinosaur family life. Adults would bring food back to the nest for their hatchlings, which were born relatively helpless and required extended parental care.
These ornithopods inhabited coastal plains and forested environments, feeding on ferns, conifers, and flowering plants. Their social behaviour and dedicated parental care revolutionised our understanding of dinosaur intelligence and family structures, proving that some dinosaurs were far more sophisticated in their behaviour than previously imagined.
Maiasaura had a relatively flat skull with a small, solid crest above the eyes and a broad duck-like bill. Its body was robust and elongated, with powerful hind limbs that were longer than the front limbs, allowing it to walk on either two or four legs depending on the situation.
Maiasaura lived in large herds and exhibited remarkable parental care, with adults bringing food to helpless hatchlings in communal nesting colonies. They built bowl-shaped nests about 2 metres across and spaced them precisely one adult body length apart, suggesting sophisticated social organisation and territorial behaviour within the colony.
Maiasaura has appeared in several dinosaur documentaries and children's books focusing on dinosaur families and parenting behaviour, though it is less commonly featured in major films compared to other dinosaurs.
Maiasaura was first described by Jack Horner and Robert Makela in 1979. The original fossils were discovered at Egg Mountain, Montana, USA.