With a beak-like skull structure to grind berries and twigs, Maiasaura was a very unique looking dinosaur. As a descendant of the Iguanodon, it had long and tough forefingers that appeared almost as hooves, letting it move quickly over the Cretaceous landscape.

Maiasaura belonged to the larger group of dinosaurs called Hadrosaurs. What makes Maiasaura uniquely interesting is how well documented its behavior is. These creatures lived in huge herds and raised their young for several years after they hatched. This is where it gets its name, the "good mother" dinosaur.

This specimen is a fossilized vertebra belonging to the Maiasaura. It was recovered from private land on the Two Medicine Formation in Montana and is over 74 million years old.

Each of these fossils is a unique piece of a prehistoric dinosaur. They are shipped in a sturdy packing carton along with a certificate of authenticity. It's the perfect addition to any paleontologist's collection!

Several Maiasaura and other Hadrosaur vertebra fossils are available in the shop and are sold separately by size. You can see them all at the collection below. We have a smaller display case sized specimen of Hadrosaur Bone available as well.

Evolution is inherently fractal, primed to spawn off divergent species specifically adapted to their own environments. For example, consider Hadrosauridae: this large family of Ornithischian dinosaurs lived during the Cretaceous Period with a world-wide distribution. There is significant evidence of migratory behavior in many species, with exception of those at the poles which typically remained in place year round. Amongst the vast umbrella of Hadrosauridea are dozens of branching species that maintain certain basic characteristics.

Descendants of the Iguanodons, Hadrosaurs did not have the specialized first digit on their forelimbs. The three middle fingers were all tipped with hooves, for support, resulting in a largely quadruped animal. The Hadrosaurs are known primarily for their "duck-bills." This beak-like structure was in fact an elongated rostral bone housing hundreds of small teeth, that allowed these giant herbivores to grind through all manner of plant material, including twigs, berries, coarse plant matter, and even rotten wood.

Maiasaura have been identified as the earliest Hadrosauridaes in Laramidia, the western most part of North America when it was divided by the Cretaceous Seaway. The genus has a special place in dinosaur paleontology, being the first female dinosaur discovered, hence its name meaning “good mother” and using the feminine saura.

These dinosaurs have earned a reputation as nurturing protectors and evidence shows that their young were raised in massive egg colonies, protected by herds that could number in the thousands. While rotting vegetation warmed the eggs, Maiasauras would patrol the borders of the colony for predators.

The discovery of Maiasaurua's nurturing behavior was a new one for dinosaurs. Previously, it was assumed that baby dinosaurs were left to themselves to survive after hatching. That changed with the discovery of Egg Mountain in Montana’s Two Medicine Formation in 1977, which preserved an impression of Maiasaura’s complex social structure and 14 egg nests in close proximity. Maiasaura’s slow maturation rate explains this need for group support. Even after hatching, a baby Maiasaura’s legs would be too weak to walk on for at least a year, instead relying on its mother for food.

Sites like Egg Mountain provide insight into Maiasaura’s development rate from hatchling to full grown dinosaur. Thanks to the close proximity of so many members of the species, we know more about Maiasaura's life cycle than nearly any other dinosaur. Hatchlings grew quickly, going from just 16 inches at birth to nearly 5 feet in their first year. They were primarily quadrupedal, but could walk on two legs during adolescence. As they grew older, increased weight would move Maiasaura into a four-legged stature, topping out at around 30 feet long and weighing 4 tons. 

Maiasaura was a mostly passive herbivore, though it could use its duck-billed skull in defense against predators or in a conspecific duel with another member of their genus. Intraspecies fights like this were likely rare–with Maiasaura, one sees an exceptionally cooperative genus that rewrote much of what we know about dinosaurs.