Dinosaurs · Large ornithopod

Maiasaura

Say it my-ah-SORE-ah. The name means ‘good mother lizard’.

Maiasaura beside a person 1.75 m tall. Ticks mark every metre.Body shape drawn for this site, showing the general build of large ornithopods

Length: 9 m
Weight: 2.5 tonnes
Diet: Plant-eaterplant material
Walked: On 2 or 4 legs
When: Late Cretaceous80 to 75 million years ago
Fossils found in: USA
Named by: Horner and Makela (1979)
Family tree: Dinosauria › Ornithischia › Ornithopoda › Hadrosauridae › Euhadrosauria › Hadrosaurinae

Where Maiasaura sits in the age of dinosaurs.Periods from the ICS chart; dinosaur dates from the Natural History Museum

Large ornithopods. Big plant-eaters that walked on two or four legs, including the duck-billed dinosaurs. See all 36

Lived at the same time

Achelousaurus · same country
Albertaceratops · same country
Avaceratops · same country
Bambiraptor · same country
Dryptosaurus · same country
Gorgosaurus · same country
Gryposaurus · same country
Lophorhothon · same country

Other large ornithopods

Hadrosaurus Late Cretaceous
Kritosaurus Late Cretaceous
Shantungosaurus Late Cretaceous
Parasaurolophus Late Cretaceous
Prosaurolophus Late Cretaceous
Bactrosaurus Late Cretaceous
Corythosaurus Late Cretaceous
Edmontosaurus Late Cretaceous

Source: Maiasaura in the Natural History Museum Dino Directory, read 12 November 2026. Sizes are the museum's estimates for a typical adult. "Lived at the same time" lists dinosaurs whose dates overlap, which does not always mean they met.