Dinosaurs · Ceratopsian

Chasmosaurus

Say it KAZ-mo-sore-us. The name means ‘chasm lizard’.

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

Length: 5 m
Weight: 2.5 tonnes
Diet: Plant-eaterplant material
Walked: On 4 legs
When: Late Cretaceous76 to 74 million years ago
Fossils found in: Canada
Family tree: Dinosauria › Ornithischia › Ceratopsidae › Chasmosaurinae

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

Ceratopsians. Horned and frilled plant-eaters, such as Triceratops. See all 29

Lived at the same time

Albertosaurus · same country
Centrosaurus · same country
Chirostenotes · same country
Corythosaurus · same country
Daspletosaurus · same country
Dromaeosaurus · same country
Edmontonia · same country
Edmontosaurus · same country

Other ceratopsians

Centrosaurus Late Cretaceous
Pentaceratops Late Cretaceous
Styracosaurus Late Cretaceous
Anchiceratops Late Cretaceous
Einiosaurus Late Cretaceous
Pachyrhinosaurus Late Cretaceous
Protoceratops Late Cretaceous
Albertaceratops Late Cretaceous

Source: Chasmosaurus 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.