Chasmosaurus

What it was like

Chasmosaurus was a horned dinosaur that grew to about 5 meters (16 feet) long, with a long, bony frill extending back from its skull. Unlike some relatives, its frill had two large openings in it, which gave the genus its name and likely made the structure lighter without weakening it much. Chasmosaurus carried a pair of horns above its eyes and a shorter horn on its nose, and moved on four sturdy legs while cropping low plants with its beaked mouth.

Its world

Chasmosaurus lived in Alberta, Canada, from about 84 to 72 million years ago, sharing its floodplain habitat with fellow horned dinosaurs such as Centrosaurus and with hadrosaurs like Lambeosaurus and Corythosaurus. Predators including Gorgosaurus and Daspletosaurus hunted across the same ground, while smaller theropods such as Troodon and Dromaeosaurus likely targeted young or weakened animals.

How it was found

Lambe named Chasmosaurus in 1914, and its remains have since turned up in about 19 separate fossil finds, all from the Dinosaur Park and Oldman formations of Alberta. It is closely related to larger horned dinosaurs such as Triceratops and Torosaurus.