Edmontosaurus

Edmontosaurus is a genus of hadrosaurid dinosaurs, commonly called duck-billed dinosaurs, that lived in western North America during the Late Cretaceous. It inhabited floodplain and riverine environments from about 73 to 66 million years ago. The animal was large, reaching about 9 to 12 meters in length and weighing several tons, with a broad skull and a long, flat beak.

Edmontosaurus possessed a dental battery—multiple rows of tightly packed teeth that wore continuously—allowing efficient processing of tough plant material. It could browse with a short forelimb and move on two legs, or rest on all fours when grazing. The skull shows large nasal passages; the snout was well-suited for cropping vegetation, and the animal had a flexible jaw joint to grind food.

The genus was named by Lawrence Lambe in 1917 from fossils found in Alberta, Canada. The two best-known species are Edmontosaurus regalis and Edmontosaurus annectens. Fossils have been found across Canada and the United States. Historically, some specimens were assigned to Anatosaurus or Anatotitan, but most modern classifications place them in Edmontosaurus.

Fossil bonebeds indicate Edmontosaurus often lived in groups. It was a widespread and common herbivore of Late Cretaceous western North America, coexisting with ceratopsians, tyrannosaurids, and other hadrosaurs. Its well-preserved skulls and jaws provide important insight into hadrosaur dental evolution and feeding mechanics.