Edmontosaurus: the duck-billed giant at the end of the Cretaceous

When and where

Edmontosaurus lived in western North America during the Late Cretaceous, from about 73 to 66 million years ago. Fossils come from Canada and the United States, including Alberta, Montana, Wyoming, and the Dakotas. That timing puts it in the same world as Tyrannosaurus, Triceratops, Ankylosaurus, and Pachycephalosaurus. Adults could reach about 12 metres long and weigh roughly 4 tonnes, so this was no background plant-eater.

How we know

The genus includes Edmontosaurus regalis and Edmontosaurus annectens. Lawrence Lambe named E. regalis in 1917 from fossils found in the Edmonton Formation, now called the Horseshoe Canyon Formation. E. annectens has a longer naming history because older names such as Anatosaurus and Anatotitan were later folded into Edmontosaurus. The fossil record is unusually rich: skulls, skeletons, skin impressions, and several "mummy" specimens preserve body outlines and soft-tissue detail that most dinosaurs lose after burial. Those specimens make Edmontosaurus one of the clearest hadrosaur body plans in the record. Source: Wikipedia.

What set it apart

Edmontosaurus had the broad snout that gave hadrosaurs their duck-billed nickname, but the mouth was built for serious chewing. Rows of replacement teeth formed dental batteries that ground tough Cretaceous plants. Its skull lacked the tall hollow crest seen in Lambeosaurus or Parasaurolophus, which makes its long, low head easy to tell apart. Some specimens preserve a soft comb-like crest above the skull, a rare clue that display features did not always fossilise as bone. Trackways and limb proportions show it could walk on all fours while feeding and rear onto two legs when moving faster across wide open floodplains.

For collectors and classrooms

Edmontosaurus works well in a classroom lineup because it connects several big ideas at once: hadrosaur chewing, skin impressions, North American fossil beds, and the final million years before the extinction. Pair it with Tyrannosaurus and Triceratops to show animals that shared the same Late Cretaceous landscapes. It also gives younger readers a plant-eater with more evidence than a single famous skeleton. For a shelf or lesson tray, start with an Edmontosaurus figurine.