Edmontosaurus (name meaning "Edmonton's Lizard"), previously called Anatotitan (name meaning "Giant Duck"), is a genus of large, flat-headed saurolophine hadrosaurid (duck-billed) ornithopod dinosaur that originated during the Late Cretaceous. A member of among the most common groups of dinosaurs, Edmontosaurus was one of the last non-avian dinosaurs on Earth before the mass extinction event. Additionally, at 13 meters long and 4 tons in weight, Edmontosaurus was among the largest members of the hadrosaur family.


Era & DiscoveryEdit

Edmontosaurus lived in western North America during the Late Cretaceous period from 76–65 million years ago. It was among the largest herbivores of its time and was also among the last member of the hadrosaur family of dinosaurs.

The first fossils named Edmontosaurus were discovered in southern Alberta and named after Edmonton, the capital city, in the Horseshoe Canyon Formation (formerly called the lower Edmonton Formation). The type species, E. regalis, was named by Lawrence Lambe in 1917, although several other species that are now classified in Edmontosaurus were named earlier. The best known of these is E. annectens, named by Othniel Charles Marsh in 1892.

Physical AttributesEdit

Edmontosaurus was a very large dinosaur with a massive 23 foot tail, arguably the largest member of the hadrosaur family. They measured over 39–43 feet (12–13 m) long, stood 13 feet (4 m) tall at the hips, and weighed 4–6 tons (8,000–12,000 lbs.), the size of a railroad box car.

It also had very large and wide hind legs and its front legs were short and chunky. Edmontosaurus had a large bill that resembled that of a modern duck - hence its original name. Inside its mouth was a large battery of teeth, designed to grind vegetation.

Behavior & TraitsEdit

Like all herbivores, Edmontosaurus lived in small groups to large herds. When feeding, huge batteries of chewing teeth made short work of the vegetation they ate. Like the earlier Iguanodon dinosaurs, Edmontosaurus walked on four legs but ran on two. When chewing, Edmontosaurus's jaws moved from side to side.

Despite its relatively large size, Edmontoasurus was preyed upon by predators, including the North American apex predator, Tyrannosaurus rex, as it viewed Edmontosaurus as a favorite prey item. However, although it had very few weapons of choice, Edmontosaurus did posses the ability to run rather quickly for creatures as large as they were. Like its ancestors, it could run on its hind legs and could also swing its tail like the arm of a crane. However, its speed never always guaranteed it safety.