Category: Dinosaur

Edmontosaurus (Edd-mont-oh-sore-us) lived during the Late Cretaceous Period, right up until the extinction event that killed almost all of the dinosaurs. It lived in what is now North America. It was a large hadrosaur, or duck-billed dinosaur.



Genera and Species

Classification: Ornithischia. Ornithopoda. Hadrosauridae.

Genus: Edmontosaurus (Lizard from Edmonton, the capital city of Alberta, Canada)

Species: E. regalis, E. annectens. Previously known as Anatosaurus, Anatotitan.


Edmontosaurus as a large hadrosaurid, meaning its head had a broad flat mouth resembling a duck’s bill. Its body was large and bulky, with shorter forelimbs than hindlimbs. Its front legs, though small, could likely be used to support the dinosaur, meaning it probably spent time on both two and four legs.

One species, E. regalis, is known to have had a fleshy “comb” on its head, like that of a rooster. It is possible that this feature was unique to males or females, and it has not yet been found on the species E. annectens.


LENGTH: 9 meters (30 feet) to 12 meters (39 feet). May have grown to 15 meters (50 feet).

WEIGHT: Up to 4 tons, possibly as much as 10 tons.


Duck-billed dinosaurs like Edmontosaurus were plant eaters. Its tightly packed teeth numbered in the hundreds, and it could rip plants from trees with its duck-like bill.

It is thought they lived in large herd groups, due to remains of numerous Edmontosaurus being discovered together

History of Discovery

Edmontosaurus is a very well-known dinosaur, with a wealth of material that includes skeletal remains, skin impressions, and even “mummified” dinosaurs with skin instact.

However, the history of its discovery is quite complicated. It was initially discovered by paleontologist Othniel Charles Marsh in 1892 and named Claosaurus annectens. It was later reclassified as belonging to the genus Trachodon and Thespesius.

It was until 1917 that Lawrence Lambe would name the skeletons discovered near the Red Deer River in Canada by Levi and George Sternberg “Edmontosaurus regalis”. Later, in 1942, an attempt was made to reconcile the complicated hadrosaur family, and the genus Anatosaurus was created. Many hadrosaurs, including Marsh’s Claosaurus annectens, would be folded into Anatosaurus. This lasted until the 1970s, when a new examination revealed that Anatosaurus annectens was actually a species of Edmontosaurus.

In 2007 an Edmontosaurus fossil, dubbed “Dakota” was found, which included preserved skin and muscle, leading to a wealth of new information about hadrosaurs and Edmontosaurus in particular.

In 2013, Phil Bell and Federico Fanti made another surprising discovery that shed light on Edmontosaurus. They uncovered a specimen that should traces of a fleshy crest on E. regalis, resembling the comb of a rooster. Bony crests had been known on many hadrosaur species such as Parasaurolophus, but nothing like this.


Edmontosaurus was a common dinosaur during its time on Earth, and remains have been found in the Horseshoe Canyon, St. Mary River, Frenchman, Hell Creek, and Lance formations. Its environment was likely a coastal, swampy floodplain similar to modern day Louisiana. It lived alongside such popular dinosaurs as Triceratops and Tyrannosaurus.


1. https://en.wikipedia.org/wiki/Edmontosaurus

2. Paul, G. (2016). The Princeton Field Guide to Dinosaurs, 2nd Edition. Princeton, New Jersey: University Press Princeton.


4. https://en.wikipedia.org/wiki/Dakota_(fossil)