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Edmontosaurus

Often referred to as the 'cows of the Cretaceous period'

WWD - Prehistoric Planet

Edmontosaurus was a hadrosaurid or duck-billed dinosaur – so called because of its beak. Its hindlimbs were longer than its forelimbs, allowing it to move about on two legs as well as four.

They call it home

Edmontosaurus preferred coastal plains around the Western Interior Seaway, the large inland sea that divided North America during the Cretaceous period. They also lived near the North Pole and are thought to have migrated long distances in search of food and breeding grounds.

What we heard about their hearing

What we heard about their hearing

Edmontosaurus might have been able to hear low-frequency sound, because other hadrosaurs that vocalised from tuba-like crests were able to hear in this way.


What big teeth you have

What big teeth you have

Edmontosaurus beaks were toothless like those of modern birds. They did, however, have teeth in their upper cheeks and main jaw bone. These held batteries of replacement teeth in columns of up to six per row.

The most fantastic find

The most fantastic find

We suspect that hadrosaurs lived in herds because their fossils are often found in huge bone beds. For instance, in one 40 hectare subsection of the Lance Formation in eastern Wyoming, between 10,000 and 25,000 individuals were discovered. As a result of this find, we think that they moved in herds of thousands. Hadrosaurs are often referred to as the 'cows of the Cretaceous'.

Edmontosaurus features

Edmontosaurus features Height: 4m (13.12ft)
Length: 12m (39.36ft)
Weight: 4 tonnes (4.48 short tons)
Top speed: 50kph (31.06mph)
Vision: Hadrosaurs, the group that includes Edmontosaurus, had large eyes, controlled by large optic nerves, for detecting predators. They would have needed this good eyesight even more during the dark polar winters.
Skin: Edmontosaurus had thin and leathery skin with small overlapping scales, like a gila monster.
Brain: Edmontosaurus' brain cavity was a quarter of the length of its skull and its brain might have taken about 50% of this space.
Prey: Edmontosaurus was once thought to have been an aquatic animal, feeding on molluscs and crustaceans. Today, scientists think they would have been grazers, feeding close to the ground, or browsers, eating leaves from trees.
Bite: Edmontosaurus jaws are thought to have moved in a unique and complicated but repetitive way. They chewed with up-and-down, side-to-side and front-to-back movements. With this complex chewing action, as well as a large fermenting gut, Edmontosaurus had no problem digesting plants.
Nest: Edmontosaurus would have laid eggs in a distinct nest, although they were too large to sit on their eggs as some dinosaurs did. Instead they might have covered their eggs in vegetation, like modern crocodiles.

Edmontosaurus facts and theories

Edmontosaurus facts and theories

  1. A few Edmontosaurus mummies have been found in latest Cretaceous rocks in the western United States. These spectacular specimens preserve details of the skin, muscles, and other soft tissues which are rarely preserved in dinosaur fossils.
  2. Edmontosaurus was a hadrosaurid or duck-billed dinosaur, like Hadrosaurus and Parasaurolophus. It was part of the crestless hadrosaurid sub-group which also included Maiasaura.
  3. Edmontosaurus is thought to have migrated to its nesting grounds. Based on what is known about its close relative Maiasaura ('good mother lizard'), palaeontologists believe it would have been an excellent parent. There is even a possibility that Edmontosaurus would regurgitate its food for its offspring, like modern birds do today.
  4. Edmontosaurus' beak was probably useful in cropping or stripping plants. And it had rather cute fleshy cheeks, like us, to retain food when chewing with its 2,000 or so cheek teeth.
  5. Hadrosaurs such as Edmontosaurus had some of the most complex teeth of any animals ever to have lived. Their teeth were comprised of six distinct tissues, which would have made them especially strong when grinding plants.
  6. Living near the poles, these dinosaurs most probably migrated in herds across the continents. It is possible that they covered distances of over 2,600km (1,600 miles) in one round-trip. To achieve this feat, they would have needed to average between 2-10kph (1-6mph) as a herd.