Home > Reptiles > Edmontosaurus

Edmontosaurus

The Edmontosaurus is a genus of duckbilled dinosaurs (Hadrosauridae) that roamed the planet in the Late Cretaceous Period. In fact, the members of the genus were incredibly gigantic, one of the largest in North America, and includes two valid species – Edmontosaurus regalis and Edmontosaurus annectens (with the former being the type species).

The Edmontosaurus was contemporary to Tyrannosaurus Rex, Triceratops, Pachycephalosaurus, and Thescelosaurus, and some paleontologists synonymize them with the disputed Anatosaurus or Anatotitan, which are now generally considered as the synonyms of Edmontosaurus.

These herbivores were one of the last non-avian dinosaurs that grazed the plains of the Canadian province of Saskatchewan during the final years of the Cretaceous period, just prior to the mysterious mass extinction.

Pictures

Scientific Classification

Kingdom Animalia
Phylum Chordata
Clade Dinosauria
Order †Ornithischia
Suborder †Ornithopoda
Family †Hadrosauridae
Subfamily †Saurolophinae
Tribe †Edmontosaurini
Genus Edmontosaurus

Quick Facts

Pronunciation ed-MON-toe-sore-us
Geological Period Late Cretaceous, 76-65 mya
Size Approximately 42 feet in total length; 10 feet high at the hips
Weight Around 3 to 4 tons
Average Lifespan Unknown
Location/Distribution & Habitat First fossil discovered in Canada, but lived all across North America especially in swampy habitats with both tall trees and low-lying, coarse vegetation
Diet Herbivorous
Predators/Enemies Primarily tyrannosaurus rex, tyrannosaurus, dakotaraptor, acheroraptor, and albertosaurus
Speed Slow (disputed)
Birth Type (Reproduction) Oviparous
Locomotion Both bipedal and quadruped

History and Discovery

The first edmontosaurus fossil was discovered first in Canada’s Alberta in 1917 by paleontologist Lawrence Lambe. After sporting several scientific names, it was Lambe who successfully renamed the newly-discovered genus as ‘edmontosaurus’.

However, back in 1871, fossils were also discovered in Alberta, Canada, that were unfortunately lost since then. Although, that fossil is thought to be belonging to a dinosaur belonging to another genus, and was named Trachodon cavatus by Edward Cope, who initially discovered it.

In 1892, again, parts of the fossil of a dinosaur had been discovered by another veteran paleontologist Othniel Charles Marsh that all were later studied to be the parts of the same genus that Lambe discovered.

Lawrence Lambe named the dinosaur after the Edmonton formation site (also known as the Horseshoe Canyon Formation) in Alberta, where the giant animal was discovered. Later, two mummified Edmontosaurus fossils were also unearthed in Wyoming. Parts of fossilized skeletons (including skull) have also been unearthed from places including Nebraska, Montana, and New Jersey.

Because of the discovery of skin samples and food residue in the creature’s stomach, several unique features and characteristics of the newly discovered dinosaur could be studied well.

Physical Description

This prehistoric creature is different from its genus members in the sense that, it lacked the characteristic bony crest atop its head, which the other hadrosaurids had.

Interestingly, biologists have discovered the fact that the Edmontosaurus had loose skin around its face, which it could blow up like a balloon. The exact purpose of this is, however, not yet known.

Like other duckbilled dinos, this reptile too possessed a horny beak. Though it had no teeth in its beak, the jaws were lined with 1,000 grinding cheek teeth that assisted the animal in chewing the rough plant matters it was used to consuming.

They moved on both two, as well as four legs. However, while running, they had to take the help of all four. They used the two hind limbs usually when standing up to reach the high branches of trees.

The mummified specimens that were unearthed had some preserved skin. This helped the researchers study its texture, though the tone or color of the skin is still unknown.

Behavior

The edmontosaurus preferred living in swampy environments. Since the discovery of the very first fossil of the reptile, it has been found throughout North America. These discoveries suggest that they were probably nomadic animals that would travel or migrate in large groups to stay safe from the then apex predators.

Its loose facial skin is thought to have been used to attract a mate. However, it is also thought to have been for the purpose of warding off competitive males during intra-species fights especially during the season of reproduction/mating or even to ward off their predators.

Edmontosaurus was relatively defenseless against any large carnivores and were unable to escape or outrun the contemporary meat-eating species, and hence, had to rely on maneuvering them by living and traveling in large herds. These gigantic animals might have also had keen senses of vision, hearing, and smell for assisting them in locating and avoiding the forthcoming dangers.

As the scientists have measured the creature’s relative brain to body weight (EQ), the ornithopod’s natural level of intelligence was midway among the other dinosaurs of the period.

Diet

Both the ancient herbivore species of edmontosaurus usually preferred plant matters like tough pine needles, cones, seeds, and twigs. They also had an appetite for low-lying plants including ginkgos, cycads, and conifers.

Interesting Facts

  • In Latin, the meaning of its name is ‘Lizard from Edmonton’.
  • The Edmontosaurus weighed as much as two black rhinos, had the length of over four cars, and stood about two stories high.
  • The Edmontosaurus would never lose a single tooth. When one tooth would fall out, another one would grow from the jaw, taking its place (which is technically termed as ‘evergrowing teeth’).
  • An adult specimen of the Edmontosaurus species E. annectens, displayed in the Denver Museum of Nature and Science, clearly shows a theropod bite in its tail region.
  • Contrary to the widely-accepted hypothesis about its slow running speed, a 2007 computer modeling suggested that these reptiles could run at high speeds, perhaps up to 45 kmph (28 mph) on all four.

Published on December 21st 2018 by under Reptiles.
Article was last reviewed on 21st December 2018.

Leave a Reply

Your email address will not be published. Required fields are marked *