Euoplocephalus

Yoo-op-loh-sef-a-lus.

Armored Dinosaur

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Tim Bollinger

Tim is the creator of Total Dino, an educational platform dedicated to making paleontology accessible, accurate, and engaging for a wide audience. With a lifelong fascination for dinosaurs and prehistoric life, Tim combines scientific research with clear, approachable writing to help readers understand the latest discoveries and the broader story of Earth’s history. In addition to writing about dinosaurs, Tim produces infographics, educational resources, and multimedia content that reach learners of all ages. His work emphasizes scientific accuracy while encouraging curiosity, creativity, and respect for the natural world. When not researching or writing, Tim enjoys creating paleoart, developing educational projects, and building a community of dinosaur enthusiasts through his online platforms.

Benjamin Gutierrez

Benjamin Gutierrez is a leading expert on dinosaurs, particularly the mighty theropods. His fieldwork in South America has uncovered new species and provided insights into dinosaur social structures.

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Name

Euoplocephalus (Well-armed head).

Phonetic

Yoo-op-loh-sef-a-lus.

Named By

Lambe - 1902.

Classification

Chordata,‭ ‬Reptilia,‭ ‬Dinosauria,‭ ‬Ornithischia,‭ ‬Thyreophora,‭ ‬Ankylosauridae,‭ ‬Ankylosaurinae.

Diet

Herbivore.

Species

E. tutus

Size

About 5.3 meters long.

Known locations

Dinosaur Provincial Park in Red Deer River, Alberta, Canada.

Time Period

Campanian of the Cretaceous.

Fossil representation

Skull, and various other parts under debate due to dubious classification.

In Depth

Euoplocephalus was one of the best-known armored dinosaurs, living in western North America during the Late Cretaceous, about 76–67 million years ago.

Its name means “well-armored head,” and it was one of the largest ankylosaurs, protected by heavy bony plates and equipped with a massive tail club.

Euoplocephalus was part of the same family as Ankylosaurus, and is one of the most completely studied members of that group.

Description

Euoplocephalus size compared to a 1.8 meter tall human
Marmelad, CC BY-SA 2.5 https://creativecommons.org/licenses/by-sa/2.5, via Wikimedia Commons

Euoplocephalus grew up to 6 meters long and weighed over 2 tons. Its body was covered in osteoderms – thick, bony plates embedded in the skin.

These plates formed rows along the back and sides, with spikes projecting outward for added protection.

The skull was low and wide, with horns at the back and cheeks, while the eyelids may even have been reinforced with bone. Its tail ended in a heavy bony club, used for defense against predators like tyrannosaurs.

Fossil Map

Interactive fossil Map of Euoplocephalus, along with its chronological bar chart of fossil discoveries.

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Classification

Euoplocephalus was a member of Ankylosauridae, the group of ankylosaurs with tail clubs.

For many years, fossils of several related ankylosaurs (Anodontosaurus, Dyoplosaurus) were all lumped into Euoplocephalus.

More recent studies have separated these species again, but Euoplocephalus itself remains one of the most important and well-understood ankylosaurs.

Further Reading

New genera and species from the Belly River Series (mid-Cretaceous) – Geological Survey of Canada Contributions to Canadian Palaeontology3 (2): 25–81. – L. M. Lambe. (1902).

A Cretaceous armoury: Multiple ankylosaurid taxa in the Late Cretaceous of Alberta, Canada and Montana, USA – Journal of Vertebrate Paleontology30 (Supplement 2): 1A – 198A. – Arbour, Victoria (2010).

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