“Well-armed head”
Late Cretaceous, 76.4-75.6 million years ago                        

An armored dinosaur like AnkylosaurusEuoplocephalus (“well-armed head”) lived up to its named. In fact, most of its body was well-armed! Hardened scales called osteoderms formed bands of flexible armor along its back, and its head and shoulders featured defensive spikes. Meanwhile, its low, wide stance kept its vulnerable belly close to the ground, and its heavy, clubbed tail warded off predators. It even had armored eyelids! Whereas many herbivores traveled in herds for safety, Euoplocephalus’s iron-clad defenses allowed it to safely push away its family and friends.

DiKNOWsaur: Don't be a bonehead, learn your dinos!


Alive during the late Cretaceous period, this dino’s name is Greek for “well-armored head,” and it’s easy to see why…

…perhaps “well-armored body” might have been better?  I mean, this guy has a clubbed tail, spikes all over, and even armored eyelids!  This herbivore was a member of the ankylosauridae (the armored dinosaurs) family, and is widely considered to be the most evolved, or “derived”, member of the family.  It’s also the most well-known member of its family among paleontologists, given that 40 mostly-complete skeletons have been found, including about 15 intact skulls!  Speaking as someone who’s had first-hand experience with fossils straight from the field, you’ve got to love it when fossils are that well-preserved.


Many euoplocephalus fossils have been found in parts of Alberta and Montana, and the majority of them date to between 76.5 and 67 mya.  They could weigh up to about 2 tons, and adults could grow to be about 20 feet long.  Other dinosaurs of the time could be much bigger (like, oh, Tyrannosaurus rex, for example), but I think it’s safe to conclude that Euoplocephalus’ body armor helped in keeping predators away quite a bit of the time.  I mean, look at this tail…

You probably wouldn’t want to run into this guy alone.

As far as social behavior goes, because there have not been large collections of Euoplocephalus fossils found in any one spot, some paleontologists believe that they may have led a solitary lifestyle.  Some other experts, however, believe that these guys might have roamed what became the northern US and southern Canada in small herds. 

One last thing - Seattle’s Woodland Park Zoo has a dinosaur exhibit up for the next few weeks, and if you get a chance, go.  It’s fun… they even had a Euoplocephalus (hence the inspiration for this post)!

- Courtney

Today’s doodle: Euoplocephalus tutus

I was working on a project the other day and everything was coming out slowly and stiff-feeling, so I decided to switch things up a bit and do a loose speed painting. The creature crossing this forest stream is Euoplocephalus tutus, an ankylosaur (armored, tail-club swinging dinosaur) from the late Cretaceous of Canada. Tyrannosaur leg bones have been found with breaks corresponding to the swinging height of ankylosaur clubs such as the one wielded by Euoplocephalus; I guess Canadian politeness must have evolved after the asteroid impact.