7 Stunning Facts for Kids about Ankylosaurus, the Prehistoric Giant Armoured Lizard

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Updated on: Educator Review By: Michelle Connolly

It is called… Ankylosaurus and it is a giant armoured lizard.

Previously in our article on dinosaurs, the most famous extinct animals, we discussed many facts about those massive creatures.

Descending from the same ancestor as crocodiles, cobras, alligators, and even leatherback sea turtles, dinosaurs appeared on Earth 243 million years ago. They survived for so long, about 177 million years. Then a major asteroid impact brought their existence to an end around 65 million years ago.

Dinosaurs lived through three different geological eras that characterised Earth back then. During these periods, the Earth was exposed to major climatic events that changed its geology and affected its ecosystem. And each one of them was ended by a catastrophe that started a new geological era.

During these three long eras, dinosaurs encountered and survived massive changes by evolving and adapting. Those that could not make it simply went extinct. 

We also learnt that dinosaurs were found all over the planet. Long, long ago, all the seven continents we have now were once one gigantic landmass. At some point in time, and because of the changes Earth was undergoing, this supermassive landmass started to break down into pieces which drifted away from one another, taking dinosaurs with them.

That is why scientists could find fossils of dinosaurs all over the planet.

Additionally, we understood that dinosaurs are believed to be the great-great-grandfather of birds. After that giant asteroid hit Earth killing most of its lifeforms, a small population of dinosaurs survived. And to adapt to the new post-catastrophe Earth, their bodies shrank, and they eventually developed wings.

So besides that and everything else we learned about dinosaurs, including the most famous one, T-Rex, and the star of Google Chrome’s offline page game, today we are going to learn about another famous supermassive creature that was not in any way less impressive.

Today, we are learning some interesting facts about Ankylosaurus, the prehistoric giant armoured lizard. So let’s hop into it.

1. Ankylosaurus Was a Kind of Dinosaur.

Dinosaurs were incredibly diverse creatures. They came in all types, colours, sizes, and body structures. After closely examining the fossils they found all over the world, scientists could conclude that there used to be over 1000 dinosaur species living on every continent. They were classified into hundreds of genera and families according to their characteristics.

Ankylosaurus was one family of dinosaurs characterised by bony armour covering the back of their heads, necks, backs, and tails.

But if dinosaurs lived for 177 million years, when exactly in time did Ankylosaurus live?

As we have just mentioned, dinosaurs lived through three geological eras that characterised our planet.

The oldest era was known as the Triassic period. It started 252 million years ago and ended 201 million years ago. The second era was the Jurassic period which started 201.3 million years ago and lasted for 56 million years. The third era and the longest of them all, was the Cretaceous period. It began 145 years ago and ended 66 million years ago.

All the 1000 named dinosaur species lived throughout these three eras. The one we are concerned about today, Ankylosaurus, thrived through the Cretaceous period. It was one of the last dinosaurs that ever lived on Earth and went extinct because of that asteroid impact.

2. Its Name Pretty Much Describes What It Is.

As we will see in a bit, scientists could tell a lot about Ankylosaurus by examining its fossils and remains, which they found in western North America, where it used to live.

On an expedition organised by the American Museum of Natural History in 1906, American palaeontologist Barnum Brown discovered a specimen of Ankylosaurus in Montana, USA.

Brown spent two years studying the specimen and realised that the dinosaur’s bones were fused. This means they were joined together to form larger, stronger bones. So he named the dinosaur A. magniventris. This is its scientific name which means fused lizard—when scientists discovered the first dinosaur fossils, they thought it was a giant lizard. Actually, the word dinosaur means terrible lizard!

That said, this armoured dinosaur was given another common still-hard-to-pronounce name, Ankylosaurus, which means great belly because, yes, this dinosaur has a massive belly.

3. It Was the Largest Member of Its Family.

Brown’s expedition, as well as many others, could find so many fossils, bones, and remains of Ankylosaurus in the western areas of Canada and the United States. Still, they did not find any complete skeletons. Yet, that did not stop them from closely studying and reimagining this giant creature.

To help you get an idea of what Ankylosaurus looked like, you may think of it as a more scarily-looking colossal version of Stitch from Disney’s animated film Lilo and Stitch before Stitch hid its armour.

One difference between both is that scientists believe Ankylosaurus had more of a brownish colour while Stitch was blue.

From the fossils, scientists also concluded that Ankylosaurus was the largest known member of the family of armoured dinosaurs. Still, it was wider and longer than taller. It was mainly characterised by its super large, triangular skull, short neck, robust body, large belly, and armour, as well as its long muscular tail and the rod-like club at the end of it.

That said, individuals still ranged in body measurements.

The largest Ankylosaurus specimen scientists got hold of was about 6.25 m long and 1.7 m tall at the hips. Its skull was as large as 64.5 cm long and 74.5 cm wide. It was as heavy as eight metric tons.

On the other hand, the smallest Ankylosaurus specimen had a skull that was 55.5 cm long and 64.5 cm wide. At the same time, the dinosaur itself was 5.4 m long, 1.4 m tall at the hips, and weighed 4.78 metric tons.

Even this smallest individual was still a giant.

As you might have concluded from the measurements given above, Ankylosaurus had relatively short legs. Typically, the rear limbs were slightly longer than the front ones. And Ankylosaurus used to walk on all four of them. 

Because of that as well as its super heavyweight, Ankylosaurus was a slow walker. Scientists estimate it walked at a speed of 7.8 km/hr. However, they also believe that Ankylosaurus could walk faster than that when it encountered danger.

Another thing that characterised Ankylosaurus is the four horns it had on its head. 

Two of them were to the back of the head, pointing backwards, while the other two were below them and pointed backwards and down.

Interestingly, the horns of the large individuals looked different from those of the small individuals.

4. Being a Giant Armoured Lizard Made It Stand Out.

The Ankylosaurus’s head, neck, back, and tail were covered with armour. That is why it, along with a few other dinosaurs, were called the shield bearers.

As defined by the dictionary, armour is a metal shield that soldiers used to wear in the past to protect themselves during battles. Surely, the making of that armour was inspired by nature, more specifically, creatures like Ankylosaurus and crocodiles.

However, Ankylosaurus’s natural armour was basically made of knobs and plates of bones that covered the head, back, and tail and were excessive on the back of the neck. These bony knobs and plates were known as osteoderms and were covered with skin and keratin, which is a protein that makes nails and hair.

The Ankylosaurus’s osteoderms had different sizes and shapes. For instance, some of them were as small as 1 cm in diameter but as long as 36 cm. Some were flat, and others had lumps.

5. It Had Embarrassingly Weak Teeth.

Ankylosaurus had a set of 72 teeth. Although it was a super large dinosaur and everything, its teeth were not its most prominent asset. These teeth were quite small, yet tall. They had the same shape as a leaf and were not sharp at all. And none of them were suitable for grounding.

This could be one reason why Ankylosaurus ate plants. Its teeth were too weak to provide the powerful bite needed to take down prey. The only thing these teeth were able to chew was plants.

In addition, these small teeth also set some limitations to the Ankylosaurus diet. For instance, it could not eat fruit or large plants.

Ankylosaurus’ jaw was not any better either. Since the jaw is connected to the skull by joints and muscles, it makes sense to say that the stronger the skull, the stronger the jaw. And because Ankylosaurus had a large, strong skull, its jaw, accordingly, should have been strong.

Yet, for some reason, it was not. Ankylosaurus’ jaw even had limited movement.

6. It Was a Plant Eater.

Scientists are usually able to learn about an extinct animal‘s diet by examining its teeth. And as we have just mentioned, the Ankylosaurus’ small, dull teeth only qualified it to eat plants.

In our previous article, we understood that dinosaurs were classified based on their diet into two main groups, herbivores and carnivores or plant-eaters and meat-eaters.

Ironically, plant-eating dinosaurs were not fitter than those that ate meat. In fact, they were much larger. This is attributed to their habitat being abundant in vegetation as the Earth’s climate at the time was quite warm. As a result, herbivorous dinosaurs grew larger.

For the same reason, Ankylosaurus was a giant.

Now let’s get more specific.

Herbivorous animals are either grazers or browsers. Grazers typically lean down to eat grass, while browsers lift their heads to eat tree leaves. Well, Ankylosaurus was both.

But because its neck was short, Ankylosaurus was a low browser. That means it targeted low branches. Well, this is how high it could reach anyway.

Thanks to its colossal body, Ankylosaurus required a lot of food every day. Scientists estimate it consumed as much as 60 kg of plants on a daily basis. 

7. It Used Its Tail as a Weapon.

Besides Ankylosaurus’ distinct armour, this dinosaur was characterised by a long, robust tail that ended with a super powerful club. In fact, Ankylosaurus’ tail grew to be three metres long, and sometimes even longer in some individuals.

The tail and the club, like Ankylosaurus’ back, were covered with armour of knobs and plates.

This club had a more circular shape. It had two large osteoderms and another pair of small ones. The smallest specimen scientists discovered had its club 68 cm long, 49 cm wide, and 19 cm tall. On the other hand, the largest specimen club was 57 cm wide.

To protect itself against attackers, Ankylosaurus used its long, muscular tail and rod-like club to hit their legs. Such a hit was so powerful that it could break the bones of the attackers. Ankylosaurus could move its tail very fast from side to side with an angle of up to 100°.

Scientists knew about the Ankylosaurus’ usage of its tail as a weapon because the fossil they found had their clubs already damaged. This means they used to get in fights with other dinosaurs.

That said, only adult Ankylosaurus could use their tails and clubs to hit their attackers as they would not fully develop unless the dinosaur reached maturity. That means young Ankylosaurus were vulnerable and more prone to attacks.


And so we get to the end of today’s episode, in which we discussed one of the most distinct armoured dinosaurs, Ankylosaurus.

In this article, we learned seven (hopefully) interesting facts about Ankylosaurus. First, we started by describing what kind of dinosaur it was, where and when it lived, and how it went extinct.

Then we looked into the discovery of its first fossil, why it was given that name, and what it typically means.

After that, we studied the dinosaur’s appearance and what makes it stand out among the rest of the 1000 dinosaur species. With armour that covered its head, neck, back and tail, Ankylosaurus’ body was well protected.

Moving on, we looked into the feeding habits of Ankylosaurus and how its weak jaw and small dull teeth might have pushed it to be a plant eater.

Finally, we finished our journey by exploring Ankylosaurus’ most prominent assets, its robust tail and powerful club, which it used to protect itself.

We hope you found this article useful as much as we loved writing it for you. You can still learn more and more about our beautiful planet on our website, so make sure you check the World Around Us and STEM pages.

And until another episode, keep learning.

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