Ankylosaurus was one of the largest armoured dinosaurs known. Its appearance was frightening, not that put off predators of its time including Tyrannosaurus Rex. It roamed the earth 68 to 66 million years ago in western North America and Canada.

Ankylosaurus is Greek for “fused lizard”, and as the name suggests the reason was down to the fused bones in its skull and other bones.


Alina Zienowicz (Ala z), e-mail, CC BY-SA 3.0, via Wikimedia Commons

Who discovered ANKYLOSAURUS?

An American palaeontologist called Barnum Brown first discovered some fossils of a skull, vertebrae, ribs, shoulder and armour while his team were digging in the notorious site of Hell Creek Formation in Montana, United States.

He named this fossil Ankylosaurus in 1908 after finding the fossils two years previously, and subsequently went on to take credit for 2 other significant finds.

All three fossil discoveries are now held at the American Museum of Natural History, in New York.

Quick Ankylosaurus Facts

Type:  Armoured Dinosaur
When it lived: Lived 66 to 68 million years ago 
Weight: Weighed between 4.7 and 7.9 tonnes
Discovered:  1906 in America
Diet: Herbivore

anklosaurus habitat 

Ankylosaurus fossils has been found in the famous American location of the Rocky Mountains which during the Cretaceous periods were a warm and subtropical climate that was rich in vegetation. There was probably tropical storms, with monsoon like weather.

Ankylosaurus shared the dinosaur rich habitat with plenty of others. Some were friendly, such as Triceratops who was around during this period and was also a herbivorous, and others were not.

Ankylosaurus needed all its armour with quick and fierce predators around such as the Tyrannosaurus Rex who patrolled the locations at the same time. Although the T- Rex would have had to be very brave to take on the Ankylosaurus due to its size and tough armour.

How big was ankylosaurus?

The length of Ankylosaurus was 10.7 meters (35 feet) with a height of 1.2 meters (4 feet). Its weight has been estimated to be between 4.7 and 7.9 tonnes which is the equivalent to in Indian Elephant.

Unlike a lot of Dinosaurs a lot of humans would have been able to run away from this particular one because its thought that the Ankylosaurus’s top speed was 6 mph (9.7 kmph). There has not been a full skeleton discovered of Ankylosaurus as yet which is why the lengths and heights are estimated.

Ankylosaurus size

Oktaytanhu, CC BY 2.0, via Wikimedia Commons


The biggest feature of the Ankylosaurus was probably its thick armour. This consisted of oval plates and knobs of bone that form within the skin. This is similar to the crocodile of today, the difference being the crocodile is a predator who has other ways to protect itself where as the Ankylosaurus relied on its armour to protect it from attack.

The biggest cluster of armour was in its neck region which was probably the most vulnerable point on its whole body so this may have helped save its life from time to time.


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Four limbs

Ankylosaurus had four limbs with the back ones being slightly bigger than its front, there have not been any identified foot prints so as yet no proof that it had toes but scientists believe like other similar dinosaurs the Ankylosaurus had 5 toes on each foot.

What did ankylosaurus Eat?

Ankylosaurus was a herbivorous, and grazed on low-lying shrubs, ferns, plants, tough leaves and pulpy fruits. It is thought Ankylosaurus could have eaten as much as a large elephant does by consuming 60kg (130Ib) each day.


The Ankylosaurus’s skull was super wide with a narrow beak that helped it strip leaves from plants. It had large teeth with 6 to 8 at the front and 5 to 7 at the back. It was heavily armoured and even spiked for further protection.


The Ankylosaurus had a strong tail that contained vertebrae which had several woven into each other to form a base of a club like at the end. Scientists have debated whether the tail was used for attracting mates or for combat purposes.

Either way it would have done some serious damage to the environment around it or to another dinosaur. There has only ever been one fossil of the tail club found which is kept at the American Museum of Natural History

Ankylosaurus Skull

Tim Evanson, CC BY-SA 2.0, via Wikimedia Commons

Similar dinosaurs to ANKYLOSAURUS


There were well over 40 armoured dinosaurs and the first one we will look at here is the Hylaeosaurus, whose name translates to Woodland lizard, an It lived around 135 million years ago. Hylaeosaurus was named in 1832 having been the first genus of armoured ankylosaur dinosaur to be discovered.

Sir Richard Owen named this dinosaur in 1842 and it was a herbivore and located in England, with only partial fossil remains discovered. It had features such as bony plates and spikes down the back and sides. Hylaeosaurus was about 5 meters long, weighed 2 tonnes and it had three long spines on the shoulders.


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Minotaurasaurus was named in 2009, meaning “man-bull lizard”. Its origins are not completely known as there is a lot of controversy around the fossilised skull. Palaeontologists have claimed that the skull was removed from the Gobi desert (based in the North China, south Mongolia region) without the permission of the Chinese Government and then sold without the correct paperwork to accompany the fossil. The skull found its way to America where it is held in a private collection.

Even though not much is known about this dinosaur it is surrounded in mystery and it is a shame the original site can’t be pinpointed so scientists can do a proper excavation.



Discovered in 1914 by an independent fossil collector and named in 1928, Scolosaurus lived around 76.5 million years ago during the Late Cretaceous period. It had distinguishing features such as its horns were longer and backswept, and its tail club knob was circular and meant it was wider.
It lived in North America, was a herbivore, and reproduced by laying eggs. There are a few fossil specimens dotted around, one at the Museum of the Rockies in Montana, America, and one at the Natural History Museum in London, England.


Nobu Tamura (, CC BY 3.0, via Wikimedia Commons


Jullius Cstonyi, CC BY 3.0, via Wikimedia Commons

Summary of ankylosaurus

  • Ankylosaurus was classed as an armoured dinosaur
  • The very first Ankylosaurus fossil was discovered in 1906 in America by a palaeontologist called Barnum Brown.
  • Ankylosaurus fossils have been found in the United States at the Hell Creek Formation location.
  • There has never been a complete fossil found of Ankylosaurus
  • Ankylosaurus roamed the earth 68 to 66 million years ago during the Cretaceous period
  • Ankylosaurus ate plants and was classed as an herbivore as it ate low-lying shrubs, ferns, plants, tough leaves and pulpy fruits.
  • Ankylosaurus weighed between 4.7 and 7.9 tonnes which is the equivalent to an Indian elephant.

Last Updated on 15/07/2022 by