The fossilized remains of possibly the largest armored dinosaur ever to have lived were discovered in Montana in 1908. The partial skeleton revealed smooth plates and bony knobs covering the back of the animal. It had four legs that carried its broad, tank-like body and a wide low skull with two horns pointing backward. Two horns at the side of its head protected the animal’s skull.
Ankylosaurus was the largest armored dinosaur ever found in the fossil record. Ankylosaurus lived between 65.5 million and 66.8 million years ago. The dinosaur’s skull was fused to its body, and thick plates of bone covered the body. The tail was armed with a formidable club at the end.
Ankylosaurus is Greek, and it means “Fused Lizard.” A fully grown specimen was estimated to be twenty to twenty-six feet in length and weighed five to eight metric tons. The Sherman Tank of the Cretaceous period was a heavily armored dinosaur with a large club at the end of its tail.
The full body armor and the fearsome tail club must have proven effective defense against predators as big as the Tyrannosaurus Rex. The Ankylosaurus was a plant-eating dinosaur that went extinct and all the other megafauna 65 million years ago.
What Were The Armored Dinosaurs?
The size and body armor of plant-eating dinosaurs evolved along with the size of the predatory meat-eating dinosaurs with which they had to live. The largest armored dinosaurs ever to have walked the earth were all herbivores, and each developed the means to protect themselves and even fight back.
Dinosaur armor was not a new evolutionary development. dinosaurs had been armoured for million of years before their hay-day during the late cretaceous period. We take a look at ten of the largest armored dinosaurs below.
What was the first armored dinosaur?
A very early armoured dinosaur was also one of the first ever dinosaurs to be found and classified as a member of dinosauria. It was called the Scelidosaurus and was found in England in the 1850s.
However even though it was an old discovered dinosaur it was also a very old dinosaur in general. It lived over 196 million years ago and was if not the first then a very early armored dinosaur and in fact a very early dinosaur of any kind!
Scelidosaurus was not the biggest but being so early we thought it worth a mention!
The Top 10 Largest Armored Dinosaurs:
- Ankylosaurus – 26 feet long, 8 tons
- Stegosaurus – 30 feet long, 3 tons
- Cedarpelta, 23 feet, 5 tons
- Euoplocephalus – 18 feet long, 2.5 tons
- Tuojiangosaurus, 23 feet, 2.5 tons
- Tarchia, 26 Feet, 2.5 tons
- Saichania, 18 feet, 2 tons
- Panoplosaurus, 16 feet, 1.8 tons
- Sauropelta, 17 feet, 1.7 tons
- Hesperosaurus, 16 feet, 1 ton+
|Dinosaur||Length In feet||Weight in Pounds||Where lived||How long ago|
|Ankylosaurus||26-32 feet||16,000 lbs||North America||68-66 million years ago – Late Cretaceous|
|Stegosaurus||30 feet long||13,000 lbs||North America / Portugal||155-145 million years ago – late Jurassic|
|Cedarpelta||23 feet||10,000 lbs||North America||108 million years ago – early Cretaceous|
|Euoplocephalus||18 feet||5500 lbs||North America||76 million years ago – Late Cretaceous|
|Tuojiangosaurus||23ft||5500 lbs||China||160 Million years ago – Late jurassic|
|Tarchia||26 feet||5000 lbs||Mongolia||70 -75 million years ago – Late Cretaceous.|
|Saichania||18 feet||4000 Lbs||Mongolia||75 Million years ago – Late Cretaceous|
|Panoplosaurus||16 feet||3500 lbs||North America||75 Million Years ago – Late Cretaceous|
|Sauropelta||17 feet||3300 Lbs||North America||108 Million years ago – Early Cretaceous|
|Hesperosaurus||16 feet||2200 lbs||North America||156 million years ago – Late Jurassic|
Largest Armored Dinosaurs: Ankylosaurus
Name Meaning: “Fused Lizard”
The Ankylosaurus lived about 68 million years ago and shared the earth with the most famous of all the meat-eating dinosaurs, Tyrannosaurus Rex. The Ankylosaurus would not have been a sought-after meal for a T-Rex as it was armed with bony plates and spikes protecting its compact body and head. It was certainly the largest armored dinosaur.
The tail was shaped like a baseball bat and, on the end, had a club head that could be wielded in a 110-degree arc. The impact of the tail club would have sufficient impact to break the leg of a T-Rex or knock it unconscious with a blow to the head.
The Ankylosaurus had four short but sturdy legs supporting its broad and robust body. A broad and low held skull was protected by hard horns pointing backward and out the side of the face.
The beak-like mouth of the Ankylosaurus was filled with leaf-shaped teeth designed to bite off and grind down its favorite plant fodder. The back of the animal was covered in armor plates (osteoderms), also covering the neck and tail shaft. At the end of the tail, the clubhead was a couple of osteoderms fused into a solid ball.
The head and neck vertebrae of the Ankylosaurs were fused, giving extra strength to this tank of the Cretaceous period. Ankylosaur is derived from Greek and means “Fused Lizard.”
Largest Armored Dinosaurs: Stegosaurus
Name Meaning: “Roof Lizard”
Stegosaurus lived during the Jurassic period some 150 million years ago and would have had some enormous predators to contend with. The Stegosaurus grew to a length of thirty feet, stood nine feet tall, and weighed as much as 14,000 lbs when fully grown.
Stegosaurus is one of the most recognizable of the dinosaurs with its broad upright leaf-shaped plates along its entire back and tail. The long tail was armed with fearsome spikes on each side of the tail. Although not the largest armored dinosaur it was the largest member of its family. you can read more about its size on the article how big was a stegosaurus.
The spiked tail was most likely the Stegosaurus’s only form of defense as the upright plates along the neck and back ridge were most likely used to display their size and virility to potential mates. The broad plates could also have helped the animal control its body temperature.
The Stegosaurus had a tiny brain, and it was thought to have been one of the least intelligent herbivores during its reign. The Stegosaurus was hunted by fearsome predators such as the Allosaurus, a smaller and lighter forerunner to the T-Rex.
Largest Armored Dinosaur: Cedarpelta
Name Meaning: “Cedar Mountain Shield”
Cedarpelta was a large herbivorous dinosaur that lived during the Early Cretaceous period around 116 to 109 million years ago. It was around 6 to 7 meters (20 to 23 feet) long, and weighed around 5 metric tons, which would be over 10,000 lbs!
The first Cedarpelta fossils were discovered in 1990 in Utah, United States. More fossils have been found in Alberta, Canada.
Cedarpelta was a heavily armored dinosaur some scientists think it may even have been similar in size to Ankylosaurus. It certainly looked similar. It would have had a thick layer of bony plates called scutes covering its back. A full skeleton has not been found yet so we are not sure if it had the club at the end of its tail.
Cedarpelta was an herbivore. It probably ate plants like ferns, cycads, and conifers.
Largest Armored Dinosaurs: Euoplocephalus
Name Meaning “Well Armed Head”
Euoplocephalus lived during the Late Cretaceous some 65 million years ago and is very similar to Ankylosaurus in build and appearance. The Euoplocephalus grew to about eighteen feet long and would weigh as much as 2.5 tons (5500 lbs) when fully grown. It may have been higher up the largest armored dinosaur list. There are various estimates on its size and we went for the lower ones.
Armor plates and high ridged oval scales covered the neck, body, and tail of the Euoplocephalus. The tail was armed with a heavy club that helped it to ward off the attention of predators such as Gorgosaurus.
Euoplocephalus grew to be about a third of the size of its bigger cousin, the Ankylosaurus, and would not have been able to ward off an attack by T-Rex type predator like gorgosaurus with as much success as Ankylosaurus.
Largest Armored Dinosaurs: Tuojiangosaurus
Name meaning: “Tuo River lizard”
Tuojiangosaurus was the size of a rhinoceros, with an arched back and pillar-like limbs. It was covered in shiny plates, which were 17 pairs thick. In addition to its plates, Tuojiangosaurus had two pairs of spikes that extend from its tail. it looked similar to the Stegosaurus from North america, just smaller.
This dinosaur, which lived in What is now China, was a plant-eater. Its name, Tuojiangosaurus, means “Tuo River lizard” and was given to it in 1977, after the first skeletal remains of this dinosaur were discovered. Today, the skeleton of the dinosaur is on display at the Municipal Museum in Chongqing, China, and a cast of it is in the Natural History Museum in London.
This herbivorous dinosaur lived in the Late Jurassic Period, around 160 -155 million years ago. The lizard was large, reaching 23 feet (7 meters) in length, and six and a half feet (2 meters) in height. It weighed approximately 2.8 tons.
This makes it around the same weight, possibly heavier, than Euoplocephalus.
Largest Armored Dinosaurs: Tarchia
Name meaning: “Brainy one”
Tarchia was a large herbivorous dinosaur that lived in the Late Cretaceous period, around 70-65 million years ago. It was one of the last surviving members of the genus Ankylosauridae, and is known from a single partial skeleton found in Mongolia in 1977.
Tarchia was a large animal, measuring up to 8 meters (24 feet) in length and weighing 5500 lbs ( 2500 Kg) this makes it the longest know Asian Ankylosaur. It had a large, rounded body, a long tail, and a small head with two rows of horns. The skeleton was heavily armoured, with thick bony plates called scutes covering the back, sides, and tail.
The function of the horns is not known for sure, but they may have been used for defence, or for display purposes. Tarchia was a herbivore, and would have fed on plants using its small teeth and beak. It probably used its tail club as a weapon against predators.
Largest Armored dinosaurs: Saichania
Name Meaning: “The beautiful one”
Saichania was a large herbivorous dinosaur that lived during the Late Cretaceous period. It was one of the last dinosaurs to exist before the mass extinction that ended the Mesozoic Era.
Saichania measured up to 22 feet (6.6 meters) long and weighed around 2.5 tons 5000 lbs . It was a quadrupedal dinosaur, meaning it walked on four legs. It had a short neck and a small head, with two rows of large teeth in its jaws.
Saichania was first discovered in Mongolia in the Gobi Desert in 1971. Its fossils have also been found in China and North America.
The name Saichania comes from the Mongolian word for “beautiful,” which was inspired by the animal’s intricate patterns of armor.
Saichania was a member of the Ankylosauridae, a family of dinosaurs that were characterized by their armored bodies. Other members of this family include Ankylosaurus and Euoplocephalus.
The armor on Saichania’s body was made up of large plates of bone that were covered in small, sharp spikes. This armor would have protected the animal from predators like tarbosaurus.
Largest Armored Dinosaurs: Panoplosaurus
Name Meaning “Well Armored Lizard”
Panoplosaurus was a genus of large armored dinosaur that lived in Canada North America during the Late Cretaceous period, around 75 million years ago. The only known species is P. mirus, It weighed up to 3500 lbs ( 1600 kg) and could be up to 21 ftt ( 7 metres) long
Panoplosaurus was first described in 1919, based on a partial skeleton found in Alberta, Canada. More complete specimens have since been discovered in both Canada and the United States, giving scientists a good idea of what this massive animal looked like. Panoplosaurus was heavily built, with a wide body and short, powerful legs. its tail has not been found so it is unknown if it had a club like other ankylosaurs.
The armor of Panoplosaurus was extremely sturdy, consisting of large, interlocking plates of bone covered in a layer of tough skin. This provided protection against predators, and may also have helped to deflect the force of blows from other ankylosaurs during fights.
Panoplosaurus was a herbivore, and would have fed on low-growing plants using its broad beak. Its teeth were set in batteries, with rows of replacement teeth waiting behind them to take over when the front ones wore down.
Largest Armored Dinosaurs: Sauropelta
Name Meaning: “Lizard Shield”
Sauropelta lived about 110 million years ago and are very similar to Ankylosaurus in appearance but significantly smaller. They grew up to seventeen feet in length and weighed as much as 1500 kg, 3300 lbs, when fully grown.
Unlike Ankylosaurus, Sauropelta did not have a club at the end of its tail. The skull was fused to the body plates, and the body and tail were covered in thick bony scutes.
It is recognisable from the large spikes sticking out of the side near the neck. and Sauropelta means “Lizard Shield” for these four large pointy spikes on each side of the neck protecting the head of the animal from the sharp-toothed jaws of predators.
Largest Armored Dinosaurs: Hesperosaurus
Hesperosaurus was a large, plant-eating dinosaur that lived during the Late Jurassic period, about 156 million years ago.
Hesperosaurus was about 16.5 feet (5 meters) long and weighed up to 1000 kg (2000 lbs) ( it was also estimated at up to 7000lbs as well) It had a long neck and tail, and its hind legs were longer than its front legs. Its head was small and had a beak-like mouth.
Hesperosaurus lived in what is now North America, Hesperosaurus probably fed on plants that grew along the shoreline of the Western Interior Seaway. Its teeth were adapted for slicing through tough vegetation. Hesperosaurus was first discovered in 1985, in Wyoming, United States. Its name means “western lizard”.
It may actually belong higher up on the list of largest armored dinosaurs as its size is argued. Some think it was larger at 21 ft long and 7000 lbs.
We also have an article on the friendliest dinosaurs as well, if you wanted to check it out.
If you are looking for the smallest dinosaurs ever to live then we have this article here on the site as well.
The largest armored dinosaurs, Sauropelta, Euoplocephalus, and Ankylosaurus etc , were very similar in physiology and behavior. All were herbivores and all had armor and or weapons to encourage hungry predators to look elsewhere for easier prey.
They need them as well as these dinosaurs lived side by side with some of the most fearsome predators ever. Like Allosaurus, Tarbosaurus, T-Rex and more.
The fossil record may yet reveal which dinosaur was the number one biggest armored dinosaur, but at the moment only one can rightfully claim to have been the biggest but for now and that’s the Ankylosaurus.
Hi, I am Roy Ford a General Studies and English Teacher who has taught all over the world. What started as a fossil collection became a great way to teach, motivate and inspire students of all ages and all over the world about dinosaurs and from that and children’s love of dinosaurs came the site dinosaur facts for kids, a resource for all ages.