Kinds of dinosaurs
Some dinosaurs carried their own armor. Stegosaurus had plates on its back and spikes on its tail. Ankylosaurus wore a suit of bone and swung a club.
And one dinosaur had a sail. The cards below tell the spiky ones apart, and further down you can read why they needed all that.
Friendly at the front. Careful at the back!
Plates and spikes
Stegosaurus (say it: STEG-oh-SORE-us) had big plates along its back and long spikes at the end of its tail. It ate plants, and it didn't run from trouble.
Stegosaurus was a big, spiky dinosaur with a tiny head, like a walnut. But don't be fooled! Its plates and tail were strong weapons that helped protect it from predators.
Stegosaurus facts for kids, with a short video.
19 plates, four spikes
A tail that left a mark
Plates in the skin
A nickname from a cartoon
Spot the difference
Look at the back first, then at the tail. The clue on each card tells you what to look for. (The pictures aren't to scale.)
Say it: STEG-oh-SORE-us · “roof lizard”
Look for: Big plates standing up along its back, and four spikes on its tail.
The most famous spiky dinosaur of all, about 9 meters (30 feet) long.
Kentrosaurus
Say it: ken-TROH-sore-us · “spiky lizard”
Look for: Small plates at the front, then long spikes all the way down its tail.
A smaller cousin of Stegosaurus, about 5 meters (16 feet) long. It lived in Africa, in the land that is now Tanzania.
Say it: an-KYE-low-SORE-us · “fused lizard”
Look for: Bony armor all over its back, and a heavy club at the end of its tail.
Low, wide and built like a tank. It swung its club from side to side.
Euoplocephalus
Say it: you-OH-plo-kef-ah-luss · “well-armored head”
Look for: Armor, spikes and a tail club, like its bigger cousin Ankylosaurus.
About 7 meters (23 feet) long, with a club made of bone.
Polacanthus
Say it: pol-a-KAN-thus · “many spines”
Look for: Armor and spikes, but NO club on its tail.
It lived in England. Not every armored dinosaur had a club.
Say it: SPINE-oh-SORE-us · “spine lizard”
Look for: A tall sail on its back, and a long snout like a crocodile's.
The only meat-eater on this page. It mostly ate fish.
All six are on page two of the free “Name that dinosaur” card, ready to print.
Armor and a club
The club belonged to Ankylosaurus (say it: an-KYE-low-SORE-us). Its name means “fused lizard”, because its bony armor was joined together.
Imagine a dinosaur as armored as a knight and as powerful as a tank: that was Ankylosaurus! This plant-eating dinosaur could grow up to 9 meters (30 feet) long and weigh up to 6 tons. But its secret weapon was its tail club, which made it even more powerful!
The club was a big knob of bone at the tip of a stiff tail. Ankylosaurus couldn't lift it up and down much, but it could swing it hard from side to side, right at the legs of a hungry meat-eater.
Club or no club?
Destroyer of shins
Built to smash
Armored dinosaurs
A knight puts his armor on in the morning. An armored dinosaur grew its own. The armor was made of bone, and it sat in the skin, like the bumpy plates on a crocodile's back. Scientists call the pieces osteoderms (say it: OSS-tee-oh-derms), which means “bone skin”.
Stegosaurus and Ankylosaurus belong to one big family of armored dinosaurs. Its name means “shield bearers”.
The best kept one in the world
Even its eyelids
A puzzle with no picture on the box
Not spikes: a sail
Spinosaurus (say it: SPINE-oh-SORE-us) is the “spine lizard”. The sail on its back was about 1.5 meters (5 feet) tall. It was a thin sail, not a hump, and scientists still argue about what it was for.
Spinosaurus was even bigger than Tyrannosaurus rex! It could grow up to 15 meters (49 feet) long, weigh 20 tons, and swim like a crocodile!
One long neck had something like it too: Amargasaurus, from Argentina, had a double row of long spines down its neck and back.
Spinosaurus facts for kids · Were there dinosaurs in the sea?
The reason
Blame the neighbors. Stegosaurus shared its world with Allosaurus, a big meat-eater. Ankylosaurus lived at the same time as T. rex. A plant-eater that couldn't run fast needed another plan: plates, spikes, armor and a club.
Katia's facts say it best. The plates and tail of Stegosaurus were “strong weapons”, and the tail club of Ankylosaurus was its “secret weapon”.
All that armor was aimed at the meat-eaters. One of them, T. rex, stands in your room in 3D.
Free, no sign-up
Two pages. One for backs and tails (plates, spikes, armor, clubs and the sail), one for heads (horns, frills, crests and the hard head). Each dinosaur comes with a “look for” clue.
Take it to a museum, or play it at home with the toy box. There's a black and white version to color in.
Free for home and classroom use. Please share the link to this page rather than the file.
Riddles
Riddle · who am I?
My head is tiny, like a walnut, it's true,but don't be fooled, I know what to do!
Big plates on my back and spikes on my tail.I swing it at danger, and I never fail!
Stegosaurus!
The true bit: The tail spikes even have a nickname: the thagomizer. (Smithsonian Magazine)
Riddle · who am I?
I'm covered in armor like a knight in a fight,but I only eat plants, from morning till night.
My tail has a club like a big bony ball.Swing! Bang! I'm the tank of them all!
Ankylosaurus!
The true bit: From our book Dinosaurs Are Back: armored like a knight and as powerful as a tank, with a club on its tail.
More like these: all the dinosaur riddles and dinosaur jokes for kids.
Questions kids ask
Keep sorting
Dinosaurs with hornsThree horns, two horns like a bull, fifteen horns, and one head as hard as a helmet.Take a look →
Dinosaur eggsEven the biggest dinosaurs hatched from eggs you could hold. And some eggs were blue-green!Take a look →
Plant-eaters and meat-eatersSort Spike's ten dinosaurs, and learn to tell a plant-eater from a meat-eater by its teeth.Take a look →
Types of dinosaursEvery dinosaur belongs to one of seven kinds, and you can tell them apart by their shape.Take a look →
Water dinosaursWere there dinosaurs in the sea? No! But one dinosaur was a real swimmer, and some still are.Take a look →
Duck-billed dinosaursDuck bills had a flat beak with hundreds of grinding teeth behind it, and some wore a crest like a helmet.Take a look →Got a big question instead? The biggest, the fastest, the fliers and the long necks. Or meet ten dinosaurs, one page each, with a fun fact and a riddle.
Our own bookA picture book · ages 6 to 10
Spike finds the Stegosauruses by the lake, upset and hauling a log out of the water. Later he runs into a whole gang of Ankylosauruses, armored like knights. All ten dinosaurs step off the page with a phone or tablet.
Katia's facts are from the fact page near the end of Dinosaurs Are Back. Everything else was checked on these pages on October 1, 2026.
Picture credits