Giant teeth, killer claws and bone-crushing bites! Meet the 12 scariest dinosaurs that ever lived, plus a few prehistoric monsters that weren't dinosaurs at all.
Quick Answer
The most terrifying dinosaur was probably Tyrannosaurus rex, with banana-sized teeth and the strongest bite of any land animal. Other scary dinosaurs include Spinosaurus (the longest meat-eater), Giganotosaurus, Carcharodontosaurus (shark teeth) and Utahraptor (the biggest raptor). Don't worry: they all died out about 66 million years ago!
Scary dinosaurs came with all kinds of weapons. Some were built to hunt, and some were built to fight back.
Giant teeth
T. rex teeth were as big as bananas, and Carcharodontosaurus had blade-like teeth with jagged edges, like a steak knife.
Sharp claws
Raptors had a curved “killing claw” on each foot, and Therizinosaurus had hand claws about as long as a baseball bat.
Huge size
The biggest meat-eaters were longer than a school bus and heavier than an elephant. Even their footprints were scary!
Speed
Small hunters like Velociraptor were quick runners, and Carnotaurus had powerful legs built for speed.
Bone-crushing bites
T. rex had the strongest bite of any land animal we know about, strong enough to crunch right through bone.
Built-in weapons
Even plant-eaters could be scary: Triceratops had long horns and Ankylosaurus swung a heavy club on its tail.
Each dinosaur gets a Scary Meter score from 1 to 5 🦖. Which one do you think was the scariest?
Say it: tie-RAN-oh-SORE-us REX
😱 Why it's scary: The strongest bite of any land animal
Scary meter:
📏 Size: About 40 feet long, as long as a school bus
🗺️ When & where: 68 to 66 million years ago, North America
🍖 Diet: Meat-eater
⭐ Its name means “tyrant lizard king.” T. rex had about 60 thick teeth, some as big as a banana, and a bite strong enough to crush bones. Scientists have found T. rex poop with crunched-up bones inside!
See the dinosaur that escaped a T. rex bite →
Say it: SPINE-oh-SORE-us
😱 Why it's scary: The longest meat-eating dinosaur ever found
Scary meter:
📏 Size: About 45 to 50 feet long, longer than T. rex
🗺️ When & where: 99 to 93 million years ago, North Africa
🍖 Diet: Fish & meat
⭐ Spinosaurus had a giant sail on its back and a long snout like a crocodile's. It spent lots of time in rivers, snapping up fish as big as a car, so it was scary on land AND in the water.
More water dinosaurs →
Say it: JIG-ah-NOH-toe-SORE-us
😱 Why it's scary: A giant hunter as big as T. rex
Scary meter:
📏 Size: About 40 feet long, as long as a school bus
🗺️ When & where: About 98 million years ago, Argentina
🍖 Diet: Meat-eater
⭐ Its name means “giant southern lizard.” It was one of the biggest meat-eaters ever, with a long head full of thin, slicing teeth. It may have hunted giant long-necked dinosaurs like Argentinosaurus.
Say it: car-KAR-oh-DON-toe-SORE-us
😱 Why it's scary: Teeth like a great white shark
Scary meter:
📏 Size: About 40 feet long
🗺️ When & where: About 95 million years ago, North Africa
🍖 Diet: Meat-eater
⭐ Its name means “shark-toothed lizard” because its flat, jagged teeth looked like a great white shark's. It lived in the same place and time as Spinosaurus. Imagine meeting both of them in one day!
Say it: YOO-tah-RAP-tor
😱 Why it's scary: The biggest raptor, with a giant toe claw
Scary meter:
📏 Size: About 20 feet long, as heavy as a grizzly bear
🗺️ When & where: About 135 million years ago, Utah, USA
🍖 Diet: Meat-eater
⭐ Utahraptor was the biggest raptor ever found. It had feathers and a curved claw on each foot about 9 inches long, as long as a pencil. Scientists think it may have hunted in groups.
Say it: AL-oh-SORE-us
😱 Why it's scary: The top hunter of the Jurassic
Scary meter:
📏 Size: About 28 to 32 feet long
🗺️ When & where: 155 to 145 million years ago, North America and Portugal
🍖 Diet: Meat-eater
⭐ Allosaurus could open its mouth super wide and slam its top jaw down like a hatchet. But it didn't always win: scientists found an Allosaurus bone with a hole poked in it by a Stegosaurus tail spike!
Say it: veh-LOSS-ih-RAP-tor
😱 Why it's scary: A quick, clever hunter with a killing claw
Scary meter:
📏 Size: About the size of a turkey, plus a long tail
🗺️ When & where: 75 to 71 million years ago, Mongolia
🍖 Diet: Meat-eater
⭐ Real Velociraptors were much smaller than the ones in movies, and they were covered in feathers. One famous fossil shows a Velociraptor locked in a fight with a Protoceratops. They were buried together while still fighting!
Why raptors had feathers →
Say it: CAR-noh-TORE-us
😱 Why it's scary: Bull horns and a speedy sprint
Scary meter:
📏 Size: About 26 to 30 feet long
🗺️ When & where: About 70 million years ago, Argentina
🍖 Diet: Meat-eater
⭐ Its name means “meat-eating bull” because of the two horns over its eyes. It had strong legs for running fast but teeny-tiny arms, even smaller than T. rex's! Its skin fossils show bumpy scales.
Say it: YOO-tie-RAN-us
😱 Why it's scary: A giant fluffy tyrant
Scary meter:
📏 Size: About 30 feet long
🗺️ When & where: About 125 million years ago, China
🍖 Diet: Meat-eater
⭐ Its name means “beautiful feathered tyrant.” This early cousin of T. rex was covered in long, fluffy feathers, which probably kept it warm in chilly winters. It's the biggest feathered animal ever found.
More feathered dinosaurs →
Say it: THERE-ih-ZEEN-oh-SORE-us
😱 Why it's scary: The longest claws of any animal ever
Scary meter:
📏 Size: About 30 feet long and taller than an elephant
🗺️ When & where: About 70 million years ago, Mongolia
🌿 Diet: Plant-eater
⭐ Its claws were about 3 feet long, as long as a baseball bat! They look terrifying, but here's a surprise: Therizinosaurus mostly ate plants. It probably used its claws to pull down branches and scare away predators.
More plant-eating dinosaurs →
Say it: an-KY-loh-SORE-us
😱 Why it's scary: A walking tank with a wrecking-ball tail
Scary meter:
📏 Size: About 20 to 26 feet long
🗺️ When & where: 68 to 66 million years ago, North America
🌿 Diet: Plant-eater
⭐ Ankylosaurus was covered in bony armor, even on its eyelids! Its tail ended in a heavy club of bone that could swing hard enough to break a predator's leg. Even T. rex had to watch out.
Say it: try-SAIR-ah-tops
😱 Why it's scary: Three horns and the guts to face T. rex
Scary meter:
📏 Size: About 30 feet long, as heavy as an elephant or more
🗺️ When & where: 68 to 66 million years ago, North America
🌿 Diet: Plant-eater
⭐ Its two long brow horns were over 3 feet long. Scientists have found Triceratops bones with T. rex tooth marks, and some Triceratops frills with healed wounds, so these two giants really did battle.
Color a Triceratops →Some of the scariest creatures from the age of dinosaurs weren't dinosaurs at all! Dinosaurs lived on land. These monsters ruled the seas, the rivers and the sky.
Giant sea lizard
Up to about 50 feet long, with an extra row of teeth on the roof of its mouth so slippery prey couldn't escape. It was a giant cousin of today's lizards and snakes.
Sea monsters of the dinosaur age →
Big-jawed sea reptile
This flippered hunter had huge jaws and swam through Jurassic seas. It could probably smell prey underwater, like a shark.
More ocean reptiles →
Giant crocodile cousin
Its name means “terrible crocodile.” At about 33 feet long, it was big enough to eat dinosaurs, and scientists have found its tooth marks on dinosaur bones!
Are crocodiles dinosaurs? →
Giant flying reptile
As tall as a giraffe with wings as wide as a small airplane. It stalked the ground like a giant stork, snapping up small animals, maybe even baby dinosaurs.
Meet the pterosaurs →Movies make dinosaurs extra scary, but some of what you see on screen isn't true. Here's what scientists really know.
Myth: Velociraptor was taller than a person.
Fact: Real Velociraptors were about the size of a turkey and covered in feathers. The giant movie raptors are closer in size to Utahraptor or Deinonychus.
Myth: T. rex can't see you if you stand still.
Fact: T. rex had big, forward-facing eyes and probably excellent eyesight, maybe better than a hawk's. Standing still would not have helped!
Myth: Dinosaurs roared like lions.
Fact: Nobody knows exactly what dinosaurs sounded like. Many scientists think big dinosaurs made deep booming or cooing sounds with their mouths closed, like crocodiles and birds do today.
Myth: Some dinosaurs spat poison.
Fact: There is no fossil evidence that any dinosaur spat venom or had a frill around its neck like a lizard. That idea was made up for the movies.
Tip for parents: if a little one gets scared, try turning the scary parts into a game. Measure out how long a T. rex was in your hallway, or stomp around and roar together!
Most scientists and dinosaur fans pick Tyrannosaurus rex. It was as long as a school bus, had banana-sized teeth and the strongest bite of any land animal ever found. Spinosaurus, Giganotosaurus and Utahraptor are close behind.
Big meat-eaters like T. rex, Giganotosaurus and Carcharodontosaurus were the most dangerous to other dinosaurs because of their size and teeth. Pack-hunting raptors like Utahraptor and Deinonychus may also have been very dangerous, because they were fast and had sharp claws.
Spinosaurus was longer than T. rex, but T. rex was bulkier and had a much stronger bite. Spinosaurus mostly hunted fish in rivers, while T. rex hunted big dinosaurs like Triceratops on land. They lived millions of years apart on different continents, so they never met.
Many people pick Mosasaurus, a giant sea reptile up to about 50 feet long, or Megalodon, a huge shark that lived long after the dinosaurs. Deinosuchus, a crocodile cousin big enough to eat dinosaurs, is another scary one.
Yes! Therizinosaurus had claws about 3 feet long but mostly ate plants. Triceratops and Ankylosaurus were plant-eaters too. They only used their horns, clubs and claws to defend themselves.
No. The giant dinosaurs died out about 66 million years ago, long before the first people were born. The only dinosaurs alive today are birds, so the scariest dinosaur you'll meet now is probably a grumpy goose!
Image credits: T. rex, Spinosaurus, Ankylosaurus and Triceratops are Puffsaurus artwork. Giganotosaurus, Carcharodontosaurus, Utahraptor, Allosaurus, Carnotaurus and the roaring T. rex at the top are original Puffsaurus drawings. Via Wikimedia Commons: Velociraptor and Yutyrannus by TotalDino (CC BY 4.0); Therizinosaurus by PaleoNeolitic (CC BY 4.0); Mosasaurus by UnexpectedDinoLesson (CC BY 4.0); Liopleurodon by Cody Lake (CC BY 4.0); Deinosuchus by Andrey Atuchin (CC BY-SA 4.0); Quetzalcoatlus by Mark Witton and Darren Naish (CC BY 3.0). Images resized.
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