Which was the fastest, the biggest, the deadliest? Check out the greatest record breakers in history: the dinosaurs!

Dinosaurs ruled the Earth for millions of years—and they still rule the record books! That's because they had to be extreme to survive in those prehistoric days. So meet the creatures that have never been equaled: 

• Edmontonia, the spikiest dinosaur
• Laellynasaura, with the longest tail ever
• Therizinosaurus, a super slasher with killer claws
• Fruitadens, the smallest plant eater
• And many more