The Stegosaurus had a brain the size of a walnut, making it one of the least intelligent dinosaurs.
The smallest dinosaur was about the size of a chicken, while the largest dinosaur was as long as a basketball court and as tall as a 6-story building.
The word "dinosaur" comes from the Greek words "deinos" meaning "terrible" and "sauros" meaning "lizard."
The earliest dinosaurs lived about 230 million years ago, while the last dinosaurs lived about 65 million years ago.
Some dinosaurs had feathers, including the Velociraptor, which is thought to have looked similar to a modern-day bird.
The T. rex had the strongest bite of any animal that has ever lived, with a bite force of about 12,800 pounds.
Triceratops had up to 800 teeth, although they only used a small portion of them at any given time.
The Spinosaurus had a sail-like structure on its back that may have helped it regulate its body temperature or attract mates.
Many dinosaurs had hollow bones, which made them lightweight and helped them move more easily.
The Deinonychus is thought to have been one of the most intelligent dinosaurs, with a brain size that was proportionally larger than many other dinosaurs.