What made dinosaurs dinosaurs? Well, it wasn’t their giant size. The average dinosaur was the size of a large cow.
So what makes them unique? For one thing, they lived mostly on land. A few might have spent time in the water like today’s hippos do. But you wouldn’t see them splashing in the middle of the ocean.
Dinosaurs also had a leg up on the world. Whether they walked on two legs or all four, they stood tall unlike other reptiles. In fact, you can see for yourself! If you find a slippery little lizard sunning itself, look closely. You’ll see that their legs stick out at the sides. (You could see the same thing with an alligator or crocodile, but maybe you want to stick with lizards.)