We all know that some dinosaurs were really, really big, but have you ever wondered why? Nowadays, the only animals that come close to being as big as dinosaurs are whales, and there have never been animals outside the ocean who grew as big as dinosaurs. Paleontologists think that one of the reasons dinosaurs grew so big was so that they could reach new sources of food. Just like the way giraffes do today, many animals ate food right from the tops of the trees! Paleontologists also have decided that the world the dinosaurs lived in was a whole lot different from the one we live in today. These differences in weather and in the amount of food available allowed dinosaurs to grow to their huge size. Let’s hope the weather and food supply doesn’t change back to that again. As much as you like your cat or dog, you’d probably like them a lot less if they were the size of your house!