Many, many years ago, there were no humans on Earth. In the beginning, there was nothing, and then many kinds of plants and animals appeared. And most notably, the famous dinosaurs. The first living creatures appeared in the water: algae, worms, sponges, jellyfish… Then came the turn of the fish and the first frogs. Some plants began to grow on land, and the ancestors of reptiles started to leave the water. Dinosaurs lived on Earth more than 200 million years ago. There were dinosaurs of every kind: some were gigantic, taller than houses, while others were no bigger than a dog. Some ate leaves, while others were fierce hunters. All of them were reptiles, like today’s lizards. In fact, the word “dinosaur” means “terrible lizard.” Their skin had scales and they laid eggs. They disappeared long before humans appeared on Earth. In reality, we do not know why.