A very special branch of science called ‘Paleontology' (pronounced pay-lee-ontol-oji). Paleontology is the study of plants and animals that lived on Earth many, many years ago. And paleontologists are scientists who study this science. Just as the ruins of an old palace can tell us things about a king from the past (like how grand his throne was, or what his favorite weapon was), there are clues deep inside the earth that can tell us many things about ancient animals. The clues come in many forms—bones, footprints, eggs, and sometimes even the body of an entire animal preserved in stone!
These animals lived millions and millions of years ago, long before apes or humans appeared on Earth! How did their remains not rot and decay? And how are they still preserved?
Well, when these creatures died and as they rotted, they got buried under layers and layers of soil. The skin and flesh decayed and disappeared, but the hard bones and teeth remained because of the tightly packed soil. All these layers of soil, along with the bones, became hard and turned into rock. Plant and animal remains preserved as imprints in this rock are called fossils.

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