Imagine a giant dinosaur moving along a lakeshore 80 million years ago. It is searching for food. The dinosaur sees some plants and wades out to them. But before it reaches the plants, it steps into a deep hole filled with soft, wet mud. The dinosaur sinks deeper and deeper into the mud, and the dinosaur drowns.
Over time, the soft parts of the animal’s body rot away. Only its bones are left, covered by mud. For many years, layers of sediment pile on top of the mud and pack it tightly around the bones. Eventually, the packed mud turns to clay. After many more years pass, the clay turns to rock.
During all this time, minerals in the water of the lake fill the hollow places in the bones. The minerals harden and the skeleton of the dinosaur is preserved. The bones in the rock are called fossils.
There are other ways for fossils to be made. And, fossils exist for many kinds of living things – from bugs to plants to woolly mammoths – not just for dinosaurs.
Picture Credit : Google
