How are fossils formed? micro-lesson

So, how are fossils formed? Firstly, the animal passes away. Next, the soft part of the animal starts to come away from the bones. This means that the animal's body is decaying and some other animals such as fish and scavengers might come to get their next source of food. Before the whole body disappears, lots of layers of sediment go on top of the bones. These sediments can be a mixture of mud or sand. Any more layers of sediment pile up on top of the bones and squish them down. This forms a sedimentary rock. As the years go on, the rock starts to harden along with the bones inside it. Finally, the bones inside of the rock are preserved for so long until somebody comes and finds them many years later. These people are called Paleontologists and they have the cool job of looking for fossils.