Fossils are the remains of ancient animals and plants that have been preserved in stone. Typically, only the hard parts like bones and shells are all that now remain. The soft parts usually rot away with the passing of time. Only in very rare and very special conditions do we get a glimpse of what the soft parts were once like. We never get to see the colour of the animal or plant when it has been fossilised.
Many fossils that we find in the rocks are from animals that no longer can be found alive on Earth, like dinosaurs and trilobites. These animals died out many millions of years ago.
However, the bits and pieces that are preserved give us clues about what the animal was like and how it once lived.
Fossils tend to be found in rocks like clay, sandstone or limestone. Usually the animal or plant dies, sinks to the seabed or riverbed and gets covered by mud or sand that washes over them. As they lie buried in this wet sediment, the shell or bone gets slowly replaced by minerals washing through the ground in the groundwater. Millions of years later we break open the rocks and find the fossilised remains of the animal or plant.
