11 How a fossil is made

HOW A FOSSIL IS MADE Fossils are the remains of things that have been dead for millions of years. All sorts of life forms have fossilised, from spectacular Stegosaurus skeletons to tiny ammonite shells. Fossils help us understand how life on our planet has changed over millions of years. Scientists called palaeontologists dig up and study fossils. STEP 1 A creature dies and its body sinks into the mud by a river. STEP 2 The creature is buried in layers of mud, sand, and ash over a period of millions of years.

STEP 3 The skeleton of the creature turns from bone to stone. STEP 4 The fossilised creature is uncovered by palacontologists. They dig out the fossil and coat it in plaster to protect it. The fossil then sent to a laboratory to be studied or to a museum to be displayed. Types of fossil Body fossils, such as bones, teeth, and shells Petrified fossils, which are soft tissues, such as muscle and leaves Trace fossils, such as fossilised footprints, which tell scientists about a creature's behaviour Coprolites-fossilised poos!