The organism generally must have hard parts such as shell, bone, teeth, or wood tissue; the remains must escape destruction after death; and the remains must be buried rapidly to stop decomposition. This does make the fossil record biased because animals with soft bodies are less likely to form fossils. It also means that particular environments will not help fossils form because the remains must be buried rapidly and escape the detection of scavengers. 4. Describe three different methods of fossilization. Organisms can be buried and preserved in substances such as frozen soil, volcanic ash, sediment, ice, oil, and amber. This process preserves even the soft parts. Hard parts such as shells, teeth, bones, and wood can also be more easily preserved because they resist weathering. Hard parts can also become altered due to carbonization (leaves only a thin film of carbonaceous material), petrifaction (gets replaced by minerals in water turning it to stone), and replacement (hard parts dissolve and get replaced by calcite, silica, dolomite, and iron compounds)
Children younger than 5, but especially children younger than 2 years old. Adults 65 years of age and older. Pregnant women (and women up to two weeks postpartum)
