The main types of fossil types are: tracks & trails, trace fossils, molds & casts, coprolites, and bones.
First, the definition of fossil according to dictionary.com is the remains, impression, or trace of a living thing of a former geologic age, as a skeleton, footprint, etc. Generally, any type living creature can become fossilized over the course of geologic time.
Typically when we think of , we think of shells, or corals, or dinosaur bones which have been buried and preserved in geologic strata. However, fossils are not limited to the skeletal remains. Other types of fossils include:
- Tracks and trails – from dinosaur tracks to the trails left by trilobites, these are examples of trace fossils. While not part of the animal that left them, they provide clues to how the animal lived and how large it was.
- Feeding traces or tubes – these are another type of trace fossil.
- Molds and casts – The impression of a fossil in the surrounding rock or sometimes the internal cast within a fossil may be all that remains to show the organism was present. This one way fossils can sometimes be found in . The best example is the remains of the residents in the area of Pompeii. The volcanic ash engulfed the people, preserving their bodies as molds.
- Coprolites – fossilized fecal remains.
- Petrified bones of animals or plant wood -have been replaced by silica or some other mineral substance.