Question about the fossil record?

Question

The fossil record is very selective. Many species that lived on Earth left no fossil trace. Explain why the fossil record over-represents some species and under-represents or fails to represent other species.

Answer 1

Good question, but it needs an essay to answer it.  Think about which parts of an organism fossilise most easily. Also think about what has to happen to a dead organism for it to become a fossil rather than simply be destroyed, and what kinds of environments this will happen in.

Answer 2

The most common fossils are those of hard parts of animals and plants.Only rarely is soft tissue fossilized.In order for something to fossilize,it must be buried quickly by sediment such as sand or mud,before it decomposes.In fact,all living organisms are potential fossils,but only a few are preserved due to many reasons including the above mentioned.

Sometimes,trace fossils such as footprints are found.

In short,fossils form in a variety of ways depending upon the environment in which the animal or plant lived and the conditions after it was buried.So,the fossil records are selective.  

Answer 3

  Adding to Paul B's answer, the environment of deposition also plays a role.