What is the fossil record?

Simple answer: It is the record of past life, be that the record of the organisms themselves—body fossils—or of their activity—trace (ichno-) fossils.

A trace fossil might be a foot print, a walking trace, a resting place, a burrow. Very different organisms can create the same trace fossil, for example Rusophycus, which is a resting place, could be made by a trilobite or a shrimp or another animal. By the same logic, the same animal can create different types of trace fossils—a trilobite walking trace will look different to a trilobite resting place. These fossils can actually tell us an awful lot about an animal because it can show us mode-of-life but unfortunately it is rare to find the animal that made the trace.

A body fossil is either the preserved form of a whole or more commonly part of an organism.

The vast majority of fossils are of marine organisms and this reflects the inherent bias of the fossil record—to preserve hard-bodies, marine animals that died or were laid to rest (figuratively of course) away from scavengers.

Having said that there are ‘sites of exceptional preservation’ known as Lagerstätten (that is the plural, the singular is Lagerstätte) such as the Burgess Shale in Canada or the Maotianshan Shales in China that can give us an exceptional insight into past life.

If you are asking this for a school/college (I’m in the UK so that is secondary and further education) essay then I recommend reading about trace fossils, body fossils and including some examples such as Rusophycus and Cruziana and Trilobites and Cephalopods respectively—you might also want to research some precambrian fossils of which there aren’t many for you’re own interest. If by chance you’re in the UK then David Attenborough did an interesting documentary on early life last year called First Life. Also research the bias of the fossil record and Lagerstätten because they are really vital to our understanding of the fossil record. The wikipedia entries on these should be sufficient for school/college level.

I hope that helps.

Short answer: what it says. What fossils show about what kinds of creatures existed in the past, and when.

Long answer: how long do you want? Look in a book.