The fossil record is the history of life as documented by fossils, which are the remains or imprints of organisms from earlier geological periods preserved in sedimentary rock. The fossil record provides snapshots of the past, which, when assembled, illustrate a panorama of evolutionary change over the past 3.5 billion years. The fossil record helps paleontologists, archaeologists, and geologists place important events and species in the appropriate geologic era. The fossil record is made up of all the fossils that have been found, along with their relative ages. Scientists can look at patterns in the fossil record to understand the history of life on Earth. For example, the fossil record shows us that there has been an overall increase in the complexity of organisms over time, and it also shows us that there have been mass extinctions in Earth’s past.

Fossils can be dated according to the strata, a distinct layer of rock, that they are found in, and another common way that fossils are dated is through radiocarbon dating. With every new fossil discovery, our understanding of the environment in a particular time becomes richer. Fossils can give us clues to what old species may have looked like or their bone structures, and we can even tell how old these fossils are. Fossils also provide the geologist a quick and easy way of assigning an age to the strata in which they occur.

The study of the fossil record has provided important information for at least three different purposes. The progressive changes observed within an animal group are used to describe the evolution of that group. Fossils also provide information about the history of Earths climate and the distribution of continents and oceans in the past. Finally, fossils provide the geologic record of life on Earth.