| A | B |
|---|
| fossil | Evidence of early life preserved in rock. |
| evolution | The process of change that produces new life forms over geologic time. |
| trace fossils | Impressions made by animals or plants such as footprints or |
| molds and casts | The hollow depressions made by animal or plant remains. |
| original remains | The actual, unchanged remains of plants and animals preserved in rock. |
| relative | Time that places events in sequence without giving an actual date for them. |
| absolute | Time that identifies the actual date of an event. |
| superposition | In an undistubed sequence of sedimentary rock, the oldest layer is the bottom layer, while the youngest layer is the uppermost layer. |
| Archaen | The oldest era. |
| Cenozoic | The youngest era. |
| period | Division of eras. |
| epoch | Division of periods |
| unconformity | A place in the rock record where layers of rock are missing. |
| geologic time table | A summary of the major events in the Earth's history preserved in the rock record. |
| included fragments | This law states that pieces of rock within another rock are older than the rock they're embedded in. |
