| A | B |
|---|
| geology | the study of the Earth |
| geologic time scale | a timeline that shows events that happened |
| era | division of time |
| Big Bang theory | suggests that all matter and space were once concentrated into a single great dense glowing mass which exploded into billions of galaxies which are now moving away from each other |
| theory | an idea based on facts already known |
| law | the principle or rule of natural phenomena |
| Pangaea | the name given to the land mass whenall the continents on the Earth were one giant land mass |
| fossils | the remains of past organisms |
| index fossils | a fossil that was used to identify time periods because the species lived only a short while |
| trilobite | an organism that existed during the Paleozoic time era |
| ammonite | an index fossil that was alive during the Mesozoic time era |
| extinct | a species that has died out and no longer exists today |
| relative dating | determining the approximate time of a fossil or event by when it happened compared to other fossils or events |
