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Unit 5 Fossils
Earth's Living History
| Question | Answer |
|---|---|
| brachiopods | small animals without backbones, look like clams |
| bryzoans | small animals without backbones, lived in small groups |
| Carbon Film | A thin coating which consists mostly of the chemical element carbon |
| Cast | A model of an organism formed when sediment FILLS a mold and hardens |
| continental drift | the gradual movement of the continents across the earth's surface through geological time. |
| Fossil | The remains or traces of an animal that lived long ago |
| fossil record | all the fossils in earth's rock layers ever discovered on Earth |
| Geologic | Relating to the study of the Earth's physical structure |
| Index Fossil | A fossil of a type of organism that lived in MANY places during a short time |
| Mass Extinction | A period which a large number of species become extinct |
| Mold | An impression formed when sediment hardens AROUND the organism |
| Paleontologist | A scientist who studies fossils to learn about organisms that lived long ago |
| Petrified | Organic matter changed into stony substance, "petrified wood |
| petrified wood | When minerals replace the plant material in a piece of wood. |
| Preserved | Maintain something in its original or existing state |
| relative age | The age of a rock compared to the ages of rock layers |
| Sedimentary | Fossils are found in this rock |
| timescale | the period of time that it takes for something to happen or to be completed in units |
| Trace Fossils | A fossil of a footprint, trail, burrow, or any other trace of an animal that is not of the animal itself |
| Trilobite | an extinct marine arthropod that occurred abundantly during the Paleozoic Era |
| trilobites | Animals both had exoskeletons and three body segments |