| A | B |
|---|
| erosion | all the natural processes that wear away earth and rock |
| evidence | the data used to draw a conclusion |
| excavation | the process of finding something by digging for it |
| extinct | no longer living on the earth; having died out |
| fossils | the hardened remains of animals or plants of prehistoric times |
| geologists | scientists who study the earth's crust and its rocks |
| hypotheses | scientific suggetions, based on what is known so far |
| paleontologist | a scientist who studies prehistoric life |
| specimens | samples taken for scientific study |
| theory | a widely held scientific explanantion that is based on evidence but cannot be stated as fact |
| prey | an animal hunted or caught by other animals for food |
| emerged | began to appear or developed |
| treacherous | dangerous |
| catastrophes | great and sudden disasters |
| traces | extremely small amounts |
| seeped | passed slowly through small openings |
| drought | a long period of little or no rainfall |
