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| The study of primate and human evolution. |
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| A comparative method of the older of two or more fossils or sites, rather than providing a specific date. |
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| The method of estimating the specific date of fossils or sites. |
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| Before Present (1950), the internationally accepted form of designating past dates. |
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| A relative dating method based on the fact that older remains are found deeper in the earth because of cumulative buildup of the earth's surface over time. |
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| A relative dating method, based on the accumulation of flourine in a bone, that tells if two bones from a site are of the same age. |
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| A relative dating method in which sites can be assigned an approximate age based on the similarity of animal remains to those from other dated sites. |
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| A method of dating sites based on the fact that the earth's magnetic field has shifted back and forth from the north to the south in the past at irregular intervals. |
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| The average length of time it takes for half of a radioactive substance to decay into another form. |
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| A chronometric dating method based on the half-life of carbon-14 that can be applied to organic remains, such as charcoal, dating back over that past 50,000 years. |
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| A chronometric dating method based on the half-life of radioactive potassium that can be used to date volcanic rock older that 100,000 years. |
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| A variation of potassium-argon dating that can be applied to very small samples of volcanic rock. |
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| A chronometric dating method based on the fact that trees in dry climates tend to accumulate one growth ring per year. |
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| A Chronometric dating method based on the number of tracks made across volcanic rock as uranium decays into lead. |
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| A chronometric dating method that uses the fact that certain heated objects accumulate trapped electrons over time, which allows that date when the object was initially heated to be determined. |
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| Electron Spin Resonance (ESR) |
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Definition
| A chronometric dating method that estimates dates from observation of radioactive atoms trapped in the calcite crystals present in a number of materials, such as bones and shells. |
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| Species identified from fossil remains based on their physical similarities and differences relative to other species. |
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| The study of what happens to plants and animals after they die. |
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| The study of ancient environments. |
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| The study of fossil pollen. |
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| Analysis of the ratios of stable (nonradioactive) isotopes of elements such as carbon that provides information about ancient diet. |
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| A field of archaeology that involves the study of the manufacture and use of tools in order to learn how they were made and used by people in the past. |
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| A major subdivision of geologic time. |
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| A subdivision of a geologic eon. |
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| A subdivision of a geologic era. |
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| A term that refers to earth's history before the Cambrian period of the Paleozoic era. Precambrian time includes the Hadean, Archean, and Proterozoic eons, and lasted from 4,600 million to 542 million years ago. |
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| The first geologic eon, dating from 4,600 to 3,850 Ma, which occurred before the oldest fossil evidence of life. |
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| The second geologic eon, dating from 3,850 to 2,500 Ma, characterized by the appearance of the first single-celled organisms. |
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| The third geologic eon, dating from 2,500 to 542 Ma, characterized by the appearance of the first multicelled organisms. |
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| The fourth geologic eon, covering the past 542 million years. |
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| The first era of the Phanerozoic eon, dating from 542 to 251 Ma, when the first vertebrates appeared. |
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| An early group of mammal-like reptiles, ancestors of later mammals. |
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| The second geologic era of the Phanerozoic eon, dating from 251 to 65.5 Ma, when the dinosaurs were dominant and when mammals and birds appeared. |
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| The third and most recent geologic era of the Phanerozoic eon, datin to the last 65.5 Ma. Primate and human evolution occurs during the Cenozoic era. |
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