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lessons 7.1,7.2
Term | Definition |
---|---|
eons | the longest units of geologic time |
era | eons are subdivided into smaller units of time |
period | eras subdivided into periods |
epoch | periods are subdivided into epochs |
mass extinction | the extinction of many species on Earth within a short period of time |
land bridge | connects two continents that were previously separated |
geographic isolation | the separation of a population of organisms from the rest of its species due to some physical barrier, such as a mountain range or an ocean |
`Paleozoic era | the oldest era of the Phanerozoic eon |
Mesozoic era | the middle era of the Phanerozoic eon |
Cenozoic era | the youngest era of the Phanerozoic eon |
inland sea | is a body of water formed when ocean water floods continents |
coal swamp | an oxygen-poor environment where, over time, plant material changes into coal |
supercontinent | an ancient landmass which separated into present-day continents |