File:Geologic time and mass extinctions.png
Geologic_time_and_mass_extinctions.png (288 × 481 pixels, file size: 3 KB, MIME type: image/png)
The Quaternary period[edit]
I checked several reputable online resources before creating this image. The Illinois State Geological Survey glossary entry for the Cenozoic era cautions "Some authors do not include the Quaternary, considering it a separate era." The Geology department at Eastern Illinois University defines the Quaternary as the "Period of geologic time from about 2 million years ago until the present," while the United States Geological Survey website says it covers the last 1.6 million years.
If the Quaternary period was shown at the same scale as the other periods it wouldn't be visible on this chart (less than 1 pixel high), so I placed it on a color gradient.
Margin of error for dates[edit]
The table below shows the discrepancies for the dates of the five major mass extinctions from a small selection of sources. To avoid making the image too clutered, I included just two date ranges for the mass extinctions whose dates vary most widely between the different sources.
| The five major Mass Extinctions | Source | ||||
|---|---|---|---|---|---|
| (millions of years ago) | |||||
| 65 | 200 | 251 | 360 | 444 | Wikipedia's Extinction event article (May 18, 2006) |
| 65 | 210 | 245 | 370 | 440 | The Sixth Extinction -- American Institute of Biological Sciences |
| 65 | 208 | 245 | 360 | 438 | College of Natural Sciences, University of Hawaii |
| 67 | 205 | 251 | 370 | 440 | A Brief History of the Universe -- University of California at Riverside |
| 65 | 205 | 245 | 367 | 438 | Scientific American special issue:"Life in the Universe" (1994) |
The author of the Sixth Mass Extinction article, paleontologist Dr. Niles Eldredge, is Curator-in-Chief of the permanent "Hall of Biodiversity" exhibition at the American Museum of Natural History. The ActionBioscience.org website belongs to the American Institute of Biological Sciences.
Summary[edit]
| Description |
Geologic time and mass extinction events. |
|---|---|
| Source |
self-made |
| Date |
2006-05-17 |
| Author |
Kerry Watson -- Bookish |
| Permission (Reusing this file) |
GFDL (self made) |
| Other versions | None |
Licensing[edit]
 | I, the creator of this work, hereby grant the permission to copy, distribute and/or modify this document under the terms of the GNU Free Documentation License, Version 1.2 or any later version published by the Free Software Foundation; with no Invariant Sections, no Front-Cover Texts, and no Back-Cover Texts. Subject to disclaimers. |
   | This work is licensed under the Creative Commons Attribution-ShareAlike 3.0 License. This licensing tag was added to this file as part of the GFDL licensing update. |
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File history
Click on a date/time to view the file as it appeared at that time.
| Date/Time | Thumbnail | Dimensions | User | Comment | |
|---|---|---|---|---|---|
| current | 04:50, 19 May 2006 | | 288 × 481 (3 KB) | Bookish (talk | contribs) | Reverted to earlier revision |
| 04:49, 19 May 2006 |  | 288 × 481 (3 KB) | Bookish (talk | contribs) | Reverted to earlier revision | |
| 19:42, 18 May 2006 |  | 288 × 481 (3 KB) | Bookish (talk | contribs) | ||
| 15:41, 18 May 2006 |  | 288 × 481 (3 KB) | Bookish (talk | contribs) | ||
| 12:17, 17 May 2006 |  | 288 × 481 (3 KB) | Bookish (talk | contribs) | == Summary == {{Information| |Description = Geologic time and mass extinction events. |Source = self-made |Date = 2006-05-17 |Author = Kerry Watson -- Bookish |Permission = GFDL (self made) |other_versions = None}} == Licensing == { |
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