顯生宙(Phanerozoic Eon)距今有5億4000萬－5億4200萬年，開始於古生代 (Paleozoic Era)的寒武紀時期 (Cambrian period)。對於顯生宙的定義，其特點為多細胞動物和植物的衍生（即使多細胞生物在元古宙 (Proterozoic Eon)晚期已確定存在）。實際上“ phanerozoic”這字有“顯露出生命”或“可看見生命”的含意（希臘語 phanero-, phaner-, -phane, -phanic, -phanous, and -phany，都包含有顯現、可看見、表露或打開的意思）。顯生宙的命名來自這一地質時期開始有生命的跡象，但據最新的研究顯示，地球上的生物在顯生宙開始前的三十億年（至少有單細胞生物）就已經出現了。前寒武紀 (Precambrian) 是指出現在顯生宙之前，由數個宙（冥古宙、太古宙和元古宙）所合併的地質年代的總稱。 多細胞生物的形成引發人類對顯生宙的興趣並大大提高對其他星球是否也有類似顯生宙時期的現象產生極濃厚的關注。
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相關連結
1. An introduction to the periods of the Phanerozoic provided by Chris at his enjoyable peripatus site.
2. This page at the University of California at Berkeley explains how we invented the geologic time scale.
3. Frederick M. Soster's very fine introduction to geologic time.
4. Don McBride offers a historical timeline covering the geological history of the planet. Interestingly, Don started the site using Hypercard, a program the authors of the historylines.net website also used in the 1980s and early 1990s before html came along.
5. As usual, the Paleos page about the Phanerozoic Eon is quite enjoyable.
This work by Eric & Chun-Chih Hadley-Ives is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International License.