Back Paleosoïkum AF Paläozoikum ALS حقبة الحياة القديمة Arabic Era Paleozoica AST Paleozoy AZ Палеазой BE Палеазой BE-X-OLD Палеозой Bulgarian প্যালিওজোয়িক Bengali/Bangla Paleozoeg BR
| Paleozoic | ||||||
|---|---|---|---|---|---|---|
| Chronology | ||||||
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| Etymology | ||||||
| Name formality | Formal | |||||
| Alternate spelling(s) | Palaeozoic | |||||
| Usage information | ||||||
| Celestial body | Earth | |||||
| Regional usage | Global (ICS) | |||||
| Time scale(s) used | ICS Time Scale | |||||
| Definition | ||||||
| Chronological unit | Era | |||||
| Stratigraphic unit | Erathem | |||||
| Lower boundary definition | Appearance of the Ichnofossil Treptichnus pedum | |||||
| Lower boundary GSSP | Fortune Head section, Newfoundland, Canada 47°04′34″N 55°49′52″W / 47.0762°N 55.8310°W | |||||
| Lower GSSP ratified | 1992 | |||||
| Upper boundary definition | First appearance of the Conodont Hindeodus parvus. | |||||
| Upper boundary GSSP | Meishan, Zhejiang, China 31°04′47″N 119°42′21″E / 31.0798°N 119.7058°E | |||||
| Upper GSSP ratified | 2001 | |||||
The Paleozoic (or Palaeozoic) Era is the earliest of three geologic eras of the Phanerozoic Eon. The name Paleozoic (IPA: /ˌpæli.əˈzoʊ.ɪk, -i.oʊ-, ˌpeɪ-/ pal-ee-ə-ZOH-ik, -ee-oh-, pay-;[1][2]) was coined by the British geologist Adam Sedgwick in 1838[3] by combining the Greek words palaiós (παλαιός, "old") and zōḗ (ζωή), "life", meaning "ancient life"[4]).
It is the longest of the Phanerozoic eras, lasting from 538.8 to 251.902 million years ago, and is subdivided into six geologic periods (from oldest to youngest):
The Paleozoic comes after the Neoproterozoic Era of the Proterozoic Eon and is followed by the Mesozoic Era.
The Paleozoic was a time of dramatic geological, climatic, and evolutionary change. The Cambrian witnessed the most rapid and widespread diversification of life in Earth's history, known as the Cambrian explosion, in which most modern phyla first appeared. Arthropods, molluscs, fish, amphibians, reptiles, and synapsids all evolved during the Paleozoic. Life began in the ocean but eventually transitioned onto land, and by the late Paleozoic, great forests of primitive plants covered the continents, many of which formed the coal beds of Europe and eastern North America. Towards the end of the era, large, sophisticated synapsids and diapsids were dominant and the first modern plants (conifers) appeared.
The Paleozoic Era ended with the largest extinction event of the Phanerozoic Eon,[a] the Permian–Triassic extinction event. The effects of this catastrophe were so devastating that it took life on land 30 million years into the Mesozoic Era to recover.[5] Recovery of life in the sea may have been much faster.[6]
- ^ "Paleozoic". Dictionary.com Unabridged (Online). n.d.
- ^ "Paleozoic". Merriam-Webster Dictionary.
- ^ Sedgwick, Adam (1838). "A synopsis of the English series of stratified rocks inferior to the Old Red Sandstone – with an attempt to determine the successive natural groups and formations". Proceedings of the Geological Society of London. 2 (58): 675–685, esp. p. 685.
- ^ "Paleozoic". Online Etymology Dictionary.
- ^ Sahney, S. & Benton, M.J. (2008). "Recovery from the most profound mass extinction of all time". Proceedings of the Royal Society B: Biological Sciences. 275 (1636): 759–65. doi:10.1098/rspb.2007.1370. PMC 2596898. PMID 18198148.
- ^ "Dead-ammonite bounce". Science & technology. The Economist. 5 July 2010.
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