The Silurian is a geologic period and system that extends from the end of the Ordovician Period, about 443.7 ± 1.5 Mya (million years ago), to the beginning of the Devonian Period, about 416.0 ± 2.8 Mya (ICS, 2004,[5] chart). As with other geologic periods, the rock beds that define the period's start and end are well identified, but the exact dates are uncertain by several million years. The base of the Silurian is set at a major extinction event when 60% of marine species were wiped out. See Ordovician-Silurian extinction events.

Ìgbà Sílúríà

Ìgbà Sílúríà
443.7–416 ẹgbẹgbẹ̀rún ọdun sẹ́yìn
Mean atmospheric O2 content over period duration ca. 14 Vol %[1]
(70 % of modern level)
Mean atmospheric CO2 content over period duration ca. 4500 ppm[2]
(16 times pre-industrial level)
Mean surface temperature over period duration ca. 17 °C[3]
(3 °C above modern level)
Sea level (above present day) Around 180m, with short-term negative excursions[4]


  1. Image:Sauerstoffgehalt-1000mj.svg
  2. Image:Phanerozoic Carbon Dioxide.png
  3. Image:All palaeotemps.png
  4. Haq, B. U.; Schutter, SR (2008). "A Chronology of Paleozoic Sea-Level Changes". Science 322 (5898): 64–68. doi:10.1126/science.1161648. PMID 18832639. 
  5. Gradstein, Felix M.; Ogg, J. G.; Smith, A. G. (2004). A Geologic Time Scale 2004. Cambridge: Cambridge University Press. ISBN 0521786738. 
Preceded by Proterozoic Eon 542 Ma - Phanerozoic Eon - Present
542 Ma - Paleozoic Era - 251 Ma 251 Ma - Mesozoic Era - 65 Ma 65 Ma - Cenozoic Era - Present
Kámbríà Ọ̀rdòfísíà Sílúríà Dẹfoníà Eléèédú Pẹ́rmíà Tríásíkì Jùrásíkì Ẹlẹ́fun Ìbíniàtijọ́ Ìbíniọ̀tun Quaternary