Ìgbà Dẹfoníà

The Devonian is a geologic period and system of the Paleozoic Era spanning from 416 to 359.2 ẹgbẹgbẹ̀rún ọdún sẹ́yìn (ICS, 2004,^[5] chart). It is named after Devon, England, where rocks from this period were first studied.

Ìgbà Dẹfoníà 416–359.2 ẹgbẹgbẹ̀rún ọdun sẹ́yìn PreЄ Є O S D C P T J K Pg N
Mean atmospheric O2 content over period duration	ca. 15 Vol %[1] (75 % of modern level)
Mean atmospheric CO2 content over period duration	ca. 2200 ppm[2] (8 times pre-industrial level)
Mean surface temperature over period duration	ca. 20 °C[3] (6 °C above modern level)
Sea level (above present day)	Relatively steady around 180m, gradually falling to 120m through period[4]

During the Devonian Period the pectoral and pelvic fins of lobe-finned fish evolved into legs^[6] as they started to walk on land as tetrapods around 397 Ma.^[7] Various terrestrial arthropods also became well-established.

Itokasi

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.
6. See Tiktaalik.
7. Fossil tracks record 'oldest land-walkers' - BBC News

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