Editing Phanerozoic (section)

====Carboniferous Period====
{{Main|Carboniferous}}
[[File:Proterogyrinus DB.jpg|thumb|239x239px|''[[Proterogyrinus]]'', a Carboniferous amphibian (non-[[amniote]] tetrapod)]]
The Carboniferous spans from 359 million to 299&nbsp;million years ago.<ref>{{cite web |url=http://www.geocraft.com/WVFossils/Carboniferous_climate.html |title=Carboniferous Era|author=Monte Hieb|work=unknown|url-status=live|archive-url=https://web.archive.org/web/20141220004649/http://www.geocraft.com/WVFossils/Carboniferous_climate.html|archive-date=20 December 2014}}</ref> Tropical [[swamp]]s dominated the Earth, and the large amounts of trees [[carbon sequestration|sequestered]] much of the carbon that became [[coal]] deposits (hence the name Carboniferous and the term "[[coal forest]]"). About 90% of all coal beds were deposited in the Carboniferous and Permian periods, which represent just 2% of the Earth's geologic history.<ref>{{cite book |last1=McGhee |first1=George R. |title=Carboniferous giants and mass extinction : the late Paleozoic Ice Age world |date=2018 |publisher=Columbia University Press |location=New York |isbn=9780231180979 |pages=98}}</ref> The high [[dioxygen in biological reactions|oxygen]] levels caused by these wetland rainforests allowed arthropods, normally limited in size by [[respiratory system of insects|their respiratory systems]], to proliferate and increase in size. Tetrapods also diversified during the Carboniferous as [[semiaquatic]] [[amphibian]]s such as the [[temnospondyl]]s, and one lineage developed [[extraembryonic membrane]]s that allowed their [[egg]]s to survive outside of the water. These tetrapods, the [[amniotes]], included the first [[sauropsid]]s (which evolved the [[reptile]]s, [[dinosaur]]s and [[bird]]s) and [[synapsid]]s (the ancestors of [[mammals]]). Throughout the Carboniferous, there was a cooling pattern, which eventually led to the glaciation of [[Gondwana]] as much of it was situated around the [[South Pole]]. This event was known as the [[Permo-Carboniferous Glaciation]] and resulted in a major loss of coal forests, known as the [[Carboniferous rainforest collapse]].<ref>{{cite web|url=http://www.ucmp.berkeley.edu/carboniferous/carboniferous.php|title=Carboniferous|author=University of California|work=University of California|url-status=live|archive-url=https://web.archive.org/web/20120210070913/http://www.ucmp.berkeley.edu/carboniferous/carboniferous.php|archive-date=10 February 2012}}</ref>