Editing Pennsylvanian (geology) (section)

==Life==
[[File:USGSBulletin1291 mapofUS MiddlePennTime.png|thumb|Generalized geographic map of the United States in middle Pennsylvanian time]]

===Fungi===
All modern [[class (biology)|classes]] of [[fungus|fungi]] have been found in rocks of Pennsylvanian age.<ref>[[Meredith Blackwell|Blackwell, Meredith]], Vilgalys, Rytas, James, Timothy Y., and Taylor, John W. [http://tolweb.org/Fungi/2377/2008.02.21 Fungi. Eumycota: mushrooms, sac fungi, yeast, molds, rusts, smuts, etc.], February 2008, [[Tree of Life Web Project]]</ref>

=== Invertebrates ===
The major forms of life at this time were the arthropods. Arthropods were far larger than modern ones. ''[[Arthropleura]]'', a giant [[millipede]], was a common sight and the giant [[griffinfly]] ''[[Meganeura]]'' "flew the skies".<ref>{{Cite book|title=Fossil Invertebrates|last=Paul D. Taylor|first=David N. Lewis|publisher=The Natural History Museum; First North American edition|year=2005|isbn=0565091832|pages=160}}</ref> It is commonly considered that is because of high oxygen level, however some of those large arthropod records are also known from period with relatively low oxygen, which suggest high oxygen pressure may not have been a primary reason for their gigantism.<ref>{{Cite journal |last1=Gand |first1=G. |last2=Nel |first2=A. N. |last3=Fleck |first3=G. |last4=Garrouste |first4=R. |date=2008-01-01 |title=The Odonatoptera of the Late Permian Lodève Basin (Insecta) |url=https://revistas.ucm.es/index.php/JIGE/article/view/JIGE0808120115A |journal=Journal of Iberian Geology |language=es |volume=34 |issue=1 |pages=115–122 |issn=1886-7995}}</ref><ref>{{Cite journal |last1=Davies |first1=Neil S. |last2=Garwood |first2=Russell J. |last3=McMahon |first3=William J. |last4=Schneider |first4=Joerg W. |last5=Shillito |first5=Anthony P. |date=2021-12-21 |title=The largest arthropod in Earth history: insights from newly discovered''Arthropleura''remains (Serpukhovian Stainmore Formation, Northumberland, England) |url=http://dx.doi.org/10.1144/jgs2021-115 |journal=Journal of the Geological Society |volume=179 |issue=3 |doi=10.1144/jgs2021-115 |issn=0016-7649}}</ref>

===Vertebrates===
[[Amphibian]]s were diverse and common; some were several meters long as adults. The [[Carboniferous Rainforest Collapse|collapse of the rainforest ecology]] in the mid-Pennsylvanian (between the Moscovian and the Kasimovian) removed many amphibian species that did not survive as well in the cooler, drier conditions. Amniotes, however, prospered due to specific key adaptations.<ref name="SahneyBentonFerry2010RainforestCollapse">{{cite journal | last1= Sahney |first1=S. |last2=Benton |first2=M.J. |last3=Falcon-Lang |first3=H.J. | year=2010 | title= Rainforest collapse triggered Pennsylvanian tetrapod diversification in Euramerica | journal=Geology | volume = 38 | pages = 1079–1082 | doi=10.1130/G31182.1 | issue=12}}</ref> One of the greatest evolutionary innovations of the Carboniferous was the [[amniote]] egg, which allowed for the further exploitation of the land by certain [[tetrapod]]s. These included the earliest [[Sauropsida|sauropsid]] reptiles (''[[Hylonomus]]''), and the earliest known "[[pelycosaur]]" [[synapsid]]s (''[[Archaeothyris]]''). Small lizard-like animals quickly gave rise to many descendants. Amniotes underwent a major evolutionary radiation, in response to the drier climate that followed the rainforest [[Ecological collapse|collapse]].

For some reason, pelycosaurs were able to reach larger sizes before reptiles could, and this trend continued until the [[Permian-Triassic extinction event|end of the Permian]], during which their [[cynodont]] descendants became smaller and [[nocturnal bottleneck|nocturnal]], as the reptilian [[archosaurs]] took over, although [[dicynodonts]] would remain megafaunal until their extinction at the [[Triassic-Jurassic extinction event|end of the Triassic]].<ref name="SahneyBentonFerry2010RainforestCollapse"/><ref name=Kazlev>{{cite web |author=Kazlev MA |year=1998 |url=http://palaeos.com/paleozoic/carboniferous/carboniferous.htm |title=Palaeos Paleozoic: Carboniferous: The Carboniferous Period |access-date=March 30, 2012 |archive-url=https://web.archive.org/web/20120309140141/http://palaeos.com/paleozoic/carboniferous/carboniferous.htm |archive-date=March 9, 2012 |url-status=dead }}</ref> Most pre-rainforest collapse tetrapods remained smaller, probably due to the land being primarily occupied by the gigantic millipedes, scorpions, and flying insects. After the rainforest collapse, the giant arthropods disappeared, allowing amniote tetrapods to achieve larger sizes.