Editing Devonian (section)

==Late Devonian extinction==
{{Main|Late Devonian extinction}}
[[File:Extinction Intensity.svg|thumb|The Late Devonian is characterised by three episodes of extinction ("Late D")]]The [[Late Devonian extinction]] is not a single event, but rather is a series of pulsed extinctions at the Givetian-Frasnian boundary, the Frasnian-Famennian boundary, and the Devonian-Carboniferous boundary.<ref name="Becker-2020">{{Citation|last1=Becker|first1=R. T.|title=Chapter 22 - The Devonian Period|date=2020-01-01|url=https://www.sciencedirect.com/science/article/pii/B978012824360200022X|work=Geologic Time Scale 2020|pages=733–810|editor-last=Gradstein|editor-first=Felix M.|publisher=Elsevier|language=en|doi=10.1016/b978-0-12-824360-2.00022-x|isbn=978-0-12-824360-2|access-date=2021-03-19|last2=Marshall|first2=J. E. A.|last3=Da Silva|first3=A. -C.|last4=Agterberg|first4=F. P.|last5=Gradstein|first5=F. M.|last6=Ogg|first6=J. G.|s2cid=241766371|editor2-last=Ogg|editor2-first=James G.|editor3-last=Schmitz|editor3-first=Mark D.|editor4-last=Ogg|editor4-first=Gabi M.|url-access=subscription}}</ref> Together, these are considered one of the "[[Extinction event#The "Big Five" mass extinctions|Big Five]]" mass extinctions in Earth's history.<ref>{{Cite journal|last1=Raup|first1=D. M.|last2=Sepkoski|first2=J. J.|date=1982-03-19|title=Mass Extinctions in the Marine Fossil Record|url=https://www.science.org/doi/10.1126/science.215.4539.1501|journal=Science|language=en|volume=215|issue=4539|pages=1501–1503|doi=10.1126/science.215.4539.1501|pmid=17788674|bibcode=1982Sci...215.1501R|s2cid=43002817|issn=0036-8075|url-access=subscription}}</ref> The Devonian extinction crisis primarily affected the marine community, and selectively affected shallow warm-water organisms rather than cool-water organisms. The most important group to be affected by this extinction event were the reef-builders of the great Devonian reef systems.<ref>{{Cite book|last=McGhee|first=George R.|url=https://www.worldcat.org/oclc/33010274|title=The Late Devonian mass extinction : the Frasnian/Famennian crisis|date=1996|publisher=Columbia University Press|isbn=0-231-07504-9|location=New York|oclc=33010274}}</ref>

Amongst the severely affected marine groups were the brachiopods, trilobites, ammonites, and [[acritarch]]s, and the world saw the disappearance of an estimated 96% of vertebrates like [[conodont]]s and [[Osteichthyes|bony fishes]], and all of the ostracoderms and placoderms.<ref name="Becker-2020" /><ref>[https://carlzimmer.com/after-a-mass-extinction-only-the-small-survive-80/ After a Mass Extinction, Only the Small Survive | Carl Zimmer]</ref> Land plants as well as freshwater species, such as our tetrapod ancestors, were relatively unaffected by the Late Devonian extinction event (there is a counterargument that the Devonian extinctions nearly wiped out the tetrapods<ref>{{cite book |last=McGhee |first=George R. |year=2013 |title=When the invasion of land failed: The legacy of the Devonian extinctions |location=New York |publisher=Columbia University Press |isbn=9780231160568}}</ref>).

The reasons for the Late Devonian extinctions are still unknown, and all explanations remain speculative.<ref>{{Cite journal|last1=Carmichael|first1=Sarah K.|last2=Waters|first2=Johnny A.|last3=Königshof|first3=Peter|last4=Suttner|first4=Thomas J.|last5=Kido|first5=Erika|date=2019-12-01|title=Paleogeography and paleoenvironments of the Late Devonian Kellwasser event: A review of its sedimentological and geochemical expression|url=https://www.sciencedirect.com/science/article/pii/S0921818118306258|journal=Global and Planetary Change|language=en|volume=183|pages=102984|doi=10.1016/j.gloplacha.2019.102984|bibcode=2019GPC...18302984C|s2cid=198415606|issn=0921-8181}}</ref><ref>{{Cite journal|last1=Lu|first1=Man|last2=Lu|first2=YueHan|last3=Ikejiri|first3=Takehitio|last4=Sun|first4=Dayang|last5=Carroll|first5=Richard|last6=Blair|first6=Elliot H.|last7=Algeo|first7=Thomas J.|last8=Sun|first8=Yongge|date=2021-05-15|title=Periodic oceanic euxinia and terrestrial fluxes linked to astronomical forcing during the Late Devonian Frasnian–Famennian mass extinction|journal=Earth and Planetary Science Letters|language=en|volume=562|pages=116839|doi=10.1016/j.epsl.2021.116839|bibcode=2021E&PSL.56216839L|s2cid=233578058|issn=0012-821X|doi-access=free}}</ref><ref>{{Cite journal|last1=Kaiser|first1=Sandra Isabella|last2=Aretz|first2=Markus|last3=Becker|first3=Ralph Thomas|date=2015-11-11|title=The global Hangenberg Crisis (Devonian–Carboniferous transition): review of a first-order mass extinction|url=https://doi.org/10.1144/SP423.9|journal=Geological Society, London, Special Publications|volume=423|issue=1|pages=387–437|doi=10.1144/sp423.9|s2cid=131270834|issn=0305-8719|url-access=subscription}}</ref><ref>{{Citation|last=Racki|first=Grzegorz|title=Chapter 2Toward understanding Late Devonian global events: few answers, many questions|date=2005-01-01|url=https://www.sciencedirect.com/science/article/pii/S0920544605800020|work=Developments in Palaeontology and Stratigraphy|volume=20|pages=5–36|editor-last=Over|editor-first=D. J.|series=Understanding Late Devonian And Permian-Triassic Biotic and Climatic Events|publisher=Elsevier|language=en|doi=10.1016/s0920-5446(05)80002-0|isbn=9780444521279|access-date=2021-03-19|editor2-last=Morrow|editor2-first=J. R.|editor3-last=Wignall|editor3-first=P. B.|url-access=subscription}}</ref> Canadian paleontologist [[Digby McLaren]] suggested in 1969 that the Devonian extinction events were caused by an asteroid impact. However, while there were Late Devonian collision events (see the [[Alamo bolide impact]]), little evidence supports the existence of a large enough Devonian crater.<ref>{{Cite journal|last1=Rendall|last2=Tapanila|date=2020|title=Impact resilience: Ecological recovery of a carbonate factory in the wake of the Late Devonian impact event|url=https://bioone.org/journals/Palaios/volume-35/issue-1/palo.2019.001/IMPACT-RESILIENCE--ECOLOGICAL-RECOVERY-OF-A-CARBONATE-FACTORY-IN/10.2110/palo.2019.001.short|journal=PALAIOS|volume=35|issue=1|pages=12–21|doi=10.2110/palo.2019.001|bibcode=2020Palai..35...12R|s2cid=210944155|url-access=subscription}}</ref>