Editing Devonian (section)

===Marine biota===
[[File:Fish evolution.png|thumb|300px|right|Spindle diagram for the evolution of vertebrates<ref>{{cite book |last=Benton |first=M. J. |date=2005 |url=https://books.google.com/books?id=VThUUUtM8A4C&q=Benton+2005+%22%27Vertebrate+Palaeontology%22 |title=Vertebrate Palaeontology |publisher=John Wiley |edition=3rd |isbn=9781405144490 |page=14}}</ref>]]
{{see also|Evolution of fish#Devonian: Age of fishes}}

Sea levels in the Devonian were generally high. Marine faunas continued to be dominated by [[conodonts]],<ref>{{Cite journal |last1=Corradini |first1=Carlo |last2=Corriga |first2=Maria G. |last3=Pondrelli |first3=Monica |last4=Suttner |first4=Thomas J. |date=1 July 2020 |title=Conodonts across the Silurian/Devonian boundary in the Carnic Alps (Austria and Italy) |url=https://www.sciencedirect.com/science/article/pii/S0031018218301718 |journal=[[Palaeogeography, Palaeoclimatology, Palaeoecology]] |series=Global Events impacting COnodont evolution |volume=549 |pages=109097 |doi=10.1016/j.palaeo.2019.02.023 |bibcode=2020PPP...54909097C |issn=0031-0182 |access-date=11 November 2023|url-access=subscription }}</ref> [[bryozoa|bryozoans]],<ref name="InfluenceAtrypid">{{cite journal |last1=Bose |first1=Rituparna |last2=Schneider |first2=Chris L. |last3=Leighton |first3=Lindsey R. |last4=Polly |first4=P. David |date=1 October 2011 |title=Influence of atrypid morphological shape on Devonian episkeletobiont assemblages from the lower Genshaw formation of the Traverse Group of Michigan: A geometric morphometric approach |url=https://www.sciencedirect.com/science/article/abs/pii/S0031018211004305 |journal=[[Palaeogeography, Palaeoclimatology, Palaeoecology]] |volume=310 |issue=3–4 |pages=427–441 |doi=10.1016/j.palaeo.2011.08.004 |bibcode=2011PPP...310..427B |access-date=4 April 2023|url-access=subscription }}</ref> diverse and abundant [[brachiopod]]s,<ref>{{cite journal |last1=Chen |first1=Zhong-Qiang |date=2 September 2023 |title=Devonian–Carboniferous brachiopod zonation in the Tarim Basin, northwest China: implications for biostratigraphy and biogeography |url=https://onlinelibrary.wiley.com/doi/10.1002/gj.967 |journal=[[Geological Journal]] |volume=39 |issue=3–4 |pages=431–458 |doi=10.1002/gj.967 |s2cid=129628791 |access-date=4 April 2023|url-access=subscription }}</ref> the enigmatic [[hederellid]]s,<ref>{{cite journal |last1=Michal |first1=Mergl |year=2021 |title=Dead or alive? Brachiopods and other shells as substrates for endo- and sclerobiont activity in the Early Devonian (Lochkovian) of the Barrandian |url=https://otik.uk.zcu.cz/handle/11025/46568 |journal=Bulletin of Geosciences |volume=96 |issue=4 |pages=401–429 |access-date=4 April 2023}}</ref> [[microconchida|microconchids]],<ref name="InfluenceAtrypid" /> and [[coral]]s.<ref>{{cite journal |last1=Zapalski |first1=Mikołaj K. |last2=Baird |first2=Andrew M. |last3=Bridge |first3=Tom |last4=Jakubowicz |first4=Michał |last5=Daniell |first5=James |date=4 February 2021 |title=Unusual shallow water Devonian coral community from Queensland and its recent analogues from the inshore Great Barrier Reef |journal=Coral Reefs |volume=40 |issue=2 |pages=417–431 |doi=10.1007/s00338-020-02048-9 |s2cid=234012936 |doi-access=free }}</ref><ref>{{cite journal |last1=Zatoń |first1=Michał |last2=Borszcz |first2=Tomasz |last3=Berkowski |first3=Błażej |last4=Rakociński |first4=Michał |last5=Zapalski |first5=Mikołaj K. |last6=Zhuravlev |first6=Andrey V. |date=15 April 2015 |title=Paleoecology and sedimentary environment of the Late Devonian coral biostrome from the Central Devonian Field, Russia |url=https://www.sciencedirect.com/science/article/abs/pii/S0031018215000772 |journal=[[Palaeogeography, Palaeoclimatology, Palaeoecology]] |volume=424 |pages=61–75 |doi=10.1016/j.palaeo.2015.02.021 |bibcode=2015PPP...424...61Z |access-date=4 April 2023|url-access=subscription }}</ref> Lily-like [[crinoid]]s (animals, their resemblance to flowers notwithstanding) were abundant, and [[trilobite]]s were still fairly common. [[Bivalvia|Bivalves]] became commonplace in deep water and outer shelf environments.<ref name=" Nagel-Myers2022">{{cite journal |last1=Nagel-Myers |first1=Judith |date=5 August 2021 |title=An updated look at the taxonomy, stratigraphy, and palaeoecology of the Devonian bivalve genus Ontario Clarke, 1904 (Cardiolidae, Bivalvia) |url=https://link.springer.com/article/10.1007/s12549-021-00491-2? |journal=Palaeobiodiversity and Palaeoenvironments |volume=102 |issue=3 |pages=541–555 |doi=10.1007/s12549-021-00491-2 |s2cid=236921239 |access-date=8 November 2022|url-access=subscription }}</ref> The first ammonites also appeared during or slightly before the early Devonian Period around 400&nbsp;Ma.<ref>{{cite web |title=Palaeos Paleozoic: Devonian: The Devonian Period – 1|url=http://palaeos.com/paleozoic/devonian/devonian.html|website=Palaeos|last1=Kazlev|first1=M. Alan|date=May 28, 1998|access-date=24 January 2019}}</ref> [[Bactritida|Bactritoids]] make their first appearance in the Early Devonian as well; their radiation, along with that of ammonoids, has been attributed by some authors to increased environmental stress resulting from decreasing oxygen levels in the deeper parts of the water column.<ref>{{cite journal |last1=Klug |first1=Christian |last2=Kroeger |first2=Bjoern |last3=Korn |first3=Dieter |last4=Ruecklin |first4=Martin |last5=Schemm-Gregory |first5=Mena |last6=De Baets |first6=Kenneth |last7=Mapes |first7=Royal H. |date=April 2008 |title=Ecological change during the early Emsian (Devonian) in the Tafilalt (Morocco), the origin of the Ammonoidea, and the first African pyrgocystid edrioasteroids, machaerids and phyllocarids |url=https://research-information.bris.ac.uk/en/publications/ecological-change-during-the-early-emsian-devonian-in-the-tafilal |journal=Palaeontographica Abteilung A |volume=283 |issue=4–6 |pages=83–U58 |doi=10.1127/pala/283/2008/83 |bibcode=2008PalAA.283...83K |access-date=8 November 2022|url-access=subscription }}</ref> Among vertebrates, jawless armored fish ([[ostracoderm]]s) declined in diversity, while the jawed fish (gnathostomes) simultaneously increased in both the sea and [[fresh water]]. Armored placoderms were numerous during the early ages of the Devonian Period and became extinct in the Late Devonian, perhaps because of competition for food against the other fish species. Early cartilaginous ([[Chondrichthyes]]) and bony fishes ([[Osteichthyes]]) also become diverse and played a large role within the Devonian seas. The first abundant genus of cartilaginous fish, ''[[Cladoselache]]'', appeared in the oceans during the Devonian Period. The great diversity of fish around at the time has led to the Devonian being given the name "The Age of Fishes" in popular culture.<ref>{{cite journal |last1=Dalton |first1=Rex |title=Hooked on fossils |journal=Nature |date=January 2006 |volume=439 |issue=7074 |pages=262–263 |doi=10.1038/439262a|pmid=16421540 |s2cid=4357313 |doi-access=free }}</ref>

[[File:Gessetal2023_environment_reconstruction.png|thumb|The Devonian period saw the development of early sharks, armoured [[placoderm]]s and various [[lobe-finned fish]]es including the [[Rhipidistia|tetrapod transitional species]]]]

[[File:Diorama of a Devonian seafloor - corals, coiled cephalopod, gastropod, crinoids (44933262614).jpg|thumb|Diorama of a Devonian seafloor]]

The Devonian saw significant expansion in the diversity of [[nekton]]ic marine life driven by the abundance of planktonic microorganisms in the free water column as well as high ecological competition in benthic habitats, which were extremely saturated; this diversification has been labeled the ''Devonian Nekton Revolution'' by many researchers.<ref>{{cite journal |last1=Klug |first1=Christian |last2=Kröger |first2=Björn |last3=Kiessling |first3=Wolfgang |last4=Mullins |first4=Gary L. |last5=Servais |first5=Thomas |last6=Frýda |first6=Jiří |last7=Korn |first7=Dieter |last8=Turner |first8=Susan |date=26 October 2010 |title=The Devonian nekton revolution |url=https://onlinelibrary.wiley.com/doi/abs/10.1111/j.1502-3931.2009.00206.x |journal=Lethaia |volume=43 |issue=4 |pages=465–477 |doi=10.1111/j.1502-3931.2009.00206.x |bibcode=2010Letha..43..465K |access-date=3 September 2022|url-access=subscription }}</ref> However, other researchers have questioned whether this revolution existed at all; a 2018 study found that although the proportion of biodiversity constituted by nekton increased across the boundary between the Silurian and Devonian, it decreased across the span of the Devonian, particularly during the Pragian, and that the overall diversity of nektonic taxa did not increase significantly during the Devonian compared to during other geologic periods, and was in fact higher during the intervals spanning from the Wenlock to the Lochkovian and from the Carboniferous to the Permian. The study's authors instead attribute the increased overall diversity of nekton in the Devonian to a broader, gradual trend of nektonic diversification across the entire Palaeozoic.<ref>{{cite journal |last1=Whalen |first1=Christopher D. |last2=Briggs |first2=Derek E. G. |date=18 July 2018 |title=The Palaeozoic colonization of the water column and the rise of global nekton |journal=Proceedings of the Royal Society B |volume=285 |issue=1883 |pages=1–9 |doi=10.1098/rspb.2018.0883 |pmid=30051837 |pmc=6083262 }}</ref>