Editing Jurassic (section)

=== Marine invertebrates ===

==== End-Triassic extinction ====
During the end-Triassic extinction, 46%–72% of all marine genera became extinct. The effects of the end Triassic extinction were greatest at tropical latitudes and were more severe in Panthalassa than the Tethys or Boreal oceans. Tropical reef ecosystems collapsed during the event, and would not fully recover until much later in the Jurassic. [[Sessility (motility)|Sessile]] [[filter feeder]]s and [[photosymbiotic]] organisms were among those most severely affected.<ref>{{Cite journal|last1=Dunhill|first1=Alexander M.|last2=Foster|first2=William J.|last3=Sciberras|first3=James|last4=Twitchett|first4=Richard J.|date=January 2018|editor-last=Hautmann|editor-first=Michael|title=Impact of the Late Triassic mass extinction on functional diversity and composition of marine ecosystems |journal=Palaeontology|language=en|volume=61|issue=1|pages=133–148|doi=10.1111/pala.12332|bibcode=2018Palgy..61..133D |doi-access=free}}</ref>

==== Marine ecosystems ====
Having declined at the Triassic–Jurassic boundary, reefs substantially expanded during the Late Jurassic, including both [[sponge reef]]s and [[scleractinia]]n [[coral reef]]s. Late Jurassic reefs were similar in form to modern reefs but had more microbial carbonates and hypercalcified [[sponge]]s, and had weak biogenic binding. Reefs sharply declined at the close of the Jurassic,<ref>{{Cite journal|last=Kiessling|first=Wolfgang|date=December 2009|title=Geologic and Biologic Controls on the Evolution of Reefs|url=http://www.annualreviews.org/doi/10.1146/annurev.ecolsys.110308.120251|journal=Annual Review of Ecology, Evolution, and Systematics|language=en|volume=40|issue=1|pages=173–192|doi=10.1146/annurev.ecolsys.110308.120251|issn=1543-592X}}</ref> which caused an associated drop in diversity in [[Decapoda|decapod]] crustaceans.<ref name="Klompmaker-2013">{{Cite journal|last1=Klompmaker|first1=A. A.|last2=Schweitzer|first2=C. E.|last3=Feldmann|first3=R. M.|last4=Kowalewski|first4=M.|date=2013-11-01|title=The influence of reefs on the rise of Mesozoic marine crustaceans|url=https://pubs.geoscienceworld.org/geology/article/41/11/1179-1182/131064|journal=Geology|language=en|volume=41|issue=11|pages=1179–1182|doi=10.1130/G34768.1|bibcode=2013Geo....41.1179K|issn=0091-7613}}</ref> The earliest planktonic foraminifera, which constitute the suborder [[Globigerinina]], are known from the late Early Jurassic (mid-Toarcian) of the western Tethys, expanding across the whole Tethys by the Middle Jurassic and becoming globally distributed in tropical latitudes by the Late Jurassic.<ref>{{Cite journal|last1=Hudson|first1=Wendy|last2=Hart|first2=Malcolm B.|last3=Smart|first3=Christopher W.|date=2009-01-01|title=Palaeobiogeography of early planktonic foraminifera|url=https://pubs.geoscienceworld.org/sgf/bsgf/article/180/1/27/123101/Palaeobiogeography-of-early-planktonic|journal=Bulletin de la Société Géologique de France|language=en|volume=180|issue=1|pages=27–38|doi=10.2113/gssgfbull.180.1.27|issn=1777-5817}}</ref> [[Coccolithophore]]s and [[dinoflagellate]]s, which had first appeared during the Triassic, radiated during the Early to Middle Jurassic, becoming prominent members of the [[phytoplankton]].<ref>{{Cite journal|last1=Wiggan|first1=Nickolas J.|last2=Riding|first2=James B.|last3=Fensome|first3=Robert A.|last4=Mattioli|first4=Emanuela|date=2018-05-01|title=The Bajocian (Middle Jurassic): A key interval in the early Mesozoic phytoplankton radiation|url=http://www.sciencedirect.com/science/article/pii/S0012825217305214|journal=Earth-Science Reviews|language=en|volume=180|pages=126–146|bibcode=2018ESRv..180..126W|doi=10.1016/j.earscirev.2018.03.009|issn=0012-8252}}</ref> [[Microconchida|Microconchid]] tube worms, the last remaining order of [[Tentaculita]], a group of animals of uncertain affinities that were convergent on ''[[Spirorbis]]'' tube worms, were rare after the Triassic and had become reduced to the single genus ''[[Punctaconchus]],'' which became extinct in the late Bathonian.<ref>{{Cite journal|last1=Zatoń|first1=M.|last2=Taylor|first2=P.D.|date=2009-12-31|title=Microconchids (Tentaculita) from the Middle Jurassic of Poland|url=http://www.geology.cz/bulletin/contents/art1167|journal=Bulletin of Geosciences|language=en|pages=653–660|doi=10.3140/bull.geosci.1167|issn=1802-8225|doi-access=free}}</ref> The oldest known [[diatom]] is from Late Jurassic–aged amber from Thailand, assigned to the living genus ''[[Hemiaulus]].''<ref>{{Cite journal|last1=Girard|first1=Vincent|last2=Saint Martin|first2=Simona|last3=Buffetaut|first3=Eric|last4=Saint Martin|first4=Jean-Paul|last5=Néraudeau|first5=Didier|last6=Peyrot|first6=Daniel|last7=Roghi|first7=Guido|last8=Ragazzi|first8=Eugenio|last9=Suteethorn|first9=Varavudh|date=2020|editor-last=Saint Martin|editor-first=J.-P.|editor2-last=Saint Martin|editor2-first=S.|title=Thai amber: insights into early diatom history?|journal=BSGF – Earth Sciences Bulletin|volume=191|pages=23|doi=10.1051/bsgf/2020028|issn=1777-5817|doi-access=free|hdl=11577/3391076|hdl-access=free}}</ref>

==== Echinoderms ====
[[Crinoid]]s diversified throughout the Jurassic, reaching their peak Mesozoic diversity during the Late Jurassic, primarily due to the radiation of sessile forms belonging to the orders [[Cyrtocrinida]] and [[Millericrinida]].<ref>{{Cite journal|last1=Gorzelak|first1=Przemysław|last2=Salamon|first2=Mariusz A.|last3=Trzęsiok|first3=Dawid|last4=Lach|first4=Rafał|last5=Baumiller|first5=Tomasz K.|date=April 2016|title=Diversity dynamics of post-Palaeozoic crinoids – in quest of the factors affecting crinoid macroevolution|url=https://onlinelibrary.wiley.com/doi/10.1111/let.12141|journal=Lethaia|language=en|volume=49|issue=2|pages=231–244|doi=10.1111/let.12141|bibcode=2016Letha..49..231G }}</ref> [[Sea urchin|Echinoids]] (sea urchins) underwent substantial diversification beginning in the Early Jurassic, primarily driven by the radiation of irregular (asymmetrical) forms, which were adapting to deposit feeding. Rates of diversification sharply dropped during the Late Jurassic.<ref>{{Cite journal|last1=Hopkins|first1=Melanie J.|last2=Smith|first2=Andrew B.|date=2015-03-24|title=Dynamic evolutionary change in post-Paleozoic echinoids and the importance of scale when interpreting changes in rates of evolution|journal=Proceedings of the National Academy of Sciences|language=en|volume=112|issue=12|pages=3758–3763|doi=10.1073/pnas.1418153112|issn=0027-8424|pmc=4378421|pmid=25713369|bibcode=2015PNAS..112.3758H|doi-access=free}}</ref>

==== Crustaceans ====
[[File:Eryon cuvieri Solnhofen.jpg|thumb|''[[Eryon]],'' a [[polychelida]]n decapod crustacean from the Late Jurassic of Germany.]]
The Jurassic was a significant time for the evolution of [[Decapoda|decapods]].<ref name="Klompmaker-2013" /> The first true crabs ([[Crab|Brachyura]]) are known from the Early Jurassic, with the earliest being ''[[Eocarcinus|Eocarcinus praecursor]]'' from the early Pliensbachian of England, which lacked the crab-like morphology ([[carcinisation]]) of modern crabs,<ref>{{Cite journal|last=Scholtz|first=Gerhard|date=November 2020|title=Eocarcinus praecursor Withers, 1932 (Malacostraca, Decapoda, Meiura) is a stem group brachyuran|journal=Arthropod Structure & Development|language=en|volume=59|pages=100991|doi=10.1016/j.asd.2020.100991|pmid=32891896|doi-access=free|bibcode=2020ArtSD..5900991S }}</ref> and [[Eoprosopon|''Eoprosopon klugi'']] from the late Pliensbachian of Germany, which may belong to the living family [[Homolodromiidae]].<ref>{{Cite journal|last1=Schweitzer|first1=Carrie E.|last2=Feldmann|first2=Rodney M.|date=2010-05-01|title=The Oldest Brachyura (Decapoda: Homolodromioidea: Glaessneropsoidea) Known to Date (Jurassic)|journal=Journal of Crustacean Biology|volume=30|issue=2|pages=251–256|doi=10.1651/09-3231.1|s2cid=84707572|issn=0278-0372|doi-access=free|bibcode=2010JCBio..30..251F }}</ref> Most Jurassic crabs are known only from [[carapace]] pieces, which makes it difficult to determine their relationships.<ref name="Guinot-2019">{{Cite journal|last=Guinot|first=Danièle|date=2019-11-14|title=New hypotheses concerning the earliest brachyurans (Crustacea, Decapoda, Brachyura)|journal=Geodiversitas|volume=41|issue=1|pages=747|doi=10.5252/geodiversitas2019v41a22|s2cid=214220075|issn=1280-9659|doi-access=free|bibcode=2019Geodv..41..747G }}</ref> While rare in the Early and Middle Jurassic, crabs became abundant during the Late Jurassic as they expanded from their ancestral silty sea floor habitat into hard substrate habitats like reefs, with crevices in reefs providing refuge from predators.<ref name="Guinot-2019" /><ref name="Klompmaker-2013" /> [[Hermit crab]]s also first appeared during the Jurassic, with the earliest known being ''[[Schobertella|Schobertella hoelderi]]'' from the late Hettangian of Germany.<ref>{{Cite journal|last1=Fraaije|first1=René|last2=Schweigert|first2=Günter|last3=Nützel|first3=Alexander|last4=Havlik|first4=Philipe|date=2013-01-01|title=New Early Jurassic hermit crabs from Germany and France|journal=Journal of Crustacean Biology|language=en|volume=33|issue=6|pages=802–817|doi=10.1163/1937240X-00002191|issn=0278-0372|doi-access=free|bibcode=2013JCBio..33..802F }}</ref> Early hermit crabs are associated with ammonite shells rather than those of gastropods.<ref>{{Cite journal|last=Mironenko|first=Aleksandr|date=January 2020|title=A hermit crab preserved inside an ammonite shell from the Upper Jurassic of central Russia: Implications to ammonoid palaeoecology|journal=Palaeogeography, Palaeoclimatology, Palaeoecology|language=en|volume=537|pages=109397|doi=10.1016/j.palaeo.2019.109397|bibcode=2020PPP...53709397M|doi-access=free}}</ref> [[Glypheidea|Glypheids]], which today are only known from two species, reached their peak diversity during the Jurassic, with around 150 species out of a total fossil record of 250 known from the period.<ref>{{Cite journal|last1=Bracken-Grissom|first1=Heather D.|last2=Ahyong|first2=Shane T.|last3=Wilkinson|first3=Richard D.|last4=Feldmann|first4=Rodney M.|last5=Schweitzer|first5=Carrie E.|last6=Breinholt|first6=Jesse W.|last7=Bendall|first7=Matthew|last8=Palero|first8=Ferran|last9=Chan|first9=Tin-Yam|last10=Felder|first10=Darryl L.|last11=Robles|first11=Rafael|date=2014-07-01|title=The Emergence of Lobsters: Phylogenetic Relationships, Morphological Evolution and Divergence Time Comparisons of an Ancient Group (Decapoda: Achelata, Astacidea, Glypheidea, Polychelida)|url=https://academic.oup.com/sysbio/article/63/4/457/2847939|journal=Systematic Biology|language=en|volume=63|issue=4|pages=457–479|doi=10.1093/sysbio/syu008|pmid=24562813|issn=1063-5157|doi-access=free}}</ref> Jurassic barnacles were of low diversity compared to present,<ref>{{Cite journal|last1=Chan|first1=Benny K K|last2=Dreyer|first2=Niklas|last3=Gale|first3=Andy S|last4=Glenner|first4=Henrik|last5=Ewers-Saucedo|first5=Christine|last6=Pérez-Losada|first6=Marcos|last7=Kolbasov|first7=Gregory A|last8=Crandall|first8=Keith A|last9=Høeg|first9=Jens T|date=2021-02-25|title=The evolutionary diversity of barnacles, with an updated classification of fossil and living forms|journal=Zoological Journal of the Linnean Society|volume=193|issue=3|pages=789–846|doi=10.1093/zoolinnean/zlaa160|issn=0024-4082|doi-access=free|hdl=11250/2990967|hdl-access=free}}</ref> but several important evolutionary innovations are known, including the first appearances of calcite shelled forms and species with an epiplanktonic mode of life.<ref>{{Cite journal|last1=Gale|first1=Andy|last2=Schweigert|first2=Günter|date=January 2016|editor-last=Hautmann|editor-first=Michael|title=A new phosphatic-shelled cirripede (Crustacea, Thoracica) from the Lower Jurassic (Toarcian) of Germany – the oldest epiplanktonic barnacle|journal=Palaeontology|language=en|volume=59|issue=1|pages=59–70|doi=10.1111/pala.12207|bibcode=2016Palgy..59...59G |s2cid=128383968 |doi-access=free}}</ref>

==== Brachiopods ====
[[Brachiopod]] diversity declined during the Triassic–Jurassic extinction. Spire-bearing brachiopods ([[Spiriferinida]] and [[Athyridida]]) did not recover their biodiversity, becoming extinct in the TOAE.<ref name="Vörös-2016">{{Cite journal|last1=Vörös|first1=Attila|last2=Kocsis|first2=Ádám T.|last3=Pálfy|first3=József|date=September 2016|title=Demise of the last two spire-bearing brachiopod orders (Spiriferinida and Athyridida) at the Toarcian (Early Jurassic) extinction event|url=https://linkinghub.elsevier.com/retrieve/pii/S0031018216302140|journal=Palaeogeography, Palaeoclimatology, Palaeoecology|language=en|volume=457|pages=233–241|bibcode=2016PPP...457..233V|doi=10.1016/j.palaeo.2016.06.022}}</ref> [[Rhynchonellida]] and [[Terebratulida]] also declined during the Triassic–Jurassic extinction but rebounded during the Early Jurassic; neither clade underwent much morphological variation.<ref>{{Cite journal|last1=Vörös|first1=Attila|last2=Kocsis|first2=Ádám T.|last3=Pálfy|first3=József|date=2019|title=Mass extinctions and clade extinctions in the history of brachiopods: Brief review and a post-Paleozoic case study|url=https://riviste.unimi.it/index.php/RIPS/article/view/12184|journal=Rivista Italiana di Paleontologia e Stratigrafia|language=en|volume=125|issue=3|doi=10.13130/2039-4942/12184|issn=2039-4942|access-date=2020-12-25|archive-date=2020-09-01|archive-url=https://web.archive.org/web/20200901035135/https://riviste.unimi.it/index.php/RIPS/article/view/12184|url-status=dead}}</ref> Brachiopods substantially declined in the Late Jurassic; the causes are poorly understood. Proposed reasons include increased predation, competition with bivalves, enhanced [[bioturbation]] or increased [[grazing pressure]].<ref>{{Cite journal|last1=Manojlovic|first1=Marko|last2=Clapham|first2=Matthew E.|date=2020-11-23|title=The role of bioturbation-driven substrate disturbance in the Mesozoic brachiopod decline|journal=Paleobiology|volume=47|language=en|pages=86–100|doi=10.1017/pab.2020.50|issn=0094-8373|doi-access=free}}</ref>

==== Bryozoans ====
Like the preceding Triassic, [[bryozoa]]n diversity was relatively low compared to the Paleozoic. The vast majority of Jurassic bryozoans are members of [[Cyclostomatida]], which experienced a radiation during the Middle Jurassic, with all Jurassic representatives belonging to the suborders [[Tubuliporina]] and [[List of Cyclostomatida families|Cerioporina]]. [[Cheilostomata]], the dominant group of modern bryozoans, first appeared during the Late Jurassic.<ref>{{Cite journal|last1=Taylor|first1=Paul D.|last2=Ernst|first2=Andrej|date=June 2008|title=Bryozoans in transition: The depauperate and patchy Jurassic biota|url=https://linkinghub.elsevier.com/retrieve/pii/S0031018208001491|journal=Palaeogeography, Palaeoclimatology, Palaeoecology|language=en|volume=263|issue=1–2|pages=9–23|doi=10.1016/j.palaeo.2008.01.028|bibcode=2008PPP...263....9T }}</ref>

==== Molluscs ====
===== Gastropods =====
Marine gastropods were significantly affected by the T-J extinction, with around 56% of genera going extinct, with [[Neritimorpha]] being particularly strongly effected, while [[Heterobranchia]] suffered much lower losses than other groups.<ref>{{Cite journal |last1=Ferrari |first1=Mariel |last2=Hautmann |first2=Michael |date=2022-11-02 |editor-last=Kiel |editor-first=Steffen |title=Gastropods underwent a major taxonomic turnover during the end-Triassic marine mass extinction event |journal=PLOS ONE |language=en |volume=17 |issue=11 |pages=e0276329 |doi=10.1371/journal.pone.0276329 |doi-access=free |issn=1932-6203 |pmc=9629647 |pmid=36322518|bibcode=2022PLoSO..1776329F }}</ref> While present, the diversity of [[Freshwater snail|freshwater]] and [[land snail]]s was much lower during the Jurassic than in contemporary ecosystems, with the diversity of these groups not reaching levels comparable to modern times until the following Cretaceous.<ref>{{Cite journal |last=Neubauer |first=Thomas A. |date=February 2024 |title=The fossil record of freshwater Gastropoda – a global review |journal=Biological Reviews |language=en |volume=99 |issue=1 |pages=177–199 |doi=10.1111/brv.13016 |issn=1464-7931|doi-access=free |pmid=37698140 }}</ref>

===== Bivalves =====
The end-Triassic extinction had a severe impact on bivalve diversity, though it had little impact on bivalve ecological diversity. The extinction was selective, having less of an impact on deep burrowers, but there is no evidence of a differential impact between surface-living (epifaunal) and burrowing (infaunal) bivalves.<ref>{{Cite journal|last1=Ros|first1=Sonia|last2=De Renzi|first2=Miquel|last3=Damborenea|first3=Susana E.|last4=Márquez-Aliaga|first4=Ana|date=November 2011|title=Coping between crises: Early Triassic–early Jurassic bivalve diversity dynamics|url=https://linkinghub.elsevier.com/retrieve/pii/S0031018211004573|journal=Palaeogeography, Palaeoclimatology, Palaeoecology|language=en|volume=311|issue=3–4|pages=184–199|doi=10.1016/j.palaeo.2011.08.020|bibcode=2011PPP...311..184R|hdl=11336/81358 |hdl-access=free}}</ref> Bivalve family level diversity after the Early Jurassic was static, though genus diversity experienced a gradual increase throughout the period.<ref>{{Cite journal|last1=Mondal|first1=Subhronil|last2=Harries|first2=Peter J.|date=February 2016|title=The Effect of Taxonomic Corrections on Phanerozoic Generic Richness Trends in Marine Bivalves with a Discussion on the Clade's Overall History|url=https://www.cambridge.org/core/product/identifier/S0094837315000354/type/journal_article|journal=Paleobiology|language=en|volume=42|issue=1|pages=157–171|doi=10.1017/pab.2015.35|bibcode=2016Pbio...42..157M |s2cid=87260961|issn=0094-8373}}</ref> [[Rudists]], the dominant reef-building organisms of the Cretaceous, first appeared in the Late Jurassic (mid-Oxfordian) in the northern margin of the western Tethys, expanding to the eastern Tethys by the end of the Jurassic.<ref>{{Cite journal|last1=Sha|first1=J.|last2=Cestari|first2=R.|last3=Fabbi|first3=S.|date=April 2020|title=Paleobiogeographic distribution of rudist bivalves (Hippuritida) in the Oxfordian–early Aptian (Late Jurassic–Early Cretaceous)|url=https://linkinghub.elsevier.com/retrieve/pii/S0195667119302782|journal=Cretaceous Research|language=en|volume=108|pages=104289|doi=10.1016/j.cretres.2019.104289|bibcode=2020CrRes.10804289S |s2cid=210248232}}</ref>

===== Cephalopods =====
[[File:Proteroctopus ribeti.jpg|thumb|Fossil specimen of ''[[Proteroctopus]]'' from the Middle Jurassic of France, formerly thought to be world's oldest known octopus]]Ammonites were devastated by the end-Triassic extinction, with only a handful of genera belonging to the family [[Psiloceratidae]] of the suborder [[Phylloceratina]] surviving and becoming ancestral to all later Jurassic and Cretaceous ammonites. Ammonites explosively diversified during the Early Jurassic, with the orders [[Psiloceratina]], [[Ammonitina]], [[Lytoceratina]], [[Haploceratoidea|Haploceratina]], [[Perisphinctoidea|Perisphinctina]] and [[Ancyloceratina]] all appearing during the Jurassic. Ammonite faunas during the Jurassic were regional, being divided into around 20 distinguishable provinces and subprovinces in two realms, the northern high latitude Pan-Boreal realm, consisting of the Arctic, northern Panthalassa and northern Atlantic regions, and the equatorial–southern Pan-Tethyan realm, which included the Tethys and most of Panthalassa.<ref>{{Cite journal |last=Page |first=Kevin N. |date=January 2008 |title=The evolution and geography of Jurassic ammonoids |url=https://linkinghub.elsevier.com/retrieve/pii/S001678780880257X |journal=Proceedings of the Geologists' Association |language=en |volume=119 |issue=1 |pages=35–57 |doi=10.1016/S0016-7878(08)80257-X|bibcode=2008PrGA..119...35P }}</ref> Ammonite diversifications occurred coevally with [[marine transgression]]s, while their diversity nadirs occurred during [[marine regression]]s.<ref>{{cite journal |last1=Sandoval |first1=José |last2=O'Dogherty |first2=Jean |last3=Guex |first3=Jean |date=1 August 2001 |title=Evolutionary Rates of Jurassic Ammonites in Relation to Sea-level Fluctuations |url=https://pubs.geoscienceworld.org/sepm/palaios/article-abstract/16/4/311/114327/Evolutionary-Rates-of-Jurassic-Ammonites-in |journal=[[PALAIOS]] |volume=16 |issue=4 |pages=311–335 |doi=10.1669/0883-1351(2001)016<0311:EROJAI>2.0.CO;2 |bibcode=2001Palai..16..311S |s2cid=129982065 |access-date=26 August 2023}}</ref>

The oldest definitive records of the squid-like [[Belemnitida|belemnites]] are from the earliest Jurassic (Hettangian–Sinemurian) of Europe and Japan; they expanded worldwide during the Jurassic.<ref>{{Cite journal|last1=Iba|first1=Yasuhiro|last2=Sano|first2=Shin-ichi|last3=Mutterlose|first3=Jörg|date=2014-05-02|editor-last=Samonds|editor-first=Karen E.|title=The Early Evolutionary History of Belemnites: New Data from Japan|journal=[[PLOS ONE]]|language=en|volume=9|issue=5|pages=e95632|doi=10.1371/journal.pone.0095632|issn=1932-6203|pmc=4008418|pmid=24788872|bibcode=2014PLoSO...995632I|doi-access=free}}</ref> Belemnites were shallow-water dwellers, inhabiting the upper 200 metres of the water column on the [[Continental shelf|continental shelves]] and in the [[littoral zone]]. They were key components of Jurassic ecosystems, both as predators and prey, as evidenced by the abundance of belemnite guards in Jurassic rocks.<ref>{{Cite journal|last1=Hoffmann|first1=René|last2=Stevens|first2=Kevin|date=February 2020|title=The palaeobiology of belemnites – foundation for the interpretation of rostrum geochemistry|journal=Biological Reviews|language=en|volume=95|issue=1|pages=94–123|doi=10.1111/brv.12557|pmid=31729839|s2cid=208036104|issn=1464-7931|doi-access=free}}</ref>

The earliest [[Vampyromorphida|vampyromorphs]], of which the only living member is the [[vampire squid]], first appeared during the Early Jurassic.<ref>{{Cite journal|last1=Fuchs|first1=Dirk|last2=Weis|first2=Robert|date=2008-07-11|title=Taxonomy, morphology and phylogeny of Lower Jurassic loligosepiid coleoids (Cephalopoda)|url=http://www.schweizerbart.de/papers/njgpa/detail/249/59331/Taxonomy_morphology_and_phylogeny_of_Lower_Jurassi?af=crossref|journal=Neues Jahrbuch für Geologie und Paläontologie – Abhandlungen|language=en|volume=249|issue=1|pages=93–112|doi=10.1127/0077-7749/2008/0249-0093|bibcode=2008NJGPA.249...93F |issn=0077-7749}}</ref> The earliest [[octopus]]es appeared during the Middle Jurassic, having split from their closest living relatives, the vampyromorphs, during the Triassic to Early Jurassic.<ref name="Fuchs-2020">{{Cite journal |last1=Fuchs |first1=Dirk |last2=Iba |first2=Yasuhiro |last3=Heyng |first3=Alexander |last4=Iijima |first4=Masaya |last5=Klug |first5=Christian |last6=Larson |first6=Neal L. |last7=Schweigert |first7=Günter |date=February 2020 |editor-last=Brayard |editor-first=Arnaud |title=The Muensterelloidea: phylogeny and character evolution of Mesozoic stem octopods |url=https://onlinelibrary.wiley.com/doi/10.1002/spp2.1254 |journal=Papers in Palaeontology |language=en |volume=6 |issue=1 |pages=31–92 |doi=10.1002/spp2.1254 |bibcode=2020PPal....6...31F |issn=2056-2802 |s2cid=198256507}}</ref> All Jurassic octopuses are solely known from the hard [[Gladius (cephalopod)|gladius]].<ref name="Fuchs-2020" /><ref>{{Cite journal|last1=Fuchs|first1=Dirk|last2=Schweigert|first2=Günter|date=June 2018|title=First Middle–Late Jurassic gladius vestiges provide new evidence on the detailed origin of incirrate and cirrate octopuses (Coleoidea)|url=http://link.springer.com/10.1007/s12542-017-0399-8|journal=PalZ|language=en|volume=92|issue=2|pages=203–217|doi=10.1007/s12542-017-0399-8|bibcode=2018PalZ...92..203F |issn=0031-0220|s2cid=135245479}}</ref> Octopuses likely originated from bottom-dwelling ([[Benthic zone|benthic]]) ancestors which lived in shallow environments.<ref name="Fuchs-2020" /> ''[[Proteroctopus]]'' from the late Middle Jurassic [[La Voulte-sur-Rhône (lagerstätte)|La Voulte-sur-Rhône lagerstätte]], previously interpreted as an early octopus, is now thought to be a basal taxon outside the clade containing vampyromorphs and octopuses.<ref>{{Cite journal|last1=Kruta|first1=Isabelle|last2=Rouget|first2=Isabelle|last3=Charbonnier|first3=Sylvain|last4=Bardin|first4=Jérémie|last5=Fernandez|first5=Vincent|last6=Germain|first6=Damien|last7=Brayard|first7=Arnaud|last8=Landman|first8=Neil|date=2016|title=Proteroctopus ribeti in coleoid evolution|journal=[[Palaeontology (journal)|Palaeontology]]|language=en|volume=59|issue=6|pages=767–773|doi=10.1111/pala.12265|bibcode=2016Palgy..59..767K |s2cid=132420410 |issn=1475-4983|doi-access=free}}</ref>