Editing Jurassic (section)

==Fauna==

=== Dinosaurs ===
[[Dinosaur]]s, which had morphologically diversified in the Late Triassic, experienced a major increase in diversity and abundance during the Early Jurassic in the aftermath of the end-Triassic extinction and the extinction of other reptile groups, becoming the dominant vertebrates in terrestrial ecosystems.<ref>{{Cite journal |last1=Brusatte |first1=Stephen L |last2=Benton |first2=Michael J |last3=Ruta |first3=Marcello |last4=Lloyd |first4=Graeme T |date=2008-12-23 |title=The first 50 Myr of dinosaur evolution: macroevolutionary pattern and morphological disparity |url= |journal=Biology Letters |volume=4 |issue=6 |pages=733–736 |doi=10.1098/rsbl.2008.0441 |pmc=2614175 |pmid=18812311}}</ref><ref name="Brusatte">{{cite journal |last1=Brusatte |first1=S. L. |last2=Benton |first2=M. J. |last3=Ruta |first3=M. |last4=Lloyd |first4=G. T. |date=2008-09-12 |title=Superiority, Competition, and Opportunism in the Evolutionary Radiation of Dinosaurs |url=http://palaeo.gly.bris.ac.uk/Benton/reprints/2008Science.pdf |url-status=dead |journal=[[Science (journal)|Science]] |volume=321 |issue=5895 |pages=1485–88 |bibcode=2008Sci...321.1485B |doi=10.1126/science.1161833 |pmid=18787166 |s2cid=13393888 |archive-url=https://web.archive.org/web/20140624204033/http://palaeo.gly.bris.ac.uk/Benton/reprints/2008Science.pdf |archive-date=2014-06-24 |access-date=2012-01-14 |hdl=20.500.11820/00556baf-6575-44d9-af39-bdd0b072ad2b}}</ref> ''[[Chilesaurus]]'', a morphologically aberrant herbivorous dinosaur from the Late Jurassic of South America, has uncertain relationships to the three main groups of dinosaurs, having been recovered as a member of all three in different analyses.<ref>{{Cite journal |last1=Temp Müller |first1=Rodrigo |last2=Augusto Pretto |first2=Flávio |last3=Kerber |first3=Leonardo |last4=Silva-Neves |first4=Eduardo |last5=Dias-da-Silva |first5=Sérgio |date=28 March 2018 |title=Comment on 'A dinosaur missing-link? Chilesaurus and the early evolution of ornithischian dinosaurs' |url= |journal=Biology Letters |language=en |volume=14 |issue=3 |pages=20170581 |doi=10.1098/rsbl.2017.0581 |issn=1744-9561 |pmc=5897605 |pmid=29593074}}</ref>

==== Theropods ====
Advanced [[Theropoda|theropods]] belonging to [[Neotheropoda]] first appeared in the Late Triassic. Basal neotheropods, such as [[Coelophysoidea|coelophysoids]] and [[Dilophosauridae|dilophosaurs]], persisted into the Early Jurassic, but became extinct by the Middle Jurassic.<ref>{{Cite journal |last1=Zahner |first1=Marion |last2=Brinkmann |first2=Winand |date=August 2019 |title=A Triassic averostran-line theropod from Switzerland and the early evolution of dinosaurs |url= |journal=Nature Ecology & Evolution |language=en |volume=3 |issue=8 |pages=1146–1152 |bibcode=2019NatEE...3.1146Z |doi=10.1038/s41559-019-0941-z |issn=2397-334X |pmc=6669044 |pmid=31285577}}</ref> The earliest [[averostra]]ns appear during the Early Jurassic, with the earliest known member of [[Ceratosauria]] being ''[[Saltriovenator]]'' from the early Sinemurian (199.3–197.5 million years ago) of Italy.<ref>{{Cite journal |last1=Sasso |first1=Cristiano Dal |last2=Maganuco |first2=Simone |last3=Cau |first3=Andrea |date=2018-12-19 |title=The oldest ceratosaurian (Dinosauria: Theropoda), from the Lower Jurassic of Italy, sheds light on the evolution of the three-fingered hand of birds |journal=PeerJ |language=en |volume=6 |pages=e5976 |doi=10.7717/peerj.5976 |issn=2167-8359 |pmc=6304160 |pmid=30588396 |doi-access=free}}</ref> The unusual ceratosaur ''[[Limusaurus]]'' from the Late Jurassic of China had a herbivorous diet, with adults having [[edentulous]] beaked jaws,<ref>{{Cite journal |last1=Wang |first1=Shuo |last2=Stiegler |first2=Josef |last3=Amiot |first3=Romain |last4=Wang |first4=Xu |last5=Du |first5=Guo-hao |last6=Clark |first6=James M. |last7=Xu |first7=Xing |date=January 2017 |title=Extreme Ontogenetic Changes in a Ceratosaurian Theropod |journal=Current Biology |language=en |volume=27 |issue=1 |pages=144–148 |bibcode=2017CBio...27..144W |doi=10.1016/j.cub.2016.10.043 |pmid=28017609 |s2cid=441498 |doi-access=free}}</ref> making it the earliest known theropod to have converted from an ancestrally carnivorous diet.<ref>{{Cite journal |last1=Zanno |first1=Lindsay E. |last2=Makovicky |first2=Peter J. |date=2011-01-04 |title=Herbivorous ecomorphology and specialization patterns in theropod dinosaur evolution |journal=Proceedings of the National Academy of Sciences |language=en |volume=108 |issue=1 |pages=232–237 |bibcode=2011PNAS..108..232Z |doi=10.1073/pnas.1011924108 |issn=0027-8424 |pmc=3017133 |pmid=21173263 |doi-access=free}}</ref> The earliest members of the [[Tetanurae]] appeared during the late Early Jurassic or early Middle Jurassic.<ref name="Rauhut-2019">{{Cite journal |last1=Rauhut |first1=Oliver W. M. |last2=Pol |first2=Diego |date=2019-12-11 |title=Probable basal allosauroid from the early Middle Jurassic Cañadón Asfalto Formation of Argentina highlights phylogenetic uncertainty in tetanuran theropod dinosaurs |journal=Scientific Reports |language=en |volume=9 |issue=1 |pages=18826 |bibcode=2019NatSR...918826R |doi=10.1038/s41598-019-53672-7 |issn=2045-2322 |pmc=6906444 |pmid=31827108 |doi-access=free}}</ref> The [[Megalosauridae]] represent the oldest radiation of the Tetanurae, first appearing in Europe during the Bajocian.<ref name="Benson-2010">{{Cite journal |last=Benson |first=R.B.J |date=2010 |title=A description of Megalosaurus bucklandii (Dinosauria: Theropoda) from the Bathonian of the UK and the relationships of Middle Jurassic theropods |journal=Zoological Journal of the Linnean Society |volume=158 |issue=4 |pages=882–935 |doi=10.1111/j.1096-3642.2009.00569.x |doi-access=free}}</ref> The oldest member of [[Allosauroidea]] has been suggested to be ''[[Asfaltovenator]]'' from the Middle Jurassic of South America.<ref name="Rauhut-2019" /> [[Coelurosauria|Coelurosaurs]] first appeared during the Middle Jurassic, including early [[Tyrannosauroidea|tyrannosaurs]] such as ''[[Proceratosaurus]]'' from the Bathonian of Britain.<ref name="rauhutetal2010">{{Cite journal |last1=Rauhut |first1=Oliver W. M. |last2=Milner |first2=Angela C. |last3=Moore-Fay |first3=Scott |year=2010 |title=Cranial osteology and phylogenetic position of the theropod dinosaur ''Proceratosaurus'' bradleyi(Woodward, 1910) from the Middle Jurassic of England |journal=Zoological Journal of the Linnean Society |volume=158 |pages=155–195 |doi=10.1111/j.1096-3642.2009.00591.x |doi-access=free}}</ref> Some coelurosaurs from the Late Jurassic of China including ''[[Shishugounykus]]'' and ''[[Haplocheirus]]'' are suggested to represent early [[Alvarezsauroidea|alvarezsaurs]],<ref>Qin, Z., Clark, J., Choiniere, J., & Xu, X. (2019). A new alvarezsaurian theropod from the Upper Jurassic Shishugou Formation of western China. Scientific Reports, 9: 11727. {{doi|10.1038/s41598-019-48148-7}}</ref> however, this has been questioned.<ref>{{Cite journal |last1=Agnolín |first1=Federico L. |last2=Lu |first2=Jun-Chang |last3=Kundrát |first3=Martin |last4=Xu |first4=Li |date=2021-06-02 |title=Alvarezsaurid osteology: new data on cranial anatomy |url=https://www.tandfonline.com/doi/full/10.1080/08912963.2021.1929203 |journal=Historical Biology |language=en |volume=34 |issue=3 |pages=443–452 |doi=10.1080/08912963.2021.1929203 |issn=0891-2963 |s2cid=236221732}}</ref> [[Scansoriopterygidae|Scansoriopterygids]], a group of small feathered coelurosaurs with membraneous, bat-like wings for gliding, are known from the Middle to Late Jurassic of China.<ref>{{Cite journal |last1=Wang |first1=Min |last2=O’Connor |first2=Jingmai K. |last3=Xu |first3=Xing |last4=Zhou |first4=Zhonghe |date=May 2019 |title=A new Jurassic scansoriopterygid and the loss of membranous wings in theropod dinosaurs |url=https://www.nature.com/articles/s41586-019-1137-z |journal=Nature |language=en |volume=569 |issue=7755 |pages=256–259 |bibcode=2019Natur.569..256W |doi=10.1038/s41586-019-1137-z |issn=1476-4687 |pmid=31068719 |s2cid=148571099}}</ref> The oldest record of [[Troodontidae|troodontids]] is suggested to be ''[[Hesperornithoides]]'' from the Late Jurassic of North America. Tooth remains suggested to represent those of [[Dromaeosauridae|dromaeosaurs]] are known from the Jurassic, but no body remains are known until the Cretaceous.<ref>{{Cite journal |last1=Hartman |first1=Scott |last2=Mortimer |first2=Mickey |last3=Wahl |first3=William R. |last4=Lomax |first4=Dean R. |last5=Lippincott |first5=Jessica |last6=Lovelace |first6=David M. |date=2019-07-10 |title=A new paravian dinosaur from the Late Jurassic of North America supports a late acquisition of avian flight |journal=PeerJ |language=en |volume=7 |pages=e7247 |doi=10.7717/peerj.7247 |issn=2167-8359 |pmc=6626525 |pmid=31333906 |doi-access=free}}</ref>

<gallery>
File:Ceratosaurus mounted white background.jpg|Skeleton of ''[[Ceratosaurus]]'', a ceratosaurid from the Late Jurassic of North America
File:Monolophosaurus jiangi.jpg|Skeleton of ''[[Monolophosaurus]]'', a basal tetanuran from the Middle Jurassic of China
File:Yi qi restoration.jpg|Restoration of ''[[Yi (dinosaur)|Yi qi]]'', a scansoriopterygid from the Middle to Late Jurassic of China
</gallery>

===== Birds =====
[[File:Archaeopteryx lithographica (Berlin specimen).jpg|thumb|upright|''[[Archaeopteryx|Archaeopteryx lithographica]]'' from the Late Jurassic (Tithonian) of Germany|alt=Fossil of complete Archaeopteryx, including indentations of feathers on wings and tail]]
The earliest [[Avialae|avialans]], which include birds and their ancestors, appear during the Middle to Late Jurassic, definitively represented by ''[[Archaeopteryx]]'' from the Late Jurassic of Germany. Avialans belong to the clade [[Paraves]] within Coelurosauria, which also includes dromaeosaurs and troodontids. The [[Anchiornithidae]] from the Middle-Late Jurassic of Eurasia have frequently suggested to be avialans, but have also alternatively found as a separate lineage of paravians.<ref name="Rauhut-2020">{{Citation |last1=Rauhut |first1=Oliver W. M. |title=The Origin of Birds: Current Consensus, Controversy, and the Occurrence of Feathers |date=2020 |work=The Evolution of Feathers: From Their Origin to the Present |pages=27–45 |editor-last=Foth |editor-first=Christian |url=https://doi.org/10.1007/978-3-030-27223-4_3 |access-date=2021-01-05 |series=Fascinating Life Sciences |place=Cham |publisher=Springer International Publishing |language=en |doi=10.1007/978-3-030-27223-4_3 |isbn=978-3-030-27223-4 |s2cid=216372010 |last2=Foth |first2=Christian |editor2-last=Rauhut |editor2-first=Oliver W. M.}}</ref>
[[File:Heterodontosaurus tucki cast - University of California Museum of Paleontology - Berkeley, CA - DSC04696.JPG|left|thumb|Skeleton of ''[[Heterodontosaurus]],'' a primitive ornithischian from the Early Jurassic of South Africa]]

==== Ornithischians ====
The earliest definitive [[ornithischia]]ns appear during the Early Jurassic, represented by basal ornithischians like ''[[Lesothosaurus]]'', [[Heterodontosauridae|heterodontosaurids]], and early members of [[Thyreophora]]. The earliest members of [[Ankylosauria]] and [[Stegosauria]] appear during the Middle Jurassic.<ref>{{Cite journal |last=Norman |first=David B |date=2021-01-01 |title=Scelidosaurus harrisonii (Dinosauria: Ornithischia) from the Early Jurassic of Dorset, England: biology and phylogenetic relationships |url=https://academic.oup.com/zoolinnean/article/191/1/1/5893854 |journal=Zoological Journal of the Linnean Society |language=en |volume=191 |issue=1 |pages=1–86 |doi=10.1093/zoolinnean/zlaa061 |issn=0024-4082}}</ref> The basal [[neornithischia]]n ''[[Kulindadromeus]]'' from the Middle Jurassic of Russia indicates that at least some ornithischians were covered in [[Feathered dinosaur|protofeathers]].<ref>{{Citation |last1=Godefroit |first1=Pascal |title=Integumentary Structures in Kulindadromeus zabaikalicus, a Basal Neornithischian Dinosaur from the Jurassic of Siberia |date=2020 |work=The Evolution of Feathers: From Their Origin to the Present |pages=47–65 |editor-last=Foth |editor-first=Christian |url=https://doi.org/10.1007/978-3-030-27223-4_4 |access-date=2021-01-05 |series=Fascinating Life Sciences |place=Cham |publisher=Springer International Publishing |language=en |doi=10.1007/978-3-030-27223-4_4 |isbn=978-3-030-27223-4 |s2cid=216261986 |last2=Sinitsa |first2=Sofia M. |last3=Cincotta |first3=Aude |last4=McNamara |first4=Maria E. |last5=Reshetova |first5=Svetlana A. |last6=Dhouailly |first6=Danielle |editor2-last=Rauhut |editor2-first=Oliver W. M.}}</ref> The earliest members of [[Ankylopollexia]], which become prominent in the Cretaceous, appeared during the Late Jurassic, represented by bipedal forms such as ''[[Camptosaurus]]''.<ref>{{Cite journal |last=McDonald |first=Andrew T. |date=2012-05-22 |editor-last=Farke |editor-first=Andrew A. |title=Phylogeny of Basal Iguanodonts (Dinosauria: Ornithischia): An Update |journal=PLOS ONE |language=en |volume=7 |issue=5 |pages=e36745 |bibcode=2012PLoSO...736745M |doi=10.1371/journal.pone.0036745 |issn=1932-6203 |pmc=3358318 |pmid=22629328 |doi-access=free}}</ref> [[Ceratopsia]]ns first appeared in the Late Jurassic of China, represented by members of [[Chaoyangsauridae]].<ref>{{Cite journal |last1=Han |first1=Fenglu |last2=Forster |first2=Catherine A. |last3=Clark |first3=James M. |last4=Xu |first4=Xing |date=2015-12-09 |title=A New Taxon of Basal Ceratopsian from China and the Early Evolution of Ceratopsia |journal=PLOS ONE |language=en |volume=10 |issue=12 |pages=e0143369 |bibcode=2015PLoSO..1043369H |doi=10.1371/journal.pone.0143369 |issn=1932-6203 |pmc=4674058 |pmid=26649770 |doi-access=free}}</ref>

==== Sauropodomorphs ====
[[File:Mamenchisaurus in Japan.jpg|left|thumb|Skeleton of ''[[Mamenchisaurus|Mamenchisaurus sinocanadorum]]'' from the Middle-Late Jurassic of China]]
[[Sauropoda|Sauropods]] became the dominant large herbivores in terrestrial ecosystems during the Jurassic.<ref name="Pol-2020">{{Cite journal |last1=Pol |first1=D. |last2=Ramezani |first2=J. |last3=Gomez |first3=K. |last4=Carballido |first4=J. L. |last5=Carabajal |first5=A. Paulina |last6=Rauhut |first6=O. W. M. |last7=Escapa |first7=I. H. |last8=Cúneo |first8=N. R. |date=2020-11-25 |title=Extinction of herbivorous dinosaurs linked to Early Jurassic global warming event |url= |journal=Proceedings of the Royal Society B: Biological Sciences |language=en |volume=287 |issue=1939 |pages=20202310 |doi=10.1098/rspb.2020.2310 |issn=0962-8452 |pmc=7739499 |pmid=33203331}}</ref> Some Jurassic sauropods reached gigantic sizes, becoming the largest organisms to have ever lived on land.<ref>{{Cite journal |last1=Sander |first1=P. Martin |last2=Christian |first2=Andreas |last3=Clauss |first3=Marcus |last4=Fechner |first4=Regina |last5=Gee |first5=Carole T. |last6=Griebeler |first6=Eva-Maria |last7=Gunga |first7=Hanns-Christian |last8=Hummel |first8=Jürgen |last9=Mallison |first9=Heinrich |last10=Perry |first10=Steven F. |last11=Preuschoft |first11=Holger |date=February 2011 |title=Biology of the sauropod dinosaurs: the evolution of gigantism |journal=Biological Reviews |language=en |volume=86 |issue=1 |pages=117–155 |doi=10.1111/j.1469-185X.2010.00137.x |pmc=3045712 |pmid=21251189}}</ref>

[[Basal (phylogenetics)|Basal]] bipedal [[Sauropodomorpha|sauropodomorphs]], such as [[Massospondylidae|massospondylids]], continued to exist into the Early Jurassic, but became extinct by the beginning of the Middle Jurassic.<ref name="Pol-2020" /> Quadrupedal sauropomorphs appeared during the Late Triassic. The quadrupedal ''[[Ledumahadi]]'' from the earliest Jurassic of South Africa reached an estimated weight of 12 tons, far in excess of other known basal sauropodomorphs.<ref>{{Cite journal |last1=McPhee |first1=Blair W. |last2=Benson |first2=Roger B.J. |last3=Botha-Brink |first3=Jennifer |last4=Bordy |first4=Emese M. |last5=Choiniere |first5=Jonah N. |date=8 October 2018 |title=A Giant Dinosaur from the Earliest Jurassic of South Africa and the Transition to Quadrupedality in Early Sauropodomorphs |journal=Current Biology |language=en |volume=28 |issue=19 |pages=3143–3151.e7 |bibcode=2018CBio...28E3143M |doi=10.1016/j.cub.2018.07.063 |pmid=30270189 |s2cid=52890502 |doi-access=free}}</ref> [[Gravisauria]]n sauropods first appeared during the Early Jurassic, with the oldest definitive record being ''[[Vulcanodon]]'' from Zimbabwe, likely of Sinemurian age.<ref>{{Cite journal |last1=Viglietti |first1=Pia A. |last2=Barrett |first2=Paul M. |last3=Broderick |first3=Tim J. |last4=Munyikwa |first4=Darlington |last5=MacNiven |first5=Rowan |last6=Broderick |first6=Lucy |last7=Chapelle |first7=Kimberley |last8=Glynn |first8=Dave |last9=Edwards |first9=Steve |last10=Zondo |first10=Michel |last11=Broderick |first11=Patricia |date=January 2018 |title=Stratigraphy of the Vulcanodon type locality and its implications for regional correlations within the Karoo Supergroup |url=https://linkinghub.elsevier.com/retrieve/pii/S1464343X17303953 |journal=Journal of African Earth Sciences |language=en |volume=137 |pages=149–156 |bibcode=2018JAfES.137..149V |doi=10.1016/j.jafrearsci.2017.10.015}}</ref> [[Eusauropoda|Eusauropods]] first appeared during the late Early Jurassic (Toarcian) and diversified during the Middle Jurassic;<ref name="Pol-2020" /> these included [[Cetiosauridae|cetiosaurids]], [[Turiasauria|turiasaurs]],<ref>{{Cite journal |last1=Royo-Torres |first1=Rafael |last2=Cobos |first2=Alberto |last3=Mocho |first3=Pedro |last4=Alcalá |first4=Luis |date=2021-01-01 |title=Origin and evolution of turiasaur dinosaurs set by means of a new 'rosetta' specimen from Spain |url=https://academic.oup.com/zoolinnean/article/191/1/201/5900936 |journal=Zoological Journal of the Linnean Society |language=en |volume=191 |issue=1 |pages=201–227 |doi=10.1093/zoolinnean/zlaa091 |issn=0024-4082 |doi-access=free}}</ref> and [[Mamenchisauridae|mamenchisaurs]].<ref>{{Cite journal |last1=Ren |first1=Xin-Xin |last2=Huang |first2=Jian-Dong |last3=You |first3=Hai-Lu |date=2020-05-27 |title=The second mamenchisaurid dinosaur from the Middle Jurassic of Eastern China |url=https://www.tandfonline.com/doi/full/10.1080/08912963.2018.1515935 |journal=Historical Biology |language=en |volume=32 |issue=5 |pages=602–610 |bibcode=2020HBio...32..602R |doi=10.1080/08912963.2018.1515935 |issn=0891-2963 |s2cid=91927243}}</ref> [[Neosauropoda|Neosauropods]] such as [[macronaria]]ns and [[Diplodocoidea|diplodocoids]] first appeared during the Middle Jurassic, before becoming abundant and globally distributed during the Late Jurassic.<ref>{{Cite journal |last1=Ren |first1=Xin-Xin |last2=Jiang |first2=Shan |last3=Wang |first3=Xu-Ri |last4=Peng |first4=Guang-Zhao |last5=Ye |first5=Yong |last6=Jia |first6=Lei |last7=You |first7=Hai-Lu |date=2022-11-14 |title=Re-examination of Dashanpusaurus dongi (Sauropoda: Macronaria) supports an early Middle Jurassic global distribution of neosauropod dinosaurs |url=https://www.sciencedirect.com/science/article/pii/S0031018222004898 |journal=Palaeogeography, Palaeoclimatology, Palaeoecology |language=en |volume=610 |pages=111318 |doi=10.1016/j.palaeo.2022.111318 |issn=0031-0182}}</ref>

=== Other reptiles ===

==== Crocodylomorphs ====
[[File:Platysuchus multiscrobiculatus 1.JPG|thumb|[[Holotype]] specimen of ''[[Platysuchus]],'' a [[Teleosauridae|telosaurid]] [[thalattosuchia]]n]]
The Triassic–Jurassic extinction decimated [[pseudosuchia]]n diversity, with [[Crocodylomorpha|crocodylomorphs]], which originated during the early Late Triassic, being the only group of pseudosuchians to survive. All other pseudosuchians, including the herbivorous [[aetosaur]]s and carnivorous "[[rauisuchians]]", became extinct.<ref>{{Cite journal|last1=Allen|first1=Bethany J.|last2=Stubbs|first2=Thomas L.|last3=Benton|first3=Michael J.|last4=Puttick|first4=Mark N.|date=March 2019|editor-last=Mannion|editor-first=Philip|title=Archosauromorph extinction selectivity during the Triassic-Jurassic mass extinction|journal=Palaeontology|language=en|volume=62|issue=2|pages=211–224|doi=10.1111/pala.12399|bibcode=2019Palgy..62..211A |s2cid=55009185|doi-access=free|hdl=1983/e3fc2e40-c849-42ed-99fe-ea17fc26b2ec|hdl-access=free}}</ref> The morphological diversity of crocodylomorphs during the Early Jurassic was around the same as that of Late Triassic pseudosuchians, but they occupied different areas of morphospace, suggesting that they occupied different [[ecological niche]]s to their Triassic counterparts and that there was an extensive and rapid radiation of crocodylomorphs during this interval.<ref>{{Cite journal|last1=Toljagić|first1=Olja|last2=Butler|first2=Richard J.|date=2013-06-23|title=Triassic–Jurassic mass extinction as trigger for the Mesozoic radiation of crocodylomorphs|url= |journal=Biology Letters|language=en|volume=9|issue=3|pages=20130095|doi=10.1098/rsbl.2013.0095|issn=1744-9561|pmc=3645043|pmid=23536443}}</ref> While living [[crocodilia]]ns are mostly confined to an aquatic ambush predator lifestyle, Jurassic crocodylomorphs exhibited a wide variety of life habits. An unnamed [[Protosuchidae|protosuchid]] known from teeth from the Early Jurassic of Arizona represents the earliest known herbivorous crocodylomorph, an adaptation that appeared several times during the Mesozoic.<ref>{{Cite journal|last1=Melstrom|first1=Keegan M.|last2=Irmis|first2=Randall B.|date=July 2019|title=Repeated Evolution of Herbivorous Crocodyliforms during the Age of Dinosaurs|journal=Current Biology|language=en|volume=29|issue=14|pages=2389–2395.e3|doi=10.1016/j.cub.2019.05.076|pmid=31257139|s2cid=195699188|doi-access=free|bibcode=2019CBio...29E2389M }}</ref>

The [[Thalattosuchia]], a clade of predominantly marine crocodylomorphs, first appeared during the Early Jurassic and became a prominent part of marine ecosystems.<ref name="Stubbs-2021">{{Cite journal|last1=Stubbs|first1=Thomas L.|last2=Pierce|first2=Stephanie E.|last3=Elsler|first3=Armin|last4=Anderson|first4=Philip S. L.|last5=Rayfield|first5=Emily J.|last6=Benton|first6=Michael J.|date=2021-03-31|title=Ecological opportunity and the rise and fall of crocodylomorph evolutionary innovation|journal=Proceedings of the Royal Society B: Biological Sciences|volume=288|issue=1947|pages=20210069|doi=10.1098/rspb.2021.0069|pmid=33757349|pmc=8059953|s2cid=232326789}}</ref> Within Thalattosuchia, the [[Metriorhynchidae]] became highly adapted for life in the open ocean, including the transformation of limbs into flippers, the development of a tail fluke, and smooth, scaleless skin.<ref>{{Cite journal|last1=Spindler|first1=Frederik|last2=Lauer|first2=René|last3=Tischlinger|first3=Helmut|last4=Mäuser|first4=Matthias|date=2021-07-05|title=The integument of pelagic crocodylomorphs (Thalattosuchia: Metriorhynchidae)|url=https://palaeo-electronica.org/content/2021/3399-metriorhynchid-skin|journal=Palaeontologia Electronica|language=English|volume=24|issue=2|pages=1–41|doi=10.26879/1099|issn=1094-8074|doi-access=free}}</ref> The morphological diversity of crocodylomorphs during the Early and Middle Jurassic was relatively low compared to that in later time periods and was dominated by terrestrial small-bodied, long-legged [[sphenosuchia]]ns, early [[crocodyliformes|crocodyliforms]] and thalattosuchians.<ref>{{Cite journal|last1=Irmis|first1=Randall B.|last2=Nesbitt|first2=Sterling J.|last3=Sues|first3=Hans-Dieter|date=2013|title=Early Crocodylomorpha|url=http://sp.lyellcollection.org/lookup/doi/10.1144/SP379.24|journal=Geological Society, London, Special Publications|language=en|volume=379|issue=1|pages=275–302|bibcode=2013GSLSP.379..275I|doi=10.1144/SP379.24|issn=0305-8719|s2cid=219190410}}</ref><ref name="Stubbs-2021" /> The [[Neosuchia]], a major group of crocodylomorphs, first appeared during the Early to Middle Jurassic. The Neosuchia represents the transition from an ancestrally terrestrial lifestyle to a freshwater aquatic ecology similar to that occupied by modern crocodilians.<ref name="Wilberg-2019">{{Cite journal|last1=Wilberg|first1=Eric W.|last2=Turner|first2=Alan H.|last3=Brochu|first3=Christopher A.|date=2019-01-24|title=Evolutionary structure and timing of major habitat shifts in Crocodylomorpha|url= |journal=Scientific Reports|language=en|volume=9|issue=1|pages=514|doi=10.1038/s41598-018-36795-1|pmid=30679529|pmc=6346023|bibcode=2019NatSR...9..514W|issn=2045-2322}}</ref> The timing of the origin of Neosuchia is disputed. The oldest record of Neosuchians has been suggested to be ''[[Calsoyasuchus]],'' from the Early Jurassic of Arizona, which in many analyses has been recovered as the earliest branching member of the neosuchian family [[Goniopholididae]], which radically alters times of diversification for crocodylomorphs. However, this placement has been disputed, with some analyses finding it outside Neosuchia, which would place the oldest records of Neosuchia in the Middle Jurassic.<ref name="Wilberg-2019" /> ''[[Razanandrongobe]]'' from the Middle Jurassic of Madagascar has been suggested to represent the oldest record of [[Notosuchia]], a primarily Gondwanan clade of mostly terrestrial crocodylomorphs, otherwise known from the Cretaceous and Cenozoic.<ref name="dalsasso2017">{{cite journal|last1=Dal Sasso|first1=C.|last2=Pasini|first2=G.|last3=Fleury|first3=G.|last4=Maganuco|first4=S.|year=2017|title=''Razanandrongobe sakalavae'', a gigantic mesoeucrocodylian from the Middle Jurassic of Madagascar, is the oldest known notosuchian|journal=PeerJ|volume=5|page=e3481|doi=10.7717/peerj.3481|pmc=5499610|pmid=28690926 |doi-access=free }}</ref>

==== Turtles ====
[[File:Thalassemys bruntrutana.jpg|thumb|''[[Thalassemys]],'' a [[thalassochelydia]]n sea turtle known from the Late Jurassic of Germany ]]
[[Stem-group]] turtles ([[Testudinata]]) diversified during the Jurassic. Jurassic stem-turtles belong to two progressively more advanced clades, the [[Mesochelydia]] and [[Perichelydia]].<ref name="Joyce-2017">{{Cite journal|last=Joyce|first=Walter G.|date=April 2017|title=A Review of the Fossil Record of Basal Mesozoic Turtles|journal=Bulletin of the Peabody Museum of Natural History|language=en|volume=58|issue=1|pages=65–113|doi=10.3374/014.058.0105|bibcode=2017BPMNH..58...65J |s2cid=54982901|issn=0079-032X|url=http://doc.rero.ch/record/288659/files/joy_rfm.pdf }}</ref> It is thought that the ancestral condition for mesochelydians is aquatic, as opposed to terrestrial for testudinates.<ref>{{Cite journal|last1=Sterli|first1=Juliana|last2=de la Fuente|first2=Marcelo S.|last3=Rougier|first3=Guillermo W.|date=2018-07-04|title=New remains of Condorchelys antiqua (Testudinata) from the Early-Middle Jurassic of Patagonia: anatomy, phylogeny, and paedomorphosis in the early evolution of turtles|url=https://www.tandfonline.com/doi/full/10.1080/02724634.2018.1480112|journal=Journal of Vertebrate Paleontology|language=en|volume=38|issue=4|pages=(1)–(17)|doi=10.1080/02724634.2018.1480112|bibcode=2018JVPal..38....1S |s2cid=109556104|issn=0272-4634|hdl=11336/99525|hdl-access=free}}</ref> The two modern groups of turtles ([[Turtle|Testudines]]), [[Pleurodira]] and [[Cryptodira]], diverged by the beginning of the Late Jurassic.<ref name="Joyce-2017" /> The oldest known pleurodires, the [[Platychelyidae]], are known from the Late Jurassic of Europe and the Americas,<ref>{{Cite journal|last1=Sullivan|first1=Patrick M.|last2=Joyce|first2=Walter G.|date=August 2017|title=The shell and pelvic anatomy of the Late Jurassic turtle Platychelys oberndorferi based on material from Solothurn, Switzerland|url=http://link.springer.com/10.1007/s13358-017-0136-7|journal=[[Swiss Journal of Palaeontology]]|language=en|volume=136|issue=2|pages=323–343|doi=10.1007/s13358-017-0136-7|bibcode=2017SwJP..136..323S |s2cid=90587841|issn=1664-2376}}</ref> while the oldest unambiguous cryptodire, ''[[Sinaspideretes]],'' an early relative of [[Trionychidae|softshell turtles]], is known from the Late Jurassic of China.<ref>{{Cite journal|last1=Evers|first1=Serjoscha W.|last2=Benson|first2=Roger B. J.|date=January 2019|editor-last=Smith|editor-first=Andrew|title=A new phylogenetic hypothesis of turtles with implications for the timing and number of evolutionary transitions to marine lifestyles in the group|url=https://onlinelibrary.wiley.com/doi/10.1111/pala.12384|journal=Palaeontology|language=en|volume=62|issue=1|pages=93–134|doi=10.1111/pala.12384|bibcode=2019Palgy..62...93E |s2cid=134736808}}</ref> The [[Thalassochelydia]], a diverse lineage of marine turtles unrelated to modern [[sea turtle]]s, are known from the Late Jurassic of Europe and South America.<ref>{{Cite journal|last1=Anquetin|first1=Jérémy|last2=Püntener|first2=Christian|last3=Joyce|first3=Walter G.|date=October 2017|title=A Review of the Fossil Record of Turtles of the Clade Thalassochelydia|url=http://www.bioone.org/doi/10.3374/014.058.0205|journal=Bulletin of the Peabody Museum of Natural History|language=en|volume=58|issue=2|pages=317–369|doi=10.3374/014.058.0205|bibcode=2017BPMNH..58..317A |s2cid=31091127|issn=0079-032X}}</ref>

==== Lepidosaurs ====
[[Rhynchocephalia]]ns (the sole living representative being the [[tuatara]]) had achieved a global distribution by the beginning of the Jurassic,<ref name="Evans-2010" /> and represented the dominant group of small reptiles during the Jurassic globally.<ref name=":20">{{Cite journal |last1=Brownstein |first1=Chase D. |last2=Meyer |first2=Dalton L. |last3=Fabbri |first3=Matteo |last4=Bhullar |first4=Bhart-Anjan S. |last5=Gauthier |first5=Jacques A. |date=2022-11-29 |title=Evolutionary origins of the prolonged extant squamate radiation |journal=Nature Communications |language=en |volume=13 |issue=1 |page=7087 |doi=10.1038/s41467-022-34217-5 |issn=2041-1723 |pmc=9708687 |pmid=36446761|bibcode=2022NatCo..13.7087B }}</ref> Rhynchocephalians reached their highest morphological diversity in their evolutionary history during the Jurassic, occupying a wide range of lifestyles, including the aquatic [[Pleurosauridae|pleurosaurs]] with long snake-like bodies and reduced limbs, the specialized herbivorous [[Eilenodontinae|eilenodontines]], as well as the [[sapheosaurs]] which had broad tooth plates indicative of [[durophagy]].<ref>{{Cite journal|last1=Herrera-Flores|first1=Jorge A.|last2=Stubbs|first2=Thomas L.|last3=Benton|first3=Michael J.|date=2017|title=Macroevolutionary patterns in Rhynchocephalia: is the tuatara (Sphenodon punctatus) a living fossil?|journal=Palaeontology|language=en|volume=60|issue=3|pages=319–328|doi=10.1111/pala.12284|bibcode=2017Palgy..60..319H |issn=1475-4983|doi-access=free}}</ref> Rhynchocephalians disappeared from Asia after the Early Jurassic.<ref name="Evans-2010">{{Citation|last1=Evans|first1=Susan E.|title=The Origin, Early History and Diversification of Lepidosauromorph Reptiles|date=2010|url=http://link.springer.com/10.1007/978-3-642-10311-7_2|work=New Aspects of Mesozoic Biodiversity|volume=132|pages=27–44|place=Berlin, Heidelberg|publisher=Springer Berlin Heidelberg|doi=10.1007/978-3-642-10311-7_2|isbn=978-3-642-10310-0|access-date=2021-01-07|last2=Jones|first2=Marc E.H.|series=Lecture Notes in Earth Sciences |bibcode=2010LNES..132...27E}}</ref> The last common ancestor of living [[Squamata|squamates]] (which includes [[lizard]]s and [[snake]]s) is estimated to have lived around 190 million years ago during the Early Jurassic, with the major divergences between modern squamate lineages estimated to have occurred during the Early to Middle Jurassic.<ref>{{Cite journal|last1=Burbrink|first1=Frank T|last2=Grazziotin|first2=Felipe G|last3=Pyron|first3=R Alexander|last4=Cundall|first4=David|last5=Donnellan|first5=Steve|last6=Irish|first6=Frances|last7=Keogh|first7=J Scott|last8=Kraus|first8=Fred|last9=Murphy|first9=Robert W|last10=Noonan|first10=Brice|last11=Raxworthy|first11=Christopher J|date=2020-05-01|editor-last=Thomson|editor-first=Robert|title=Interrogating Genomic-Scale Data for Squamata (Lizards, Snakes, and Amphisbaenians) Shows no Support for Key Traditional Morphological Relationships|url=https://academic.oup.com/sysbio/article/69/3/502/5573126|journal=Systematic Biology|language=en|volume=69|issue=3|pages=502–520|doi=10.1093/sysbio/syz062|pmid=31550008|issn=1063-5157}}</ref> Squamates first appear in the fossil record during the Middle Jurassic<ref name="Cleary-2018">{{Cite journal|last1=Cleary|first1=Terri J.|last2=Benson|first2=Roger B. J.|last3=Evans|first3=Susan E.|last4=Barrett|first4=Paul M.|date=21 March 2018|title=Lepidosaurian diversity in the Mesozoic–Palaeogene: the potential roles of sampling biases and environmental drivers|url= |journal=Royal Society Open Science|volume=5|issue=3|pages=171830|doi=10.1098/rsos.171830|pmc=5882712|pmid=29657788|bibcode=2018RSOS....571830C}}</ref> including members of modern clades such as [[Scincomorpha]],<ref>{{Cite journal|last=Evans|first=S. E.|date=1998|title=Crown group lizards (Reptilia, Squamata) from the Middle Jurassic of the British Isles|journal=Palaeontographica, Abteilung A |volume=250|issue=4–6 |pages=123–154|doi=10.1127/pala/250/1998/123 |bibcode=1998PalAA.250..123E |s2cid=246932992 }}</ref> though many Jurassic squamates have unclear relationships to living groups.<ref>{{Cite journal|last1=Dong|first1=Liping|last2=Wang|first2=Yuan|last3=Mou|first3=Lijie|last4=Zhang|first4=Guoze|last5=Evans|first5=Susan E.|date=2019-09-13|title=A new Jurassic lizard from China|journal=Geodiversitas|volume=41|issue=16|pages=623|doi=10.5252/geodiversitas2019v41a16|s2cid=204256127|issn=1280-9659|doi-access=free|bibcode=2019Geodv..41..623D }}</ref> ''[[Eichstaettisaurus]]'' from the Late Jurassic of Germany has been suggested to be an early relative of [[gecko]]s and displays adaptations for climbing.<ref>{{Cite journal|last1=Simões|first1=Tiago R.|last2=Caldwell|first2=Michael W.|last3=Nydam|first3=Randall L.|last4=Jiménez-Huidobro|first4=Paulina|date=September 2016|title=Osteology, phylogeny, and functional morphology of two Jurassic lizard species and the early evolution of scansoriality in geckoes |journal=Zoological Journal of the Linnean Society|language=en|doi=10.1111/zoj.12487}}</ref> ''[[Dorsetisaurus]]'' from the Late Jurassic of North America and Europe represents the oldest widely accepted record of [[Anguimorpha]].<ref>{{Cite journal|last1=Daza|first1=J. D.|last2=Bauer|first2=A. M.|last3=Stanley|first3=E. L.|last4=Bolet|first4=A.|last5=Dickson|first5=B.|last6=Losos|first6=J. B.|date=2018-11-01|title=An Enigmatic Miniaturized and Attenuate Whole Lizard from the Mid-Cretaceous Amber of Myanmar|url=https://bioone.org/journals/breviora/volume-563/issue-1/MCZ49.1/An-Enigmatic-Miniaturized-and-Attenuate-Whole-Lizard-from-the-Mid/10.3099/MCZ49.1.full|journal=Breviora|volume=563|issue=1|pages=1|doi=10.3099/MCZ49.1|hdl=1983/0955fcf4-a32a-4498-b920-1421dcea67de |s2cid=91589111|issn=0006-9698|hdl-access=free}}</ref> ''[[Marmoretta]]'' from the Middle Jurassic of Britain has been suggested to represent a late surviving [[Lepidosauromorpha|lepidosauromorph]] outside both Rhynchocephalia and Squamata, though some studies have recovered it as a stem-squamate.<ref name="Griffiths spp2.1400">{{Cite journal |last1=Griffiths |first1=Elizabeth F. |last2=Ford |first2=David P. |last3=Benson |first3=Roger B.J. |last4=Evans |first4=Susan E. |date=September 2021 |editor-last=Ruta |editor-first=Marcello |title=New information on the Jurassic lepidosauromorph Marmoretta oxoniensis |url=https://onlinelibrary.wiley.com/doi/10.1002/spp2.1400 |journal=Papers in Palaeontology |language=en |volume=7 |issue=4 |pages=2255–2278 |doi=10.1002/spp2.1400 |bibcode=2021PPal....7.2255G |issn=2056-2799 |s2cid=239140732}}</ref>

<gallery>
File:Vadasaurus herzogi holotype (fossil).jpg|''[[Vadasaurus|Vadasaurus herzogi]]'', a rynchocephalian from the Upper Jurassic [[Solnhofen Limestone]] of Germany
File:Homeosaurus maximiliani, lizard, Jurassic, Solnhofen Limestone, Eichstatt, Bavaria, Germany - Houston Museum of Natural Science - DSC01988.JPG|''[[Homoeosaurus|Homeosaurus maximiliani]]'', a rynchocephalian from the Solnhofen Limestone
File:Pleurosaurus 783534.jpg|''[[Pleurosaurus]],'', an aquatic rhynchocephalian from the Late Jurassic of Europe
File:Eichstaettisaurus schroederi.JPG|''[[Eichstaettisaurus|Eichstaettisaurus schroederi]],'', an extinct lizard from the Solnhofen Limestone 
</gallery>

==== Choristoderes ====
[[File:Coeruleodraco paratype.jpg|left|thumb|upright=0.6|Skeleton of ''[[Coeruleodraco]]'']]
The earliest known remains of [[Choristodera]], a group of freshwater aquatic reptiles with uncertain affinities to other reptile groups, are found in the Middle Jurassic. Only two genera of choristodere are known from the Jurassic. One is the small lizard-like ''[[Cteniogenys]]'', thought to be the most basal known choristodere; it is known from the Middle to Late Jurassic of Europe and Late Jurassic of North America, with similar remains also known from the upper Middle Jurassic of Kyrgyzstan and western Siberia.<ref>{{Cite journal |last1=Matsumoto |first1=R. |last2=Evans |first2=S. E. |date=2010 |title=Choristoderes and the freshwater assemblages of Laurasia |url=http://revistas.ucm.es/index.php/JIGE/article/view/JIGE1010220253A |journal=Journal of Iberian Geology |volume=36 |issue=2 |pages=253–274 |doi=10.5209/rev_JIGE.2010.v36.n2.11 |issn=1698-6180 |doi-access=free |bibcode=2010JIbG...36..253M}}</ref> The other is ''[[Coeruleodraco]]'' from the Late Jurassic of China, which is a more advanced choristodere, though still small and lizard-like in morphology.<ref>{{Cite journal |last1=Matsumoto |first1=Ryoko |last2=Dong |first2=Liping |last3=Wang |first3=Yuan |last4=Evans |first4=Susan E. |date=2019-06-18 |title=The first record of a nearly complete choristodere (Reptilia: Diapsida) from the Upper Jurassic of Hebei Province, People's Republic of China |url=https://www.tandfonline.com/doi/full/10.1080/14772019.2018.1494220 |journal=Journal of Systematic Palaeontology |language=en |volume=17 |issue=12 |pages=1031–1048 |doi=10.1080/14772019.2018.1494220 |bibcode=2019JSPal..17.1031M |s2cid=92421503 |issn=1477-2019}}</ref>

==== Ichthyosaurs ====
[[File:Ichthyosaurus communis in London.jpg|thumb|Fossil of ''[[Ichthyosaurus somersetensis]]'' at the [[Natural History Museum, London]]|alt=Skeleton of an icthyosaur in side view]]
[[Ichthyosaur]]s suffered an [[evolutionary bottleneck]] during the end-Triassic extinction, with all non-[[neoichthyosauria]]ns becoming extinct. Ichthyosaurs reached their apex of species diversity during the Early Jurassic, with an array of morphologies including the huge [[apex predator]] ''[[Temnodontosaurus]]'' and swordfish-like ''[[Eurhinosaurus]],'' though Early Jurassic ichthyosaurs were significantly less morphologically diverse than their Triassic counterparts.<ref name="Thorne-2011">{{Cite journal|last1=Thorne|first1=P. M.|last2=Ruta|first2=M.|last3=Benton|first3=M. J.|date=2011-05-17|title=Resetting the evolution of marine reptiles at the Triassic-Jurassic boundary|journal=Proceedings of the National Academy of Sciences|language=en|volume=108|issue=20|pages=8339–8344|bibcode=2011PNAS..108.8339T|doi=10.1073/pnas.1018959108|issn=0027-8424|pmc=3100925|pmid=21536898|doi-access=free}}</ref><ref name="Moon-2020">{{Cite journal|last1=Moon|first1=Benjamin C.|last2=Stubbs|first2=Thomas L.|date=2020-02-13|title=Early high rates and disparity in the evolution of ichthyosaurs|url= |journal=Communications Biology|language=en|volume=3|issue=1|page=68|doi=10.1038/s42003-020-0779-6|pmid=32054967|pmc=7018711|issn=2399-3642}}</ref> At the Early–Middle Jurassic boundary, between the end of the Toarcian and the beginning of the Bajocian, most lineages of ichythosaur appear to have become extinct, with the first appearance of the [[Ophthalmosauridae]], the clade that would encompass almost all ichthyosaurs from then on, during the early Bajocian.<ref name="Fischer-2021">{{Cite journal|last1=Fischer|first1=Valentin|last2=Weis|first2=Robert|last3=Thuy|first3=Ben|date=2021-02-22|title=Refining the marine reptile turnover at the Early–Middle Jurassic transition|journal=PeerJ|language=en|volume=9|pages=e10647|doi=10.7717/peerj.10647|pmid=33665003|pmc=7906043|issn=2167-8359 |doi-access=free }}</ref> Ophthalmosaurids were diverse by the Late Jurassic, but failed to fill many of the niches that had been occupied by ichthyosaurs during the Early Jurassic.<ref name="Fischer-2021" /><ref name="Thorne-2011" /><ref name="Moon-2020" />

==== Plesiosaurs ====
[[File:Rhomaleosaurus cramptoni (fossil).jpg|thumb|''[[Rhomaleosaurus|Rhomaleosaurus cramptoni]]'' at the Natural History Museum, London]]
[[Plesiosauria|Plesiosaurs]] originated at the end of the Triassic (Rhaetian). By the end of the Triassic, all other [[sauropterygia]]ns, including [[Placodontia|placodonts]] and [[nothosaur]]s, had become extinct. At least six lineages of plesiosaur crossed the Triassic–Jurassic boundary.<ref>{{Cite journal|last1=Wintrich|first1=Tanja|last2=Hayashi|first2=Shoji|last3=Houssaye|first3=Alexandra|last4=Nakajima|first4=Yasuhisa|last5=Sander|first5=P. Martin|date=2017-12-01|title=A Triassic plesiosaurian skeleton and bone histology inform on evolution of a unique body plan|url= |journal=Science Advances|language=en|volume=3|issue=12|pages=e1701144|doi=10.1126/sciadv.1701144|pmid=29242826|pmc=5729018|bibcode=2017SciA....3E1144W|issn=2375-2548}}</ref> Plesiosaurs were already diverse in the earliest Jurassic, with the majority of plesiosaurs in the Hettangian-aged Blue Lias belonging to the [[Rhomaleosauridae]]. Early plesiosaurs were generally small-bodied, with body size increasing into the Toarcian.<ref>{{Cite journal|last1=Benson|first1=Roger B. J.|last2=Evans|first2=Mark|last3=Druckenmiller|first3=Patrick S.|date=2012-03-16|title=High Diversity, Low Disparity and Small Body Size in Plesiosaurs (Reptilia, Sauropterygia) from the Triassic–Jurassic Boundary|journal=PLOS ONE|language=en|volume=7|issue=3|pages=e31838|doi=10.1371/journal.pone.0031838|issn=1932-6203|pmc=3306369|pmid=22438869|bibcode=2012PLoSO...731838B|doi-access=free}}</ref> There appears to have been a strong turnover around the Early–Middle Jurassic boundary, with [[Microcleididae|microcleidids]] and rhomaleosaurids becoming extinct and nearly extinct respectively after the end of the Toarcian with the first appearance of the dominant clade of plesiosaurs of the latter half of the Jurassic, the [[Cryptoclididae]] during the Bajocian.<ref name="Fischer-2021" /> The Middle Jurassic saw the evolution of short-necked and large-headed [[Thalassophonea|thalassophonean pliosaurs]] from ancestrally small-headed, long-necked forms''.''<ref>{{Cite journal|last=O'Keefe|first=F. Robin|date=2002|title=The evolution of plesiosaur and pliosaur morphotypes in the Plesiosauria (Reptilia: Sauropterygia)|url=https://www.cambridge.org/core/journals/paleobiology/article/abs/evolution-of-plesiosaur-and-pliosaur-morphotypes-in-the-plesiosauria-reptilia-sauropterygia/8A68F79F7BCF0D56D2D7435D3A018704|journal=Paleobiology|language=en|volume=28|issue=1|pages=101–112|doi=10.1666/0094-8373(2002)028<0101:TEOPAP>2.0.CO;2|bibcode=2002Pbio...28..101O |s2cid=85753943 |issn=0094-8373}}</ref><ref name="Fischer-2021" /> Some thalassophonean pliosaurs, such as some species of ''[[Pliosaurus]]'', had skulls up to two metres in length with body lengths estimated around {{convert|10|–|12|m|ft|sp=us}}, making them the apex predators of Late Jurassic oceans.<ref>{{Cite journal|last1=Benson|first1=Roger B. J.|last2=Evans|first2=Mark|last3=Smith|first3=Adam S.|last4=Sassoon|first4=Judyth|last5=Moore-Faye|first5=Scott|last6=Ketchum|first6=Hilary F.|last7=Forrest|first7=Richard|date=2013-05-31|title=A Giant Pliosaurid Skull from the Late Jurassic of England|journal=PLOS ONE|language=en|volume=8|issue=5|pages=e65989|doi=10.1371/journal.pone.0065989|issn=1932-6203|pmc=3669260|pmid=23741520|bibcode=2013PLoSO...865989B|doi-access=free}}</ref><ref name="Fischer-2021" /> Plesiosaurs invaded freshwater environments during the Jurassic, with indeterminate remains of small-bodied pleisosaurs known from freshwater sediments from the Jurassic of China and Australia.<ref>{{Cite journal|last1=Gao|first1=Ting|last2=Li|first2=Da-Qing|last3=Li|first3=Long-Feng|last4=Yang|first4=Jing-Tao|date=2019-08-13|title=The first record of freshwater plesiosaurian from the Middle Jurassic of Gansu, NW China, with its implications to the local palaeobiogeography|journal=Journal of Palaeogeography|volume=8|issue=1|pages=27|doi=10.1186/s42501-019-0043-5|bibcode=2019JPalG...8...27G|s2cid=199547716|issn=2524-4507|doi-access=free}}</ref><ref>{{Cite journal|last=Kear|first=Benjamin P.|date=2 August 2012|title=A revision of Australia's Jurassic plesiosaurs |journal=Palaeontology|language=en|volume=55|issue=5|pages=1125–1138|doi=10.1111/j.1475-4983.2012.01183.x|bibcode=2012Palgy..55.1125K |doi-access=free}}</ref>

==== Pterosaurs ====
[[File:Rhamphorhynchus Lauer.jpg|thumb|Skeleton of ''[[Rhamphorhynchus|Rhamphorhynchus muensteri]]'' at [[Teylers Museum]], [[Haarlem]]|left]]
[[Pterosaur]]s first appeared in the Late Triassic. A major radiation of Jurassic pterosaurs is the [[Rhamphorhynchidae]], which first appeared in the late Early Jurassic (Toarcian);<ref>{{Cite journal|last1=O’Sullivan|first1=Michael|last2=Martill|first2=David M.|date=2017-11-17|title=The taxonomy and systematics of Parapsicephalus purdoni (Reptilia: Pterosauria) from the Lower Jurassic Whitby Mudstone Formation, Whitby, U.K|url=https://www.tandfonline.com/doi/full/10.1080/08912963.2017.1281919|journal=Historical Biology|language=en|volume=29|issue=8|pages=1009–1018|doi=10.1080/08912963.2017.1281919|bibcode=2017HBio...29.1009O |s2cid=132532024|issn=0891-2963}}</ref> they are thought to been [[Piscivore|piscivorous]].<ref name="Bestwick-2018">{{Cite journal|last1=Bestwick|first1=Jordan|last2=Unwin|first2=David M.|last3=Butler|first3=Richard J.|last4=Henderson|first4=Donald M.|last5=Purnell|first5=Mark A.|date=November 2018|title=Pterosaur dietary hypotheses: a review of ideas and approaches: Pterosaur dietary hypotheses |journal=Biological Reviews|language=en|volume=93|issue=4|pages=2021–2048|doi=10.1111/brv.12431|pmc=6849529|pmid=29877021}}</ref> [[Anurognathidae|Anurognathids]], which first appeared in the Middle Jurassic, possessed short heads and densely furred bodies, and are thought to have been insectivores.<ref name="Bestwick-2018" /> Derived [[monofenestrata]]n pterosaurs such as [[Wukongopteridae|wukongopterids]] appeared in the late Middle Jurassic. Advanced short-tailed [[Pterodactyloidea|pterodactyloids]] first appeared at the Middle–Late Jurassic boundary. Jurassic pterodactyloids include the [[Ctenochasmatoidea|ctenochasmatids]], like ''[[Ctenochasma]]'', which have closely spaced needle-like teeth that were presumably used for [[Filter feeder|filter feeding]].<ref name="Bestwick-2018" /> The bizarre Late Jurassic [[Ctenochasmatoidea|ctenochasmatoid]] ''[[Cycnorhamphus]]'' had a jaw with teeth only at the tips, with bent jaws like those of living [[openbill stork]]s that may have been used to hold and crush hard invertebrates.<ref name="Bestwick-2018" />

=== Amphibians ===
[[File:Karaurus sharovi.JPG|thumb|upright|Skeleton of ''[[Karaurus|Karaurus sharovi]],'' a stem-group salamander from the Middle to Late Jurassic of Kazakhstan|alt=Topside view of a salamander skeleton]]
The diversity of [[Temnospondyli|temnospondyls]] had progressively declined through the Late Triassic, with only [[Brachyopoidea|brachyopoids]] surviving into the Jurassic and beyond.<ref>{{Citation|last=Lucas|first=Spencer G.|title=Late Triassic Terrestrial Tetrapods: Biostratigraphy, Biochronology and Biotic Events|date=2018|url=http://link.springer.com/10.1007/978-3-319-68009-5_10|work=The Late Triassic World|series=Topics in Geobiology|volume=46|pages=351–405|editor-last=Tanner|editor-first=Lawrence H.|place=Cham|publisher=Springer International Publishing |doi=10.1007/978-3-319-68009-5_10|isbn=978-3-319-68008-8|access-date=2021-04-25}}</ref> Members of the family [[Brachyopidae]] are known from Jurassic deposits in Asia,<ref>{{Cite journal|last1=Averianov|first1=Alexander O.|last2=Martin|first2=Thomas|last3=Skutschas|first3=Pavel P. |last4=Rezvyi|first4=Anton S.|last5=Bakirov|first5=Aizek A.|title=Amphibians from the Middle Jurassic Balabansai Svita in the Fergana Depression, Kyrgyzstan (Central Asia)|date=March 2008 |journal=Palaeontology|language=en|volume=51|issue=2|pages=471–485|doi=10.1111/j.1475-4983.2007.00748.x |bibcode=2008Palgy..51..471A |doi-access=free}}</ref> while the [[Chigutisauridae|chigutisaurid]] ''[[Siderops]]'' is known from the Early Jurassic of Australia.<ref>{{Cite journal|last1=Warren|first1=A. A.|last2=Hutchinson|first2=M. N.|last3=Hill|first3=Dorothy|date=1983-09-13|title=The last Labyrinthodont? A new brachyopoid (Amphibia, Temnospondyli) from the early Jurassic Evergreen formation of Queensland, Australia|url=https://royalsocietypublishing.org/doi/10.1098/rstb.1983.0080|journal=Philosophical Transactions of the Royal Society of London. B, Biological Sciences|volume=303|issue=1113|pages=1–62|doi=10.1098/rstb.1983.0080|bibcode=1983RSPTB.303....1W}}</ref> Modern [[lissamphibia]]ns began to diversify during the Jurassic. The Early Jurassic ''[[Prosalirus]]'' thought to represent the first frog relative with a morphology capable of hopping like living frogs.<ref>{{Cite journal|last1=Reilly|first1=Stephen M.|last2=Jorgensen|first2=Michael E.|date=February 2011 |title=The evolution of jumping in frogs: Morphological evidence for the basal anuran locomotor condition and the radiation of locomotor systems in crown group anurans |journal=Journal of Morphology|language=en|volume=272|issue=2|pages=149–168|doi=10.1002/jmor.10902 |pmid=21210487 |s2cid=14217777}}</ref> Morphologically recognisable stem-frogs like the South American ''[[Notobatrachus]]'' are known from the Middle Jurassic,<ref>{{Cite journal|last1=Báez|first1=Ana Maria|last2=Nicoli|first2=Laura|date=March 2008|title=A new species of Notobatrachus (Amphibia, Salientia) from the Middle Jurassic of northwestern Patagonia|url=http://dx.doi.org/10.1666/06-117.1|journal=Journal of Paleontology |volume=82|issue=2|pages=372–376|doi=10.1666/06-117.1|bibcode=2008JPal...82..372B |s2cid=130032431|issn=0022-3360|hdl=11336/135748|hdl-access=free}}</ref> with modern crown-group frogs like ''[[Enneabatrachus]]'' and ''[[Rhadinosteus]]'' appearing by the Late Jurassic.<ref>{{Cite journal |last1=Marjanović |first1=David |last2=Laurin |first2=Michel |date=2014-07-04 |title=An updated paleontological timetree of lissamphibians, with comments on the anatomy of Jurassic crown-group salamanders (Urodela) |url=http://www.tandfonline.com/doi/abs/10.1080/08912963.2013.797972 |journal=Historical Biology |language=en |volume=26 |issue=4 |pages=535–550 |doi=10.1080/08912963.2013.797972 |bibcode=2014HBio...26..535M |s2cid=84581331 |issn=0891-2963}}</ref> While the earliest salamander-line amphibians are known from the Triassic,<ref>{{Cite journal|last1=Schoch|first1=Rainer R. |last2=Werneburg|first2=Ralf|last3=Voigt|first3=Sebastian|date=2020-05-26|title=A Triassic stem-salamander from Kyrgyzstan and the origin of salamanders|journal=Proceedings of the National Academy of Sciences|language=en|volume=117|issue=21|pages=11584–11588|doi=10.1073/pnas.2001424117 |issn=0027-8424|pmc=7261083|pmid=32393623|bibcode=2020PNAS..11711584S |doi-access=free}}</ref> [[crown group]] salamanders first appear during the Middle to Late Jurassic in Eurasia, alongside stem-group relatives. Many Jurassic stem-group salamanders, such as ''[[Marmorerpeton]]'' and ''[[Kokartus]]'', are thought to have been [[Neoteny|neotenic]].<ref>{{Cite journal|last1=Skutschas|first1=Pavel|last2=Stein|first2=Koen |date=April 2015|title=Long bone histology of the stem salamander Kokartus honorarius (Amphibia: Caudata) from the Middle Jurassic of Kyrgyzstan |journal=Journal of Anatomy|language=en|volume=226|issue=4|pages=334–347|doi=10.1111/joa.12281|pmc=4386933|pmid=25682890}}</ref> Early representatives of crown group salamanders include ''[[Chunerpeton]], [[Pangerpeton]]'' and ''[[Linglongtriton]]'' from the Middle to Late Jurassic [[Yanliao Biota]] of China. Some of these are suggested to belong to [[Cryptobranchoidea]], which contains living [[Asiatic salamander|Asiatic]] and [[giant salamander]]s.<ref>{{Cite journal|last1=Jia|first1=Jia|last2=Gao|first2=Ke-Qin|date=2019-03-04|title=A new stem hynobiid salamander (Urodela, Cryptobranchoidea) from the Upper Jurassic (Oxfordian) of Liaoning Province, China |url=https://www.tandfonline.com/doi/full/10.1080/02724634.2019.1588285|journal=Journal of Vertebrate Paleontology|language=en|volume=39|issue=2|pages=e1588285|doi=10.1080/02724634.2019.1588285|bibcode=2019JVPal..39E8285J |s2cid=164310171|issn=0272-4634}}</ref> ''[[Beiyanerpeton]]'', and ''[[Qinglongtriton]]'' from the same biota are thought to be early members of [[Salamandroidea]], the group which contains all other living salamanders.<ref>{{Cite journal|last1=Gao|first1=K.-Q.|last2=Shubin|first2=N. H. |date=2012-04-10|title=Late Jurassic salamandroid from western Liaoning, China|journal=Proceedings of the National Academy of Sciences |language=en|volume=109|issue=15|pages=5767–5772|doi=10.1073/pnas.1009828109|issn=0027-8424|pmc=3326464|pmid=22411790|bibcode=2012PNAS..109.5767G |doi-access=free}}</ref><ref>{{Cite journal|last1=Jia|first1=Jia|last2=Gao|first2=Ke-Qin|date=2016-05-04|title=A New Basal Salamandroid (Amphibia, Urodela) from the Late Jurassic of Qinglong, Hebei Province, China|journal=PLOS ONE|language=en|volume=11|issue=5|pages=e0153834 |doi=10.1371/journal.pone.0153834|issn=1932-6203|pmc=4856324|pmid=27144770|bibcode=2016PLoSO..1153834J|doi-access=free}}</ref> Salamanders dispersed into North America by the end of the Jurassic, as evidenced by ''[[Iridotriton]]'', found in the Late Jurassic [[Morrison Formation]].<ref>{{cite journal|last1=Evans|first1=S. E.|last2=Lally|first2=C.|last3=Chure|first3=D. C.|last4=Elder|first4=A.|last5=Maisano|first5=J. A. |year=2005 |title=A Late Jurassic salamander (Amphibia: Caudata) from the Morrison Formation of North America|journal=Zoological Journal of the Linnean Society |volume=143 |issue=4 |pages=599–616 |doi=10.1111/j.1096-3642.2005.00159.x|doi-access=free}}</ref> The stem-[[caecilian]] ''[[Eocaecilia]]'' is known from the Early Jurassic of Arizona.<ref>{{Cite journal|last1=Santos|first1=Rodolfo Otávio|last2=Laurin|first2=Michel |last3=Zaher|first3=Hussam|date=2020-11-03|title=A review of the fossil record of caecilians (Lissamphibia: Gymnophionomorpha) with comments on its use to calibrate molecular timetrees|journal=Biological Journal of the Linnean Society|volume=131|issue=4|language=en|pages=737–755 |doi=10.1093/biolinnean/blaa148|issn=0024-4066|doi-access=free}}</ref> The fourth group of lissamphibians, the extinct salamander-like [[Albanerpetontidae|albanerpetontids]], first appeared in the Middle Jurassic, represented by ''[[Anoualerpeton|Anoualerpeton priscus]]'' from the Bathonian of Britain, as well as indeterminate remains from equivalently aged sediments in France and the [[Anoual Formation]] of Morocco.<ref>{{Cite journal|last1=Haddoumi|first1=Hamid|last2=Allain|first2=Ronan|last3=Meslouh|first3=Said|last4=Metais|first4=Grégoire|last5=Monbaron |first5=Michel|last6=Pons|first6=Denise|last7=Rage|first7=Jean-Claude|last8=Vullo|first8=Romain|last9=Zouhri|first9=Samir|date=January 2016 |title=Guelb el Ahmar (Bathonian, Anoual Syncline, eastern Morocco): First continental flora and fauna including mammals from the Middle Jurassic of Africa|url=http://doc.rero.ch/record/258861/files/mon_gab.pdf|journal=Gondwana Research|volume=29|issue=1|pages=290–319 |doi=10.1016/j.gr.2014.12.004|bibcode=2016GondR..29..290H|issn=1342-937X}}</ref>[[File:Henkeloth.jpg|left|thumb|''[[Henkelotherium]],'' a likely arboreal dyolestoid from the Late Jurassic of Portugal]]

=== Mammaliaformes ===
[[Mammaliaformes]], including [[mammal]]s, having originated from [[cynodont]]s at the end of the Triassic, diversified extensively during the Jurassic.<ref name="Lee-2015" /> While most Jurassic mammalaliaforms are solely known from isolated teeth and jaw fragments, exceptionally preserved remains have revealed a variety of lifestyles.<ref name="Lee-2015">{{Cite journal|last1=Lee|first1=Michael S.Y.|last2=Beck|first2=Robin M.D.|date=31 August 2015|title=Mammalian Evolution: A Jurassic Spark|journal=Current Biology|language=en|volume=25|issue=17|pages=R759–R761 |doi=10.1016/j.cub.2015.07.008|pmid=26325137|s2cid=11088107|doi-access=free|bibcode=2015CBio...25.R759L }}</ref> The [[docodonta]]n ''[[Castorocauda]]'' was adapted to aquatic life, similarly to the [[platypus]] and [[otter]]s.<ref name="Ji2006">{{cite journal|last1=Ji |first1=Q.|last2=Luo|first2=Z.-X.|last3=Yuan|first3=C.-X.|last4=Tabrum|first4=A. R.|year=2006|title=A swimming mammaliaform from the Middle Jurassic and ecomorphological diversification of early mammals|journal=Science|volume=311|issue=5,764|pages=1,123–1,127 |bibcode=2006Sci...311.1123J |doi=10.1126/science.1123026|pmid=16497926|s2cid=46067702|url=http://doc.rero.ch/record/13437/files/PAL_E249.pdf}}</ref> Some members of [[Haramiyida]]<ref>{{Cite journal|last1=Meng|first1=Qing-Jin|last2=Grossnickle|first2=David M.|last3=Liu|first3=Di |last4=Zhang|first4=Yu-Guang|last5=Neander|first5=April I.|last6=Ji|first6=Qiang|last7=Luo|first7=Zhe-Xi|date=August 2017|title=New gliding mammaliaforms from the Jurassic|url=https://www.nature.com/articles/nature23476|journal=Nature|language=en|volume=548|issue=7667|pages=291–296 |doi=10.1038/nature23476|pmid=28792929|bibcode=2017Natur.548..291M|s2cid=205259206|issn=1476-4687}}</ref> and the [[eutriconodonta]]n tribe [[Volaticotherini]]<ref name="desc">Meng, J.; Hu, Y.-M.; Wang, Y.-Q.; Wang, X.-L.; Li, C.-K. (2007). "Corrigendum: A Mesozoic gliding mammal from northeastern China". Nature 446 (7131): 102. {{Bibcode|2007Natur.446Q.102M}}. {{doi|10.1038/nature05639}}.</ref> had a [[patagium]] akin to those of [[flying squirrel]]s, allowing them to glide through the air. The [[aardvark]]-like mammal ''[[Fruitafossor]]'', of uncertain taxonomy, was likely a specialist on colonial insects, similarly to living [[anteater]]s.<ref name="Luo2005">{{cite journal|last1=Luo|first1=Z.-X.|last2=Wible |first2=J.R.|year=2005|title=A Late Jurassic Digging Mammal and Early Mammalian Diversification|journal=Science|volume=308|issue=5718|pages=103–107|bibcode=2005Sci...308..103L|doi=10.1126/science.1108875|issn=0036-8075|pmid=15802602|s2cid=7031381}}</ref> [[Australosphenida]], a group of mammals possibly related to living [[monotreme]]s, first appeared in the Middle Jurassic of Gondwana.<ref>{{Cite journal|last1=Luo|first1=Zhe-Xi |last2=Cifelli|first2=Richard L.|last3=Kielan-Jaworowska|first3=Zofia|date=January 2001|title=Dual origin of tribosphenic mammals |url=http://www.nature.com/articles/35051023|journal=Nature|language=en|volume=409|issue=6816|pages=53–57|doi=10.1038/35051023|pmid=11343108 |bibcode=2001Natur.409...53L|s2cid=4342585|issn=0028-0836|via=}}</ref> The earliest records of [[Multituberculata|multituberculates]], one of the longest lasting and most successful orders of mammals, are known from the Middle Jurassic.<ref>{{Cite journal |last1=Mao |first1=Fangyuan |last2=Brewer |first2=Philippa |last3=Hooker |first3=Jerry J. |last4=Meng |first4=Jin |date=2022-12-31 |title=New allotherian specimens from the Middle Jurassic Woodeaton Quarry (Oxfordshire) and implications for haramiyidan diversity and phylogeny |url=https://www.tandfonline.com/doi/full/10.1080/14772019.2022.2097021 |journal=Journal of Systematic Palaeontology |language=en |volume=20 |issue=1 |pages=1–37 |doi=10.1080/14772019.2022.2097021 |issn=1477-2019}}</ref> [[Theria]]n mammals, represented today by living [[Placentalia|placentals]] and [[marsupial]]s, diversified meteorically during the Middle Jurassic.<ref>{{Cite journal |last1=Close |first1=Roger A. |last2=Friedman |first2=Matt |last3=Lloyd |first3=Graeme T. |last4=Benson |first4=Roger B. J. |date=17 August 2015 |title=Evidence for a Mid-Jurassic Adaptive Radiation in Mammals |url=https://www.sciencedirect.com/science/article/pii/S0960982215007411 |journal=[[Current Biology]] |language=en |volume=25 |issue=16 |pages=2137–2142 |doi=10.1016/j.cub.2015.06.047 |pmid=26190074 |bibcode=2015CBio...25.2137C |access-date=4 November 2024 |via=Elsevier Science Direct}}</ref> They have their earliest records during the early Late Jurassic, represented by ''[[Juramaia]],'' a [[eutheria]]n mammal closer to the ancestry of placentals than marsupials.<ref name="Juramaia">{{cite journal|author=Zhe-Xi Luo|author2=Chong-Xi Yuan|author3=Qing-Jin Meng|author4=Qiang Ji|date=25 August 2011|title=A Jurassic eutherian mammal and divergence of marsupials and placentals |url=http://211.144.68.84:9998/91keshi/Public/File/34/476-7361/pdf/nature10291.pdf|url-status=dead |journal=Nature |volume=476 |issue=7361 |pages=442–445 |doi=10.1038/nature10291 |pmid=21866158 |bibcode=2011Natur.476..442L |s2cid=205225806 |archive-url=https://web.archive.org/web/20131110134026/http://211.144.68.84:9998/91keshi/Public/File/34/476-7361/pdf/nature10291.pdf|archive-date=10 November 2013}} [http://www.nature.com/nature/journal/v476/n7361/extref/nature10291-s1.pdf Electronic supplementary material]</ref> ''Juramaia'' is much more advanced than expected for its age, as other therian mammals are not known until the Early Cretaceous, and it has been suggested that ''Juramaia'' may also originate from the Early Cretaceous instead.<ref>{{Cite journal|last1=King|first1=Benedict|last2=Beck|first2=Robin M. D.|date=2020-06-10|title=Tip dating supports novel resolutions of controversial relationships among early mammals|url= |journal=Proceedings of the Royal Society B: Biological Sciences|volume=287|issue=1928|pages=20200943|doi=10.1098/rspb.2020.0943|pmc=7341916|pmid=32517606}}</ref> Two groups of non-mammaliaform cynodonts persisted beyond the end of the Triassic. The insectiviorous [[Tritheledontidae]] has a few records from the Early Jurassic. The [[Tritylodontidae]], a herbiviorous group of cynodonts that first appeared during the Rhaetian, has abundant records from the Jurassic, overwhelmingly from the Northern Hemisphere.<ref>{{Cite journal|last1=Ruta|first1=Marcello|last2=Botha-Brink|first2=Jennifer |last3=Mitchell|first3=Stephen A.|last4=Benton|first4=Michael J.|date=2013-10-22|title=The radiation of cynodonts and the ground plan of mammalian morphological diversity|url= |journal=Proceedings of the Royal Society B: Biological Sciences|language=en|volume=280|issue=1769 |pages=20131865|doi=10.1098/rspb.2013.1865|issn=0962-8452|pmc=3768321|pmid=23986112}}</ref><ref>{{Citation|last1=Abdala|first1=Fernando|title=The Late Triassic Record of Cynodonts: Time of Innovations in the Mammalian Lineage|date=2018|url=http://link.springer.com/10.1007/978-3-319-68009-5_11|work=The Late Triassic World|volume=46|pages=407–445|editor-last=Tanner|editor-first=Lawrence H.|place=Cham|publisher=Springer International Publishing|language=en|doi=10.1007/978-3-319-68009-5_11|isbn=978-3-319-68008-8|access-date=2021-05-24|last2=Gaetano|first2=Leandro C. |series=Topics in Geobiology }}</ref>

=== Fish ===

==== Jawless fish ====
[[File:Yanliaomyzon.png|thumb|Fossils and life restorations of the two species of ''[[Yanliaomyzon]] ,'' a [[lamprey]] known from the Middle Jurassic of China]]
The last known species of [[conodont]], a class of [[Agnatha|jawless fish]] whose hard, tooth-like elements are key index fossils, finally became extinct during the earliest Jurassic after over 300 million years of evolutionary history, with an asynchronous extinction occurring first in the Tethys and eastern Panthalassa and survivors persisting into the earliest Hettangian of Hungary and central Panthalassa.<ref>{{Cite journal |last1=Du|first1=Yixing|last2=Chiari|first2=Marco|last3=Karádi|first3=Viktor|last4=Nicora|first4=Alda|last5=Onoue|first5=Tetsuji|last6=Pálfy |first6=József|last7=Roghi|first7=Guido|last8=Tomimatsu|first8=Yuki|last9=Rigo|first9=Manuel|date=April 2020|title=The asynchronous disappearance of conodonts: New constraints from Triassic-Jurassic boundary sections in the Tethys and Panthalassa |url=https://linkinghub.elsevier.com/retrieve/pii/S0012825220302221|journal=Earth-Science Reviews|language=en|volume=203|pages=103176 |doi=10.1016/j.earscirev.2020.103176|bibcode=2020ESRv..20303176D|hdl=11577/3338908 |s2cid=216173452}}</ref> End-Triassic conodonts were represented by only a handful of species and had been progressively declining through the Middle and Late Triassic.<ref>{{Cite journal |last1=Ginot|first1=Samuel|last2=Goudemand|first2=Nicolas|date=December 2020|title=Global climate changes account for the main trends of conodont diversity but not for their final demise|url=https://linkinghub.elsevier.com/retrieve/pii/S0921818120302162|journal=Global and Planetary Change |language=en|volume=195|pages=103325|doi=10.1016/j.gloplacha.2020.103325|bibcode=2020GPC...19503325G|s2cid=225005180}}</ref> ''[[Yanliaomyzon]]'' from the Middle Jurassic of China represents the oldest post Paleozoic [[lamprey]], and the oldest lamprey to have the toothed feeding apparatus and likely the three stage life cycle typical of modern members of the group.<ref name="Wu-2023">{{Cite journal |last1=Wu |first1=Feixiang |last2=Janvier |first2=Philippe |last3=Zhang |first3=Chi |date=2023-10-31 |title=The rise of predation in Jurassic lampreys |journal=Nature Communications |language=en |volume=14 |issue=1 |pages=6652 |doi=10.1038/s41467-023-42251-0 |issn=2041-1723|doi-access=free |pmid=37907522 |pmc=10618186 |bibcode=2023NatCo..14.6652W }}</ref>

==== Sarcopterygii ====
[[File:Coelacanth, Late Late Jurassic, Tithonian Age, Solnhofen Lithographic Limestone, Solnhofen, Bavaria, Germany - Houston Museum of Natural Science - DSC01858.JPG|thumb|Coelacanth from the Solnhofen Limestone|left]]
[[Lungfish]] (Dipnoi) were present in freshwater environments of both hemispheres during the Jurassic.<ref>{{Cite journal|last1=Kemp|first1=Anne |last2=Cavin|first2=Lionel|last3=Guinot|first3=Guillaume|date=April 2017|title=Evolutionary history of lungfishes with a new phylogeny of post-Devonian genera|journal=Palaeogeography, Palaeoclimatology, Palaeoecology|language=en|volume=471|pages=209–219|doi=10.1016/j.palaeo.2016.12.051 |bibcode=2017PPP...471..209K|doi-access=free}}</ref> Some studies have proposed that the last common ancestor of all living lungfish lived during the Jurassic.<ref>{{Cite journal |last1=Brownstein |first1=Chase Doran |last2=Harrington |first2=Richard C |last3=Near |first3=Thomas J. |date=July 2023 |title=The biogeography of extant lungfishes traces the breakup of Gondwana |url=https://onlinelibrary.wiley.com/doi/10.1111/jbi.14609 |journal=Journal of Biogeography |language=en |volume=50 |issue=7 |pages=1191–1198 |doi=10.1111/jbi.14609 |bibcode=2023JBiog..50.1191B |issn=0305-0270}}</ref> [[Mawsoniidae|Mawsoniids]], a marine and freshwater/brackish group of [[coelacanth]]s, which first appeared in North America during the Triassic, expanded into Europe and South America by the end of the Jurassic.<ref>{{Cite journal|last1=Cavin|first1=Lionel|last2=Cupello|first2=Camila|last3=Yabumoto|first3=Yoshitaka|last4=Léo|first4=Fragoso|last5=Deersi |first5=Uthumporn|last6=Brito|first6=Paul M.|date=2019|title=Phylogeny and evolutionary history of mawsoniid coelacanths |url=http://www.kmnh.jp/wp-content/uploads/2019/05/A17-3-Cavin.pdf|journal=Bulletin of the Kitakyushu Museum of Natural History and Human History, Series A|volume=17|pages=3–13}}</ref> The marine [[Latimeriidae]], which contains the living coelacanths of the genus ''[[Latimeria]]'', were also present in the Jurassic, having originated in the Triassic, with a number of records from the Jurassic of Europe including ''[[Swenzia]]'', thought to be the closest known relative of living coelacanths.<ref>{{Cite journal |last=Clement|first=Gaël|date=2005-09-30|title=A new coelacanth (Actinistia, Sarcopterygii) from the Jurassic of France, and the question of the closest relative fossil to Latimeria|url=http://www.tandfonline.com/doi/abs/10.1671/0272-4634%282005%29025%5B0481%3AANCASF%5D2.0.CO%3B2 |journal=Journal of Vertebrate Paleontology|language=en|volume=25|issue=3|pages=481–491|doi=10.1671/0272-4634(2005)025[0481:ANCASF]2.0.CO;2 |s2cid=86338307 |issn=0272-4634}}</ref>

==== Actinopterygii ====
[[File:Thrissops cf formosus 01.jpg|thumb|upright=1.15|Fossil of ''[[Thrissops]],'' an [[ichthyodectid]] stem-group teleost from the Late Jurassic Solnhofen Limestone of Germany, showing preserved colouration]]
Ray-finned fish ([[Actinopterygii]]) were major components of Jurassic freshwater and marine ecosystems. Archaic "[[Palaeonisciformes|palaeoniscoid]]" fish, which were common in both marine and freshwater habitats during the preceding Triassic declined during the Jurassic, being largely replaced by more [[Derived (phylogenetics)|derived]] actinopterygian lineages.<ref>{{Cite journal |last=Skrzycka |first=Roksana|date=2014-07-03|title=Revision of two relic actinopterygians from the Middle or Upper Jurassic Karabastau Formation, Karatau Range, Kazakhstan |url=http://www.tandfonline.com/doi/abs/10.1080/03115518.2014.880267|journal=Alcheringa: An Australasian Journal of Palaeontology |language=en|volume=38|issue=3|pages=364–390|doi=10.1080/03115518.2014.880267|bibcode=2014Alch...38..364S |s2cid=129308632|issn=0311-5518}}</ref> The oldest known [[Acipenseriformes]], the group that contains living [[sturgeon]] and [[paddlefish]], are from the Early Jurassic.<ref>{{Cite journal |last1=Hilton|first1=Eric J.|last2=Grande|first2=Lance|last3=Jin|first3=Fan|date=January 2021|title=Redescription of † Yanosteus longidorsalis Jin et al., (Chondrostei, Acipenseriformes, †Peipiaosteidae) from the Early Cretaceous of China |url=https://www.cambridge.org/core/product/identifier/S0022336020000803/type/journal_article|journal=Journal of Paleontology |language=en |volume=95 |issue=1|pages=170–183|doi=10.1017/jpa.2020.80|bibcode=2021JPal...95..170H |s2cid=225158727|issn=0022-3360}}</ref> [[Amiiformes|Amiiform]] fish (which today only includes the [[bowfin]]) first appeared during the Early Jurassic, represented by ''[[Caturus]]'' from the Pliensbachian of Britain; after their appearance in the western Tethys, they expanded to Africa, North America and Southeast and East Asia by the end of the Jurassic,<ref name="Poyato-Ariza-2020" /> with the modern family [[Amiidae]] appearing during the Late Jurassic.<ref>{{Cite journal |last1=Deesri |first1=Uthumporn |last2=Naksri |first2=Wilailuck |last3=Jintasakul |first3=Pratueng |last4=Noda |first4=Yoshikazu |last5=Yukawa |first5=Hirokazu |last6=Hossny |first6=Tamara El |last7=Cavin |first7=Lionel |date=2023-03-27 |title=A New Sinamiin Fish (Actinopterygii) from the Early Cretaceous of Thailand: Implications on the Evolutionary History of the Amiid Lineage |journal=Diversity |language=en |volume=15 |issue=4 |pages=491 |doi=10.3390/d15040491 |issn=1424-2818 |doi-access=free |bibcode=2023Diver..15..491D }}</ref> [[Pycnodontiformes]], which first appeared in the western Tethys during the Late Triassic, expanded to South America and Southeast Asia by the end of the Jurassic, having a high diversity in Europe during the Late Jurassic.<ref name="Poyato-Ariza-2020">{{Cite journal|last1=Poyato-Ariza|first1=Francisco José|last2=Martín-Abad |first2=Hugo|date=2020-07-19|title=History of two lineages: Comparative analysis of the fossil record in Amiiformes and Pycnodontiformes (Osteischtyes, Actinopterygii)|url=https://ojs.uv.es/index.php/sjpalaeontology/article/view/17833|journal=Spanish Journal of Palaeontology |volume=28 |issue=1|pages=79|doi=10.7203/sjp.28.1.17833|issn=2255-0550|doi-access=free|hdl=10486/710030|hdl-access=free}}</ref> During the Jurassic, the [[Ginglymodi]], the only living representatives being [[gar]]s (Lepisosteidae) were diverse in both freshwater and marine environments. The oldest known representatives of anatomically modern gars appeared during the Late Jurassic.<ref>{{Cite journal |last1=Brito |first1=Paulo M. |last2=Alvarado-Ortega|first2=Jésus|last3=Meunier|first3=François J.|date=December 2017|title=Earliest known lepisosteoid extends the range of anatomically modern gars to the Late Jurassic|journal=Scientific Reports |language=en |volume=7 |issue=1 |pages=17830 |doi=10.1038/s41598-017-17984-w |issn=2045-2322|pmc=5736718|pmid=29259200|bibcode=2017NatSR...717830B}}</ref> Stem-group [[teleost]]s, which make up over 99% of living Actinopterygii, had first appeared during the Triassic in the western Tethys; they underwent a major diversification beginning in the Late Jurassic, with early representatives of modern teleost clades such as [[Elopomorpha]] and [[Osteoglossoidei]] appearing during this time.<ref>Arratia G. Mesozoic halecostomes and the early radiation of teleosts. In: Arratia G, Tintori A, editors. Mesozoic Fishes 3 – Systematics, Paleoenvironments and Biodiversity. München: Verlag Dr. Friedrich Pfeil; 2004. p. 279–315.</ref><ref>{{Cite journal |last1=Tse |first1=Tze-Kei |last2=Pittman |first2=Michael|last3=Chang|first3=Mee-mann|date=2015-03-26|title=A specimen of Paralycoptera Chang & Chou 1977 (Teleostei: Osteoglossoidei) from Hong Kong (China) with a potential Late Jurassic age that extends the temporal and geographical range of the genus |journal=PeerJ |language=en|volume=3|pages=e865|doi=10.7717/peerj.865|pmid=25834774|pmc=4380157|issn=2167-8359 |doi-access=free }}</ref> The [[Pachycormiformes]], a group of marine stem-teleosts, first appeared in the Early Jurassic and included both [[tuna]]-like predatory and filter-feeding forms, the latter included the largest bony fish known to have existed: ''[[Leedsichthys]]'', with an estimated maximum length of over 15 metres, known from the late Middle to Late Jurassic.<ref name="Liston2013">Liston, J., Newbrey, M., Challands, T., and Adams, C., 2013, "Growth, age and size of the Jurassic pachycormid ''Leedsichthys problematicus'' (Osteichthyes: Actinopterygii) in: Arratia, G., Schultze, H. and Wilson, M. (eds.) ''Mesozoic Fishes 5 – Global Diversity and Evolution''. Verlag Dr. Friedrich Pfeil, München, Germany, pp. 145–175</ref>

==== Chondrichthyes ====
[[File:Naturkundemuseum Engelhai Pseudorhina sp.17RM1984.jpg|thumb|Fossil of ''[[Pseudorhina]]'' from the Late Jurassic of Germany, a close relative of modern [[angelshark]]s.]]
During the Early Jurassic, the shark-like [[Hybodontiformes|hybodonts]], which represented the dominant group of [[Chondrichthyes|chondrichthyans]] during the preceding Triassic, were common in both marine and freshwater settings; however, by the Late Jurassic, hybodonts had become minor components of most marine communities, having been largely replaced by modern [[Neoselachii|neoselachians]], but remained common in freshwater and restricted marine environments.<ref>{{Cite journal |last1=Rees |first1=Jan |last2=Underwood |first2=Charlie J. |date=2008-01-17 |title=Hybodont sharks of the English Bathonian and Callovian (Middle Jurassic) |journal=Palaeontology |language=en |volume=51 |issue=1 |pages=117–147 |doi=10.1111/j.1475-4983.2007.00737.x |bibcode=2008Palgy..51..117R |doi-access=free}}</ref><ref>{{Cite journal |last1=Corso |first1=Jacopo Dal |last2=Bernardi |first2=Massimo |last3=Sun |first3=Yadong |last4=Song |first4=Haijun |last5=Seyfullah |first5=Leyla J. |last6=Preto |first6=Nereo |last7=Gianolla |first7=Piero |last8=Ruffell |first8=Alastair |last9=Kustatscher |first9=Evelyn |last10=Roghi |first10=Guido |last11=Merico |first11=Agostino |date=September 2020 |title=Extinction and dawn of the modern world in the Carnian (Late Triassic) |journal=Science Advances |volume=6 |issue=38 |language=EN |doi=10.1126/sciadv.aba0099 |pmc=7494334 |pmid=32938682 |bibcode=2020SciA....6...99D}}</ref> The Neoselachii, which contains all living sharks and rays, radiated beginning in the Early Jurassic.<ref>{{Cite journal |last=Underwood |first=Charlie J. |date=March 2006 |title=Diversification of the Neoselachii (Chondrichthyes) during the Jurassic and Cretaceous |url=http://www.bioone.org/doi/abs/10.1666/04069.1 |journal=Paleobiology |language=en |volume=32 |issue=2 |pages=215–235 |doi=10.1666/04069.1 |bibcode=2006Pbio...32..215U |s2cid=86232401 |issn=0094-8373}}</ref> The oldest known ray ([[Batoidea]]) is ''[[Antiquaobatis]]'' from the Pliensbachian of Germany.<ref>{{Cite journal |last1=Stumpf |first1=Sebastian |last2=Kriwet |first2=Jürgen |date=2019-12-01 |title=A new Pliensbachian elasmobranch (Vertebrata, Chondrichthyes) assemblage from Europe, and its contribution to the understanding of late Early Jurassic elasmobranch diversity and distributional patterns |journal=PalZ |language=en |volume=93 |issue=4 |pages=637–658 |doi=10.1007/s12542-019-00451-4 |issn=1867-6812 |doi-access=free |bibcode=2019PalZ...93..637S |s2cid=181782998}}</ref> Jurassic batoids known from complete remains retain a conservative, [[guitarfish]]-like morphology.<ref>{{Cite journal |last1=Underwood |first1=Charlie J. |last2=Claeson |first2=Kerin M. |date=June 2019 |title=The Late Jurassic ray Kimmerobatis etchesi gen. et sp. nov. and the Jurassic radiation of the Batoidea |url=https://linkinghub.elsevier.com/retrieve/pii/S0016787817300949 |journal=Proceedings of the Geologists' Association |language=en |volume=130 |issue=3–4 |pages=345–354 |doi=10.1016/j.pgeola.2017.06.009 |bibcode=2019PrGA..130..345U |s2cid=90691006}}</ref> The oldest known [[Hexanchiformes]] and [[carpet shark]]s (Orectolobiformes) are from the Early Jurassic (Pliensbachian and Toarcian, respectively) of Europe.<ref>{{Cite journal|last1=Kriwet|first1=Jürgen|last2=Klug|first2=Stefanie|date=December 2011|title=A new Jurassic cow shark (Chondrichthyes, Hexanchiformes) with comments on Jurassic hexanchiform systematics|journal=[[Swiss Journal of Geosciences]]|language=en|volume=104|issue=S1|pages=107–114|doi=10.1007/s00015-011-0075-z|s2cid=84405176|issn=1661-8726|doi-access=free|bibcode=2011SwJG..104..107K }}</ref><ref>{{Cite journal |last1=Srdic |first1=Alex |last2=Duffin |first2=Christopher J. |last3=Martill |first3=David M. |date=August 2016 |title=First occurrence of the orectolobiform shark Akaimia in the Oxford Clay Formation (Jurassic, Callovian) of England |url=https://linkinghub.elsevier.com/retrieve/pii/S0016787816300785 |journal=Proceedings of the Geologists' Association |language=en |volume=127 |issue=4 |pages=506–513 |doi=10.1016/j.pgeola.2016.07.002|bibcode=2016PrGA..127..506S }}</ref> The oldest known members of the [[Heterodontiformes]], the only living members of which are the [[bullhead shark]] (''Heterodontus''), first appeared in the Early Jurassic, with representatives of the living genus appearing during the Late Jurassic.<ref>{{Cite journal |last1=Slater |first1=Tiffany S. |last2=Ashbrook |first2=Kate |last3=Kriwet |first3=Jürgen |date=August 2020 |editor-last=Cavin |editor-first=Lionel |title=Evolutionary relationships among bullhead sharks (Chondrichthyes, Heterodontiformes) |url=https://onlinelibrary.wiley.com/doi/10.1002/spp2.1299 |journal=Papers in Palaeontology |language=en |volume=6 |issue=3 |pages=425–437 |doi=10.1002/spp2.1299 |bibcode=2020PPal....6..425S |s2cid=214133104 |issn=2056-2802 |hdl=10468/10339 |hdl-access=free}}</ref> The oldest record of angelsharks ([[Squatiniformes]]) is ''[[Pseudorhina]]'' from the Late Jurassic (Oxfordian–Tithonian) of Europe, which already has a bodyform similar to members of the only living genus of the order, ''[[Squatina]]''.<ref>{{Cite journal |last1=López-Romero |first1=Faviel A. |last2=Stumpf |first2=Sebastian |last3=Pfaff |first3=Cathrin |last4=Marramà |first4=Giuseppe |last5=Johanson |first5=Zerina |last6=Kriwet |first6=Jürgen |date=2020-07-28 |title=Evolutionary trends of the conserved neurocranium shape in angel sharks (Squatiniformes, Elasmobranchii) |journal=Scientific Reports |language=en |volume=10 |issue=1 |pages=12582 |doi=10.1038/s41598-020-69525-7 |pmid=32724124 |pmc=7387474 |bibcode=2020NatSR..1012582L |issn=2045-2322}}</ref> The oldest known remains of [[Carcharhiniformes]], the largest order of living sharks, first appear in the late Middle Jurassic (Bathonian) of the western Tethys (England and Morocco). Known dental and exceptionally preserved body remains of Jurassic Carchariniformes are similar to those of living [[Scyliorhinidae|catshark]]s.<ref>{{Cite journal |last1=Stumpf |first1=Sebastian |last2=Scheer |first2=Udo |last3=Kriwet |first3=Jürgen |date=2019-03-04 |title=A new genus and species of extinct ground shark, †Diprosopovenator hilperti, gen. et sp. nov. (Carcharhiniformes, †Pseudoscyliorhinidae, fam. nov.), from the Upper Cretaceous of Germany |journal=Journal of Vertebrate Paleontology |volume=39 |issue=2 |pages=e1593185 |doi=10.1080/02724634.2019.1593185 |bibcode=2019JVPal..39E3185S |s2cid=155785248 |issn=0272-4634 |doi-access=free}}</ref> [[Synechodontiformes]], an extinct group of sharks closely related to Neoselachii, were also widespread during the Jurassic.<ref>{{Cite journal |last1=Klug |first1=Stefanie |last2=Tütken |first2=Thomas |last3=Wings |first3=Oliver |last4=Pfretzschner |first4=Hans-Ulrich |last5=Martin |first5=Thomas |date=September 2010 |title=A Late Jurassic freshwater shark assemblage (Chondrichthyes, Hybodontiformes) from the southern Junggar Basin, Xinjiang, Northwest China |url=http://link.springer.com/10.1007/s12549-010-0032-2 |journal=Palaeobiodiversity and Palaeoenvironments |language=en |volume=90 |issue=3 |pages=241–257|doi=10.1007/s12549-010-0032-2 |bibcode=2010PdPe...90..241K |s2cid=129236098 |issn=1867-1594}}</ref> The oldest remains of modern [[chimaera]]s are from the Early Jurassic of Europe, with members of the living family [[Callorhinchidae]] appearing during the Middle Jurassic. Unlike most living chimaeras, Jurassic chimeras are often found in shallow water environments.<ref>{{Cite journal |last1=Popov |first1=Evgeny V. |last2=Delsate |first2=Dominique |last3=Felten |first3=Roland |date=2019-07-02 |title=A New Callorhinchid Genus (Holocephali, Chimaeroidei) from the Early Bajocian of Ottange-Rumelange, on the Luxembourg-French Border |url=https://bioone.org/journals/paleontological-research/volume-23/issue-3/2018PR021/A-New-Callorhinchid-Genus-Holocephali-Chimaeroidei-from-the-Early-Bajocian/10.2517/2018PR021.full |journal=Paleontological Research |volume=23 |issue=3 |pages=220 |doi=10.2517/2018PR021 |bibcode=2019PalRe..23..220P |s2cid=198423356 |issn=1342-8144}}</ref> The closely related [[Myriacanthidae|myriacanthids]] and the flattened ''[[Squaloraja]]'' are also known from the Jurassic of Europe.<ref>{{Cite journal |last1=Duffin|first1=Christopher J. |last2=Milàn |first2=Jesper |date=2017-11-14|title=A new myriacanthid holocephalian from the Early Jurassic of Denmark |url=https://2dgf.dk/publikationer/bulletin/bulletin-volume-65-2017/#10 |journal=Bulletin of the Geological Society of Denmark |language=en |volume=65 |pages=161–170|doi=10.37570/bgsd-2017-65-10|issn=2245-7070 |doi-access=free|bibcode=2017BuGSD..65..161D }}</ref>

=== Insects and arachnids ===
[[File:Lichnomesopsyche daohugouensis.jpg|left|thumb|''[[Lichnomesopsyche|Lichnomesopsyche daohugouensis]]'', an extinct [[Mesopsychidae|mesopsychid]] [[Mecoptera|scorpionfly]] from the Late Jurassic of China]]
There appears to have been no major extinction of insects at the Triassic–Jurassic boundary.<ref name="Lucas-2015" /> Many important insect fossil localities are known from the Jurassic of Eurasia, the most important being the [[Karabastau Formation]] of Kazakhstan and the various Yanliao Biota deposits in Inner Mongolia, China, such as the Daohugou Bed, dating to the Callovian–Oxfordian. The diversity of insects stagnated throughout the Early and Middle Jurassic, but during the latter third of the Jurassic origination rates increased substantially while extinction rates remained flat.<ref>{{Citation|last=Labandeira|first=Conrad C.|title=The Fossil History of Insect Diversity|date=2018-05-23 |work=Insect Biodiversity|pages=723–788|place=Chichester, UK|publisher=John Wiley & Sons, Ltd|language=en|doi=10.1002/9781118945582.ch24|isbn=978-1-118-94558-2}}</ref> The increasing diversity of insects in the Middle–Late Jurassic corresponds with a substantial increase in the diversity of [[insect mouthparts]].<ref>{{Cite journal|last1=Nel|first1=Patricia|last2=Bertrand|first2=Sylvain|last3=Nel|first3=André|date=December 2018|title=Diversification of insects since the Devonian: a new approach based on morphological disparity of mouthparts|journal=Scientific Reports|language=en|volume=8|issue=1|pages=3516|doi=10.1038/s41598-018-21938-1|issn=2045-2322|pmc=5824790|pmid=29476087|bibcode=2018NatSR...8.3516N}}</ref> The Middle to Late Jurassic was a time of major diversification for [[beetle]]s,<ref>{{Cite journal|last1=McKenna|first1=Duane D.|last2=Shin|first2=Seunggwan|last3=Ahrens|first3=Dirk|last4=Balke|first4=Michael|last5=Beza-Beza|first5=Cristian|last6=Clarke|first6=Dave J.|last7=Donath|first7=Alexander|last8=Escalona|first8=Hermes E.|last9=Friedrich|first9=Frank|last10=Letsch|first10=Harald|last11=Liu|first11=Shanlin|date=2019-12-03|title=The evolution and genomic basis of beetle diversity|journal=Proceedings of the National Academy of Sciences|language=en|volume=116|issue=49|pages=24729–24737|doi=10.1073/pnas.1909655116|issn=0027-8424|pmc=6900523|pmid=31740605|bibcode=2019PNAS..11624729M |doi-access=free}}</ref> particularly for the suborder [[Polyphaga]], which represents 90% of living beetle species but which was rare during the preceding Triassic.<ref>{{Cite journal |last1=Beutel |first1=Rolf G. |last2=Xu |first2=Chunpeng |last3=Jarzembowski |first3=Edmund |last4=Kundrata |first4=Robin |last5=Boudinot |first5=Brendon E. |last6=McKenna |first6=Duane D. |last7=Goczał |first7=Jakub |date=13 February 2024 |title=The evolutionary history of Coleoptera (Insecta) in the late Palaeozoic and the Mesozoic |journal=Systematic Entomology |language=en |volume=49 |issue=3 |pages=355–388 |doi=10.1111/syen.12623 |bibcode=2024SysEn..49..355B |issn=0307-6970|doi-access=free }}</ref> [[Weevil]]s first appear in the fossil record during the Middle to Late Jurassic, but are suspected to have originated during the Late Triassic to Early Jurassic.<ref>{{Cite journal|last1=Shin|first1=Seunggwan|last2=Clarke|first2=Dave J|last3=Lemmon|first3=Alan R|last4=Moriarty Lemmon|first4=Emily|last5=Aitken|first5=Alexander L|last6=Haddad|first6=Stephanie|last7=Farrell|first7=Brian D|last8=Marvaldi|first8=Adriana E|last9=Oberprieler|first9=Rolf G|last10=McKenna|first10=Duane D|date=2018-04-01|title=Phylogenomic Data Yield New and Robust Insights into the Phylogeny and Evolution of Weevils|url=https://academic.oup.com/mbe/article/35/4/823/4765916|journal=Molecular Biology and Evolution|language=en|volume=35|issue=4|pages=823–836|doi=10.1093/molbev/msx324|issn=0737-4038|pmid=29294021|s2cid=4366092|doi-access=free|hdl=11336/57287|hdl-access=free}}</ref> [[Orthoptera]]n diversity had declined during the Late Triassic, but recovered during the Early Jurassic,<ref>{{Cite journal |last1=Xu |first1=Chunpeng |last2=Fang |first2=Yanan |last3=Fang |first3=Yan |last4=Wang |first4=He |last5=Zhou |first5=Qian |last6=Jiang |first6=Xueying |last7=Zhang |first7=Haichun |date=14 February 2024 |title=Early Jurassic orthopteran insects from the southern Junggar Basin, NW China, with discussion of biodiversity changes of Orthoptera across the Triassic–Jurassic boundary |url=https://www.lyellcollection.org/doi/10.1144/SP538-2021-184 |journal=Geological Society, London, Special Publications |language=en |volume=538 |issue=1 |pages=147–154 |doi=10.1144/SP538-2021-184 |issn=0305-8719 |access-date=22 June 2024 |via=Lyell Collection Geological Society Publications}}</ref> with the [[Hagloidea]], a superfamily of [[ensifera]]n orthopterans today confined to a few living species, being particularly diverse during the Jurassic.<ref>{{Cite journal |last1=Woodrow |first1=Charlie |last2=Baker |first2=Ed |last3=Jonsson |first3=Thorin |last4=Montealegre-Z |first4=Fernando |date=2022-08-10 |editor-last=Nityananda |editor-first=Vivek |title=Reviving the sound of a 150-year-old insect: The bioacoustics of Prophalangopsis obscura (Ensifera: Hagloidea) |journal=PLOS ONE |language=en |volume=17 |issue=8 |pages=e0270498 |doi=10.1371/journal.pone.0270498 |doi-access=free |issn=1932-6203 |pmc=9365155 |pmid=35947546|bibcode=2022PLoSO..1770498W }}</ref> The oldest known [[lepidoptera]]ns (the group containing butterflies and moths) are known from the Triassic–Jurassic boundary, with wing scales belonging to the suborder [[Glossata]] and [[Micropterigidae]]-grade moths from the deposits of this age in Germany.<ref>{{Cite journal|last1=van Eldijk|first1=Timo J. B.|last2=Wappler|first2=Torsten|last3=Strother|first3=Paul K.|last4=van der Weijst|first4=Carolien M. H.|last5=Rajaei|first5=Hossein|last6=Visscher|first6=Henk|last7=van de Schootbrugge|first7=Bas|date=January 2018|title=A Triassic-Jurassic window into the evolution of Lepidoptera|url= |journal=Science Advances|language=en|volume=4|issue=1|pages=e1701568|bibcode=2018SciA....4.1568V|doi=10.1126/sciadv.1701568|issn=2375-2548|pmc=5770165|pmid=29349295}}</ref> Modern representatives of both [[Dragonfly|dragonflies]] and [[Damselfly|damselflies]] also first appeared during the Jurassic.<ref>{{Cite journal|last1=Kohli|first1=Manpreet Kaur|last2=Ware|first2=Jessica L.|last3=Bechly|first3=Günter|date=2016|title=How to date a dragonfly: Fossil calibrations for odonates|url=http://palaeo-electronica.org/content/fc-8|journal=Palaeontologia Electronica|volume=19|issue=1|page=576 |doi=10.26879/576|doi-access=free|bibcode=2016PalEl..19..576K }}</ref> Although modern representatives are not known until the Cenozoic, [[ectoparasitic]] insects thought to represent primitive [[flea]]s, belonging to the family [[Pseudopulicidae]], are known from the Middle Jurassic of Asia. These insects are substantially different from modern fleas, lacking the specialised morphology of the latter and being larger.<ref>{{Cite journal|last1=Huang|first1=DiYing|last2=Engel|first2=Michael S.|last3=Cai|first3=ChenYang|last4=Nel|first4=André|date=May 2013|title=Mesozoic giant fleas from northeastern China (Siphonaptera): Taxonomy and implications for palaeodiversity|journal=Chinese Science Bulletin|language=en|volume=58|issue=14|pages=1682–1690|bibcode=2013ChSBu..58.1682H|doi=10.1007/s11434-013-5769-3|issn=1001-6538|s2cid=53578959|doi-access=free|hdl=1808/14426|hdl-access=free}}</ref><ref>{{Cite journal|last1=Gao|first1=Taiping|last2=Shih|first2=Chungkun|last3=Rasnitsyn|first3=Alexandr P.|last4=Xu|first4=Xing|last5=Wang|first5=Shuo|last6=Ren|first6=Dong|date=July 2013|title=New Transitional Fleas from China Highlighting Diversity of Early Cretaceous Ectoparasitic Insects|journal=Current Biology|language=en|volume=23|issue=13|pages=1261–1266|doi=10.1016/j.cub.2013.05.040|pmid=23810530|s2cid=9646168|doi-access=free|bibcode=2013CBio...23.1261G }}</ref> [[Parasitoid wasp]]s ([[Apocrita]]) first appeared during the Early Jurassic and subsequently became widespread, reshaping terrestrial food webs.<ref>{{Citation|last1=Labandeira|first1=Conrad C.|title=The History of Insect Parasitism and the Mid-Mesozoic Parasitoid Revolution|date=2021|url=https://link.springer.com/10.1007/978-3-030-42484-8_11|work=The Evolution and Fossil Record of Parasitism|volume=49|pages=377–533|editor-last=De Baets|editor-first=Kenneth|place=Cham|publisher=Springer International Publishing|language=en|doi=10.1007/978-3-030-42484-8_11|isbn=978-3-030-42483-1|access-date=2021-12-02|last2=Li|first2=Longfeng|series=Topics in Geobiology |s2cid=236738176|editor2-last=Huntley|editor2-first=John Warren}}</ref> The Jurassic saw also saw the first appearances of several other groups of insects, including [[Phasmatodea]] (stick insects),<ref>{{Cite journal|last1=Yang|first1=Hongru|last2=Shi|first2=Chaofan|last3=Engel|first3=Michael S|last4=Zhao|first4=Zhipeng|last5=Ren|first5=Dong|last6=Gao|first6=Taiping|date=2020-04-02|title=Early specializations for mimicry and defense in a Jurassic stick insect|journal=National Science Review|volume=8|issue=1|language=en|pages=nwaa056|doi=10.1093/nsr/nwaa056|pmid=34691548|pmc=8288419|issn=2095-5138|doi-access=free}}</ref> [[Mantophasmatidae]] (gladiators),<ref>{{Cite journal|last1=Huang|first1=Di-ying|last2=Nel|first2=André|last3=Zompro|first3=Oliver|last4=Waller|first4=Alain|date=2008-06-11|title=Mantophasmatodea now in the Jurassic|url=https://www.researchgate.net/publication/5311278|journal=Naturwissenschaften|volume=95|issue=10|pages=947–952|bibcode=2008NW.....95..947H|doi=10.1007/s00114-008-0412-x|issn=0028-1042|pmid=18545982|s2cid=35408984}}</ref> [[Embioptera]] (webspinners),<ref>{{Cite journal|last1=Huang|first1=Di-Ying|last2=Nel|first2=André|date=August 2009|title=Oldest webspinners from the Middle Jurassic of Inner Mongolia, China (Insecta: Embiodea)|journal=Zoological Journal of the Linnean Society|language=en|volume=156|issue=4|pages=889–895|doi=10.1111/j.1096-3642.2008.00499.x|doi-access=free}}</ref> and [[Raphidioptera]] (snakeflies).<ref>{{Cite journal |last1=Engel |first1=Michael S. |last2=Winterton |first2=Shaun L. |last3=Breitkreuz |first3=Laura C.V. |date=2018-01-07 |title=Phylogeny and Evolution of Neuropterida: Where Have Wings of Lace Taken Us? |url=https://www.annualreviews.org/doi/10.1146/annurev-ento-020117-043127 |journal=Annual Review of Entomology |language=en |volume=63 |issue=1 |pages=531–551 |doi=10.1146/annurev-ento-020117-043127 |pmid=29324039 |issn=0066-4170}}</ref> The earliest [[scale insect]] (Coccomorpha) '''i'''s known from amber dating to the Late Jurassic, though the group probably originated earlier during the Triassic.<ref name="Jankotejacoccidae">{{Cite journal |last1=Vršanský |first1=P. |last2=Sendi |first2=H. |last3=Kotulová |first3=J. |last4=Szwedo |first4=J. |last5=Havelcová |first5=M. |last6=Palková |first6=H. |last7=Vršanská |first7=L. |last8=Sakala |first8=J. |last9=Puškelová |first9=L. |last10=Golej |first10=M. |last11=Biroň |first11=A. |last12=Peyrot |first12=D. |last13=Quicke |first13=D. |last14=Néraudeau |first14=D. |last15=Uher |first15=P. |year=2024 |title=Jurassic Park approached: a coccid from Kimmeridgian cheirolepidiacean Aintourine Lebanese amber |journal=National Science Review |at=nwae200 |doi=10.1093/nsr/nwae200 |doi-access=free |last16=Maksoud |first16=S. |last17=Azar |first17=D.|volume=12 |issue=3 |pmid=40070804 |pmc=11895504 }}</ref> 
[[File:Mongolarachne.jpg|thumb|''[[Mongolarachne]]'' from the Late Jurassic of China]]
Only a handful of records of mites are known from the Jurassic, including ''[[Jureremus]]'', an [[Oribatida|oribatid]] mite belonging to the family [[Cymbaeremaeidae]] known from the Late Jurassic of Britain and Russia,<ref>{{Cite journal|last1=Selden|first1=Paul A.|last2=Baker|first2=Anne S.|last3=Phipps|first3=Kenneth J.|date=2008|title=An Oribatid Mite (arachnida: Acari) from the Oxford Clay (jurassic: Upper Callovian) of South Cave Station Quarry, Yorkshire, Uk|url=https://onlinelibrary.wiley.com/doi/abs/10.1111/j.1475-4983.2008.00769.x|journal=Palaeontology|language=en|volume=51|issue=3|pages=623–633|doi=10.1111/j.1475-4983.2008.00769.x|bibcode=2008Palgy..51..623S |issn=1475-4983|hdl=1808/8353|s2cid=54046836 |hdl-access=free}}</ref> and a member of the still living orbatid genus ''[[Hydrozetes]]'' from the Early Jurassic of Sweden.<ref>{{Cite journal|last1=Sivhed|first1=Ulf|last2=Wallwork|first2=John A.|date=March 1978|title=An Early Jurassic oribatid mite from southern Sweden|url=https://www.tandfonline.com/doi/full/10.1080/11035897809448562|journal=Geologiska Föreningen i Stockholm Förhandlingar|language=en|volume=100|issue=1|pages=65–70|doi=10.1080/11035897809448562|issn=0016-786X}}</ref> Spiders diversified through the Jurassic.<ref name="Magalhaes-2020">{{Cite journal|last1=Magalhaes|first1=Ivan L. F.|last2=Azevedo|first2=Guilherme H. F.|last3=Michalik|first3=Peter|last4=Ramírez|first4=Martín J.|date=February 2020|title=The fossil record of spiders revisited: implications for calibrating trees and evidence for a major faunal turnover since the Mesozoic|url=https://onlinelibrary.wiley.com/doi/abs/10.1111/brv.12559|journal=Biological Reviews|language=en|volume=95|issue=1|pages=184–217|doi=10.1111/brv.12559|issn=1464-7931|pmid=31713947|s2cid=207937170}}</ref> The Early Jurassic ''[[Seppo koponeni]]'' may represent a stem group to [[Palpimanoidea]].<ref name="Seppo">{{cite journal|last1=Selden|first1=Paul A.|last2=Dunlop|first2=Jason A.|year=2014|title=The first fossil spider (Araneae: Palpimanoidea) from the Lower Jurassic (Grimmen, Germany)|journal=Zootaxa|volume=3894|issue=1|pages=161–168|doi=10.11646/zootaxa.3894.1.13|pmid=25544628}}</ref> ''[[Eoplectreurys]]'' from the Middle Jurassic of China is considered a stem lineage of [[Synspermiata]]. The oldest member of the family [[Archaeidae]], ''[[Patarchaea]]'', is known from the Middle Jurassic of China.<ref name="Magalhaes-2020" /> ''[[Mongolarachne]]'' from the Middle Jurassic of China is among the largest known fossil spiders, with legs over 5 centimetres long.<ref name="Selden2013">{{cite journal|last1=Selden|first1=P. A.|last2=Shih|first2=C.K.|last3=Ren|first3=D.|year=2013|title=A giant spider from the Jurassic of China reveals greater diversity of the orbicularian stem group|journal=Naturwissenschaften|volume=100|issue=12|pages=1171–1181|bibcode=2013NW....100.1171S|doi=10.1007/s00114-013-1121-7|pmc=3889289|pmid=24317464}}</ref> The only scorpion known from the Jurassic is ''[[Liassoscorpionides]]'' from the Early Jurassic of Germany, of uncertain placement.<ref>{{Cite journal|last1=Dunlop|first1=Jason A.|last2=Kamenz|first2=Carsten|last3=Scholtz|first3=Gerhard|date=June 2007|title=Reinterpreting the morphology of the Jurassic scorpion Liassoscorpionides|url=https://linkinghub.elsevier.com/retrieve/pii/S1467803906000673|journal=Arthropod Structure & Development|language=en|volume=36|issue=2|pages=245–252|doi=10.1016/j.asd.2006.09.003|pmid=18089103|bibcode=2007ArtSD..36..245D }}</ref> [[Eupnoi]] harvestmen ([[Opiliones]]) are known from the Middle Jurassic of China, including members of the family [[Sclerosomatidae]].<ref>{{Cite journal|last1=Huang|first1=Diying|last2=Selden|first2=Paul A.|last3=Dunlop|first3=Jason A.|date=August 2009|title=Harvestmen (Arachnida: Opiliones) from the Middle Jurassic of China|url=http://link.springer.com/10.1007/s00114-009-0556-3|journal=Naturwissenschaften|language=en|volume=96|issue=8|pages=955–962|bibcode=2009NW.....96..955H|doi=10.1007/s00114-009-0556-3|issn=0028-1042|pmid=19495718|s2cid=9570512}}</ref><ref>{{Cite journal|last1=Giribet|first1=Gonzalo|last2=Tourinho|first2=Ana Lúcia|last3=Shih|first3=ChungKun|last4=Ren|first4=Dong|date=March 2012|title=An exquisitely preserved harvestman (Arthropoda, Arachnida, Opiliones) from the Middle Jurassic of China|url=http://link.springer.com/10.1007/s13127-011-0067-x|journal=Organisms Diversity & Evolution|language=en|volume=12|issue=1|pages=51–56|doi=10.1007/s13127-011-0067-x|bibcode=2012ODivE..12...51G |issn=1439-6092|s2cid=15658216}}</ref>

=== 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>