Tithonian

The Tithonian was introduced in scientific literature by German stratigrapher Albert Oppel in 1865. The name Tithonian is unusual in geological stage names because it is derived from Greek mythology. Tithonus was the son of Laomedon of Troy and fell in love with Eos, the Greek goddess of dawn. His name was chosen by Albert Oppel for this stratigraphical stage because the Tithonian finds itself hand in hand with the dawn of the Cretaceous.{{cite book | title=The Geologic Timescale 2012 | publisher=Elsevier |veditors=Gradstein FM, Ogg JG, Schmitz MD, Ogg GM | year=2012 | page=746 | isbn=978-0-44-459390-0}}

The base of the Tithonian stage is at the base of the ammonite biozone of Hybonoticeras hybonotum. A global reference profile (a GSSP or golden spike) for the base of the Tithonian had in 2009 not yet been established.

The top of the Tithonian stage (the base of the Berriasian Stage and the Cretaceous System) is marked by the first appearance of small globular calpionellids of the species Calpionella alpina, at the base of the Alpina Subzone .

The Tithonian is often subdivided into Lower/Early, Middle and Upper/Late substages or subages. The Late Tithonian is coeval with the Portlandian Age of British stratigraphy.

The Tithonian stage contains seven ammonite biozones in the Tethys domain, from top to base:

• zone of Durangites
• zone of Micracanthoceras micranthum
• zone of Micracanthoceras ponti or Burckardticeras peroni
• zone of Semiformiceras fallauxi
• zone of Semiformiceras semiforme
• zone of Semiformiceras darwini
• zone of Hybonoticeras hybonotum

Sedimentary rocks that formed in the Tethys Ocean during the Tithonian include limestones, which preserve fossilized remains of, for example, cephalopods. The Solnhofen limestone of southern Germany, which is known for its fossils (especially Archaeopteryx), is of Tithonian age.

The later part of the Tithonian stage experienced an extinction event.{{Cite journal |last1=Benson |first1=Roger B. J. |last2=Druckenmiller |first2=Patrick S. |date=2014 |title=Faunal turnover of marine tetrapods during the Jurassic-Cretaceous transition |url=https://onlinelibrary.wiley.com/doi/10.1111/brv.12038 |journal=Biological Reviews |language=en |volume=89 |issue=1 |pages=1–23 |doi=10.1111/brv.12038|pmid=23581455 |s2cid=19710180 |url-access=subscription }}{{Cite journal |last1=Tennant |first1=Jonathan P. |last2=Mannion |first2=Philip D. |last3=Upchurch |first3=Paul |last4=Sutton |first4=Mark D. |last5=Price |first5=Gregory D. |date=2017 |title=Biotic and environmental dynamics through the Late Jurassic-Early Cretaceous transition: evidence for protracted faunal and ecological turnover: Jurassic-Cretaceous biotic and abiotic dynamics |journal=Biological Reviews |language=en |volume=92 |issue=2 |pages=776–814 |doi=10.1111/brv.12255 |pmc=6849608 |pmid=26888552}} It has been referred to as the Tithonian extinction,{{Cite journal |last=Hallam |first=A. |date=1986 |title=The Pliensbachian and Tithonian extinction events |url=http://www.nature.com/articles/319765a0 |journal=Nature |language=en |volume=319 |issue=6056 |pages=765–768 |doi=10.1038/319765a0 |bibcode=1986Natur.319..765H |s2cid=4310433 |issn=0028-0836|url-access=subscription }}{{cite book |title=Global Events and Event Stratigraphy in the Phanerozoic |vauthors=Sepkoski JJ |chapter=Patterns of Phanerozoic Extinction: A Perspective from Global Data Bases |publisher=Springer Berlin Heidelberg |year=1996 |isbn=978-3-642-79636-4 |veditors=Walliser OH |place=Berlin & Heidelberg, DE |pages=35–51 |language=en |doi=10.1007/978-3-642-79634-0_4 |access-date=2022-08-14 |chapter-url=http://link.springer.com/10.1007/978-3-642-79634-0_4}}{{Citation |last=Hallam |first=Anthony |title=Major Bio-Events in the Triassic and Jurassic |date=1996 |url=http://link.springer.com/10.1007/978-3-642-79634-0_13 |work=Global Events and Event Stratigraphy in the Phanerozoic |pages=265–283 |editor-last=Walliser |editor-first=Otto H. |access-date=2023-04-24 |place=Berlin, Heidelberg |publisher=Springer Berlin Heidelberg |language=en |doi=10.1007/978-3-642-79634-0_13 |isbn=978-3-642-79636-4|url-access=subscription }} Jurassic-Cretaceous (J–K) extinction,{{Cite journal |last1=Royo-Torres |first1=Rafael |last2=Upchurch |first2=Paul |last3=Kirkland |first3=James I. |last4=DeBlieux |first4=Donald D. |last5=Foster |first5=John R. |last6=Cobos |first6=Alberto |last7=Alcalá |first7=Luis |date=2017-10-30 |title=Descendants of the Jurassic turiasaurs from Iberia found refuge in the Early Cretaceous of western USA |journal=Scientific Reports |language=en |volume=7 |issue=1 |page=14311 |doi=10.1038/s41598-017-14677-2 |pmid=29085006 |pmc=5662694 |bibcode=2017NatSR...714311R |issn=2045-2322}} or end-Jurassic extinction.{{Cite journal |last1=Fischer |first1=Valentin |last2=Maisch |first2=Michael W. |last3=Naish |first3=Darren |last4=Kosma |first4=Ralf |last5=Liston |first5=Jeff |last6=Joger |first6=Ulrich |last7=Krüger |first7=Fritz J. |last8=Pérez |first8=Judith Pardo |last9=Tainsh |first9=Jessica |last10=Appleby |first10=Robert M. |date=2012-01-03 |title=New Ophthalmosaurid Ichthyosaurs from the European Lower Cretaceous Demonstrate Extensive Ichthyosaur Survival across the Jurassic–Cretaceous Boundary |journal=PLOS ONE |language=en |volume=7 |issue=1 |pages=e29234 |doi=10.1371/journal.pone.0029234 |issn=1932-6203 |pmc=3250416 |pmid=22235274 |bibcode=2012PLoSO...729234F |doi-access=free }}{{Cite journal |last1=Tennant |first1=Jonathan P. |last2=Mannion |first2=Philip D. |last3=Upchurch |first3=Paul |date=2016-09-02 |title=Sea level regulated tetrapod diversity dynamics through the Jurassic/Cretaceous interval |journal=Nature Communications |language=en |volume=7 |issue=1 |page=12737 |doi=10.1038/ncomms12737 |pmid=27587285 |pmc=5025807 |bibcode=2016NatCo...712737T |issn=2041-1723}} This event was fairly minor and selective, by most metrics outside the top 10 largest extinctions since the Cambrian. Nevertheless, it was still one of the largest extinctions of the Jurassic Period, alongside the Toarcian Oceanic Anoxic Event (TOAE) in the Early Jurassic.{{Cite journal |vauthors=Bambach RK |date=May 2006 |title=Phanerozoic Biodiversity Mass Extinctions |journal=Annual Review of Earth and Planetary Sciences |language=en |volume=34 |issue=1 |pages=127–155 |bibcode=2006AREPS..34..127B |doi=10.1146/annurev.earth.33.092203.122654 |issn=0084-6597}}

The Tithonian extinction has not been studied in great detail, but it is usually attributed to habitat loss via a major marine regression (sea level fall). There is good evidence for a marine regression in Europe across the Jurassic-Cretaceous boundary, which may explain the localized nature of the extinction.{{Cite journal |last=Hallam |first=A. |date=1989 |title=The case for sea-level change as a dominant causal factor in mass extinction of marine invertebrates |url=https://royalsocietypublishing.org/doi/10.1098/rstb.1989.0098 |journal=Philosophical Transactions of the Royal Society of London. B, Biological Sciences |language=en |volume=325 |issue=1228 |pages=437–455 |doi=10.1098/rstb.1989.0098 |bibcode=1989RSPTB.325..437H |issn=0080-4622|url-access=subscription }} On the other hand, there is no clear consensus on a correlation between sea level and terrestrial diversity during the Jurassic and Cretaceous. Some authors support a fundamental correlation (the so-called "common cause hypothesis"), while others strongly voice doubts.{{Cite journal |last1=Butler |first1=Richard J. |last2=Benson |first2=Roger B. J. |last3=Carrano |first3=Matthew T. |last4=Mannion |first4=Philip D. |last5=Upchurch |first5=Paul |date=2011-04-22 |title=Sea level, dinosaur diversity and sampling biases: investigating the 'common cause' hypothesis in the terrestrial realm |journal=Proceedings of the Royal Society B: Biological Sciences |language=en |volume=278 |issue=1709 |pages=1165–1170 |doi=10.1098/rspb.2010.1754 |issn=0962-8452 |pmc=3049076 |pmid=20880889}} Sea level fall was likely related to the Tithonian climate, which was substantially colder and drier than the preceding Kimmeridgian stage. Northern coral reef ecosystems, such as those of the European Tethys, would have been particularly vulnerable to global cooling during this time.

{{Annotated image|image=EmperorSeamounts.jpg|caption=The Shatsky Rise labelled on a map of North Pacific volcanic features|width=295|height=195|image-width=300|image-left=0|image-top=0|annotations={{Annotation|61|121|Shatsky Rise|font-weight=bold|color=black}}

{{Annotation|60|120|Shatsky Rise|font-weight=bold|color=yellow}}}}Few Jurassic-Cretaceous boundary sections are precisely associated with carbon isotope anomalies.{{Cite journal |last1=Price |first1=Gregory D. |last2=Főzy |first2=István |last3=Pálfy |first3=József |date=2016 |title=Carbon cycle history through the Jurassic–Cretaceous boundary: A new global δ13C stack |url=https://linkinghub.elsevier.com/retrieve/pii/S0031018216300244 |journal=Palaeogeography, Palaeoclimatology, Palaeoecology |language=en |volume=451 |pages=46–61 |doi=10.1016/j.palaeo.2016.03.016|bibcode=2016PPP...451...46P |hdl=10026.1/4782 |hdl-access=free }} Several Arctic outcrops show a moderate (up to 5‰) negative organic δ13C excursion in the middle part of the Tithonian. This excursion, sometimes called the Volgian Isotopic Carbon Excursion (VOICE), may be a consequence of volcanic activity.{{Cite journal |last1=Galloway |first1=Jennifer M. |last2=Vickers |first2=Madeleine L. |last3=Price |first3=Gregory D. |last4=Poulton |first4=Terence |last5=Grasby |first5=Stephen E. |last6=Hadlari |first6=Thomas |last7=Beauchamp |first7=Benoit |last8=Sulphur |first8=Kyle |date=2020 |title=Finding the VOICE: organic carbon isotope chemostratigraphy of Late Jurassic – Early Cretaceous Arctic Canada |url=https://www.cambridge.org/core/product/identifier/S0016756819001316/type/journal_article |journal=Geological Magazine |language=en |volume=157 |issue=10 |pages=1643–1657 |doi=10.1017/S0016756819001316 |bibcode=2020GeoM..157.1643G |hdl=10026.1/15324 |s2cid=213590881 |issn=0016-7568|hdl-access=free }} The Tithonian stage saw the emplacement of the Shatsky Rise, a massive volcanic plateau in the North Pacific. During the Late Jurassic and Early Cretaceous, numerous volcanic deposits can be found along the margin of Gondwana, which was beginning to fragment into smaller continents.

File:Morokweng Impact.jpg, with the Morokweng impactor in the background, moments before impact]]

Three large impact craters have been tentatively dated to the Tithonian: the Morokweng Impact Structure (South Africa, 80+ km diameter), Mjølnir crater (Barents Sea, 40 km diameter), and Gosses Bluff crater (Australia, 22 km diameter). These impacts would have caused local devastation, but likely had minimal impact on global ecosystems. Most volcanic events or extraterrestrial impacts in the Late Jurassic were concentrated around Gondwana, in contrast to the extinction event, which was centered on Laurasian ecosystems.

It has been suggested that the putative extinction is a consequence of sampling biases. The Late Jurassic is packed with marine lagerstätten, exceptionally diverse and well-preserved fossil beds. A lack of earliest Cretaceous marine lagerstätten may appear as a loss of diversity, simply looking at the raw data alone.{{Cite journal |last1=Dean |first1=Christopher D. |last2=Mannion |first2=Philip D. |last3=Butler |first3=Richard J. |date=2016 |editor-last=Benson |editor-first=Roger |title=Preservational bias controls the fossil record of pterosaurs |journal=Palaeontology |language=en |volume=59 |issue=2 |pages=225–247 |doi=10.1111/pala.12225 |pmc=4878658 |pmid=27239072|bibcode=2016Palgy..59..225D }} Sampling bias may also explain apparent extinctions in terrestrial environments, which have a similar disconnect in fossil abundance. This is most obvious in sauropod-bearing deposits, which are abundant in the Late Jurassic and rare in the earliest Cretaceous.{{Cite journal |last1=Starrfelt |first1=Jostein |last2=Liow |first2=Lee Hsiang |date=2016-04-05 |title=How many dinosaur species were there? Fossil bias and true richness estimated using a Poisson sampling model |journal=Philosophical Transactions of the Royal Society B: Biological Sciences |language=en |volume=371 |issue=1691 |page=20150219 |doi=10.1098/rstb.2015.0219 |issn=0962-8436 |pmc=4810813 |pmid=26977060}} Most studies relevant to the Tithonian extinction attempt to counteract sampling biases when estimating diversity loss or extinction rates. Depending on the sampling method or the taxonomic group, the Tithonian extinction may still be apparent even once sampling biases are accounted for.{{Cite journal |last1=Tennant |first1=Jonathan P. |last2=Chiarenza |first2=Alfio Alessandro |last3=Baron |first3=Matthew |date=2018-02-19 |title=How has our knowledge of dinosaur diversity through geologic time changed through research history? |journal=PeerJ |language=en |volume=6 |pages=e4417 |doi=10.7717/peerj.4417 |pmid=29479504 |s2cid=3548488 |issn=2167-8359|pmc=5822849 |doi-access=free }}

In 1986, Jack Sepkoski argued that the Late Tithonian extinction was the largest extinction event between the end of the Triassic and the end of the Cretaceous. He estimated that a staggering 37% of genera died out during the Tithonian stage.{{cite book |title=Patterns and Processes in the History of Life |vauthors=Sepkoski JJ |publisher=Springer Berlin Heidelberg |year=1986 |isbn=978-3-642-70833-6 |veditors=Raup DM, Jablonski D |place=Berlin & Heidelberg, DE |pages=277–295 |language=en |chapter=Phanerozoic overview of mass extinction |series=Dahlem Workshop Reports |doi=10.1007/978-3-642-70831-2_15 |access-date=2022-08-14 |chapter-url=http://link.springer.com/10.1007/978-3-642-70831-2_15}} Benton (1995) found a lower estimate, with the extinction of 5.6 to 13.3% of genera in the Tithonian. Proportional extinction was higher for continental genera (5.8–17.6%) than marine genera (5.1–6.1%).{{cite journal |vauthors=Benton MJ |date=April 1995 |title=Diversification and extinction in the history of life |url=http://doc.rero.ch/record/14806/files/PAL_E1962.pdf |journal=Science |volume=268 |issue=5207 |pages=52–58 |bibcode=1995Sci...268...52B |doi=10.1126/science.7701342 |pmid=7701342}} Sepkoski (1996) estimated that about 18% of multiple-interval marine genera (those originating prior to the Tithonian) died out in the Tithonian. Based on an updated version of Sepkoski's genera compendium, Bambach (2006) found a similar estimate of 20% of genera going extinct in the Late Tithonian.{{Cite journal |vauthors=Bambach RK |date=May 2006 |title=Phanerozoic Biodiversity Mass Extinctions |journal=Annual Review of Earth and Planetary Sciences |language=en |volume=34 |issue=1 |pages=127–155 |bibcode=2006AREPS..34..127B |doi=10.1146/annurev.earth.33.092203.122654 |issn=0084-6597}}

European bivalve diversity is severely depleted across the J–K boundary.{{Cite journal |last=Hallam |first=A. |date=1977 |title=Jurassic bivalve biogeography |url=https://www.cambridge.org/core/product/identifier/S009483730000511X/type/journal_article |journal=Paleobiology |language=en |volume=3 |issue=1 |pages=58–73 |doi=10.1017/S009483730000511X |bibcode=1977Pbio....3...58H |s2cid=89578740 |issn=0094-8373|url-access=subscription }}{{Cite journal |last=Liu |first=Chun-lian |date=2000 |title=Extinction Events Among Jurassic Bivalves |url=http://www.paper.edu.cn/scholar/showpdf/NUD2ENyINTD0ExeQh |journal=Acta Scientiarium Naturalium |volume=39 |issue=1}} However, bivalve fossils from the Andes and Siberia show little ecological turnover, so bivalve extinctions may have localized to the Tethys Sea. Only a fraction of Jurassic ammonite species survive to the Cretaceous, though extinction rates were actually lower in the late Tithonian relative to adjacent time intervals. Moderate diversity declines have been estimated or observed in gastropods, brachiopods, radiolarians, crustaceans, and scleractinian corals. This may have been related to the replacement of Jurassic-style coral reefs by Cretaceous-style rudist reefs. Reef decline was likely a gradual process, stretched out between the Oxfordian stage and the Valanginian stage.{{Citation |last1=FLÜGEL |first1=ERIK |date=2002 |url=https://www.researchgate.net/publication/285704083 |work=Phanerozoic Reef Patterns |pages=691–733 |access-date=2023-04-25 |publisher=SEPM (Society for Sedimentary Geology) |doi=10.2110/pec.02.72.0691 |last2=KIESSLING |first2=WOLFGANG|title=Patterns of Phanerozoic Reef Crises |isbn=1-56576-081-6 }}

File:Naturkundemuseum Plesiochelys sp. 17RM1993.jpg]]

Marine actinopterygians (ray-finned fishes) show elevated extinction rates across the Tithonian-Berriasian boundary. Most losses were quickly offset by substantial diversification in the Early Cretaceous. Sharks, rays, and freshwater fishes were nearly unaffected by the extinction.{{Cite journal |last1=Guinot |first1=Guillaume |last2=Cavin |first2=Lionel |date=2016 |title='Fish' (Actinopterygii and Elasmobranchii) diversification patterns through deep time: 'Fish' diversification patterns through deep time |url=https://onlinelibrary.wiley.com/doi/10.1111/brv.12203 |journal=Biological Reviews |language=en |volume=91 |issue=4 |pages=950–981 |doi=10.1111/brv.12203|pmid=26105527 |s2cid=25157060 |url-access=subscription }}

Marine reptiles were strongly affected by the Tithonian extinction.{{Cite journal |last=Bardet |first=Nathalie |date=1994 |title=Extinction events among Mesozoic marine reptiles |url=http://www.tandfonline.com/doi/abs/10.1080/10292389409380462 |journal=Historical Biology |language=en |volume=7 |issue=4 |pages=313–324 |doi=10.1080/10292389409380462 |bibcode=1994HBio....7..313B |issn=0891-2963}} Thalassochelydians, the most prominent Jurassic clade of marine turtles, were pushed to the brink of extinction. Only a single thalassochelydian fossil (an indeterminate skull from the Purbeck Group of England) is known from the Cretaceous.{{Cite journal |last1=Anquetin |first1=Jérémy |last2=André |first2=Charlotte |date=2020 |title=The last surviving Thalassochelydia—A new turtle cranium from the Early Cretaceous of the Purbeck Group (Dorset, UK) |url=https://paleorxiv.org/7pa5c/ |journal=PaleorXiv |issue=7paf5c |doi=10.31233/osf.io/7pa5c|s2cid=226481039 }} Among plesiosaurs, only a few species of Pliosauridae and Cryptoclididae persisted, and they too would die out in the Early Cretaceous. Conversely, the Tithonian extinction acted as a trigger for a Cretaceous diversification event for plesiosaurs in the clade Xenopsaria, namely elasmosaurids and leptocleidians. This turnover of marine reptile faunas may be a consequence of the turnover of reefs and marine fishes, which would have benefited generalized predators more than specialists.

It has long been suggested that ichthyosaurs and marine teleosauroid crocodyliforms declined across the J–K boundary, with the latter group even going extinct.{{Cite journal |last1=Mannion |first1=Philip D. |last2=Benson |first2=Roger B. J. |last3=Carrano |first3=Matthew T. |last4=Tennant |first4=Jonathan P. |last5=Judd |first5=Jack |last6=Butler |first6=Richard J. |date=2015-09-24 |title=Climate constrains the evolutionary history and biodiversity of crocodylians |journal=Nature Communications |language=en |volume=6 |issue=1 |page=8438 |doi=10.1038/ncomms9438 |pmid=26399170 |pmc=4598718 |bibcode=2015NatCo...6.8438M |issn=2041-1723}}{{Cite journal |last1=Tennant |first1=Jonathan P. |last2=Mannion |first2=Philip D. |last3=Upchurch |first3=Paul |date=2016-03-16 |title=Environmental drivers of crocodyliform extinction across the Jurassic/Cretaceous transition |journal=Proceedings of the Royal Society B: Biological Sciences |language=en |volume=283 |issue=1826 |page=20152840 |doi=10.1098/rspb.2015.2840 |issn=0962-8452 |pmc=4810856 |pmid=26962137}} More recent finds suggest that ichthyosaurs diversity remained stable or even increased in the Early Cretaceous. Early Cretaceous ichthyosaur fossils are rare enough that this hypothesis is still a matter of debate. European teleosauroids did indeed suffer total extinction,{{Cite journal |last1=Young |first1=Mark T. |last2=Brandalise de Andrade |first2=Marco |last3=Cornée |first3=Jean-Jacques |last4=Steel |first4=Lorna |last5=Foffa |first5=Davide |date=2014 |title=Re-description of a putative Early Cretaceous "teleosaurid" from France, with implications for the survival of metriorhynchids and teleosaurids across the Jurassic-Cretaceous Boundary |url=https://linkinghub.elsevier.com/retrieve/pii/S0753396914000172 |journal=Annales de Paléontologie |language=en |volume=100 |issue=2 |pages=165–174 |doi=10.1016/j.annpal.2014.01.002|bibcode=2014AnPal.100..165Y |url-access=subscription }} but teleosauroids as a whole survived into the Early Cretaceous in other parts of the world.{{Cite journal |last1=Fanti |first1=Federico |last2=Miyashita |first2=Tetsuto |last3=Cantelli |first3=Luigi |last4=Mnasri |first4=Fawsi |last5=Dridi |first5=Jihed |last6=Contessi |first6=Michela |last7=Cau |first7=Andrea |date=2016 |title=The largest thalattosuchian (Crocodylomorpha) supports teleosaurid survival across the Jurassic-Cretaceous boundary |url=https://linkinghub.elsevier.com/retrieve/pii/S0195667115301178 |journal=Cretaceous Research |language=en |volume=61 |pages=263–274 |doi=10.1016/j.cretres.2015.11.011|bibcode=2016CrRes..61..263F |hdl=11585/529635 |hdl-access=free }}{{Cite journal |last1=Cortés |first1=Dirley |last2=Larsson |first2=Hans C.E. |last3=Maxwell |first3=Erin E. |last4=Parra Ruge |first4=Mary Luz |last5=Patarroyo |first5=Pedro |last6=Wilson |first6=Jeffrey A. |date=2019-10-06 |title=An Early Cretaceous Teleosauroid (Crocodylomorpha: Thalattosuchia) from Colombia |url=https://bioone.org/journals/ameghiniana/volume-56/issue-5/AMGH.26.09.2019.3269/An-Early-Cretaceous-Teleosauroid-Crocodylomorpha-Thalattosuchia-from-Colombia/10.5710/AMGH.26.09.2019.3269.full |journal=Ameghiniana |volume=56 |issue=5 |page=365 |doi=10.5710/AMGH.26.09.2019.3269 |s2cid=210110716 |issn=0002-7014|url-access=subscription }}{{Cite journal |last1=Johnson |first1=Michela M. |last2=Young |first2=Mark T. |last3=Brusatte |first3=Stephen L. |date=2020-10-08 |title=The phylogenetics of Teleosauroidea (Crocodylomorpha, Thalattosuchia) and implications for their ecology and evolution |journal=PeerJ |language=en |volume=8 |pages=e9808 |doi=10.7717/peerj.9808 |pmid=33083104 |pmc=7548081 |issn=2167-8359 |doi-access=free }} Metriorhynchoids, the other major group of marine crocodyliforms, were not strongly affected by the Tithonian extinction.

File:Louisae.jpg, were strongly impacted by the Tithonian extinction]]

On land, sauropod dinosaur diversity was significantly reduced according to many{{Cite journal |last1=Mannion |first1=Philip D. |last2=Upchurch |first2=Paul |last3=Carrano |first3=Matthew T. |last4=Barrett |first4=Paul M. |date=2011 |title=Testing the effect of the rock record on diversity: a multidisciplinary approach to elucidating the generic richness of sauropodomorph dinosaurs through time |url=https://onlinelibrary.wiley.com/doi/10.1111/j.1469-185X.2010.00139.x |journal=Biological Reviews |language=en |volume=86 |issue=1 |pages=157–181 |doi=10.1111/j.1469-185X.2010.00139.x|pmid=20412186 |s2cid=9831073 |url-access=subscription }}{{Cite journal |last1=Upchurch |first1=P. |last2=Mannion |first2=P. D. |last3=Benson |first3=R. B. J. |last4=Butler |first4=R. J. |last5=Carrano |first5=M. T. |date=2011 |title=Geological and anthropogenic controls on the sampling of the terrestrial fossil record: a case study from the Dinosauria |url=https://www.geokniga.org/bookfiles/geokniga-comparing-geological-and-fossil-records.pdf#page=209 |journal=Geological Society, London, Special Publications |volume=358 |issue=1 |pages=209–240 |doi=10.1144/sp358.14 |bibcode=2011GSLSP.358..209U |s2cid=130777837 |issn=0305-8719}} (but not all){{Cite journal |last1=Cashmore |first1=Daniel D. |last2=Mannion |first2=Philip D. |last3=Upchurch |first3=Paul |last4=Butler |first4=Richard J. |date=2020 |editor-last=Benson |editor-first=Roger |title=Ten more years of discovery: revisiting the quality of the sauropodomorph dinosaur fossil record |journal=Palaeontology |language=en |volume=63 |issue=6 |pages=951–978 |doi=10.1111/pala.12496 |bibcode=2020Palgy..63..951C |s2cid=219090716 |issn=0031-0239|doi-access=free }} estimates. Diplodocids, basal macronarians, and mamenchisaurids took the brunt of the extinction, though a few species of each group survived to the Early Cretaceous.{{Cite journal |last1=McPhee |first1=Blair W. |last2=Mannion |first2=Philip D. |last3=de Klerk |first3=William J. |last4=Choiniere |first4=Jonah N. |date=2016 |title=High diversity in the sauropod dinosaur fauna of the Lower Cretaceous Kirkwood Formation of South Africa: Implications for the Jurassic–Cretaceous transition |url=https://linkinghub.elsevier.com/retrieve/pii/S0195667115301142 |journal=Cretaceous Research |language=en |volume=59 |pages=228–248 |doi=10.1016/j.cretres.2015.11.006|bibcode=2016CrRes..59..228M |hdl=10044/1/27470 |hdl-access=free }}{{Cite journal |last1=Wang |first1=Jun |last2=Norell |first2=Mark A. |last3=Pei |first3=Rui |last4=Ye |first4=Yong |last5=Chang |first5=Su-Chin |date=2019 |title=Surprisingly young age for the mamenchisaurid sauropods in South China |url=https://linkinghub.elsevier.com/retrieve/pii/S0195667119300333 |journal=Cretaceous Research |language=en |volume=104 |page=104176 |doi=10.1016/j.cretres.2019.07.006|bibcode=2019CrRes.10404176W |s2cid=199099072 |url-access=subscription }}{{Cite journal |last1=Moore |first1=Andrew J. |last2=Upchurch |first2=Paul |last3=Barrett |first3=Paul M. |last4=Clark |first4=James M. |last5=Xing |first5=Xu |date=2020-08-17 |title=Osteology of Klamelisaurus gobiensis (Dinosauria, Eusauropoda) and the evolutionary history of Middle–Late Jurassic Chinese sauropods |url=https://www.tandfonline.com/doi/full/10.1080/14772019.2020.1759706 |journal=Journal of Systematic Palaeontology |language=en |volume=18 |issue=16 |pages=1299–1393 |doi=10.1080/14772019.2020.1759706 |bibcode=2020JSPal..18.1299M |s2cid=219749618 |issn=1477-2019|url-access=subscription }} Conversely, rebbachisaurids and somphospondyls saw the opportunity to diversify in the Cretaceous. Turiasaurs also survived the extinction and even expanded into North America during the Early Cretaceous. Theropod diversity declined through the entire Late Jurassic, with medium-sized predators such as megalosaurids being the hardest hit. Ornithischian (particularly stegosaur) diversity saw a small drop across the J–K boundary. Theropod and ornithischian extinctions were notably less pronounced than in sauropods.

Most non-pterodactyloid pterosaurs perished by the end of the Jurassic. Practically no earliest Cretaceous sites are known to preserve pterosaur fossils, so the precise timing of non-pterodactyloid extinctions is very uncertain. Coastal and freshwater crocodyliforms experienced high extinction rates across the J–K boundary, preceding a significant diversification of more terrestrially-adapted metasuchians in the Cretaceous. Coastal and freshwater turtle diversity also declined, at least in Europe. Many tetrapod groups saw strong (albeit gradual) ecological turnover through the J-K boundary. These groups include lissamphibians, lepidosaurs, choristoderes, and mammaliaforms.

{{reflist}}

• {{aut|Gradstein, F.M.; Ogg, J.G. & Smith, A.G.}}; (2004): A Geologic Time Scale 2004, Cambridge University Press.
• {{aut|Oppel, C.A.}}; 1865: Die Tithonische Etage, Zeitschrift der Deutschen Geologischen Gesellschaft, 1865: pp 535–558. {{in lang|de}}

• [http://www.stratigraphy.org/bak/geowhen/stages/Tithonian.html GeoWhen Database - Tithonian]
• [http://stratigraphy.science.purdue.edu/charts/Timeslices/5_JurCret.pdf Jurassic-Cretaceous timescale], at the website of the subcommission for stratigraphic information of the ICS
• [https://web.archive.org/web/20060518101431/http://norges.uio.no/timescale/Fig17.1_Jur_colA.pdf Stratigraphic chart of the Upper Jurassic], at the website of Norges Network of offshore records of geology and stratigraphy

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Category:Geological ages