Editing Miocene (section)

==Life==
Life during the Miocene Epoch was mostly supported by the two newly formed [[biome]]s, [[kelp forest]]s and grasslands{{according to whom|date=January 2024}}{{citation needed|date=January 2024}}. Grasslands allow for more grazers, such as [[horse]]s, [[rhinoceros]]es, and [[hippo]]s. Ninety-five percent of modern plants existed by the end of this epoch{{citation needed|date=January 2024}}. Modern bony fish genera were established.<ref>{{Cite journal |last1=Carolin |first1=Nora |last2=Bajpai |first2=Sunil |last3=Maurya |first3=Abhayanand Singh |last4=Schwarzhans |first4=Werner |year=2022 |title=New perspectives on late Tethyan Neogene biodiversity development of fishes based on Miocene (~ 17 Ma) otoliths from southwestern India |journal=[[PalZ]] |volume=97 |pages=43–80 |doi=10.1007/s12542-022-00623-9 |s2cid=249184395 }}</ref> A modern-style latitudinal biodiversity gradient appeared ~15 Ma.<ref>{{cite journal |last1=Fenton |first1=Isabel S. |last2=Aze |first2=Tracy |last3=Farnsworth |first3=Alexander |last4=Valdes |first4=Paul |last5=Saupe |first5=Erin E. |date=15 February 2023 |title=Origination of the modern-style diversity gradient 15 million years ago |url=https://www.nature.com/articles/s41586-023-05712-6?error=cookies_not_supported&code=680853fc-d4b8-40cd-bf4e-eb0f4cd03b8b |journal=[[Nature (journal)|Nature]] |volume=614 |issue=7949 |pages=708–712 |bibcode=2023Natur.614..708F |doi=10.1038/s41586-023-05712-6 |pmid=36792825 |s2cid=256899993 |archive-url=https://web.archive.org/web/20230412162117/https://www.nature.com/articles/s41586-023-05712-6?error=cookies_not_supported&code=680853fc-d4b8-40cd-bf4e-eb0f4cd03b8b |archive-date=12 April 2023 |access-date=12 April 2023 |url-status=dead}}</ref>

===Flora===
[[File:Socotra dragon tree.JPG|thumbnail|The [[Dracaena cinnabari|dragon blood tree]] is considered a remnant of the Mio-Pliocene Laurasian subtropical forests that are now almost extinct in North Africa.<ref>{{Cite journal| doi = 10.1016/j.biocon.2007.05.009| title = Will dragonblood survive the next period of climate change? Current and future potential distribution of Dracaena cinnabari (Socotra, Yemen)| year = 2007| last1 = Attorre | first1 = F.| last2 = Francesconi | first2 = F.| last3 = Taleb | first3 = N.| last4 = Scholte | first4 = P.| last5 = Saed | first5 = A.| last6 = Alfo | first6 = M.| last7 = Bruno | first7 = F.| journal = [[Biological Conservation (journal)|Biological Conservation]]| volume = 138| issue = 3–4| pages = 430–439| bibcode = 2007BCons.138..430A| hdl = 11573/234206}}</ref>]]

The [[coevolution]] of [[phytolith|gritty]], fibrous, fire-tolerant [[Poaceae|grasses]] and long-legged [[herd behavior|gregarious]] [[ungulate]]s with [[hypsodont|high-crowned teeth]], led to a major expansion of grass-grazer [[ecosystems]]{{citation needed|date=January 2024}}. Herds of large, [[cursorial|swift]] [[Grazing|grazers]] were hunted by [[Predation|predators]] across broad sweeps of open [[grassland]]s, displacing desert, woodland, and browsers{{citation needed|date=January 2024}}.

The higher organic content and water retention of the deeper and richer [[Mollisol|grassland soils]], with long-term [[Carbon sequestration|burial of carbon]] in sediments, produced a [[Greenhouse gas|carbon and water vapor]] sink. This, combined with higher surface albedo and lower [[evapotranspiration]] of grassland, contributed to a cooler, drier climate.<ref>{{cite journal
 |last        = Retallack
 |first       = Gregory
 |title       = Cenozoic Expansion of Grasslands and Climatic Cooling
 |year        = 2001
 |journal     = [[The Journal of Geology]]
 |volume      = 109
 |issue       = 4
 |pages       = 407–426
 |publisher   = University of Chicago Press
 |url         = http://pages.uoregon.edu/dogsci/_media/directory/faculty/greg/grasslandscooling.pdf?id=directory%3Afaculty%3Agreg%3Aabout&cache=cache
 |bibcode     = 2001JG....109..407R
 |doi         = 10.1086/320791
 |s2cid = 15560105
 |archive-url  = https://web.archive.org/web/20130506232759/http://pages.uoregon.edu/dogsci/_media/directory/faculty/greg/grasslandscooling.pdf?id=directory%3Afaculty%3Agreg%3Aabout&cache=cache
 |archive-date = 2013-05-06
}}</ref> [[C4 carbon fixation#The evolution and advantages of the C4 pathway|C<sub>4</sub>]] grasses, which are able to assimilate [[carbon dioxide]] and water more efficiently than [[C3 carbon fixation|C<sub>3</sub>]] grasses, expanded to become ecologically significant near the end of the Miocene between 6 and 7 million years ago,<ref name="Osborne2006">{{cite journal |author=Osborne, C.P. |author2=Beerling, D.J. |author-link2=David Beerling |year=2006 |title=Nature's green revolution: the remarkable evolutionary rise of C4 plants |journal=[[Philosophical Transactions of the Royal Society B: Biological Sciences]] |volume=361 |issue=1465 |pages=173–194 |doi=10.1098/rstb.2005.1737 |pmc=1626541 |pmid=16553316}}</ref> although they did not expand northward during the Late Miocene.<ref>{{Cite journal |last1=Fraser |first1=Danielle |last2=Theodor |first2=Jessica M. |date=1 January 2013 |title=Ungulate diets reveal patterns of grassland evolution in North America |url=https://www.sciencedirect.com/science/article/pii/S0031018212006311 |journal=[[Palaeogeography, Palaeoclimatology, Palaeoecology]] |language=en |volume=369 |pages=409–421 |doi=10.1016/j.palaeo.2012.11.006 |access-date=1 November 2024 |via=Elsevier Science Direct}}</ref> The expansion of grasslands and [[Evolutionary radiation|radiations]] among terrestrial herbivores correlates to fluctuations in CO<sub>2</sub>.<ref>{{cite journal |author=Wolfram M. Kürschner, Zlatko Kvacek & David L. Dilcher |title=The impact of Miocene atmospheric carbon dioxide fluctuations on climate and the evolution of terrestrial ecosystems |year=2008 |journal=[[Proceedings of the National Academy of Sciences of the United States of America]] |volume=105 |issue=2 |pages=449–53 |doi=10.1073/pnas.0708588105 |bibcode = 2008PNAS..105..449K |pmid=18174330 |pmc=2206556|doi-access=free }}</ref> One study, however, has attributed the expansion of grasslands not to a CO<sub>2</sub> drop but to the increasing seasonality and aridity, coupled with a monsoon climate, which made wildfires highly prevalent compared to before.<ref>{{cite journal |last1=Keeley |first1=Jon E. |last2=Rundel |first2=Philip W. |date=28 April 2005 |title=Fire and the Miocene expansion of C4 grasslands |url=https://onlinelibrary.wiley.com/doi/10.1111/j.1461-0248.2005.00767.x |journal=[[Ecology Letters]] |volume=8 |issue=7 |pages=683–690 |doi=10.1111/j.1461-0248.2005.00767.x |bibcode=2005EcolL...8..683K |access-date=21 March 2023}}</ref> The Late Miocene expansion of grasslands had cascading effects on the global carbon cycle, evidenced by the imprint it left in carbon isotope records.<ref>{{Cite journal |last1=Du |first1=Jinlong |last2=Tian |first2=Jun |last3=Ma |first3=Wentao |date=15 April 2022 |title=The Late Miocene Carbon Isotope Shift driven by synergetic terrestrial processes: A box-model study |url=https://www.sciencedirect.com/science/article/pii/S0012821X22000930 |journal=[[Earth and Planetary Science Letters]] |volume=584 |pages=117457 |doi=10.1016/j.epsl.2022.117457 |bibcode=2022E&PSL.58417457D |s2cid=247307062 |issn=0012-821X |access-date=30 December 2023 |via=Elsevier Science Direct}}</ref>

[[Cycad]]s between 11.5 and 5 million years ago began to rediversify after previous declines in variety due to climatic changes, and thus modern cycads are not a good model for a "living fossil".<ref>{{cite journal |author=Susanne S. Renner |title=Living fossil younger than thought |year=2011 |journal=[[Science (journal)|Science]] |volume=334 |issue=6057 |pages=766–767 |doi=10.1126/science.1214649 |pmid=22076366|bibcode = 2011Sci...334..766R|s2cid=206537832 }}</ref> [[Eucalyptus]] fossil leaves occur in the Miocene of [[New Zealand]], where the genus is not native today, but have been introduced from [[Australia]].<ref>{{cite web|url=https://mikepole.wordpress.com/2014/09/22/eucalyptus-fossils-in-new-zealand-the-thin-end-of-the-wedge/|title=Eucalyptus fossils in New Zealand - the thin end of the wedge - Mike Pole|date=2014-09-22}}</ref>

===Fauna===
{{Human timeline}}
[[Image:CamelFootprintBarstowMiocene.jpg|upright|thumb|Cameloid footprint (''Lamaichnum alfi'' Sarjeant and Reynolds, 1999; convex hyporelief) from the [[Barstow Formation]] (Miocene) of Rainbow Basin, California.]]
[[File:Daeodon shoshonensis 2.png|thumb|Life restoration of ''[[Daeodon]]'']]
Both marine and continental [[fauna]] were fairly modern, although marine mammals were less numerous. Only in isolated South America and Australia did widely divergent fauna exist.

In Eurasia, genus richness shifted southward to lower latitudes from the Early to the Middle Miocene.<ref>{{Cite journal |last1=Madern |first1=P.A. (Anneke) |last2=van den Hoek Ostende |first2=Lars W. |date=15 April 2015 |title=Going south: Latitudinal change in mammalian biodiversity in Miocene Eurasia |url=https://www.sciencedirect.com/science/article/pii/S003101821500067X |journal=[[Palaeogeography, Palaeoclimatology, Palaeoecology]] |language=en |volume=424 |pages=123–131 |doi=10.1016/j.palaeo.2015.02.011 |access-date=1 November 2024 |via=Elsevier Science Direct}}</ref> Europe's large mammal diversity significantly declined during the Late Miocene.<ref>{{Cite journal |last1=Costeur |first1=Loïc |last2=Legendre |first2=Serge |date=24 April 2008 |title=Spatial and temporal variation in European Neogene large mammals diversity |url=https://www.sciencedirect.com/science/article/pii/S0031018208000370 |journal=[[Palaeogeography, Palaeoclimatology, Palaeoecology]] |language=en |volume=261 |issue=1–2 |pages=127–144 |doi=10.1016/j.palaeo.2008.01.011 |access-date=1 November 2024 |via=Elsevier Science Direct}}</ref>

In the Early Miocene, several Oligocene groups were still diverse, including [[Nimravidae|nimravids]], [[entelodont]]s, and three-toed equids. As in the previous Oligocene Epoch, [[Merycoidodontoidea|oreodonts]] were still diverse, only to disappear in the earliest Pliocene. During the later Miocene mammals were more modern, with easily recognizable [[Canidae|canids]], [[bear]]s, [[red pandas]], [[Procyonidae|procyonids]], [[Equidae|equids]], [[beaver]]s, [[deer]], [[camelid]]s, and [[whale]]s, along with now-extinct groups like [[Borophaginae|borophagine canids]], certain [[gomphothere]]s, [[Miohippus|three-toed horses]], and hornless rhinos like ''[[Teleoceras]]'' and ''[[Aphelops|Aphelos]].'' The late Miocene also marks the extinction of the last-surviving members of the [[Hyaenodonta|hyaenodonts]]. Islands began to form between South and North America in the Late Miocene, allowing ground sloths like ''[[Thinobadistes]]'' to [[Oceanic dispersal|island-hop]] to North America. The expansion of [[Phytolith|silica-rich]] [[C4 carbon fixation#The evolution and advantages of the C4 pathway|C<sub>4</sub>]] grasses led to worldwide extinctions of herbivorous species without [[hypsodont|high-crowned teeth]].<ref>{{cite book |author=Steven M. Stanley |year=1999 |title=Earth System History |pages=525–526 |publisher=Freeman |location=New York |isbn=0-7167-2882-6}}</ref> [[Mustelids]] diversified into their largest forms as terrestrial predators like ''[[Ekorus]]'', ''[[Eomellivora]]'', and ''[[Megalictis]]'' and bunodont otters like ''[[Enhydriodon]]'' and ''Sivaonyx'' appeared. [[Eulipotyphla]]ns were widespread in Europe, being less diverse in Southern Europe than farther north due to the aridity of the former.<ref>{{Cite journal |last1=Furió |first1=Marc |last2=Casanovas-Vilar |first2=Isaac |last3=van den Hoek Ostende |first3=Lars W. |date=1 May 2011 |title=Predictable structure of Miocene insectivore (Lipotyphla) faunas in Western Europe along a latitudinal gradient |url=https://www.sciencedirect.com/science/article/pii/S0031018210000623 |journal=[[Palaeogeography, Palaeoclimatology, Palaeoecology]] |series=The Neogene of Eurasia: Spatial gradients and temporal trends - The second synthesis of NECLIME |volume=304 |issue=3 |pages=219–229 |doi=10.1016/j.palaeo.2010.01.039 |bibcode=2011PPP...304..219F |issn=0031-0182 |access-date=12 January 2024 |via=Elsevier Science Direct}}</ref>

Unequivocally-recognizable [[dabbling duck]]s, [[plover]]s, [[typical owl]]s, [[cockatoo]]s and [[crow]]s appear during the Miocene. By the epoch's end, all or almost all modern bird groups are believed to have been present; the few post-Miocene bird fossils which cannot be placed in the evolutionary tree with full confidence are simply too badly preserved, rather than too equivocal in character. Marine birds reached their highest diversity ever in the course of this epoch{{citation needed|date=January 2024}}.

The youngest representatives of [[Choristodera]], an extinct order of aquatic reptiles that first appeared in the [[Middle Jurassic]], are known from the Miocene of Europe, belonging to the genus ''[[Lazarussuchus]],'' which had been the only known surviving genus of the group since the beginning of the Eocene.<ref name=":0">{{cite journal|vauthors=Matsumoto R, Evans SE|year=2010|title=Choristoderes and the freshwater assemblages of Laurasia|journal=[[Journal of Iberian Geology]]|volume=36|issue=2|pages=253–274|doi=10.5209/rev_jige.2010.v36.n2.11|doi-access=free|bibcode=2010JIbG...36..253M }}</ref>

The last known representatives of the archaic primitive mammal order [[Meridiolestida]], which dominated South America during the Late Cretaceous, are known from the Miocene of Patagonia, represented by the mole-like ''[[Necrolestes]].''<ref>{{Cite journal|last1=Rougier|first1=Guillermo W.|last2=Wible|first2=John R.|last3=Beck|first3=Robin M. D.|last4=Apesteguía|first4=Sebastian|date=2012-12-04|title=The Miocene mammal Necrolestes demonstrates the survival of a Mesozoic nontherian lineage into the late Cenozoic of South America|journal=[[Proceedings of the National Academy of Sciences of the United States of America]]|language=en|volume=109|issue=49|pages=20053–20058|doi=10.1073/pnas.1212997109|issn=0027-8424|pmid=23169652|pmc=3523863|bibcode=2012PNAS..10920053R|doi-access=free}}</ref><ref name="Chimentoetal">{{cite journal |author=Nicolás R. Chimento, Federico L. Agnolin and Fernando E. Novas |year=2012 |title=The Patagonian fossil mammal ''Necrolestes'': a Neogene survivor of Dryolestoidea |journal=Revista del Museo Argentino de Ciencias Naturales |series=Nueva Serie |volume=14 |issue=2 |pages=261–306 |url=http://www.macn.secyt.gov.ar/investigacion/descargas/publicaciones/revista/14/rns_vol14-2_261-306.pdf |access-date=2017-08-08 |archive-url=https://web.archive.org/web/20131104202302/http://www.macn.secyt.gov.ar/investigacion/descargas/publicaciones/revista/14/rns_vol14-2_261-306.pdf |archive-date=2013-11-04 }}</ref>

The youngest known representatives of [[metatheria]]ns (the broader grouping to which [[marsupial]]s belong) in Europe, Asia and Africa are known from the Miocene, including the European herpetotheriid ''[[Amphiperatherium]],'' the peradectids ''[[Siamoperadectes]]'' and ''Sinoperadectes'' from Asia,<ref>{{Cite journal |last1=Furió |first1=Marc |last2=Ruiz-Sánchez |first2=Francisco J. |last3=Crespo |first3=Vicente D. |last4=Freudenthal |first4=Matthijs |last5=Montoya |first5=Plinio |date=July 2012 |title=The southernmost Miocene occurrence of the last European herpetotheriid Amphiperatherium frequens (Metatheria, Mammalia) |url=https://linkinghub.elsevier.com/retrieve/pii/S1631068312000504 |journal=Comptes Rendus Palevol |language=en |volume=11 |issue=5 |pages=371–377 |doi=10.1016/j.crpv.2012.01.004|bibcode=2012CRPal..11..371F }}</ref><ref name=":02">{{Cite journal |last1=Bennett |first1=C. Verity |last2=Upchurch |first2=Paul |last3=Goin |first3=Francisco J. |last4=Goswami |first4=Anjali |date=2018-02-06 |title=Deep time diversity of metatherian mammals: implications for evolutionary history and fossil-record quality |journal=[[Paleobiology (journal)|Paleobiology]] |volume=44 |issue=2 |pages=171–198 |doi=10.1017/pab.2017.34 |bibcode=2018Pbio...44..171B |s2cid=46796692 |issn=0094-8373|doi-access=free }}</ref> and the possible herpetotheriid ''Morotodon'' from the late Early Miocene of Uganda.<ref>{{Cite journal |last1=Crespo |first1=Vicente D. |last2=Goin |first2=Francisco J. |last3=Pickford |first3=Martin |date=2022-06-03 |title=The last African metatherian |url=https://fr.pensoft.net/article/80706/ |journal=Fossil Record |volume=25 |issue=1 |pages=173–186 |doi=10.3897/fr.25.80706 |s2cid=249349445 |issn=2193-0074|doi-access=free }}</ref>

Approximately 100 species of [[ape]]s lived during this time{{citation needed|date=January 2024}}, ranging throughout Africa, Asia and Europe and varying widely in size, diet, and anatomy. Due to scanty fossil evidence it is unclear which ape or apes contributed to the modern [[hominid]] clade, but molecular evidence indicates this ape lived between 18 and 13 million years ago.<ref>{{cite web|url=http://phys.org/news/2012-08-genetic-humans-great-apes-diverged.html|title=New genetic data shows humans and great apes diverged earlier than thought|last=Yirka|first=Bob|publisher=phys.org|date=August 15, 2012}}</ref> The first [[hominini|hominins]] ([[bipedalism|bipedal]] apes of the human lineage) appeared in Africa at the very end of the Miocene, including ''[[Sahelanthropus]]'', ''[[Orrorin]]'', and an early form of ''[[Ardipithecus]]'' (''[[Ardipithecus kadabba|A. kadabba]]''). The [[Chimpanzee–human last common ancestor|chimpanzee–human divergence]] is thought to have occurred at this time.<ref>{{cite web|url=http://anthropology.utoronto.ca/Faculty/Begun/handbook.pdf|title=Fossil Record of Miocene Hominoids|last=Begun|first=David|publisher=University of Toronto|access-date=July 11, 2014|archive-url=https://web.archive.org/web/20131030004151/http://anthropology.utoronto.ca/Faculty/Begun/handbook.pdf|archive-date=October 30, 2013}}</ref> The evolution of bipedalism in apes at the end of the Miocene instigated an increased rate of faunal turnover in Africa.<ref>{{Cite journal |last=van der Made |first=Jan |date=1 April 2014 |title=Late Pleistocene European and Late Miocene African accelerations of faunal change in relation to the climate and as a background to human evolution |url=https://linkinghub.elsevier.com/retrieve/pii/S104061821300921X |journal=[[Quaternary International]] |language=en |volume=326-327 |pages=431–447 |doi=10.1016/j.quaint.2013.12.003 |access-date=20 July 2024 |via=Elsevier Science Direct}}</ref> In contrast, European apes met their end at the end of the Miocene due to increased habitat uniformity.<ref>{{Cite journal |last1=Merceron |first1=Gildas |last2=Kaiser |first2=Thomas M. |last3=Kostopoulos |first3=Dimitris S. |last4=Schulz |first4=Ellen |date=2 June 2010 |title=Ruminant diets and the Miocene extinction of European great apes |journal=[[Proceedings of the Royal Society B: Biological Sciences]] |language=en |volume=277 |issue=1697 |pages=3105–3112 |doi=10.1098/rspb.2010.0523 |issn=0962-8452 |pmc=2982054 |pmid=20519220 }}</ref>

The expansion of grasslands in North America also led to an explosive radiation among snakes.<ref name="Holman2000">{{cite book|last1=Holman|first1=J. Alan|title=Fossil Snakes of North America|date=2000|publisher=Indiana University Press|location=Bloomington, IN|isbn=0-253-33721-6|pages=284–323|edition=First}}</ref> Previously, snakes were a minor component of the North American fauna, but during the Miocene, the number of species and their prevalence increased dramatically with the first appearances of [[Viperidae|vipers]] and [[Elapidae|elapids]] in North America and the significant diversification of [[Colubridae]] (including the origin of many modern genera such as ''[[Nerodia]]'', ''[[Lampropeltis]]'', ''[[Pituophis]]'' and ''[[Pantherophis]]'').<ref name="Holman2000"/>

Arthropods were abundant, including in areas such as Tibet where they have traditionally been thought to be undiverse.<ref>{{Cite journal |last1=Li |first1=Qijia |last2=Deng |first2=Weiyudong |last3=Wappler |first3=Torsten |last4=Utescher |first4=Torsten |last5=Maslova |first5=Natalia |last6=Liu |first6=Yusheng (Christopher) |last7=Jia |first7=Hui |last8=Song |first8=Chengyu |last9=Su |first9=Tao |last10=Quan |first10=Cheng |date=February 2022 |title=High frequency of arthropod herbivore damage in the Miocene Huaitoutala flora from the Qaidam Basin, northern Tibetan Plateau |url=https://linkinghub.elsevier.com/retrieve/pii/S0034666721001937 |journal=[[Review of Palaeobotany and Palynology]] |language=en |volume=297 |pages=104569 |doi=10.1016/j.revpalbo.2021.104569 |access-date=20 July 2024 |via=Elsevier Science Direct}}</ref> [[Neoisoptera|Neoisopterans]] diversified and expanded into areas they previously were absent from, such as Madagascar and Australia.<ref>{{Cite journal |last1=Wang |first1=Menglin |last2=Hellemans |first2=Simon |last3=Buček |first3=Aleš |last4=Kanao |first4=Taisuke |last5=Arora |first5=Jigyasa |last6=Clitheroe |first6=Crystal |last7=Rafanomezantsoa |first7=Jean-Jacques |last8=Fisher |first8=Brian L. |last9=Scheffrahn |first9=Rudolf |last10=Sillam-Dussès |first10=David |last11=Roisin |first11=Yves |last12=Šobotník |first12=Jan |last13=Bourguignon |first13=Thomas |date=21 April 2023 |title=Neoisoptera repeatedly colonised Madagascar after the Middle Miocene climatic optimum |url=https://onlinelibrary.wiley.com/doi/10.1111/ecog.06463 |journal=[[Ecography]] |language=en |volume=2023 |issue=7 |doi=10.1111/ecog.06463 |issn=0906-7590 |access-date=4 June 2024}}</ref>

====Oceanic====
In the oceans, [[brown algae]], called [[kelp]], proliferated, supporting new species of sea life, including [[otter]]s, [[fish]] and various [[invertebrate]]s.

Corals suffered a significant local decline along the northeastern coast of Australia during the Tortonian, most likely due to warming seawater.<ref>{{Cite journal |last1=Petrick |first1=Benjamin |last2=Reuning |first2=Lars |last3=Auer |first3=Gerald |last4=Zhang |first4=Yige |last5=Pfeiffer |first5=Miriam |last6=Schwark |first6=Lorenz |date=10 March 2023 |title=Warm, not cold temperatures contributed to a Late Miocene reef decline in the Coral Sea |journal=[[Scientific Reports]] |language=en |volume=13 |issue=1 |pages=4015 |doi=10.1038/s41598-023-31034-8 |pmid=36899047 |pmc=10006184 |bibcode=2023NatSR..13.4015P |issn=2045-2322 }}</ref>

[[Cetaceans]] attained their greatest diversity during the Miocene,<ref name="G">{{Cite book
 |author1       = Peter Klimley
 |author2       = David Ainley
 |name-list-style = amp
 |title         = Great White Sharks: the Biology of ''Carcharodon carcharias''
 |year          = 1996
 |publisher     = Academic Press
 |url           = http://www.elsevier.com/wps/find/bookdescription.cws_home/673659/description#description
 |isbn          = 0-12-415031-4
 |access-date   = 2011-08-12
 |archive-url   = https://web.archive.org/web/20121012190507/http://www.elsevier.com/wps/find/bookdescription.cws_home/673659/description#description
 |archive-date  = 2012-10-12
 }}</ref> with over 20 recognized genera of [[baleen whale]]s in comparison to only six living genera.<ref>{{Cite journal |last1=Dooley |first1=Alton C. |last2=Fraser |first2=Nicholas C. |last3=Luo |first3=Zhe-Xi |year=2004 |title=The earliest known member of the rorqual—gray whale clade (Mammalia, Cetacea) |url=https://www.academia.edu/7488679 |journal=[[Journal of Vertebrate Paleontology]] |language=en |volume=24 |issue=2 |pages=453–463 |bibcode=2004JVPal..24..453D |doi=10.1671/2401 |issn=0272-4634 |s2cid=84970052}}</ref> This diversification correlates with emergence of gigantic macro-predators such as megatoothed sharks and raptorial [[sperm whale]]s.<ref name="LV">{{Cite journal
 |author1=Olivier Lambert |author2=Giovanni Bianucci |author3=Klaas Post |author4=Christian de Muizon |author5=Rodolfo Salas-Gismondi |author6=Mario Urbina |author7=Jelle Reumer |title=The giant bite of a new raptorial sperm whale from the Miocene epoch of Peru
 |year=2010 |journal=[[Nature (journal)|Nature]] |volume=466 |issue=7302 |pages=105–108
 |pmid=20596020 |doi=10.1038/nature09067|bibcode = 2010Natur.466..105L |s2cid=4369352 }}</ref> Prominent examples are ''[[Megalodon|O. megalodon]]'' and ''[[Livyatan|L. melvillei]]''.<ref name="LV" /> Other notable large sharks were ''[[Otodus chubutensis|O. chubutensis]]'', ''Isurus hastalis'', and ''[[Hemipristis serra]]''.

Crocodilians also showed signs of diversification during the Miocene. The largest form among them was a gigantic [[caiman]] ''[[Purussaurus]]'' which inhabited South America.<ref>{{cite journal
 |author      = Orangel A. Aguilera, Douglas Riff & Jean Bocquentin-Villanueva
 |title       = A new giant ''Pusussaurus'' (Crocodyliformes, Alligatoridae) from the Upper Miocene Urumaco Formation, Venezuela
 |year        = 2006
 |journal     = [[Journal of Systematic Palaeontology]]
 |volume      = 4
 |issue       = 3
 |pages       = 221–232
 |url         = http://www.paleovertebrados.museunacional.ufrj.br/publicacoes/douglas_riff/purussaurusmirandai.pdf
 |doi         = 10.1017/S147720190600188X
 |bibcode = 2006JSPal...4..221A
 |s2cid = 85950121
 |archive-url  = https://web.archive.org/web/20120329034001/http://www.paleovertebrados.museunacional.ufrj.br/publicacoes/douglas_riff/purussaurusmirandai.pdf
 |archive-date = 2012-03-29
}}</ref> Another gigantic form was a [[false gharial]] ''[[Rhamphosuchus]]'', which inhabited modern age [[India]]. A strange form, ''[[Mourasuchus]]'' also thrived alongside ''Purussaurus''. This species developed a specialized filter-feeding mechanism, and it likely preyed upon small fauna despite its gigantic size.<ref name=":1" />

The youngest members of [[Sebecidae]], a clade of large terrestrial predatory [[crocodyliformes]] distantly related to modern crocodilians, from which they likely diverged over 180 million years ago, are known from the Miocene of South America.<ref name=":1">{{Cite journal|last1=Cidade|first1=Giovanne M.|last2=Fortier|first2=Daniel|last3=Hsiou|first3=Annie Schmaltz|date=March 2019|title=The crocodylomorph fauna of the Cenozoic of South America and its evolutionary history: a review|url=https://linkinghub.elsevier.com/retrieve/pii/S0895981118303699|journal=Journal of South American Earth Sciences|language=en|volume=90|pages=392–411|doi=10.1016/j.jsames.2018.12.026|bibcode=2019JSAES..90..392C|s2cid=134902094}}</ref><ref>{{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 |journal=Scientific Reports |language=en |volume=9 |issue=1 |page=514 |doi=10.1038/s41598-018-36795-1 |issn=2045-2322 |pmc=6346023 |pmid=30679529|bibcode=2019NatSR...9..514W }}</ref>

The last [[Desmostylians]] thrived during this period before becoming the only extinct marine mammal order.

The [[pinniped]]s, which appeared near the end of the Oligocene, became more aquatic. A prominent genus was ''[[Allodesmus]]''.<ref>{{cite journal
 |author1=Lawrence G. Barnes |author2=Kiyoharu Hirota
 |name-list-style=amp |title=Miocene pinnipeds of the otariid subfamily Allodesminae in the North Pacific Ocean: systematics and relationships
 |year=1994 |journal=[[Island Arc]] |volume=3 |issue=4 |pages=329–360
 |doi=10.1111/j.1440-1738.1994.tb00119.x|bibcode=1994IsArc...3..329B
 }}</ref> A ferocious [[walrus]], ''[[Pelagiarctos]]'' may have preyed upon other species of pinnipeds including ''Allodesmus''.

Furthermore, [[South America]]n waters witnessed the arrival of ''[[Megapiranha|Megapiranha paranensis]]'', which were considerably larger than modern age [[piranha]]s.

[[New Zealand]]'s Miocene fossil record is particularly rich. Marine deposits showcase a variety of [[cetaceans]] and [[penguins]], illustrating the evolution of both groups into modern representatives. The early Miocene [[Saint Bathans Fauna]] is the only Cenozoic terrestrial fossil record of the landmass, showcasing a wide variety of not only [[bird]] species, including early representatives of clades such as [[moa]], [[Kiwi (bird)|kiwi]] and [[adzebill]]s, but also a diverse herpetofauna of [[sphenodontia]]ns, [[crocodile]]s and [[turtle]]s as well as a rich terrestrial mammal fauna composed of various species of [[bats]] and the enigmatic [[Saint Bathans Mammal]].

<gallery widths="200" heights="145">
File:Calvert Zone 10 Calvert Co MD.jpg|Miocene fossils from the [[Calvert Formation]], [[Calvert County, Maryland]], US
File:The Childrens Museum of Indianapolis - Miocene crab.jpg|A Miocene crab (''[[Tumidocarcinus giganteus]]'') from the collection of the [[Children's Museum of Indianapolis]]
</gallery>

===Microbiota===
Microbial life in the igneous crust of the [[Fennoscandian Shield]] shifted from being dominated by [[methanogen]]s to being primarily composed of [[sulfate-reducing microorganism|sulphate-reducing prokaryotes]]. The change resulted from fracture reactivation during the Pyrenean-Alpine orogeny, enabling sulphate-reducing microbes to permeate into the Fennoscandian Shield via descending surficial waters.<ref>{{cite journal |last1=Drake |first1=Henrik |last2=Roberts |first2=Nick M. W. |last3=Reinhardt |first3=Manuel |last4=Whitehouse |first4=Martin |last5=Ivarsson |first5=Magnus |last6=Karlsson |first6=Andreas |last7=Kooijman |first7=Ellen |last8=Kielmann-Schmitt |first8=Melanie |date=3 June 2021 |title=Biosignatures of ancient microbial life are present across the igneous crust of the Fennoscandian shield |url=https://www.nature.com/articles/s43247-021-00170-2?error=cookies_not_supported&code=dc672908-be0f-4c99-8663-e442770a53fa |journal=[[Communications Earth & Environment]] |volume=2 |pages=1–13 |doi=10.1038/s43247-021-00170-2 |s2cid=235307116 |access-date=14 January 2023}}</ref>

Diatom diversity was inversely correlated with carbon dioxide levels and global temperatures during the Miocene. Most modern lineages of diatoms appeared by the Late Miocene.<ref>{{cite journal |last1=Lazarus |first1=David |last2=Barron |first2=John |last3=Renaudie |first3=Johan |last4=Diver |first4=Patrick |last5=Türke |first5=Andreas |date=22 January 2014 |title=Cenozoic Planktonic Marine Diatom Diversity and Correlation to Climate Change |journal=[[PLOS ONE]] |volume=9 |issue=1 |pages=e84857 |doi=10.1371/journal.pone.0084857 |pmid=24465441 |pmc=3898954 |bibcode=2014PLoSO...984857L |doi-access=free }}</ref>