Miocene ( /ˈmaɪəˌsiːn/) is the first geological epoch
Neogene Period and extends from about 23.03 to 5.333
million years ago (Ma). The
Miocene was named by Charles Lyell; its
name comes from the Greek words μείων (meiōn, “less”) and
καινός (kainos, “new”) and means "less recent" because it
has 18% fewer modern sea invertebrates than the Pliocene. The Miocene
Oligocene and is followed by the Pliocene.
As the earth went from the
Oligocene through the
Miocene and into the
Pliocene, the climate slowly cooled towards a series of ice ages. The
Miocene boundaries are not marked by a single distinct global event
but consist rather of regionally-defined boundaries between the warmer
Oligocene and the cooler
Apes arose and diversified during the Miocene, becoming widespread in
the Old World. By the end of this epoch, the ancestors of humans had
split away from the ancestors of the chimpanzees to follow their own
evolutionary path (7.5 to 5.6 million years ago). As in the
Oligocene before it, grasslands continued to expand and forests to
dwindle in extent. In the seas of the Miocene, kelp forests made their
first appearance and soon became one of Earth's most productive
The plants and animals of the
Miocene were recognizably modern.
Mammals and birds were well-established. Whales, pinnipeds, and kelp
Miocene is of particular interest to geologists and
palaeoclimatologists as major phases of the geology of the Himalaya
occurred during the Miocene, affecting monsoonal patterns in Asia,
which were interlinked with glacial periods in the northern
2.1 South America
Middle Miocene disruption
7 See also
9 Further reading
10 External links
view • discuss • edit
Earliest stone tools
Earliest exit from Africa
Earliest fire use
Earliest in Europe
Axis scale: million years
Also see: Life timeline and Nature timeline
Miocene faunal stages from youngest to oldest are typically named
according to the International Commission on Stratigraphy:
Regionally, other systems are used, based on characteristic land
mammals; some of them overlap with the preceding
European Land Mammal Ages
Turolian (9.0 to 5.3 Ma)
Vallesian (11.6 to 9.0 Ma)
Astaracian (16.0 to 11.6 Ma)
Orleanian (20.0 to 16.0 Ma)
Agenian (23.8 to 20.0 Ma)
North American Land Mammal Ages
Hemphillian (10.3 to 4.9 Ma)
Clarendonian (13.6 to 10.3 Ma)
Barstovian (16.3 to 13.6 Ma)
Hemingfordian (20.6 to 16.3 Ma)
Arikareean (30.6 to 20.6 Ma)
South American Land Mammal Ages
Montehermosan (6.8 to 4.0 Ma)
Huayquerian (9.0 to 6.8 Ma)
Mayoan (11.8 to 9.0 Ma)
Laventan (13.8 to 11.8 Ma)
Colloncuran (15.5 to 13.8 Ma)
Friasian (16.3 to 15.5 Ma)
Santacrucian (17.5 to 16.3 Ma)
Colhuehuapian (21.0 to 17.5 Ma)
Continents continued to drift toward their present positions. Of the
modern geologic features, only the land bridge between South America
North America was absent, although
South America was approaching
the western subduction zone in the Pacific Ocean, causing both the
rise of the
Andes and a southward extension of the Meso-American
Mountain building took place in western North America, Europe, and
East Asia. Both continental and marine
Miocene deposits are common
worldwide with marine outcrops common near modern shorelines. Well
studied continental exposures occur in the North American Great Plains
and in Argentina.
India continued to collide with Asia, creating dramatic new mountain
ranges. The Tethys Seaway continued to shrink and then disappeared as
Africa collided with
Eurasia in the Turkish–Arabian region between
19 and 12 Ma. The subsequent uplift of mountains in the western
Mediterranean region and a global fall in sea levels combined to cause
a temporary drying up of the
Mediterranean Sea (known as the Messinian
salinity crisis) near the end of the Miocene.
The global trend was towards increasing aridity caused primarily by
global cooling reducing the ability of the atmosphere to absorb
moisture. Uplift of East
Africa in the late
Miocene was partly
responsible for the shrinking of tropical rain forests in that region,
Australia got drier as it entered a zone of low rainfall in the
Early Miocene large swathes of
subject to a marine transgression. The transgression might have
temporarily linked the Pacific and Atlantic Oceans, as inferred from
the findings of marine invertebrate fossils of both Atlantic and
Pacific affinity in La Cascada Formation. Connection would have
occurred through narrow epicontinental seaways that formed channels in
a dissected topography. The
Antarctic Plate started to subduct
South America 14 million years ago in the Miocene, forming the
Chile Triple Junction. At first the
Antarctic Plate subducted only in
the southernmost tip of Patagonia, meaning that the Chile Triple
Junction lay near the Strait of Magellan. As the southern part of
Nazca Plate and the
Chile Rise became consumed by subduction the more
northerly regions of the
Antarctic Plate begun to subduct beneath
Patagonia so that the
Chile Triple Junction advanced to the north over
time. The asthenospheric window associated to the triple junction
disturbed previous patterns of mantle convection beneath Patagonia
inducing an uplift of ca. 1 km that reversed the
Climates remained moderately warm, although the slow global cooling
that eventually led to the
Pleistocene glaciations continued.
Although a long-term cooling trend was well underway, there is
evidence of a warm period during the
Miocene when the global climate
rivalled that of the Oligocene. The
Miocene warming began 21 million
years ago and continued until 14 million years ago, when global
temperatures took a sharp drop—the
Middle Miocene Climate Transition
(MMCT). By 8 million years ago, temperatures dropped sharply once
again, and the
Antarctic ice sheet
Antarctic ice sheet was already approaching its
present-day size and thickness.
Greenland may have begun to have large
glaciers as early as 7 to 8 million years ago,
although the climate for the most part remained warm enough to support
forests there well into the Pliocene.
Life during the
Miocene Epoch was mostly supported by the two newly
formed biomes, kelp forests and grasslands. Grasslands allow for more
grazers, such as horses, rhinoceroses, and hippos. Ninety five percent
of modern plants existed by the end of this epoch.
The dragon blood tree is considered a remnant of the Mio-Pliocene
Laurasian subtropical forests that are now almost extinct in North
The coevolution of gritty, fibrous, fire-tolerant grasses and
long-legged gregarious ungulates with high-crowned teeth, led to a
major expansion of grass-grazer ecosystems, with roaming herds of
large, swift grazers pursued by predators across broad sweeps of open
grasslands, displacing desert, woodland, and browsers. The higher
organic content and water retention of the deeper and richer grassland
soils, with long term burial of carbon in sediments, produced a carbon
and water vapor sink. This, combined with higher surface albedo and
lower evapotranspiration of grassland, contributed to a cooler, drier
climate. C4 grasses, which are able to assimilate carbon dioxide
and water more efficiently than C3 grasses, expanded to become
ecologically significant near the end of the
Miocene between 6 and 7
million years ago. The expansion of grasslands and radiations
among terrestrial herbivores correlates to fluctuations in CO2.
Cycads between 11.5 and 5 m.y.a. 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".
Cameloid footprint (Lamaichnum alfi Sarjeant and Reynolds, 1999;
convex hyporelief) from the
Barstow Formation (Miocene) of Rainbow
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 the Early Miocene, several
Oligocene groups were still diverse,
including nimravids, entelodonts, and three-toed equids. Like in the
Oligocene epoch, oreodonts were still diverse, only to
disappear in the earliest Pliocene. During the later
were more modern, with easily recognizable canids, bears, procyonids,
equids, beavers, deer, camelids, and whales, along with now extinct
groups like borophagine canids, certain gomphotheres, three-toed
horses, and semiaquatic and hornless rhinos like
Aphelops. Islands began to form between South and
North America in the
Late Miocene, allowing ground sloths like
Thinobadistes to island-hop
to North America. The expansion of silica-rich C4 grasses led to
worldwide extinctions of herbivorous species without high-crowned
Miocene fauna of North America
A few basal mammal groups endured into this epoch in southern
landmasses, including the south american dryolestoid
Patagonia and New Zealand's Saint Bathans Mammal.
Non-marsupial metatherians were also still around, such as the
American and Eurasian herpetotheriids and peradectids such as
Siamoperadectes, and the South American sparassodonts.
Unequivocally recognizable dabbling ducks, plovers, typical owls,
cockatoos and crows 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.
Approximately 100 species of apes lived during this time, ranging
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 7 and 8 million years ago. The
first hominins (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 (A. kadabba) The chimpanzee–human
divergence is thought to have occurred at this time.
The expansion of grasslands in
North America also led to an explosive
radiation among snakes. 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 vipers and elapids in
North America and the significant
Colubridae (including the origin of many modern
genera such as Nerodia, Lampropeltis,
Pituophis and Pantherophis).
In the oceans, brown algae, called kelp, proliferated, supporting new
species of sea life, including otters, fish and various invertebrates.
Cetaceans attained their greatest diversity during the Miocene,
with over 20 recognized genera in comparison to only six living
genera. This diversification correlates with emergence of gigantic
macro-predators such as megatoothed sharks and raptorial sperm
whales. Prominent examples are C. megalodon and L. melvillei.
Other notable large sharks were C. chubutensis, Isurus hastalis, and
Crocodilians also showed signs of diversification during Miocene. The
largest form among them was a gigantic caiman
inhabited South America. 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.
The pinnipeds, which appeared near the end of the Oligocene, became
more aquatic. Prominent genus was Allodesmus. A ferocious walrus,
Pelagiarctos may have preyed upon other species of pinnipeds including
Furthermore, South American waters witnessed the arrival of
Megapiranha paranensis, which were considerably larger than modern age
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 moas, kiwis
and adzebills, but also a diverse herpetofauna of sphenodontians,
crocodiles and turtle as well as a rich terrestrial mammal fauna
composed of various species of bats and the enigmatic Saint Bathans
Fossils from the Calvert Formation, Zone 10, Calvert Co., MD
Miocene crab (Tumidocarcinus giganteus) from the collection of the
Children's Museum of Indianapolis
There is evidence from oxygen isotopes at Deep Sea Drilling Program
sites that ice began to build up in Antarctica about 36 Ma during the
Eocene. Further marked decreases in temperature during the Middle
Miocene at 15 Ma probably reflect increased ice growth in Antarctica.
It can therefore be assumed that East Antarctica had some glaciers
during the early to mid
Miocene (23–15 Ma). Oceans cooled partly due
to the formation of the Antarctic Circumpolar Current, and about 15
million years ago the ice cap in the southern hemisphere started to
grow to its present form. The
Greenland ice cap developed later, in
Pliocene time, about 3 million years ago.
Middle Miocene disruption
Middle Miocene disruption
Middle Miocene disruption" refers to a wave of extinctions of
terrestrial and aquatic life forms that occurred following the Miocene
Climatic Optimum (18 to 16 Ma), around 14.8 to 14.5 million years ago,
Langhian stage of the mid-Miocene. A major and permanent
cooling step occurred between 14.8 and 14.1 Ma, associated with
increased production of cold Antarctic deep waters and a major growth
of the East Antarctic ice sheet. A
Middle Miocene δ18O increase, that
is, a relative increase in the heavier isotope of oxygen, has been
noted in the Pacific, the Southern Ocean and the South Atlantic.
Geologic time scale
List of fossil sites
^ "Tinescale Chart". www.stratigraphy.org.
Dictionary.com Unabridged. Random House.
^ "Miocene". Online Etymology Dictionary. Retrieved 2016-01-20.
^ "BBC Nature -
Miocene epoch videos, news and facts". BBC. Retrieved
^ Zhisheng, An; Kutzbach, John E.; Prell, Warren L.; Porter, Stephen
C. (3 May 2001). "Evolution of Asian monsoons and phased uplift of the
Himalaya–Tibetan plateau since
Late Miocene times". Nature. 411
(6833): 62–66. doi:10.1038/35075035.
^ Robert A. Rohde (2005). "GeoWhen Database". Retrieved March 8,
^ a b Encinas, Alfonso; Pérez, Felipe; Nielsen, Sven; Finger, Kenneth
L.; Valencia, Victor; Duhart, Paul (2014). "Geochronologic and
paleontologic evidence for a Pacific–Atlantic connection during the
Miocene in the Patagonian
Journal of South American Earth Sciences. 55: 1–18.
^ Nielsen, S.N. (2005). "
Cenozoic Strombidae, Aporrhaidae, and
Struthiolariidae (Gastropoda, Stromboidea) from Chile: their
significance to biogeography of faunas and climate of the south-east
Pacific". Journal of Paleontology. 79: 1120–1130.
^ a b Guillame, Benjamin; Martinod, Joseph; Husson, Laurent; Roddaz,
Martin; Riquelme, Rodrigo (2009). "
Neogene uplift of central eastern
Patagonia: Dynamic response to active spreading ridge subduction?".
^ Cande, S.C.; Leslie, R.B. (1986). "Late
Cenozoic Tectonics of the
Southern Chile Trench". Journal of Geophysical Research-Solid Earth
and Planets. 91: 471–496. Bibcode:1986JGR....91..471C.
^ Guillaume, Benjamin; Gautheron, Cécile; Simon-Labric, Thibaud;
Martinod, Joseph; Roddaz, Martin; Douville, Eric (2013). "Dynamic
topography control on Patagonian relief evolution as inferred from low
temperature thermochronology". Earth and Planetary Science Letters. 3:
^ Attorre, F.; Francesconi, F.; Taleb, N.; Scholte, P.; Saed, A.;
Alfo, M.; Bruno, F. (2007). "Will dragonblood survive the next period
of climate change? Current and future potential distribution of
Dracaena cinnabari (Socotra, Yemen)". Biological Conservation. 138
(3–4): 430–439. doi:10.1016/j.biocon.2007.05.009.
^ Retallack, Gregory (2001). "
Cenozoic Expansion of Grasslands and
Climatic Cooling" (PDF). The Journal of Geology. University of Chicago
Press. 109 (4): 407–426. Bibcode:2001JG....109..407R.
doi:10.1086/320791. Archived from the original (PDF) on
^ Osborne, C.P.; Beerling, D.J. (2006). "Nature's green revolution:
the remarkable evolutionary rise of C4 plants". Philosophical
Transactions of the Royal Society B: Biological Sciences. 361 (1465):
173–194. doi:10.1098/rstb.2005.1737. PMC 1626541 .
^ Wolfram M. Kürschner, Zlatko Kvacek & David L. Dilcher (2008).
"The impact of
Miocene atmospheric carbon dioxide fluctuations on
climate and the evolution of terrestrial ecosystems". Proceedings of
the National Academy of Sciences. 105 (2): 449–53.
PMC 2206556 . PMID 18174330.
^ Susanne S. Renner (2011). "Living fossil younger than thought".
Science. 334 (6057): 766–767. Bibcode:2011Sci...334..766R.
doi:10.1126/science.1214649. PMID 22076366.
^ Steven M. Stanley (1999). Earth System History. New York: Freeman.
pp. 525–526. ISBN 0-7167-2882-6.
^ Yirka, Bob (August 15, 2012). "New genetic data shows humans and
great apes diverged earlier than thought". phys.org.
^ Begun, David. "Fossil Record of
Miocene Hominoids" (PDF). University
of Toronto. Retrieved July 11, 2014.
^ a b Holman, J. Alan (2000). Fossil Snakes of
North America (First
ed.). Bloomington, IN: Indiana University Press. pp. 284–323.
^ Peter Klimley & David Ainley (1996). Great White Sharks: the
Biology of Carcharodon carcharias. Academic Press.
^ Alton C. Dooley Jr.,
Nicholas C. Fraser & Zhe-Xi Luo (2004).
"The earliest known member of the rorqual–gray whale clade
(Mammalia, Cetacea)" (PDF). Journal of Vertebrate Paleontology. 24
(2): 453–463. doi:10.1671/2401. [permanent dead link]
^ a b Olivier Lambert; Giovanni Bianucci; Klaas Post; Christian de
Muizon; Rodolfo Salas-Gismondi; Mario Urbina; Jelle Reumer (2010).
"The giant bite of a new raptorial sperm whale from the
of Peru". Nature. 466 (7302): 105–108. Bibcode:2010Natur.466..105L.
doi:10.1038/nature09067. PMID 20596020.
^ Orangel A. Aguilera, Douglas Riff & Jean Bocquentin-Villanueva
(2006). "A new giant Pusussaurus (Crocodyliformes, Alligatoridae) from
Miocene Urumaco Formation, Venezuela" (PDF). Journal of
Systematic Palaeontology. 4 (3): 221–232.
doi:10.1017/S147720190600188X. Archived from the original (PDF) on
^ Lawrence G. Barnes & Kiyoharu Hirota (1994). "
of the otariid subfamily Allodesminae in the North Pacific Ocean:
systematics and relationships". Island Arc. 3 (4): 329–360.
^ Kenneth G. Miller & Richard G. Fairbanks (1983). "Evidence for
Middle Miocene abyssal circulation changes in the western
North Atlantic". Nature. 306 (5940): 250–253.
Cox, C. Barry & Moore, Peter D. (1993): Biogeography. An
ecological and evolutionary approach (5th ed.). Blackwell Scientific
Publications, Cambridge. ISBN 0-632-02967-6
Ogg, Jim (2004): "Overview of Global Boundary Stratotype Sections and
Points (GSSP's)". Retrieved 2006-04-30.
Wikimedia Commons has media related to Miocene.
Wikisource has original works on the topic: Cenozoic#Neogene
PBS Deep Time: Miocene
Miocene Epoch Page
Miocene Microfossils: 200+ images of
Human Timeline (Interactive) – Smithsonian, National Museum of
Natural History (August 2016).
Geologic history of Earth
Quaternary (present–2.588 Mya)
Holocene (present–11.784 kya)
Pleistocene (11.784 kya–2.588 Mya)
Neogene (2.588–23.03 Mya)
Pliocene (2.588–5.333 Mya)
Miocene (5.333–23.03 Mya)
Paleogene (23.03–66.0 Mya)
Oligocene (23.03–33.9 Mya)
Eocene (33.9–56.0 Mya)
Paleocene (56.0–66.0 Mya)
Cretaceous (66.0–145.0 Mya)
Late (66.0–100.5 Mya)
Early (100.5–145.0 Mya)
Jurassic (145.0–201.3 Mya)
Late (145.0–163.5 Mya)
Middle (163.5–174.1 Mya)
Early (174.1–201.3 Mya)
Triassic (201.3–251.902 Mya)
Late (201.3–237 Mya)
Middle (237–247.2 Mya)
Early (247.2–251.902 Mya)
Permian (251.902–298.9 Mya)
Lopingian (251.902–259.8 Mya)
Guadalupian (259.8–272.3 Mya)
Cisuralian (272.3–298.9 Mya)
Carboniferous (298.9–358.9 Mya)
Pennsylvanian (298.9–323.2 Mya)
Mississippian (323.2–358.9 Mya)
Devonian (358.9–419.2 Mya)
Late (358.9–382.7 Mya)
Middle (382.7–393.3 Mya)
Early (393.3–419.2 Mya)
Silurian (419.2–443.8 Mya)
Pridoli (419.2–423.0 Mya)
Ludlow (423.0–427.4 Mya)
Wenlock (427.4–433.4 Mya)
Llandovery (433.4–443.8 Mya)
Ordovician (443.8–485.4 Mya)
Late (443.8–458.4 Mya)
Middle (458.4–470.0 Mya)
Early (470.0–485.4 Mya)
Cambrian (485.4–541.0 Mya)
Furongian (485.4–497 Mya)
Series 3 (497–509 Mya)
Series 2 (509–521 Mya)
Terreneuvian (521–541.0 Mya)
(541.0 Mya–2.5 Gya)
Neoproterozoic era (541.0 Mya–1 Gya)
Ediacaran (541.0-~635 Mya)
Cryogenian (~635-~720 Mya)
Tonian (~720 Mya-1 Gya)
Mesoproterozoic era (1–1.6 Gya)
Stenian (1-1.2 Gya)
Ectasian (1.2-1.4 Gya)
Calymmian (1.4-1.6 Gya)
Paleoproterozoic era (1.6–2.5 Gya)
Statherian (1.6-1.8 Gya)
Orosirian (1.8-2.05 Gya)
Rhyacian (2.05-2.3 Gya)
Siderian (2.3-2.5 Gya)
Archean eon² (2.5–4 Gya)
Neoarchean (2.5–2.8 Gya)
Mesoarchean (2.8–3.2 Gya)
Paleoarchean (3.2–3.6 Gya)
Eoarchean (3.6–4 Gya)
Hadean eon² (4–4.6 Gya)
kya = thousands years ago. Mya = millions years ago.
Gya = billions
years ago.¹ =
Phanerozoic eon. ² =
Source: (2017/02). International Commission on Stratigraphy. Retrieved
13 July 2015. Divisions of Geologic Time—Major Chronostratigraphic
and Geochronologic Units USGS Retrieved 10 March 2013.