The Pliocene ( ; also Pleiocene) Epoch
is the epoch in the geologic timescale
that extends from 5.333 million to 2.58
[See the 2014 version of the ICS geologic time scale](_blank)
million years BP
. It is the second and youngest epoch of the Neogene
Period in the Cenozoic Era
. The Pliocene follows the Miocene
Epoch and is followed by the Pleistocene
Epoch. Prior to the 2009 revision of the geologic time scale, which placed the four most recent major glaciations entirely within the Pleistocene, the Pliocene also included the Gelasian
stage, which lasted from 2.588 to 1.806 million years ago, and is now included in the Pleistocene.
As with other older geologic periods, the geological strata
that define the start and end are well identified but the exact dates of the start and end of the epoch are slightly uncertain. The boundaries defining the Pliocene are not set at an easily identified worldwide event but rather at regional boundaries between the warmer Miocene and the relatively cooler Pliocene. The upper boundary was set at the start of the Pleistocene glaciations.
(later Sir Charles) gave the Pliocene its name in ''Principles of Geology'' (volume 3, 1833).
The word ''pliocene'' comes from the Greek words (, "more") and (, "new" or "recent")
and means roughly "continuation of the recent", referring to the essentially modern marine mollusc
These reflect the understanding that these are all ''new'' relative to the Mesozoic
("middle life" - the age of dinosaurs
) and Paleozoic
("old life" - Trilobites
, coal forest
s, and the earliest Synapsida
In the official timescale of the ICS
, the Pliocene is subdivided into two stages
. From youngest to oldest they are:
The Piacenzian is sometimes referred to as the Late Pliocene, whereas the Zanclean is referred to as the Early Pliocene.
In the system of
* North American Land Mammal Ages
(NALMA) include Hemphillian
(9–4.75 Ma), and Blancan
(4.75–1.806 Ma). The Blancan extends forward into the Pleistocene
* South American Land Mammal Ages
(SALMA) include Montehermosan
(6.8–4.0 Ma), Chapadmalalan
(4.0–3.0 Ma) and Uquian
In the Paratethys
area (central Europe
and parts of western Asia) the Pliocene contains the Dacian
(roughly equal to the Zanclean) and Romanian
(roughly equal to the Piacenzian and Gelasian together) stages. As usual in stratigraphy, there are many other regional and local subdivisions in use.
the Pliocene is divided into the following stages (old to young): Gedgravian, Waltonian
, Pre-Ludhamian, Ludhamian, Thurnian, Bramertonian
or Antian, Pre-Pastonian
or Baventian, Pastonian
. In the Netherlands
the Pliocene is divided into these stages (old to young): Brunssumian C, Reuverian A, Reuverian B, Reuverian C, Praetiglian
A, Tiglian B, Tiglian C1-4b, Tiglian C4c, Tiglian C5, Tiglian C6 and Eburonian
. The exact correlations between these local stages and the International Commission on Stratigraphy
(ICS) stages is still a matter of detail.
The global average temperature in the mid-Pliocene (3.3–3 mya) was 2–3 °C higher than today, carbon dioxide levels were the same as today, and global sea level was 25 m higher. The northern hemisphere ice sheet was ephemeral before the onset of extensive glaciation
that occurred in the late Pliocene around 3 Ma.
The formation of an Arctic ice cap is signaled by an abrupt shift in oxygen isotope
ratios and ice-rafted
cobbles in the North Atlantic
and North Pacific ocean
[Van Andel (1994), p. 226.]
Mid-latitude glaciation was probably underway before the end of the epoch. The global cooling that occurred during the Pliocene may have spurred on the disappearance of forests and the spread of grasslands and savannas.
Continents continued to drift
, moving from positions possibly as far as 250 km from their present locations to positions only 70 km from their current locations. South America
became linked to North America through the Isthmus of Panama
during the Pliocene, making possible the Great American Interchange
and bringing a nearly complete end to South America's distinctive large marsupial predator
and native ungulate
faunas. The formation of the Isthmus had major consequences on global temperatures, since warm equatorial ocean currents were cut off and an Atlantic cooling cycle began, with cold Arctic and Antarctic waters dropping temperatures in the now-isolated Atlantic Ocean.
's collision with Europe
formed the Mediterranean Sea
, cutting off the remnants of the Tethys Ocean
. The border between the Miocene and the Pliocene is also the time of the Messinian salinity crisis
Sea level changes exposed the land bridge
Pliocene marine rocks are well exposed in the Mediterranean, India
, and China
. Elsewhere, they are exposed largely near shores.
During the Pliocene parts of southern Norway and southern Sweden that had been near sea level rose. In Norway this rise elevated the Hardangervidda plateau
to 1200 m in the Early Pliocene. In Southern Sweden similar movements elevated the South Swedish highlands
leading to a deflection of the ancient Eridanos river
from its original path across south-central Sweden into a course south of Sweden.
The change to a cooler, dry, seasonal climate had considerable impacts on Pliocene vegetation, reducing tropical species worldwide. Deciduous
forests proliferated, coniferous
forests and tundra
covered much of the north, and grassland
s spread on all continents (except Antarctica). Tropical forests were limited to a tight band around the equator, and in addition to dry savannahs
appeared in Asia and Africa.
Both marine and continental faunas were essentially modern, although continental faunas were a bit more primitive than today. The first recognizable hominins
, the australopithecine
s, appeared in the Pliocene.
The land mass collisions meant great migration and mixing of previously isolated species, such as in the Great American Interchange
got bigger, as did specialized predators.
Image:Oliva sayana.jpg|The gastropod ''Oliva sayana'', from the Pliocene of Florida.
Image:Cladocora.jpg|The coral ''Cladocora'' from the Pliocene of Cyprus.
Image:CyprusPlioceneGastropod.JPG|A gastropod and attached serpulid wormtube from the Pliocene of Cyprus.
Image:Turritellatricarinata.jpg|The gastropod ''Turritella carinata'' from the Pliocene of Cyprus.
Image:SpondylusPliocene.jpg|The thorny oyster ''Spondylus'' right and left valve interiors from the Pliocene of Cyprus.
Image:SpondylusArticulated.jpg|Articulated ''Spondylus'' from the Pliocene of Cyprus.
Image:Diodoraitalica.jpg|The limpet ''Diodora italica'' from the Pliocene of Cyprus.
Image:DentaliumPliocene.jpg|The scaphopod ''Dentalium'' from the Pliocene of Cyprus.
File:Aporrhais from Pliocene.jpg|The gastropod ''Aporrhais'' from the Pliocene of Cyprus.
Image:AnadaraPliocene.jpg|The arcid bivalve ''Anadara'' from the Pliocene of Cyprus.
Image:Amusium cristatum Cyprus.jpg|The pectenid bivalve ''Ammusium cristatum'' from the Pliocene of Cyprus.
Image:Petaloconchus Cyprus Pliocene.JPG|Vermetid gastropod ''Petaloconchus intortus'' attached to a branch of the coral ''Cladocora'' from the Pliocene of Cyprus.
In North America, rodents
, large mastodon
s and gomphothere
s, and opossum
s continued successfully, while hoofed animals (ungulate
s) declined, with camel
all seeing populations recede. Rhinos
, three-toed horses (''Nannippus
s, and chalicothere
s became extinct. Borophagine dogs
'' became extinct, but other carnivores
including the weasel
family diversified, and dog
s and short-faced bear
s did well. Ground sloth
s, huge glyptodont
s, and armadillo
s came north with the formation of the Isthmus of Panama.
rodents did well, while primate
distribution declined. Elephant
s and stegodon
ts were successful in Asia, and hyrax
es migrated north from Africa. Horse
diversity declined, while tapirs and rhinos did fairly well. Cow
s and antelope
s were successful, and some camel species crossed into Asia from North America. Hyenas
and early saber-toothed cat
s appeared, joining other predators including dogs, bears and weasels.
Africa was dominated by hoofed animals, and primates continued their evolution, with australopithecine
s (some of the first hominin
s) appearing in the late Pliocene. Rodents were successful, and elephant populations increased. Cows and antelopes continued diversification and overtook pig
s in numbers of species. Early giraffe
s appeared. Horses and modern rhinos came onto the scene. Bears, dogs and weasels (originally from North America) joined cats, hyenas and civet
s as the African predators, forcing hyenas to adapt as specialized scavengers.
South America was invaded by North American species for the first time since the Cretaceous
, with North American rodents and primates mixing with southern forms. Litoptern
s and the notoungulate
s, South American natives, were mostly wiped out, except for the macrauchenids
, which managed to survive. Small weasel-like carnivorous mustelid
s and short-faced bears
migrated from the north. Grazing glyptodont
s, browsing giant ground sloth
s and smaller caviomorph rodents
s, and armadillos
did the opposite, migrating to the north and thriving there.
The marsupials remained the dominant Australian mammals, with herbivore forms including wombat
s and kangaroo
s, and the huge ''Diprotodon
''. Carnivorous marsupials continued hunting in the Pliocene, including dasyurid
s, the dog-like thylacine
and cat-like ''Thylacoleo
''. The first rodents arrived in Australia. The modern platypus
, a monotreme
The predatory South American phorusrhacids
were rare in this time; among the last was ''Titanis
'', a large phorusrhacid that migrated to North America and rivaled mammals as top predator. Other birds probably evolved at this time, some modern (such as the genera ''Cygnus
'' and ''Corvus
''), some now extinct.
Reptiles and amphibians
s and crocodile
s died out in Europe as the climate cooled. Venomous snake
genera continued to increase as more rodents and birds evolved. Rattlesnake
s first appeared in the Pliocene. The modern species ''Alligator mississippiensis
'', having evolved in the Miocene, continued into the Pliocene, except with a more northern range; specimens have been found in very late Miocene deposits of Tennessee
. Giant tortoises
still thrived in North America, with genera like ''Hesperotestudo
''. Madtsoid snake
s were still present in Australia. The amphibian order Allocaudata
Oceans continued to be relatively warm during the Pliocene, though they continued cooling. The Arctic ice cap
formed, drying the climate and increasing cool shallow currents in the North Atlantic. Deep cold currents flowed from the Antarctic.
The formation of the Isthmus of Panama about 3.5 million years ago cut off the final remnant of what was once essentially a circum-equatorial current that had existed since the Cretaceous and the early Cenozoic
. This may have contributed to further cooling of the oceans worldwide.
The Pliocene seas were alive with sea cow
s, sea lion
s and shark
In 2002, Narciso Benítez ''et al.'' calculated that roughly 2 million years ago, around the end of the Pliocene epoch, a group of bright O and B stars
called the Scorpius-Centaurus OB association
passed within 130 light-years of Earth and that one or more supernova
explosions gave rise to a feature known as the Local Bubble
. Such a close explosion could have damaged the Earth's ozone layer
and caused the extinction of some ocean life (at its peak, a supernova of this size could have the same absolute magnitude
as an entire galaxy of 200 billion stars).
[Comins & Kaufmann (2005), p. 359.]
isotopes that have been found in ancient seabed deposits further back this finding, as there are no natural sources for this radioactive isotope on Earth, but they can be produced in supernovae. Furthermore, iron-60 residues point to a huge spike 2.6 million years ago, but an excess scattered over 10 million years can also be found, suggesting that there may have been multiple, relatively close supernovae.
In 2019, researchers found more of these interstellar iron-60 isotopes in Antarctica, which have been associated with the Local Interstellar Cloud
* List of fossil sites
''(with link directory)''
* ; 2004: ''A Geologic Time Scale 2004'', Cambridge University
Mid-Pliocene Global Warming: NASA/GISS Climate Modeling"Supernova dealt deaths on Earth? Stellar blasts may have killed ancient marine life" ''Science News Online''
retrieved February 2, 2002
Pliocene Microfossils: 100+ images of Pliocene ForaminiferaHuman Timeline (Interactive)
, National Museum of Natural History