Pliocene

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system series step ≈ age ( mya )
after that after that after that younger
Neogene Pliocene Piacenzium 2.588
⬍
3.6
Zancleum 3.6
⬍
5.333
Miocene Messinium 5.333
⬍
7,246
Tortonium 7,246
⬍
11.62
Serravallium 11.62
⬍
13.82
Langhium 13.82
⬍
15.97
Burdigalium 15.97
⬍
20.44
Aquitanium 20.44
⬍
23.03
before before before older

The Pliocene is a chronostratigraphic series (= time interval) of the Neogene in the history of the earth . It started about 5.333 million years ago and ended about 2.588 million years ago. The Miocene lies before the Pliocene . It is followed by the Pleistocene , the Ice Age, with a change from warm and cold periods to the Holocene , the geological present.

Naming and history

The name (from Greek πλεῖον = more and καινός = new, unusual) comes from Charles Lyell , who proposed it in 1847 to subdivide the tertiary .

By 2004, the Pliocene was considered the last series of the Tertiary before the Quaternary . Then Gradstein et al. in their publication A Geologic Timescale suggested abandoning the Quaternary altogether and placing the Pleistocene and Holocene as the Neogene . However, this provoked violent opposition on the part of the various Quaternary associations with the result that the Quaternary as a system with the two series Pleistocene and Holocene is preserved. The top level of the Pliocene, the Gelasian , was also added to the Pleistocene . The ratification of this proposal by the International Union of Geological Sciences (IUGS) took place in June 2009.

Definition and GSSP

The upper limit of the magnetic polarity chronozone C3r (around 100,000 years before the Thvera normal-polar subchronozone C3n.4n) was defined as the basis of the series (and as the basis of the level of the Zancleum ). In addition, the border is close to the extinction horizon of the calcareous nanoplankton species Triquetrorhabdulus rugosus (= base of the CN10b zone) and the first appearance of the calcareous nanoplankton species Ceratolithus acutus . The upper limit of the Pliocene (after removal of the Gelasium) is the isotope level 103, the basis of the magnetic polarity chronozone C2r (Matuyama chronozone), and slightly above the extinction horizons of the calcareous nanoplankton species Discoaster pentaradiatus and Discoaster surculus . The GSSP (= global calibration point) for the beginning of the Pliocene (and thus also the Zancleum / Messinian border ) is located near the ancient city of Herakleia Minoa ( Sicily , Italy ).

Breakdown

The Pliocene used to be divided into three stages , after the gelasia has been hived off, there are only two stages:

In the large sedimentation basins of Central Europe, the sediments deposited there are mainly divided into regional levels. The following regional levels are used for the central Paratethys basin:

climate

In the Pliocene, the climate was relatively stable and warm. The proportion of carbon dioxide in the earth's atmosphere was determined by examining Δ13C of organic material from marine sediments and petrified leaves and was around 360 to 400 ppm in the mid-Pliocene; a concentration of 400 ppm was reached again in 2014.

The annual average temperatures were initially around 2 to 3 ° C above pre-industrial temperatures for around two million years. Various climate proxies document a sea level that is 15–25 meters higher than it is today. It is controversial whether and to what extent the volcanic eruptions of the Altiplano – Puna volcano complex (APVC) 3.5 and 5.6 million years ago due to the ash, sulfur dioxide and chlogase as the main drivers responsible for the temperature changes. Both eruptions roughly correspond to that of the better-known Yellowstone super volcano. Its eruption and the associated global darkening by ash is generally recognized as the tipping point for global cooling.

In the late Pliocene 3.2 million years ago, a gradual cooling heralded the impending Quaternary Ice Age , with CO 2 levels falling to 275-300 ppm over several 100,000 years, with a further reduction during the subsequent cold periods. With the glaciation of the Arctic in the Gelasium , the Quaternary began and continues to this day.

Paleogeography

The land bridge between North and South America began to form, having a greater impact on the spread of many species of animals , e.g. B. the proboscis from Africa via Asia to North and South America. In the South American animal world , which had developed independently in the isolation of the continent, the immigrant saber-toothed cats displaced the terror birds from the top of the food pyramid.

fauna

Europe

Hipparion, a horse of the Pliocene

Many animal species of the Pliocene had already lived in the preceding Miocene. The largest animals in Europe were represented at the beginning of the epoch by the elephant-like proboscis anancus and by zygodontic mastodons of the mammoth genus . Giraffes and Boselaphine horned bearers (relatives of the Nilgau antelope ) were widespread in Europe for the last time in this era. Gazelles ( Gazella , Hispanodorcas ) were also typical of Europe at that time . Large horn-bearers survived with Parabos from the Miocene and produced even larger forms with the genus Alephis . The more advanced forms of deer ( Croizetoceros and Pliocervus ) produced increasingly complex and larger antlers. Propotamochoerus survived among the pigs from the Miocene. The first real pigs of the genus Sus with Sus arvernensis also appeared. In Europe, the hippopotamus ( Hexaprotodon ) temporarily disappeared while the camels in the Pliocene with Paracamelus were particularly common in the southeast. Fossil aardvarks ( Orycteropus ) are known from the Perpignan area.

The rhinos lost a large part of their variety of forms at the beginning of the Pliocene. All polled forms died out in Europe and the eastern Mediterranean. The genera Ceratotherium and Diceros , which are still represented in Africa today by the white rhinoceros and black rhinoceros, as well as the hornless, hippopotamus-like Brachypotherium, were restricted to Africa since the beginning of the Pliocene. In Europe, only Stephanorhinus survived of the rhinos . The horses were common with Hipparion , tapirs ( Tapirus ) were mainly found in southern Europe.

Megantereon

The two saber-toothed cats Machairodus and Paramachairodus disappeared from Europe at the beginning of the Pliocene. Metailurus was replaced by Dinofelis . Hyenas were represented by bone-cracking forms such as Pachycrocuta and small predators such as Plioviverrops . In addition there were the so-called cheetah hyenas ( Chasmaporthetes ), which were less adapted to breaking bones and more to fast chases. The genus Chasmaportestes was also widespread in Africa and Asia and migrated to North America via the Bering Strait. Cheetahs were also common in Europe with Acinonyx pardinensis . Smaller predators were represented by foxes ( Vulpes ) and raccoon dogs ( Nyctereutes ). With Agriotherium , the bears from the Miocene to the Pliocene also survived. The genus Ursus , which may have developed from Ursavus in the Miocene of Asia , first appeared in Europe in the Pliocene with Ursus minimus . Were monkeys Macaca prisca a relative of, Barbary apes , as well as the genera Paradolichopithecus , Dolichopithecus and Mesopithecus also common. The hominoids , however, disappeared from Europe in the late Miocene.

The rodents were still represented in the Pliocene of Europe by various genera of murids ( Apodemus etc.) as well as by Cricetids ( Ruscinomys and Apocricetus ) from the Miocene. Flying squirrels ( Pliopetaurista ) and beavers ( Castor ) are also common. Crocodiles and giant tortoises were found in southern Europe. A brief cool phase in the otherwise mild climate of the early Pliocene led to the immigration of steppe rodents with sigmodontic teeth such as Trilophomys , Celadensia and Bjornkurtenia to Europe around 4 million years ago .

Towards the end of the Pliocene, around 3.2 million years ago, the last giraffes disappeared in Europe. The large hornbearer Parabos was replaced by the genus Leptobos at that time , which was already reminiscent of today's cattle of the genus Bos . Other horn carriers that immigrated to Europe were Gazellospira , Megalovis , and Pliotragus . In addition there were the first deer of the current genus Cervus and the first representatives of the giant deer ( Arvernoceros ). The puma-like cat Viretailurus schaubi also appeared for the first time among the carnivores about 3 million years ago . In addition, highly developed machairodontine saber-toothed cats such as Megantereon and Homotherium first appeared .

At the end of the Pliocene, about 2.6 million years ago, the earth's climate began to cool, during which mammoths ( Mammuthus ) immigrated and replaced the ancient trunk animals such as anancus . At the same time, the hipparions were replaced by modern horses of the genus Equus , which previously evolved from Pliohippus in America . Two other immigrants at the end of the epoch were Eucladoceros , a large deer with very complex antlers, and Libralces , an early elk. Then there were the horn-bearers Gallogoral and Preaovibos . The latter was a forerunner of today's musk ox and apparently replaced Megalovis and Pliotragus . At the same time the gazelles ( Gazella , Gazellospira ) disappeared from Europe. The new immigrants also included the precursors of today's wolves, who appeared in Europe with Canis etruscus , and the European jaguar ( Panthera gombaszoegensis ). The cheetah hyenas were disappearing at this time, and the big cat Dinofelis had even withdrawn from Europe a little earlier. The crocodiles, giant tortoises and tapirs also disappeared from Europe. Due to this change, the fauna of the following epoch of the Pleistocene already resembled the animal world of today.

Asia

Asia was connected to Europe and was home to mostly similar animal forms. However, some forms survived here, such as the chalicotheria and giraffes. The rhino genus Rhinoceros is also typical of the Pliocene of Asia .

Africa

Deinotherium

The trunk animals were richly represented in the Pliocene of Africa by elephants ( Elephas , Loxodonta , Mammuthus ), gomphotheria ( Anancus ) and Deinotheria ( Deinotherium ). The two rhinoceros species still alive today ( white rhinoceros and black rhinoceros ) have occurred since the middle Pliocene . Until the end of the Pliocene about 2 million years ago, the Chalicotheria survived with Ancylotherium hennigi in Africa. The horses were represented by hipparions until the genus Equus appeared at the beginning of the Pleistocene . Various pigs ( Notochoerus , Kolpochoerus , Metridichoerus ) and numerous horn carriers are known. The impalas as well as the genera Gazella and Tragelaphus were already represented. Giraffes were represented by long-necked forms ( Giraffa jumae ) as well as by the extinct cattle giraffes ( Sivatherium ). Hippos are mainly represented by the genus Hexaprotodon . Camels are generally rare in Africa's fossil record, but at least reached Malawi in the Pliocene southward. The large predators were represented by various hyenas, dogs and cats. The big cats included Dinofelis , Megantereon , Homotherium and, since the later Pliocene, the genera Panthera and Acinonyx . Lion-sized Panthera forms are known from Laetoli in Tanzania. In the Pliocene, bears with Agriotherium were also widespread as far as southern Africa. In addition, the Australopithecines lived as ancestors of humans in the Pliocene .

North America

With Teleoceras , the rhinos were also common in North America until the Pliocene.

At the beginning of the Pliocene of North America, horses, tapirs, trunk animals, camels and large saber-toothed cats ( megantereon ) were represented. The bone-cracking hyenas were represented in the Pliocene of North America by large dogs of the genus Osteoborus . During the Pliocene, the Central American Land Bridge was formed, connecting the North American with the South American continent for the first time in millions of years of isolation. During this great American fauna exchange , ground sloths , glyptodons , pampatheria and armadillos immigrated from South America and colonized North America. In contrast, the rhinos finally disappeared from North America with genera such as Teleoceras during the Pliocene .

South America

Thylacosmilus was replaced by real saber-toothed cats in the Pliocene. In the left background a glyptodon

The South American continent was more affected by the large fauna exchange than North America. Numerous mammal families typical of South America today migrated over the newly created Central American land bridge in the Pliocene. Among them were the cats, dogs, camels, deer, umbilical pigs and tapirs. Some families that only disappeared from South America at the very end of the Pleistocene, such as horses and gomphotheries, also immigrated at that time. They largely replaced the unique fauna of the South American Pliocene. Numerous South American mammals that had developed in isolation in South America became extinct and were replaced by the immigrants from the north. Among them was the saber-tooth robber Thylacosmilus . Among the forms that were able to assert themselves were mainly various secondary joint animals (sloths, anteaters, glyptodons, armadillos) as well as some South American ungulates such as toxodon and macrauchenia . In addition, numerous rodents and primates survived, which had immigrated to South America as "island hoppers" over narrow estuaries.

Alpid mountain formation

The in Neogen running (especially in the Miocene) Alpidic orogeny of the Alps , Carpathians and other mountains in Eurasia ( Himalayas ) came almost to a standstill (low elevations there are to date). The large sediment masses in Europe's plains and tectonic basins were only covered by a relatively thin formation in the Pliocene , before the glaciers and gravel of the first great cold ages shaped today's landscapes .

Mass extinction

At the end of the Pliocene there was a mass extinction that was only discovered in mid-2017. The marine megafauna was affected . About a third of the genera of large marine animals disappeared. Affected were whales, the Mediterranean manatees, sharks, sea birds and sea turtles, including the great shark Otodus megalodon . The cause of the mass extinction was the global cooling caused by the beginning ice age. This caused the sea level to sink, so that the shallow coastal seas of the continental shelf areas, the habitat of the affected species, shrank sharply.

literature

  • Charles Lyell: Principles of geology: or the modern changes of the earth and its inhabitants. 7th ed., XVI, 810 pp., Murray, London 1847.
  • Hans Murawski & Wilhelm Meyer: Geological dictionary . 10., rework. u. exp. Ed., 278, Enke Verlag, Stuttgart 1998 ISBN 3-432-84100-0 .
  • John A. Van Couvering, Davide Castradori, Maria Bianca Cita, Frederik J. Hilgen and Domenico Rio: The base of the Zanclean Stage and of the Pliocene Series. Episodes, 23 (3): pp. 179-187, Beijing 2000 ISSN  0705-3797 episodes.org (PDF).
  • Jordi Augusti: Mammoths, Sabertooths and Hominids 65 Million Years of Mammalian Evolution in Europe . Columbia University Press, 2002, ISBN 0-231-11640-3
  • Alan Turner & Mauricio Anton: Evolving Eden. An Illustrated Guide to the Evolution of the African Large-Mammal Fauna . Columbia University Press, New York, 2004. ISBN 0-231-11944-5
  • LG Marshall: Land Mammals and the Great American Interchange . (PDF) In: Sigma Xi (Ed.): American Scientist . 76, No. 4, July-August 1988, ISSN  0003-0996 , pp. 380-388. Retrieved June 6, 2009.
  • German Stratigraphic Commission (Ed.): Stratigraphische Tisch von Deutschland 2002 . Potsdam 2002, ISBN 3-00-010197-7 ( stratigraphie.de [PDF; 6.6 MB ; accessed on January 9, 2017]).

Individual evidence

  1. ↑ stratigraphy.org
  2. ^ ME Raymo, B. Grant, M. Horowitz, GH Rau: Mid-Pliocene warmth: Stronger greenhouse and stronger conveyor . In: Marine Micropaleontology . 27, No. 1-4, 1996, pp. 313-326. doi : 10.1016 / 0377-8398 (95) 00048-8 .
  3. ↑ World Cup Kurschner, J. van der Burgh, H. Visscher, DL Dilcher: Oak leaves as biosensors of late Neogene and early Pleistocene paleoatmospheric CO 2 Concentrations . In: Marine Micropaleontology . 27, No. 1-4, 1996, pp. 299-312. doi : 10.1016 / 0377-8398 (95) 00067-4 .
  4. ↑ IPCC (Ed.): Climate Change 2007: Working Group I: The Physical Science Basis . Cambridge University Press, 2007, Chapter 6.3.2: What Does the Record of the Mid-Pliocene Show? (English, ipcc.ch ): "Geologic evidence and isotopes agree that sea level was at least 15 to 25 m above modern levels."
  5. ^ Matteo Willeit, Andrey Ganopolski, Reinhard Calov, Alexander Robinson, Mark Maslin: The role of CO 2 decline for the onset of Northern Hemisphere glaciation . (PDF) In: Quaternary Science Reviews . 119, July 2015, pp. 22–34. doi : 10.1016 / j.quascirev.2015.04.015 .
  6. ↑ Catalina Pimiento, John N. Griffin, Christopher F. Clements, Daniele Silvestro, Sara Varela, Mark D. Uhen, Carlos Jaramillo. The Pliocene marine megafauna extinction and its impact on functional diversity. Nature Ecology & Evolution, 2017, DOI: 10.1038 / s41559-017-0223-6

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