Pleistocene

from Wikipedia, the free encyclopedia
system series step ≈  age  ( mya )
quaternary Holocene Meghalayum 0
⬍
0.012
Northgrippium
Greenlandium
Pleistocene Young Pleistocene
(Tarantium) 		0.012
⬍
0.126
Middle Pleistocene
(Ionian) 		0.126
⬍
0.781
Calabrium 0.781
⬍
1.806
Gelasium 1,806
⬍
2,588
deeper deeper deeper older

The Pleistocene ( ancient Greek πλεῖστος pleistos "most" and καινός kainos "new") is a period in the history of the earth . It began about 2,588,000 years ago and ended about 11,700 years ago ( BP ) with the beginning of the Holocene - series , of the present time. Thus the Pleistocene lasted about 2.5 million years.

In the hierarchy of chronostratigraphic time units, the Pleistocene is the lower series of the Quaternary . The Pliocene preceded the Pleistocene . Traditionally, the boundary between the Pliocene and the Pleistocene was 1.8 million years old. Since 2009, however , the Gelasian is no longer the youngest section of the Pliocene, but rather the oldest section of the Pleistocene. The Pleistocene is mainly characterized by the alternation of cold and warm periods . After same-cold time in the Alps Günz cold period called Elster - / Mindel - and Saale - / crack -Kaltzeit is the Pleistocene at the end of the last ( Vistula - / Würm -) cold period from Holocene replaced, the series in which we today Life.

Use of terms

Until the 19th century, the Pleistocene was referred to as Diluvium with reference to the Flood ( Latin diluere , washing away = flood ). This term and the associated adjective diluvial were still used by geologists in the 20th century - without reference to the myth of the Flood.

Colloquially, the Pleistocene is often equated with today's Ice Age. The Cenozoic Ice Age began over 30 million years ago with the glaciation of the Antarctic . What is correct, however, is that the beginning of the Pleistocene roughly coincides with the beginning of the glaciation of the Arctic around 2.6 million years ago.

Naming and conceptual history

During long periods of the Pleistocene, the climate was significantly colder than it is today. Illustration of a late Pleistocene landscape in northern Spain

At the beginning of the 19th century one had learned to clearly differentiate the chaotic deposits in Northern Europe, Northwest Europe and in the Alpine region from the layers below, but the interpretations of these Ice Age sediments were shaped by biblical views.

It was only after the Ice Age theory prevailed that the most recent deposits were assigned to the Quaternary and subdivided into the Diluvium and the Alluvium. These terms were later replaced by the Pleistocene and Holocene, with the result that the Pleistocene largely ends with the Holocene to this day, although this is part of the interglacial period.

The term Quaternary was proposed by Jules Desnoyers as early as 1829 to refer to sediments in the Paris Basin that were significantly younger than the Tertiary deposits. The Quaternary strata were very thick in certain basin locations, but geologically only of a short age. This resulted in a very imbalanced subdivision of the New Earth Era (Cenozoic) into the 63.7 million year Tertiary and the only 1.6–1.8 million years long Quaternary with the epochs Pleistocene and Holocene (geological present). When the geological time scale was redefined, this imbalance led to the replacement of the terms Tertiary and Quaternary by the terms Paleogene and Neogene with new stratigraphic boundaries and meanings. The period of the Neogene comprised the epochs Miocene (beginning 23.03 million years ago), Pliocene (beginning 5.33 million years ago), Pleistocene (beginning 2.6 million years ago) and Holocene .

The Quaternary was reintroduced as an intermediate term in 2005 and now encompasses the entire Holocene and Pleistocene (including the Gelasian as a former younger section of the Pliocene).

Definition according to ICS

The last two glacial periods in the Pleistocene: Weichsel / Würm complex and Saale / Riss complex. The glacier advances were interrupted by warmer periods during which the archaic people of Europe (the Neanderthals as the successor to Homo heidelbergensis ) spread beyond the permafrost limit to the north and northeast. From around 40,000 BC. The modern Cro-Magnon humans colonized these areas.

According to the definition of the International Commission on Stratigraphy , the Pleistocene begins magnetostratigraphically with the base of the polarity chronozone C2r (Matuyama). Biostratigraphically , it begins with the extinction of the coccolithophores Discoaster pentaradiatus and Discoaster surculus . The lower limit of the Pleistocene is also within Marine Isotope Stage 103. The reference profile ( GSSP ) is on Monte San Nicola , near the town of Gela , Sicily , Italy .

Subdivision

The woolly mammoth is a characteristic species of the Pleistocene

The Pleistocene is divided into four sections or chronostratigraphic levels on the geological time scale . In the past, the Pleistocene comprised three stages (Lower, Middle and Upper Pleistocene or Old, Middle and Young Pleistocene). The beginning of the Pleistocene and the end of the Pliocene were traditionally considered to be around 1.8 million years old. Since the Pleistocene is mainly defined by the change in the stable climate to periodically occurring cold periods, and the first of these cold periods already occurred 2.5 million years ago, there have been long deliberations to move the beginning of the Pleistocene back by definition. In 2009 the Gelasian , which was the top level of the Pliocene, was placed as the bottom level of the Pleistocene by the IUGS . A proposal has already been made for the formal naming of the subsequent stages in Ionium and Calabrium :

Young Pleistocene

The Young Pleistocene includes a warm period ( called Eem warm period in Europe ) and a subsequent glaciation phase, the last cold period . The Eem warm period lasted only around 10,000 years, and the glaciation of large parts of the continents in the northern hemisphere lasted more than 100,000 years.

Geographically, a distinction is made between:

The development of culture and the spread of man today also fell into the Young Pleistocene . The first works of art are known from the Middle Paleolithic (around 80,000 years ago).

fauna

The musk ox evolved from the genus Praeovibos in the middle Pleistocene

The fauna of the Pleistocene was already very similar to today's fauna. Most of the genera were already identical to those of today and most of the species known today were created in the course of this era. However, numerous large animal species of the Pleistocene disappeared in the course of the Quaternary extinction wave .

Eurasia

If it was previously assumed that homotherium disappeared in Europe in the Middle Pleistocene, new finds show that the saber-toothed cat was present in northwestern Europe, similar to America, up to the end of the epoch

Typical for the early Pleistocene in Eurasia was the first appearance of voles ( Allophaiomys pliocaenicus ) with constantly growing, rootless molars. The success of these voles is also due to the cooling of the climate and the associated spread of large open landscapes in the Pleistocene. Together with the voles, other species that were characteristic of the beginning Pleistocene spread. Some large ungulates were particularly noticeable, such as Soergelia , Praeovibos, the ancestor of the musk ox, the giant deer Megaloceros and the first bison . At the beginning of the epoch there were still numerous genera that already existed in the Pliocene, but soon disappeared. One of them was the deer Eucladoceros , which was replaced by the giant deer, another was Leptobos, a large horn-bearer that was replaced by bison and ancestral aurochs. The saber-toothed cats Megantereon and Homotherium as well as the hyena Pachycrocuta were already common in the Pliocene. While Megantereon and Pachycrocuta became extinct in the Middle Pleistocene, Homotherium seems to have survived in Europe until the end of the epoch. Dogs of the genus Canis and horses of the genus Equus as well as the first panther cats ( Panthera ) and mammoths ( Mammuthus ) existed at least since the late Pliocene. The Eurasian puma ( Puma pardoides ) has also been widespread in Eurasia for at least 2.1 million years. In the early Pleistocene, moose ( Prealces, Alces ), which presumably emerged from the genus Libralces , and the reindeer ( Rangifer ) appeared for the first time. In addition, various pigs ( Sivachoerus, Hippohyus, Tetraconodon ) were widespread in Eurasia in the early Pleistocene, in addition to today's genera . Also in the early Pleistocene, the giant Trogontherium beaver occurred. Among the primates of South Asia, the giant monkey Gigantopithecus stands out alongside today's forms such as macaques, slender monkeys ( Presbytis ), gibbons ( Hylobates ) and orangutans ( Pongo ) . Orangutans were much more common in the Pleistocene than they are today. Their fossil remains can be found from Java to southern China. In Europe primates were distributed among other things by macaques ( Macaca ). At the beginning of the early Pleistocene, hominids first appeared on the edges of Europe. In Dmanissi, in present-day Georgia, remains of prehistoric humans of the genus Homo , which are around 1.8 million years old, have been found.

Among the martens in the Pleistocene, in addition to the current genera, there were also some more, including baranogals and oxyvormela as bandiltissas and the Grisons Pannonictis and Enhydrictis . Agriotheria were also widespread among the bears in the early Pleistocene . Black bears were widespread with Ursus thibetanus mediterraneus in warm periods as far as southern and central Europe. The polar bear, on the other hand, first appeared as a very young species in the Young Pleistocene.

The leopard was also found in Central Europe until the late Pleistocene

Many of today's forms were much more common in the Pleistocene. The bamboo bear was very common in East Asia. Raccoon dogs and red dogs ( Cuon ) reached Europe, whereas today they are limited to Asia. The African warthogs Metridichoerus and Phaccochoerus were temporarily widespread in the Middle East. Hippopotamus ( Hippopotamus ), water buffalo ( Bubalus ), fallow deer ( Dama ), musk ox ( Ovibos ), reindeer ( Rangifer ), saiga antelope ( Saiga ), thare ( Hemitragus ), lions and leopards were very widespread at times and even reached Central Europe. Hippopotamuses of the genus Hippopotamus lived on Mediterranean islands, in Southeast Asia there were hippopotamuses of the genus Hexaprotodon . Camels ( Paracamelus, Camelus ) were common as far as Eastern Europe. The early bison were distributed in the Old Pleistocene through Bos schoetensacki in the forests and Bos priscus in the steppes. Today's forest wisent ( Bos bonasus ) did not appear until the Upper Pleistocene. The tapirs disappeared from Europe in the early Pleistocene, the chalicotheria from Asia and Africa and thus for good. In addition to today's genera ( Rhinoceros, Dicerorhinus ), rhinos are represented by woolly rhinos ( Coelodonta ) and the genus Stephanorhinus until the late Pleistocene . The Elasmotherien survived at least until the Middle Pleistocene. The mammoths ( Mammuthus ) developed from the southern elephant via the steppe mammoth to the woolly mammoth, while the mammoths and primitive elephant relatives with mammoth and anancus disappeared from Eurasia in the early Pleistocene. In addition to today's Asian elephants of the genus Elephas , trunk animals of the genera Stegodon and Palaeoloxodon were also common in the Pleistocene of Eurasia .

In the middle Pleistocene around 500,000 years ago, pre-humans reached latitudes around 45 ° N for the first time during mild climatic phases. During the Vistula Glacial Period in the late Pleistocene around 40,000 years ago, anatomically modern humans ( Homo sapiens ) immigrated to Europe and displaced the Neanderthals who were previously native there .

At the end of the Pleistocene, numerous Eurasian large animal species disappeared in the wake of the worldwide Quaternary extinction . The forest rhinoceros and the European forest elephant were among the first species to disappear, and the woolly rhinoceros and the giant deer were among the last . The cave bear died out a little earlier. The woolly mammoth survived into the Holocene, at least in some areas .

Africa

New for the Pleistocene of Africa are horses of the genus Equus , which replaced the last hipparions of the Pliocene ( Eurygnatohyippus ) at the beginning of the epoch . In addition to numerous genera that are still widespread on the African continent today, at the beginning of the Pleistocene there were also Dinotheria ( Deinotherium ), Chalicotherium ( Ancylotherium ), saber-toothed cats ( Megantereon , Homotherium ), Metailurine cats ( Dinofelis ), and large hyrax ( Gigantohyrax ) , and cattle giraffes ( Sivatherium ). These relics from the Pliocene all died out in the early Pleistocene. In addition to elephants of the genus Loxodonta , which also includes today's African elephants, there was also the genus Elephas , which is now restricted to Asia, in the Pleistocene of Africa . The mammoths ( Mammuthus ), on the other hand, had apparently already disappeared and instead produced a greater abundance of forms in Eurasia and North America. Pleistocene genera that no longer occur today also include cattle of the genus Pelorovis , giant hartebeest ( Megalotragus ), antelopes ( Parmularius ), waterbuck ( Menelikia ), large warthogs ( Metridichoerus , Notochoerus ) and primates ( Dinopithecus ). Some forms such as the white rhinoceros and the jelada, which in historical times were limited to relatively small areas, became much more widespread in the Pleistocene. North of the Sahara, woolly rhinos, giant deer, aurochs, wild ass, fallow deer and red deer also appeared. In the Pleistocene, camels of the genus Camelus reached at least East Africa from the north.

Australia

Skeleton of a Diprotodon , in the background a Eurasian giant deer

Also, Australia was home to a rich fauna large animal in the Pleistocene. These included large herbivores such as Diprotodon , the Beuteltapir palorchestes and various large sthenurinae ( procoptodon ) as well as thylacoleonidae , giant potoroidae ( propleopus ) Riesenwarane Megalania , soil crocodiles ( quinkana ) and Thunderbirds genyornis . Around 50,000 years ago, humans ( Homo sapiens ) also reached the remote continent for the first time . Most of these large animal genera are likely to have become extinct around this time.

America

Native Americans watch a glyptodon (illustration)

North and South America have been linked by a land bridge since the Pliocene . Throughout the entire Pleistocene, the American double continent was home to fauna that, in addition to today's species or their predecessors, also featured a large number of conspicuous large animal species. These included North American mammoths , Mammutiden , camels , helmet muskox , Busch oxen , American lions , Direwölfe . Toxodonts , Macrauchenia and Gomphotheria lived in South America . Saber-toothed cats , giant sloths and giant armadillos ( Glyptodon ) were represented on both continents . At the end of the Pleistocene, during a tight timeframe (around 12,000 years ago), all of these species disappeared. Today's fauna is essentially represented by the survivors of this mass extinction. It was around this time that humans first appeared in America.

literature

  • Edmund Blair Bolles: Ice Age. How a professor, a politician and a poet discovered the eternal ice . Berlin 2000, ISBN 3-87024-522-0 (On the history of research, especially Louis Agassiz, Charles Lyell and Elisha Kent Kane).
  • Hansjürgen Müller-Beck: The Ice Ages. Natural history and human history . Munich 2005, ISBN 3-406-50863-4 (Brief introduction from the Beck series).
  • Josef Klostermann: The Climate in the Ice Age . Stuttgart 1999, ISBN 3-510-65189-8 .
  • R. Chris L. Wilson, Stephen A. Drury, Jenny L. Chapman: The Great Ice Age. Climate change and life . London 2000, ISBN 0-415-19841-0 .
  • Felix M. Gradstein, James G. Ogg, Martin van Kranendonk: On the Geologic Time Scale 2008 . In: Newsletters on Stratigraphy , 43/1, Bornträger, Berlin / Stuttgart 2008, pp. 5–13 doi: 10.1127 / 0078-0421 / 2008 / 0043-0005 .

Web links

Commons : Pleistocene  - collection of images, videos and audio files
Wiktionary: Pleistocene  - explanations of meanings, word origins, synonyms, translations

Individual evidence

  1. ↑ Johann Mathesius, Martinus Oberdorffer: Diluvium: Historia, has ... the flood, characterized ... erseufft God a terrible example of his wrath against sin, times to Noah, the first unrepentant world . Ed. Johann, Rosen, 1605.
  2. ^ Franz Eugen Geinitz: The Diluvium of Germany. E. Swiss beard, 1920.
  3. ^ Wilhelm Weiler: Pliocene and Diluvium in southern Rheinhessen. In: Notes from the Hessian State Office for Soil Research. Volume 80, 1952, pp. 147-170.
  4. ^ Pleistocene Series International Commission on Stratigraphy
  5. ^ John A. Van Couvering: The Pleistocene Boundary and the Beginning of the Quaternary. Cambridge University Press; Edition: New Ed (December 16, 2004). ISBN 0-521-61702-2
  6. ↑ Riccardi, Alberto C. (June 30, 2009) “IUGS ratified ICS Recommendation on redefinition of Pleistocene and formal definition of base of Quaternary” International Union of Geological Sciences
  7. ↑ Maria Bianca Cita, Luca Capraro, Neri Ciaranfi, Enrico Di Stefano, Maria Marino, Domenico Rio, Rodolfo Sprovieri and Gian Battista Vai: Calabrian and Ionian: A proposal for the definition of Mediterranean stages for the Lower and Middle Pleistocene. Episodes, 29 (2): pp. 107-114, Beijing 2006
  8. ↑ Ancient stone marks may roll back date of 'modern behavior'. The Japan Times, January 13, 2002.
  9. ↑ a b c Jordi Augusti: Mammoths, Sabertooths and Hominids 65 Million Years of Mammalian Evolution in Europe . Columbia University Press, 2002, ISBN 0-231-11640-3
  10. ↑ H. Hemmer, R.-D. Kahlike, AK Vekua The Old World puma Puma pardoides (Owen, 1846) (Carnivora: Felidae) in the Lower Villafranchian (Upper Pliocene) of Kvabebi (East Georgia, Transcaucasia) and its evolutionary and biogeographical significance . In: New Yearbook for Geology and Paleontology, Abhandlungen , 233, 2004, pp. 197–233.
  11. ↑ a b c d Erich Thenius : Basics of the fauna and distribution history of mammals . A historical animal geography. 2nd, completely revised edition, Gustav Fischer Verlag, Stuttgart 1980. ISBN 3-437-30312-0 (first edition under the title: Basic features of the spreading history of mammals . Gustav Fischer Verlag, Jena 1972).
  12. ↑ R. Dennell: hominid dispersals and Asian Biogeography during the Lower and Early Middle Pleistocene, c. 2.0-0.5 Mya. In: Asian Perspectives , Volume 43, Number 2, 2004, pp. 205-226.
  13. ^ Alan Turner, Mauricio Antón: 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 .
  14. Jump up ↑ Roberts, RG, TF Flannery, LA Ayliffe, H. Yoshida, JM Olley, GJ Prideaux, GM Laslett, A. Baynes, MA Smith, R. Jones, and BL Smith. 2001. New ages for the last Australian megafauna: continent-wide extinction about 46,000 years ago. Science 292: 1888-1892.