Quaternary extinction wave

from Wikipedia, the free encyclopedia
Artist's impression of a possible late Pleistocene landscape in America

The Quaternary extinction wave was a mass extinction of the last glacial period , in which numerous animal species disappeared on different continents. The process, which mainly affected large and very large species of the Ice Age megafauna , was limited to the Quaternary Age and reached its climax at the transition from the Pleistocene to the Holocene (the post-ice age). The scientific discussion of the phenomenon is still divided into two camps, since on the one hand human influences ( "overkill" ) and on the other hand climatic changes are seen as the main cause. A combination of both factors could also have caused the mass extinction.

The extinct species

Temporal correlation of the extinction of large animal faunas in different regions with the occurrence of humans

Up to the end of the Pleistocene all continents were populated by a rich fauna of large animals, comparable to today's African habitats. During the last glacial period (in Central Europe the Würm Ice Age in southern Germany or the Vistula Ice Age in the north) and especially at its end, numerous large animal species disappeared in a relatively short period of time. Only in Africa and partly in South Asia did some animal giants such as rhinos and elephants and also significantly more other large mammal species survive than on other continents. With the exception of Africa and southern Asia , all species weighing over 1000 kilograms and 80% of all species weighing 100 to 1000 kilograms died out worldwide, mostly at the same time as the gradual advance of modern humans . In some regions such as northern Eurasia or America, the mass extinction also correlates relatively well with climatic changes. The proportion of extinct species weighing less than 45 kg is negligible.

Africa and South Asia

The tropics of the Old World are the only regions on earth that have a distinctive large animal fauna. Only here do species with a body weight of over 1000 kg still exist today. These include the African elephant , the Asian elephant as well as the hippopotamus and various rhinos . The reason given is occasionally given that man developed in Africa and reached the southern parts of Asia since the early Pleistocene. Due to their common evolution, the animals of these regions would have had the opportunity to develop flight reflexes and thus to adapt to the hunted by humans. However, this region also lost a relatively large number of large animal forms, especially in the early or middle Pleistocene, without being represented by successor species. It has therefore been suggested that the early hominids of the early or mid-Pleistocene may have exterminated some species of the ancient tropics. Large mammals that became extinct in Africa and South Asia in the early and middle Pleistocene include, for example, the dinotheria , the chalicotheria , the bovine giraffe and various saber-toothed cats ( Megantereon , Homotherium , Dinofelis ). The disappearance of the saber-toothed cats about 1.5 million years ago in Africa correlates strongly with the first appearance of the Acheul culture , so that a connection is sometimes suspected. In contrast, the losses of the African fauna in the late Pistocene are low. These include a giant hartebeest ( Megalotragus ) and the giant buffalo ( Pelorovis ( Syncerus ) antiquus ).

Australia

Diprotodon

The Australian continent, including Tasmania and New Guinea, lost all land-living mammals, birds and reptiles weighing over 100 kg in the late Pleistocene. In addition, all genera containing species between 45 and 100 kg disappeared, with the exception of one. The only large animal genus that survived the Pleistocene in Australia was the kangaroo genus Macropus . For most species of Australia, which disappeared, included Diprotodon and zygomaturus (rhino large marsupials), the Beuteltapir palorchestes , the thylacoleonidae ( marsupial lion ), a giant musk rats kangaroo , giant wombat ( Phascolonus ) and up to three meters high giant kangaroos (genus procoptodon , simosthenurus , Sthenurus , Protemnodon ). Then there was the large, flightless bird Genyornis and large reptiles such as the giant monitor lizard Megalania . All of these species seem to have died out around 40,000 to 50,000 years ago, which correlates very strongly with the earliest human occurrence there. Diprotodon bones were also found in one of the oldest known human camps in Australia.

Northern Eurasia

Skeleton of the woolly mammoth and the woolly rhinoceros

In Eurasia this process extended over a longer period of time, from 50,000 to 12,000 years ago, and reached its climax at the end of the Pleistocene . The species that became extinct in Europe by at least 12,000 years ago include woolly mammoth ( Mammuthus primigenius ), woolly rhinoceros ( Coelodonta antiquitatis ), giant deer ( Megaloceros giganteus ), steppe wisent ( Bos priscus ), cave lion ( Panthera spelaea ) and cave hyena ( Crocuta spelaea ).

Some species that became extinct during the last glacial period ( Worm Ice Age or Vistula Ice Age ) disappeared before the end of the Pleistocene. This mainly affects heat-loving species such as the European forest elephant ( Palaeoloxodon antiquus ), the forest rhinoceros ( Stephanorhinus kirchbergensis ) and the steppe rhinoceros ( Stephanorhinus hemitoechus ), which were initially displaced from Central to Southern Europe during the early Worm Ice Age about 100,000 years ago and there in Became extinct over the next few decades. As far as we know today, the European cave bear ( Ursus spelaeus ) disappeared before the last cold peak of the Worm Ice Age, during the archaeological culture of Gravettia about 27,000 years ago. Around the same time, the saber-toothed cat ( Homotherium ) was also recorded for the last time in Europe.

North America

Smilodon reconstruction

In North America, extinction was on a tight timeframe (around 12,000 years ago) and very sudden. There disappeared including the woolly mammoth , the prairie mammoth , the American mastodon , all camels ( Camelops , Hemiauchenia , Palaeolama ) and horses, the helmet-musk ox , the Busch Ox , and the saber-toothed cat ( Smilodon , Homotherium ), four giant sloths ( eremotherium , Megalonyx , Paramylodon , Nothroteriops ) and giant armadillos ( Glyptotherium , Holmesina ). In addition, the American lion , the American cheetah , the great wolf Canis dirus , the short -snouted bear, Florida spectacled bear, capybaras and tapirs as well as various species of deer, pronghorn and peccary disappeared . At least 17 genera of America's extinct megafauna disappeared in a very narrow window of time, 11,400 to 10,800 radiocarbon years ago . Extinction on the American continent correlates with climate change at the end of the Pleistocene and with the first appearance of humans in the new world. The largest animal species that survived the mass extinction is the American bison .

South America

In South America, most species appear to have died out around the same time or a little later than in North America. Here, however, the fossil documentation is less secure in this regard. During this mass extinction , South America lost all of its proboscis ( Cuvieronius , Notiomastodon ), all giant sloths (e.g. Megatherium , Glossotherium , Mylodon , Scelidotherium ), glyptodons , giant armadillos ( Pampatheria ) and horses ( Equus , Hippidion ), as well as the peculiar macaws and toxodon smokers ( Toxodon , Mixotoxodon ). In addition, the flat-headed pekari , various deer and camels ( Palaeolama , Hemiauchenia ) disappeared around the same time . At the beginning of the Holocene, the saber-toothed cat Smilodon , various wild dogs ( Canis dirus , Protocyon ) and bears disappeared among the predators . Overall, 80% of all large mammals over 44 kg and all species with a body weight of over 300 kg in South America died out at the beginning of the Holocene. The largest surviving mammal on the South American continent is the Central American tapir .

Haast's eagle attacks Moas at

Remote islands

The woolly mammoth, which disappeared on the Eurasian and North American mainland at the end of the Pleistocene, survived on some remote Arctic islands well into the Holocene. The longest on the Siberian Wrangel Island , where the animals became extinct about 4000 years ago. The same applies to the ground sloths of the Caribbean islands . While these animals became extinct on the mainland at the end of the Pleistocene, larger sloths ( Megalocnus , Parocnus ) survived on the Caribbean islands at least until around 5000 years ago. Various hippos and pygmy elephants as well as the cave goat disappeared on the Mediterranean islands during the Holocene . Most of Madagascar's large animals only died out around 2,000 years ago . These included Malagasy hippos , the giant fossa ( Cryptoprocta spelea ), giant lemurs such as Archaeoindris , Megaladapis or Palaeopropithecus and elephant birds . Madagascar was first settled by humans around 2,300 years ago. In New Zealand a few centuries ago the moas ( Dinornis , Pachyornis , and Euryapteryx ) and the great eagle disappeared . Overall, the disappearance of many species, especially the larger ones on remote islands, correlates with the respective first appearance of humans.

The human being as the cause

The spread of modern humans ( Homo sapiens ) (first occurrence in years before today)

For a long time, humans have been the cause of the extinction of the Ice Age megafauna. In favor of these species becoming extinct through human overhunting , the facts that the time of extinction correlates strikingly with the global spread of humans and that no such size restriction could be observed in any of the earlier extinction phases. The concept was developed by Paul S. Martin in the 1960s under the name "Overkill Hypothesis" . Martin imagined extinction in a very short time, he spoke of over-kill in the form of a blitzkrieg. Today you can see phases of extinction from centuries to millennia. However, the weighting of the impact factors climate change and overhunting is still controversial.

Native Americans watch a Glyptodon (painting by Heinrich Harder around 1920 )

In particular, the fact that the extinction wave in Australia about 50,000 years ago correlates very well with the occurrence of humans, but practically not with noticeable climatic changes, suggests that human influences were the main cause of the disappearance of the megafauna. Strikingly, the last representatives of the Australian megafauna seem to have survived on the island of Tasmania , which was apparently only inhabited by humans some 1000 years after the Australian mainland. The last of the giant Pleistocene kangaroos Protemnodon anak existed there until 40,000 years ago.

Proponents of the overhunting hypothesis also cite an analogous process on islands that were only colonized later. In Madagascar, where people have only lived for around 1,500 years, the hippos , the elephant footbirds , two species of endemic aardvark, a crocodile species, the giant fossas and numerous large primate species , including the giant lemur Megaladapis , disappeared in the centuries that followed. In New Zealand , in addition to the moas , many other flightless birds and the giant eagle Harpagornis disappeared soon after the Māori colonization around 800.

Discussion of the overhunting hypothesis

Opponents of the overhunting hypothesis point to the primitive hunting methods of early humans, which cannot have such a great influence on the population size, and point to Africa, where humans have been around for much longer and where there has been no significant mass extinction. However, show a model calculations that especially large and slow-reproducing animals are threatened even with low hunting in the long run with extinction, so that it is easy to overuse can cause the natural supply. On the other hand, experiments with replica spears with flint tips have shown that even animals as large as elephants can be killed with them, so the Stone Age hunters were able to kill practically any animal. This is especially true when the animals have no reflexes to flee towards humans.

It is unclear why some large species, which were similar in size and way of life to the extinct species and which have been proven to have been hunting prey by humans, survived into the present or into the historical modern age, also in Central Europe, for example the elk (corresponds to the size from Megaloceros ), the large cattle species such as bison , wisent or Ur (which corresponded to the size of the extinct bush ox ( Euceratherium )).

A main point of criticism of the opponents of the hypothesis is that in America only relatively few hunting grounds with extinct species are known, while such places from Eurasia (rhinos, horses, etc.) are known in large numbers. Proponents of the overhunting hypothesis explain this fact with the fact that the North American fauna became extinct within only a few hundred years, leaving little potential for fossil evidence.

Some researchers assume that climatic as well as human influences were responsible for the extinction of large animal species at the end of the Pleistocene and that so many species only became extinct when they interacted. According to this, the Stone Age people would only have wiped out the already weakened populations. Proponents of the overkill hypothesis note, however, that most of these species would have recovered without the influence of humans, as they did after the previous climatic changes of the Ice Age. Basically, even with this weakened form of the overkill hypothesis, humans would probably have been the decisive factor for the mass deaths.

Hunting scene (painting by Heinrich Harder around 1920 )

Occurrence on islands and continents

There is little doubt that the extinction of endemic animal species on some remote islands such as Madagascar (approx. 500 AD), Mauritius (approx. 1650 AD), New Zealand (approx. 1300 AD) and Guam (around 1950 AD) was caused by human influence in historical times. Islands such as Malta , Sicily or Wrangel Island , where the last, dwarfed elephants and woolly mammoths lived, also suffered this fate when the first humans arrived. On such islands this applied to all easy-to-kill giant animals. Other (smaller) animal species died out as a result of the subsequent agricultural use. In some cases, they were also exterminated by the pets they brought with them or introduced animals such as rats or snakes. Proponents of the overhunting hypothesis put the settlement of these islands in line with the settlement of the continents America and Australia. The opponents of the overhunting hypothesis emphasize that the mass extinction at the end of the Ice Age cannot be compared with the extinction of animals on these islands. The extinction on the islands would probably have been mainly due to the fact that these animals did not develop any flight reflexes, as they often had few natural enemies or did not recognize humans as such. In addition, they could not have escaped from their habitat and would have been easy and harmless prey for the hunted people. However, it is difficult to transfer this to the processes at the end of the Pleistocene. Island populations would be more susceptible to catastrophic events because of their mostly smaller range and smaller population size.

The climate as a cause

In addition to the overhunting hypothesis, the climate hypothesis is by far the most frequently cited explanation of the mass extinction at the end of the Pleistocene. On the American double continent, the occurrence of humans and the climatic changes at the end of the Pleistocene fall in the same period and are therefore difficult to separate. The extinction of Australia's large animal fauna around 45,000 years ago does not correlate at all with known climatic fluctuations, but does correlate with the first appearance of humans. However, the data for the Australian events are less precise because they are older. Another problem is that there were numerous climatic fluctuations throughout the Pleistocene that did not lead to mass extinctions. Data from ice cores show that earlier climatic fluctuations were in no way inferior in strength or speed to those at the end of the Pleistocene, which are held responsible for the extinction of the megafauna.

Clovis comet hypothesis

In a publication from 2007 it was suggested that an asteroid impact is said to be responsible for the extinction of species, especially in America. The hypothesis was put forward by James Kennett ( University of California, Santa Barbara ), Richard Firestone ( Lawrence Berkeley National Laboratory ) as well as Douglas Kennett and Jon Erlandson ( University of Oregon ) and states that about 12,900 years ago an asteroid struck Canada be. This Clovis comet is the reason for the mass extinction of the Ice Age megafauna and is said to have put an end to the Stone Age Clovis culture that existed at the same time . The findings could not be confirmed by an independent research group. A study of the demographic development of the Paleo-Indians for the period in question published in August 2008 also found no evidence of the population decline mentioned in the hypothesis.

In January 2009 the magazine Science reported on the electron microscopic confirmation of the alleged existence of nanodiamonds at the geological time of the event in question, which was also received in the International Herald Tribune ; according to Douglas Kennett, this is evidence of a collision of one or more comets with the earth at the end of the Pleistocene, which had a serious impact on the flora and fauna of North America. However, this publication has been heavily criticized by other scientists. The conclusions could not be confirmed by other sources and further studies showed no evidence of nanodiamonds In April 2010, Bill Napier (professor of astrobiology at Cardiff University ) stated in Monthly Notices (a journal of the Royal Astronomical Society ) that the earth with Debris from a huge comet originally sized 50 to 100 kilometers in diameter, which entered our solar system 30,000 years ago and then broke, collided, and that the impact of the debris triggered a firestorm that left the atmosphere with ash and dust and significantly reduced heat and solar radiation and triggered a sudden "mini ice age" of the Younger Dryas . What seems unsatisfactory about the alleged comet impact as an explanation for the mass extinction is the fact that the ice age animals of North America, which previously survived much cooler epochs, are said to have been fatally affected by the moderate cooling of the Younger Dryas. A summarizing article from 2011 on the impact hypothesis in Earth Science Reviews came to the conclusion that there was no evidence of an impact (samples with terrestrial origin, misinterpretation of measurement results).

In the following years, on the other hand, several studies presented a number of indications, including a platinum anomaly found in South Africa and molten glass discovered in northern Syria, which the authors believe support the impact hypothesis.

Further explanatory hypotheses

A more recent hypothesis by American scientists states that it was not hunting alone, but rather epidemics brought in by humans and their domestic animals or their cultural followers , that was the decisive factor in the extinction of large animals. In contrast to the smaller animals with faster generation sequences, these animals would not have been able to adapt their immune systems to the pathogens in time. However, it seems questionable whether epidemics could eradicate so many different animal species (also because many of their often only insignificantly smaller conspecifics survived), especially when you consider that North America was repeatedly in flora and fauna exchange with Eurasia and most of the large animals (proboscis , Dogs, cats, bison, bears, camels and horses) also came from there.

Another hypothesis of more recent origin is that of LaViolette that there was a solar protuberance or a coronal mass ejection in about 12,837 BP , for which corresponding C14 traces were found in the Venezuelan Cariaco basin. This protuberance was about 125 times as large as the largest directly measured protuberance so far in 1956. It led to radiation doses of up to 3 sieverts on the ground within the first three days and to years of destruction of the ozone layer, which allowed further radiation to pass through to flora and fauna. This hypothesis could also explain the part of the Quaternary extinction wave that took place around 15,000 years ago. This is countered by the fact that extinction did not take place synchronously worldwide.

In northern regions, extensive waterlogging and swamping of the landscape by the meltwater from the thawing glaciers and the associated decline in grazing areas could have played a decisive role in the extinction of large glacial mammals.

literature

  • Göran Burenhult: The first humans. Weltbild Verlag, 2000, ISBN 3-8289-0741-5 .
  • Peter D. Ward : Extinct or Extinct? Why the mammoths couldn't survive the Ice Age. Birkhäuser Verlag, 2001, ISBN 3-7643-5915-3 .
  • Ted Oakes: Land of Lost Monsters: Man Against Beast. The Prehistoric Battle for the Planet. 2003.
  • Alan Weisman, The World Without Us . Travel across an unpopulated earth. Piper, Munich 2007, ISBN 978-3-492-05132-3 (German edition).
  • Bernisches Historisches Museum (Ed.): Hunting and collecting. Festschrift for Hans-Georg Bandi on the occasion of his 65th birthday (September 3, 1985), dedicated by the staff of the Bern Historical Museum, the Prehistory Seminar at the University of Bern, as well as by friends and specialist colleagues at home and abroad, by the Bernisches Historisches Museum, Hans-Georg Bandi , Rudolf Fellmann , Georg Germann, Karl Zimmermann; Published by Stämpfli & Cie

Individual evidence

  1. ↑ Martin, P., S., Wright, H., E., Jr. (1967). Pleistocene Extinctions. The Search for a Cause. New Haven and London, Yale University Press.
  2. ↑ Arribas, A., Palmqvist, P., 1999. On the Ecological Connection Between Saber-tooths and Hominids: Faunal Dispersal Events in the Lower Pleistocene and a Review of the Evidence for the First Human Arrival in Europe. Journal of Archaeological Science 26, 571-585.
  3. 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.
  4. ^ Dani Cooper: Oldest known evidence of Aboriginal settlement in arid Australia found in Flinders Ranges rock shelter. ABC News , November 3, 2016, accessed November 3, 2016 .
  5. ↑ Martina Pacher & Anthony J. Stuart: Extinction chronology and palaeobiology of the cave bear ( Ursus spelaeus ) , 2009. Boreas, Volume 38 Issue 2, Pages 189-206. doi : 10.1111 / j.1502-3885.2008.00071.x
  6. ↑ Early end for Ice Age giants. In: Image of Science. November 26, 2008, accessed September 8, 2019 .
  7. ↑ Jelle WF Reumera et al .: Late Pleistocene Survival of the Saber-toothed Cat Homotherium in northwestern Europe. Journal of Vertebrate Paleontology, Volume 23, Issue 1 (March 2003).
  8. ↑ Dick Mol, Wilrie van Logchem, Kees van Hooijdonk & Remie Bakker (2007): The Saber-toothed Cat of the North Sea. Uitgeverij DrukWare, KS Norg. ISBN 90-78707-04-6 .
  9. ↑ a b c d e Stuart Fiedel, Gary Haynes: A premature burial: comments on Grayson and Meltzer's “Requiem for overkill” Journal of Archaeological Science 31 (2004) 121–131, doi : 10.1016 / j.jas.2003.06.004 .
  10. ^ Cione, AL, Tonni, EP, Soibelzon, L. (2003). The Broken Zig-Zag: Late Cenozoic large mammal and tortoise extinction in South America. Rev. Mus. Argentino Cienc. Nat., 5 (1), 1-19. ISSN  1514-5158 .
  11. ↑ David L. Fox, Daniel C. Fisher, Sergey Vartanyan, Alexei N. Tikhonov, Dick Mol, Bernard Buigues: Paleoclimatic implications of oxygen isotopic variation in late Pleistocene and Holocene tusks of Mammuthus primigenius from northern Eurasia. In: Quaternary International 169-170, 2007, pp. 154-165
  12. ↑ Steadman, DW, Martin, PS, McPhee, RDE, Jull, AJT, McDonald, HG, Woods, CA, Iturralde-Vinent, M., Hodgins, GWL (2005). Asynchronous extinction of late quaternary sloths on continents and islands. PNAS vol. 102 no. 33 11763–11768
  13. ↑ Perez, V., R., Godfrey, L., R., Nowak-Kemp, M., Burney, D., A., Ratsimbazafy, J., Vasey, N. (2005). Evidence of early butchery of Giant lemurs in Madagascar. Journal of Human Evolution, 49, 722-742
  14. ↑ PS Martin, Prehistoric overkill. In: PS Martin and HE Wright (Eds.), Pleistocene Extinctions: The Search for a Cause. Yale University Press, New Haven (1967), pp. 75-120. ISBN 0-8165-1100-4
  15. ^ SL Whittington and B. Dyke: Simulating overkill: experiments with the Mosimann and Martin model. In: PS Martin and RG Klein, Editors, Quaternary Extinctions: A Prehistoric Revolution, University of Arizona Press, Tucson (1984), pp. 451-465.
  16. ↑ J. Alroy, A multispecies overkill simulation of the end-Pleistocene megafaunal mass extinction, Science 292 (2001), pp. 1893-1896.
  17. ↑ DC Fisher: Season of death, growth rates, and life history of North American mammoths. In: D. West, Editor, Proceedings of the International Conference on Mammoth Site Studies. Publications in Anthropology 22, University of Kansas, Lawrence, KS (2001), pp. 121-135.
  18. ^ PS Martin and RG Klein, Editors, Quaternary Extinctions: A Prehistoric Revolution, University of Arizona Press, Tucson (1984).
  19. ^ RDE MacPhee, Editor, Extinctions in Near Time: Causes, Contexts, and Consequences, Kluwer / Plenum, New York (1999).
  20. ↑ Anthony D. Barnosky , PL Koch, RS Feranec, SL Wing and AB Shabel, Assessing the causes of Late Pleistocene extinctions on the continents, Science 306 (2005), pp. 70-75.
  21. ↑ DK Grayson, DJ Meltzer, A requiem for North American overkill . Journal of Archaeological Science 30 (2003), pp. 585-593.
  22. ↑ Sander van der Kaars, Gifford H. Miller, Chris SM Turney, Ellyn J. Cook, Dirk Nürnberg, Joachim Schönfeld, A. Peter Kershaw, Scott J. Lehman: Humans rather than climate the primary cause of Pleistocene megafaunal extinction in Australia. In: Nature Communications. 8, 2017, p. 14142, doi : 10.1038 / ncomms14142 .
  23. ↑ Chris SM Turneya, Timothy F. Flannery, Richard G. Roberts, Craig Reid, L. Keith Fifield, Tom FG Higham , Zenobia Jacobs, Noel Kemp, Eric A. Colhoun, Robert M. Kalin, Neil Ogle: Late-surviving megafauna in Tasmania, Australia, implicate human involvement in their extinction . PNAS, vol. 105, no. 34, pp. 12150-12153, Aug. 26, 2008
  24. ↑ Morten Erik Allentoft, Rasmus Heller, Charlotte L. Oskam, Eline D. Lorenzen, Marie L. Hale, M. Thomas P. Gilbert, Christopher Jacomb, Richard N. Holdaway, Michael Bunce: Extinct New Zealand megafauna were not in decline before human colonization. In: Proceedings of the National Academy of Sciences. 111, 2014, p. 4922, doi : 10.1073 / pnas.1314972111 .
  25. ↑ Barry W. Brook, David A. Burney, Timothy F. Flannery, Michael K. Gagan, Richard Gillespie, Christopher N. Johnson, Peter Kershaw, John W. Magee, Paul S. Martin, Gifford H. Miller, Benny Peiser, Richard G. Roberts: Would the Australian megafauna have become extinct if humans had never colonized the continent? Comments on `` A review of the evidence for a human role in the extinction of Australian megafauna and an alternative explanation '' by S. Wroe and J. Field. QSR Correspondence. Quaternary Science Reviews 26 (2007) 560-564
  26. ↑ Firestone, RB, et al .: Evidence for an extraterrestrial impact 12,900 years ago that contributed to the megafaunal extinctions and Younger Dryas cooling. Proceedings of the National Academy of Sciences 104, 2007. pp. 16016-16021. Abstract
  27. ↑ Surovell, TA, Holliday, VT, Gingerich, JAM, Ketron, C., Haynes, CV Jr., Hilman, I., Wagner, DP, Johnson, E., Claeys, P. (2009). An independent evaluation of the Younger Dryas extraterrestrial impact hypothesis. PNAS. vol. 106, no. 43, pp. 18155-18158.
  28. ↑ Briggs Buchanan, Mark Collard, Kevan Edinborough: Paleoindian demography and the extraterrestrial impact hypothesis. Proceedings of the National Academy of Sciences 105, 2008. pp. 11651-11654. Abstract
  29. ^ Richard A. Kerr: Did the Mammoth Slayer Leave a Diamond Calling Card? . In: American Association for the Advancement of Science (Ed.): Science . 323., No. 5910, January 2009, p. 26. doi : 10.1126 / science.323.5910.26 .
  30. ↑ Kenneth Chang: Diamonds linked to quick cooling eons ago . In: Health and Science, International Herald Tribune , International Herald Tribune , January 2, 2009. Retrieved January 3, 2009. 
  31. ↑ DJ Kennett Kennett, JP Kennett, A. West, C. Mercer, SS Que Hee, L. Bement, TE Bunch, M. Sellers, WS Wolbach: Nanodiamonds in the Younger Dryas Boundary Sediment Layer . In: American Association for the Advancement of Science (Ed.): Science . 323., No. 5910, January 2009, p. 94. doi : 10.1126 / science.1162819 .
  32. ^ Rex Dalton: Comet Theory Comes Crashing to Earth ( en ) In: Pacific Standard Magazine . Sara Miller McCune. 2011. Retrieved November 28, 2018.
  33. ↑ TL Daulton, N. Pinter, AC Scott (August 30, 2010): No evidence of nanodiamonds in Younger – Dryas sediments to support an impact event. Proc. Natl. Acad. Sci. USA 107 (37): 16043-7.
  34. ↑ Did comet smashup unleash Earth's mini Ice Age? on: dawn.com April 3, 2010, accessed November 28, 2018.
  35. ↑ Pinter, N. et al. (2011): The Younger Dryas impact hypothesis: A requiem. Earth-Science Reviews 106, 247-264, doi : 10.1016 / j.earscirev.2011.02.005 .
  36. ↑ Mario Pino, Ana M. Abarzúa, Giselle Astorga, Alejandra Martel-Cea, Nathalie Cossio-Montecinos, R. Ximena Navarro, Maria Paz Lira, Rafael Labarca, Malcolm A. LeCompte, Victor Adedeji, Christopher R. Moore, Ted E. Bunch, Charles Mooney, Wendy S. Wolbach, Allen West, James P. Kennett: Sedimentary record from Patagonia, southern Chile supports cosmic-impact triggering of biomass burning, climate change, and megafaunal extinctions at 12.8 ka . In: Nature Scientific Reports . March 9, 2019. doi : 10.1038 / s41598-018-38089-y .
  37. ↑ Andrew MT Moore, James P. Kennett, William M. Napier, Ted E. Bunch, James C. Weaver, Malcolm LeCompte, A. Victor Adedeji, Paul Hackley, Gunther Kletetschka, Robert E. Hermes, James H. Wittke, Joshua J. Razink, Michael W. Gaultois, Allen West: Evidence of Cosmic Impact at Abu Hureyra, Syria at the Younger Dryas onset (~ 12.8 ka): high-temperature melting at> 2200 ° C . In: Nature Scientific Reports . March 10, 2020. doi : 10.1038 / s41598-020-60867-w .
  38. ^ Francis Thackeray, Louis Scott, P. Pieterse: The Younger Dryas interval at Wonderkrater (South Africa) in the context of a platinum anomaly . (PDF) In: Palaeontologia Africana . 54, October 2019, pp. 30–35. doi : 10.5067 / ASTER / ASTGTM.002 .
  39. ↑ Ewe, Thorwald: The great dying, in Focus-online.de (March 23, 2008)
  40. ^ Paul A. LaViolette: Evidence for a Solar Flare Cause of the Pleistocene Mass Extinction . In: Dept. of Geosciences, University of Arizona (Ed.): Radiocarbon . No. 53 (2) , June 2011, pp. 303-323 , doi : 10.2458 / azu_js_rc.53.3464 .
  41. ^ Anthony J. Stuart: Late Quaternary megafaunal extinctions on the continents: A short review . In: Liverpool Geological Society (Ed.): Geological Journal . No. 50 (3) , December 2014, p. 342 , doi : 10.1002 / gj.2633 .
  42. ↑ M. Timothy Rabanus-Wallace, Matthew J. Wooller, Grant D. Zazula, Elen Shute, A. Hope Jahre, Pavel Kosintsev, James A. Burns, James Breen, Bastien Llamas, Alan Cooper. Megafaunal isotopes reveal role of increased moisture on rangeland during late Pleistocene extinctions. Nature Ecology & Evolution, 2017; 1 (5): 0125 DOI: 10.1038 / s41559-017-0125