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| '''Pleistocene megafauna''' is the term used to describe the larger ] of ]s, ]s and ]s that lived on earth during the ] era. These animals suffered a massive ] event as humanity expanded out of ] and ], continents that are the only two still to retain some ] equivalent to what was lost. Three competing ] have been given for these extinctions; ] by the spreading people, ], and spreading ]. Many scientists believe that a combination of these theories may have been responsible. | |||
| ==Pleistocene megafauna by region== | |||
| ===American Pleistocene megafauna=== | |||
| ] ] in the Americas included ]s, the ], ]s, ]s (like the ]), ], ]s, wide-horned ], ]s, ], ]s and ]s, giant ]s, and giant ]s. In contrast today the largest ] land mammal is the ]. ]n megafauna comprised of many of the same elements as that of North America. Notable species not found in North America include the giant armadillos (]s). | |||
| ===Australian Pleistocene megafauna=== | |||
| ], then as now, was characterized by ]s and ]s. Pleistocene Australia supported large carnivorous ]s, ], a giant ], the ] (''Thylacoleo carnifex''), the 3-meter flightless bird ], the 5-meter ] ] and the giant ] ]. | |||
| ''See also:'' ] | |||
| ===Eurasian Pleistocene megafauna=== | |||
| As with South America, elements of North American fauna could be found in ]. Among the most famous Eurasian species are the ], ], ]s, ] and ]. | |||
| ===Other Pleistocene megafauna=== | |||
| Many ]s had unique megafauna that went extinct on the arrival of humans. These included giant bird forms in ] such as the ]s and the ] (giant eagle); gorilla-sized ]s; two species of ] in ]; giant birds, land turtles and ] in ]; and giant geese and ] (giant ducks) in ]. | |||
| ==Extinction== | |||
| There are three major theories that attempt to explain why these species went extinct so quickly. The possible causes can be summarised as "kill, chill and ill". | |||
| ===Hunting=== | |||
| The "kill" theory is that Pleistocene humans triggered the megafaunal extinction. This theory has two variants, "]" and "sitzkrieg" or "slow burn". The blitzkrieg theory is that humans hunted the megafauna to extinction in a short time. There is strong evidence of this in several forms. Firstly is the fossil evidence of megafauna found in conjunction with human remains, particularly with evidence of hunting, such as embedded arrows and tool cut marks in the bones, and ]s depicting ]. Secondly is the ] evidence; the areas of the world where humans evolved still have some megafauna (the ]s and ]s of ] and ]) whereas the areas that didn't have early man, ], the ], ] and ], all lost their megafauna. It is theorised that the megafauna of Asia and Africa evolved with man, and learnt to be wary of them, whereas in other parts of the world the wildlife was ] and was easier to hunt. This is particularly true of the island fauna. Thirdly, the close correlation between humanity in an area and the extinction of the megafauna in that area also provides weight to the theory of human-caused extinction. The "sitzkrieg" theory is that human encroachment gradually destroyed habitat, and that habitat loss led to a die out. | |||
| ===Climate change=== | |||
| The "chill" theory explains the extinctions by climatic change following the last ]. Since there were multiple Ice Ages prior to the last one, the climatic theory raises the question, why did the extinctions occur only after the Last Ice Age? One tentative answer is that a nearby ] altered the ] environment and as a consequence exaggerated the climatic perturbation. It will require data from space research to advance this claim beyond speculation. | |||
| ===Disease=== | |||
| The "ill" theory is that a ] or hyperdisease caused the megafaunal extinction. According to this theory, large mammals were particularly vulnerable because they were fewer in number than smaller species. Body size and population size tend to be inversely related (because larger species require more food per individual to survive). One suggestion that has been well received, even if it will be difficult to prove, is that pathogens were transmitted by the expanding humans via the domesticated dogs they brought with them. Diseases imported by people have been responisble for extinctions in the recent past; for example, bringing avian ] to Hawaii has had a major impact on the isolated birds of the island. The researcher McPhee is searching ] in mammoth remains from ] in ]. He hopes to find evidence of ]. | |||
| ===Combined factors=== | |||
| Some experts claim that various combinations of these factors are responsible for the extinctions. For example, while it is certain in the case of the moa and some other species that hunting was primarily responsible, other species may have been 'pushed over the edge' by hunting when they were already struggling due to imported diseases and climate change. | |||
| ==Megafauna and legend== | |||
| Throughout history, humans wondered about the large, ]ized ] and ]s they discovered from time to time. During the classical age, the bones of ]s were reputed to have been found. In ] times, fossils were attributed to ] such as ]s and ]s. During the ], while ]es went off in hot pursuit of ], glory and pretty women, ] ]s had time for tamer endeavors. Some speculated about the large bones that could be found in the ]. The ] have legends of ]s, and the ] believed in giants. | |||
| With modern tools, ]s have reconstructed a world of beasts as amazing as the dragons and unicorns of ], including many larger versions of contemporary ], ] and ] families. Scientists and historians, who long dismissed legends of monstrous creatures as merely ]s, are beginning to look at these stories in a new light. The sites where the ] claimed to find the bones of giants today produce the bones of mammoths. Similar finds have been made in Central America. Since humans coexisted with these animals, some researchers wonder if the beasts might also be remembered in legend. For example the Australian ] legends refer to the ]l species. The mythical ], source of creation and destruction, may be based on the ''Wonambi naracoortensis''. The hairy manlike ] may be the Diprotodon, filtered through legend. Clearly it is difficult to translate the poetic vocabulary of myth into the technical language of paleontology. In its fossil form, ''Wonambi naracoortensis'' does not need the legend to deserve the name "Rainbow Serpent". Its fossils have ]d and now they shimmer in all colors of the spectrum. | |||
| ==External links== | |||
| * | |||
| ] | |||
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