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Pleistocene megafauna - Wikipedia

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Recreation of a scene in late Pleistocene northern Spain, by Mauricio Antón

Pleistocene megafauna is the set of large animals that lived on Earth during the Pleistocene epoch and became extinct during the Quaternary extinction event. Megafauna are any animals with an adult body weight of over 45 kilograms (99 lb).

Paleoecology[edit]

The last glacial period, commonly referred to as the 'Ice Age', spanned 125,000[2] to 14,500[3] years ago and was the most recent glacial period within the current ice age which occurred during the final years of the Pleistocene epoch.[2] The Ice Age reached its peak during the last glacial maximum, when ice sheets commenced advancing from 33,000 years BP and reached their maximum positions 26,500 years BP. Deglaciation commenced in the Northern Hemisphere approximately 19,000 years BP, and in Antarctica approximately 14,500 years BP which is consistent with evidence that this was the primary source for an abrupt rise in the sea level 14,500 years ago.[3]

A vast mammoth steppe stretched from the Iberian peninsula across Eurasia and over the Bering land bridge into Alaska and the Yukon where it was stopped by the Wisconsin glaciation. This land bridge existed because more of the planet's water was locked up in glaciation than now and therefore the sea levels were lower. When the sea levels began to rise this bridge was inundated around 11,000 years BP.[4] During the last glacial maximum, the continent of Europe was much colder and drier than it is today, with polar desert in the north and the remainder steppe or tundra. Forest and woodland was almost non-existent, except for isolated pockets in the mountain ranges of southern Europe.[5]

The fossil evidence from many continents points to the extinction mainly of large animals at or near the end of the last glaciation. These animals have been termed the Pleistocene megafauna. Scientists frequently define megafauna as the set of animals with an adult body weight of over 45 kg (or 99 lbs).[6] Across Eurasia, the straight-tusked elephant became extinct between 100,000-50,000 years BP. The cave bear (Ursus spelaeus), interglacial rhinoceros (Stephanorhinus), heavy-bodied Asian antelope (Spirocerus), and the Eurasian hippopotamuses died out between 50,000-16,000 years BP. The woolly rhinoceros and mammoths died out between 16,000-11,500 years BP. The giant deer died out after 11,500 BP with the last pocket having survived until about 7,700 years BP in western Siberia.[7] A pocket of mammoths survived on Wrangel Island until 4,500 years BP.[8] As some species became extinct, so too did their predators. Among the top predators, the sabre-toothed cat (Homotherium) died out 28,000 years BP,[9] the cave lion 11,900 years BP,[10] and the leopard in Europe died out 27,000 years BP.[11] The Late Pleistocene was characterized by a series of severe and rapid climate oscillations with regional temperature changes of up to 16 °C, which has been correlated with megafaunal extinctions. There is no evidence of megafaunal extinctions at the height of the LGM, indicating that increasing cold and glaciation were not factors. Multiple events appear to also involve the rapid replacement of one species by one within the same genus, or one population by another within the same species, across a broad area.[12]

The ancestors of modern humans first appeared in East Africa 195,000 years ago.[13] Some migrated out of Africa 60,000 years ago, with one group reaching Central Asia 50,000 years ago.[14] From there they reached Europe, with human remains dated to 43,000-45,000 years BP discovered in Italy,[15] Britain,[16] and in the European Russian Arctic dated to 40,000 years ago.[17][18] Another group left Central Asia and reached the Yana River, Siberia, well above the Arctic circle, 27,000 years ago.[19] Remains of mammoth that had been hunted by humans 45,000 YBP have been found at Yenisei Bay in the central Siberian Arctic.[20] Modern humans then made their way across the Bering land bridge and into North America between 20,000-11,000 years ago, after the Wisconsin glaciation had retreated but before the Bering land bridge became inundated by the sea.[21] These people then populated the Americas. In the Fertile crescent the first agriculture was developing 11,500 years ago.[22]

Extinction[edit]

Four theories have been advanced as likely causes of these extinctions: hunting by the spreading humans (or overkill hypothesis, initially developed by geoscientist Paul S. Martin),[23] the change in climate at the end of the last glacial period, disease, and an impact from an asteroid or comet.[24] These factors are not necessarily exclusive: any or all may have combined to cause the extinctions. Of these, climate change and the overkill hypothesis[25] have the most support,[26] with evidence weighing towards the overkill hypothesis.[27]

Although not mutually exclusive, which factor was more important still remains contested.[28][27] Where humans appeared on the scene, megafauna went extinct;[29][30] but at the same time, the climate was also warming. Large body size is an adaptation to colder climes, so a warming climate would have provided a stressor for these large animals; however, many fauna simply evolved a smaller body size over time.[31] There is overwhelming archaeological evidence suggesting humans did indeed hunt some or many of the now extinct species, such as the mammoth in North America;[32] on the other hand, there is not much evidence for this in Australia for most of the megafauna that went extinct there,[25] aside from a large bird.[33] A 2017 study in Nature Communications asserts that humans were the primary driver of the extinction of Australian megafauna.[34] One paper arguing genetic evidence shows there were many species of megafauna that went extinct "invisibly" argues that this means climate change was primarily responsible.[28]

Regions affected[edit]

Africa[edit]

Background and scope[edit]

English: Exhibit in the San Diego Museum of Man, San Diego, California, USA. This artwork is old enough so that it is in the public domain. Photography was permitted in the museum without restriction.

The proportion of extinct large mammal species (more than or equal to 10 kg) in each TDWG country during the last 132 000 years, only counting extinctions earlier than 1000 years

Australopithecus afarensis Johanson & White, 1978 - fossil hominid from the Pliocene of eastern Africa. (replica, public display, Cleveland Museum of Natural History, Cleveland, Ohio, USA)

While North America was most notably impacted by the Pleistocene Megafaunal extinction, Eurasia, Africa and the Insular regions were also affected and experienced some extinction towards the end of the Pleistocene period. Megafaunal losses are poorly understood on continental Africa during both the Late Pleistocene and the Holocene periods. During the late Pleistocene and early Holocene period an estimated breadth of 24 large mammal species, of greater than 45 kg, were lost from continental Africa. These losses are best understood to have occurred between 13,000 and 6,000 years ago. The species of megafauna which were lost in continental Africa are best understood to have been grazers who lived on grasslands. However, other sources report that over 27 species were lost in the last million years. Sources vary in the breadth of the issue, however it is clear that significant biodiversity loss occurred in Africa.

Acheulean polyhedron in quartzite that proceeds from a superficial site in the Valladolid province (Spain), in the valley of Douro river.

Acheulean Levallois flake that proceeds from a superficial site in the Zamora province (Spain), in the valley of a tributary of Douro river.

Anthropogenic involvement[edit]

At sites in the Americas such as Olduvai, Olorgesailie, Kariandusi, Hopefield, Islmilia, and the Vaal River gravels most genera found were found in stratigraphic association with hand tools wielded by early human ancestors.[35] These artifacts were from Archeulean origins. Arceulean tools include handaxes made from stone. These hand tools were made with a distinctly pear shaped morphology. Homo erectus was thought to wield these hand tools for a variety of purposes. Hand axes could be used to butcher and skin game, cut, chop, scrape, cut other instruments, digging in soil, cutting wood, cutting plant material.[35] These tools were first discovered in 1847.[35] These handaxes have been discovered on multiple continents including Southern Africa, Northern Europe, Western Europe and the Indian sub-continent. These Archulean tools were found to have been being produced and utilized for roughly a million years.[35] The earliest Archulean artifacts were discovered in Africa to have existed for over 1.6 million years ago whereas the earliest Archulean tools are thought to have existed in Europe as early as 800,000 years ago.[35] These hand axes measure 12-20 cm long. There is notable difference in the size, quality and efficacy of these tools depending on the workmanship of the crafter.

Arguments have existed regarding whether these early humans could have contributed significantly to megafauna extinction in Africa, Eurasia, and North America utilizing stone tools such as the Archulean hand tools which have been discussed. It is important to note that these analyses are considered incomplete by many contemporary scholars.[36] However, despite the lack of scientific consensus surrounding this theory, this is being applied to contemporary biodiversity losses.[37]

"A growing body of literature proposes that our ancestors contributed to large mammal extinctions in Africa long before the appearance of Homo sapiens, with some arguing that premodern hominins (e.g., Homo erectus) triggered the demise of Africa's largest herbivores and the loss of carnivoran diversity. Though such arguments have been around for decades, they are now increasingly accepted by those concerned with biodiversity decline in the present-day, despite the near complete absence of critical discussion or debate. To facilitate that process, here we review ancient anthropogenic extinction hypotheses and critically examine the data underpinning them. Broadly speaking, we show that arguments made in favor of ancient anthropogenic extinctions are based on problematic data analysis and interpretation, and are substantially weakened when extinctions are considered in the context of long-term evolutionary, ecological, and environmental changes." [37] At the present moment - according to this source, there is no definitive empirical evidence to suggest that hominins have had widespread impact on the biodiversity of Pleistocene Africa.

Other sources propose alternate hypotheses: "To our knowledge, the earliest proposal of ancient hominin impacts in Africa can be traced to J. Desmond Clark's (1959) overview of southern African prehistory. Referring to a handful of large herbivores whose last appearances in southern Africa are now known to range in age from ∼1 Ma to the onset of the Holocene (Brink et al., 2012; Faith, 2014; Klein et al., 2007), including Stylohipparion (= Eurygnathohippus cornelianus), Griquatherium (= Sivatherium maurusium), and Homoioceras (= Syncerus antiquus), Clark (1959:57) suggested that "[t]heir final extinction may well have been due to man's improved methods of hunting these overspecialized and probably clumsy beasts." Clark did not specify which hominin species was to blame, but from the evidence available to him at the time, it was clear that at least some of these extinct taxa (e.g., Stylohipparion and Griquatherium) disappeared long before the Pleistocene-Holocene transition (Clark, 1959:54) and were associated with hominins that preceded the emergence of H. sapiens, including H. heidelbergensis (Drennan, 1953)".[38] This discussion of Megafaunal losses in Africa during the Pleistocene period would suggest that anthropogenic influence could have been a significant impetus for extinction.

Another hypothesis suggests a more environmentally focused cause for the megafaunal extinction in Pleistocene Africa, "The current lack of evidence (for hominin attributed extinction) does not preclude it from being produced in the future, though we are not optimistic that it will be. Looking to the last ∼100,000 years-a time interval encompassing massive demographic and technological change among human populations-it is clear that African megafaunal extinctions are readily explained by environmental changes (Faith, 2014). In particular, grassland herbivores disappeared following alterations in the structure, distribution, or productivity of their habitats (Faith, 2014), consistent with broader changes in herbivore community composition spanning the last 1 Myr (Faith et al., 2019)".[39] Environmental factors implicated in this explanation include structure, distribution and biological productivity of the environment. This explanation minimizes human impact and emphasizes environmental factors.

African Pleistocene Megafauna losses[edit]

African primate species from the Early Middle Pleistocene (1.0-2.0 million years ago) included Gorgopithecus, Dinopithecus, Cercopithecoidea, Australopithecus, Paranthropus, Telanthropus, Parapapio. Primates that existed during the Late Middle Pleistocene extinction period (100,000 years) included Simopithecus. Living genera in Africa include Pan, Gorilla and Mandrillus. African Carnivora from the Early Middle Pleistocene included Lycaena, Meganteron, and Homotherium. Carnivores that existed during the Late Middle Pleistocene extinction period included Machairodus.[40] Living genera in Africa include Actinonyx, Panthera, Hyaena, and Crocuta. Interestingly, no Tubulidentata existed during the Early Middle or Late Middle Pleistocene periods. However, Orycteropus is included in the living African genera. Similarly no Hippopotamidae existed during the Early Middle or Late Middle Pleistocene periods. However, Hippopotamus and Choeropis are present in the living African genera. Bovidae from the Early Middle Pleistocene include Pultiphagonides and numidocapra. Bovidae that existed during the Late Middle Pleistocene extinction period included Homoioceras, Bulcharus, Pelorovis, Lunaloceras, Megalotragus, Makapania and Phenacotragus. Living Bovidae genera include Tragelaphus, Coocercus, Taurotragus, Syncerus, Cephalophus, Kobus, Redunca, Hippotragus, Oryx, Addax, Damaliscus, Alcelaphus, Beatragus, Connochaetos, Aepyceros, Litocranius, Gazelle, Capra, Ammotragus.[41]

Contrasting Africa's losses with North America[edit]

The rate of extinction in the Pleistocene period between Africa and North America shows striking differences. In America, an estimated 35 genera of large mammals disappeared at the end of the Rancholabrean period. Most of these animals were lost within the last 12,000 years. However, in the preceding one to two million years prior to the end of the Rancholabrean period, an estimated 13 genera of megafauna were lost. This may be attributed to a poor understanding of fauna that existed prior to this period. To compare this rate of megafaunal loss with Africa, the differences between the earlier, middle and later Pleistocene faunal losses are less drastic to compare. In the first 1.5 million years 19 megafaunal genera were lost. Within the last 100,000 years 26 or more genera were lost. This rate of megafaunal extinction in Africa in the last 100,000 years was an estimated 20 times greater in magnitude as the losses that occurred within the preceding 1.5 million years.

Africa[edit]

Sub-Saharan Africa is the region of the world with the highest amount of Pleistocene megafauna surviving to the present day. These surviving species include the bush elephant (Loxodonta africana), the forest elephant (Loxodonta cyclotis), the black rhinoceros (Diceros bicornis), the white rhinoceros (Ceratotherium simum) and the hippopotamus (Hippopotamus amphibius). All of these species maintained populations in sub-Saharan Africa even after many of them were extirpated from Eurasia during the early Holocene.[42] This means that all of the largest herbivore genera present in Pleistocene Africa are still present today.[43] Overall, estimates as to the proportion of Africa's Quaternary megafauna which went extinct range from 5% to 18%, much lower than for all the other continents.[44][45]

Multiple reasons have been suggested by scientists as to why Africa apparently had a much milder experience during the Quaternary extinction. First, some have suggested that the Late Quaternary extinction has been comparatively less studied in Africa than in other regions. As a result of this lack of studying, there is little evidence that paleontologists are able to draw upon when trying to develop a timeline of extinctions in Sub-Saharan Africa. This hypothesis therefore also argues that further investigation into sites with Late Quaternary fossils in Sub-Saharan Africa will reveal previously-undiscovered extinct taxa of African megafauna.[42]

Other scientists have suggested an explanation for the relative lack of extinction among Africa's Pleistocene megafauna which follows the overkill hypothesis as the cause of the Quaternary extinction. According to this hypothesis, many of the extinctions during this time period were due to overhunting by humans who had recently migrated to their continents. In sub-Saharan Africa, the megafauna species had evolved alongside the different species of hominids present in Quaternary Africa. As a result, these species had adapted to withstand the predation pressure from humans. This meant that both humans and megafauna were able to coexist, and the high levels of extinction seen in the Americas and Australasia were not seen in Africa.[42]

An illustration of a blue antelope (Hippotragus leucophaeus) from 1778.

While one of the popular explanations for the Quaternary extinction is due to the changing climate of the time period, the climate of Africa has not been suggested as a potential cause. This is because of the high level of megafaunal extinction in South America during this time period. Since Sub-Saharan Africa has about the same types of climate as South America, but South America had many more extinctions of megafauna taxa, climate was not deemed by these scientists to be a sufficient cause to explain the relative lack of extinctions in Africa.[42]

Despite the high level of continuity present in Africa's megafauna community from the Quaternary to the Holocene period, there were several species of megafauna which did go extinct during this time period. One such species was Pelorovis antiquus, the Long-horned African Buffalo. This species is theorized to either have gone extinct due to climate change, overhunting by humans, or both. It was extirpated from Sub-Saharan Africa about 12,000 years ago and became entirely extinct about 4,000 years before present.[44] Another was the giant antelope that was very similar to a hartebeest or a wildebeest known as Megalotragus priscus. M. priscus was the last of its genus, and it died out approximately 7,500 years ago.[46] Similarly, there was an extinct species of zebra known as the Cape Zebra, Equus capensis. The Cape zebra lived throughout Africa during the Quaternary period but went extinct by its end.[47] One species of Quaternary megafauna would also go extinct later on after contact with European settlers, after having its range reduced during the Quaternary extinction event. This species was the blue antelope, Hippotragus leucophaeus. This species had its range restricted changing habitats during the early Holocene period, so that by the time European colonists arrived, they were restricted to one lone population. This population was then wiped out by habitat loss and hunting by European colonists. The blue antelope went extinct in 1800.[48]

North America[edit]

During the American megafaunal extinction event around 12,700 years ago, 90 genera of mammals weighing over 44 kilograms became extinct.[49][50] The Late Pleistocene fauna in North America included giant sloths, short-faced bears, several species of tapirs, peccaries (including the long-nosed and flat-headed peccaries), the American lion, giant tortoises, Miracinonyx ("American cheetahs", not true cheetahs), the saber-toothed cat Smilodon and the scimitar-toothed cat Homotherium,[51] dire wolves, saiga, camelids such as two species of now-extinct llamas and Camelops,[52] at least two species of bison, the stag-moose, the shrub-ox and Harlan's muskox, 14 species of pronghorn (of which 13 are now extinct), horses, mammoths and mastodons, the beautiful armadillo and the giant armadillo-like Glyptotherium,[53] and giant beavers, as well as birds like giant condors and teratorns. In contrast, today the largest North American land animal is the American bison.[54][40][55]

During this megafaunal extinction event, North America lost 70% of its megafauna species. The reasons for the extinction event are still being debated today. This extinction event has largely been attributed to both climate change and human-driven extinction.[56]

The climatic change that occurred at the end of the Pleistocene is called the Younger Dryas(YD) cooling event. The problem with looking at North America as a whole for the extinction event is that it is such a large area; the climate for the period varied spatially, temporally, and seasonally so it is hard to generalize the entire continent.[56]

Human-driven extinction is related to the immigration of humans from Asia. There are various human impacts that could have occurred putting pressure on different megafauna species. The main human impacts considered are direct overhunting or cascading trophic interactions. Clovis culture is "the earliest, widespread archeological culture in the New World" [56] that dates to 13.15-12.85ka. It is largely identified by "Clovis points" which are "large, lanceolate, and fluted stone spear points".[56] Some researchers attribute the extinction of megafauna to the presence of Clovis hunting, along with significant human population increases which would have increased hunting intensity and frequency.

As mentioned above, the majority of scientists agree that the megafauna extinction in North America was largely caused by both human-impacts and climate change since they occurred during the same 5000 year period.[57] However, it is important to consider that the causes can significantly vary for different species and different regions of North America. The extinction of megafauna and first appearance of humans did not completely correlate across North America, meaning that each area needs to be separately considered when attempting to determine the cause of extinction.

Megafauna extinctions that are most consistent with human activity in North America are of the mammoth, horse, and saber-toothed cat. Humans directly impacted the mammoth and horse by overhunting the species. While the saber-tooth tiger was pushed to extinction by humans due to the overhunting of their prey, which is considered to be an indirect impact. There are two species of megafauna whose extinctions appear to have no link to human hunting, they are the Shasta ground sloth and mastodon.[56]

Alaska[edit]

Alaska is situated in the northwestern most part of North America. These higher latitudes generally had earlier last appearances for megafauna species. This means that the megafauna either all died out or migrated out of the area to get away from the YD cooling event. It has been determined that the demise of the megafauna species occurred about 1000 to 4000 years before there was significant human presence in Alaska, meaning that their demise is most attributed to climate change.[57][58]

The Great Lakes Region[edit]

The Great Lakes Region had last appearances for megafauna species that were considerably more recent than in higher latitudes, such as Alaska. Along with that the first appearances for human species were considerably older for this region compared to other regions in North America. Due to the overlaps of these two appearances, it has been suggested from the fossil record that humans and megafauna overlapped in the region for 7000 years.[57] Just because there was an overlap with humans and megafauna doesn't mean that the megafauna extinction event in the region was solely attributed to human-impact. There has been significant evidence into the cause of extinction in this area being related to the fact that both climate change and human impacts hit simultaneously.[58]

The West/ Pacific Coast[edit]

The Pacific Coast was one of the areas that had earlier first appearances of humans. This is probably due to the fact that humans seemed to have migrated to the Americas through a pathway that went along the Pacific Coast. However an interesting thing about this area is that there was little overlap between humans and megafauna species, which doesn't seem correct since it should have been the first place humans interacted if they came from Asia. One potential for this could be due to poor sampling due to sea-level rise that could have "obscured older coastal sites".[57]

South America[edit]

South American megafauna during the Pleistocene

About 10,000 years ago, the landscape of South America contained numerous species of megafauna, many of which have no modern species for comparison.  South America was home to bears, sabertooth cats, large capybaras and llamas.  Additionally, there were huge terrestrial sloths, armored glyptodonts (similar to an armadillo, but the size of a hippo), and animals similar to camels and rhinoceroses (macrauchenids and toxodonts). These animals went extinct during the Quaternary Period and all South American mammal species larger than 100 kg were lost.  The explanation for their extinction has not been definitively answered, and is a topic of debate among scientists.[59]

The continent of South America was isolated for millions of years during the Cenozoic Period, which had a significant impact on its wildlife.[60] This isolation helped foster species that were not found anywhere else on Earth. Approximately 3 million years ago, the Great American Biotic Interchange occurred due to the Isthmus of Panama, which allowed for the mixing of North and South American faunas. The mixing of faunas created new opportunities for expansion, competition, and replacement of species.[59] South American wildlife in the Pleistocene varied greatly; an example is the giant ground sloth, Megatherium.[61] The continent also had quite a few grazers and mixed feeders such as the camel-like litoptern Macrauchenia, Cuvieronius, Doedicurus, Glyptodon, Hippidion and Toxodon. There were also Stegomastodons, found as far south as Patagonia.[62] The main predators of the region were Arctotherium and Smilodon.

Eurasia[edit]

As with South America, some elements of the Eurasian megafauna were similar to those of North America. Among the most recognizable Eurasian species are the woolly mammoth, steppe mammoth, straight-tusked elephant, European hippopotamuses, aurochs, steppe bison, cave lion, cave bear, cave hyena, Homotherium, Irish elk, giant polar bears, woolly rhinoceros, Merck's rhinoceros, narrow-nosed rhinoceros, and Elasmotherium. In contrast, today the largest European land mammal is the European bison or wisent.

By the advent and proliferation of modern humans (Homo sapiens) circa 315,000 BP,[63][64][65] the most common species of the genus Homo in Eurasia were the Denisovans and Neanderthals (fellow H. heidelbergensis descendants), and Homo erectus in Eastern Asia.[66] Homo sapiens is the only species of the genus Homo that remains extant.

Extinction Analysis[edit]

Two major events towards the end of the Pleistocene era had ultimately impacted the species that were inhabiting Eurasia; the last glacial period and the introduction of Homo Sapiens from Old World Africa. These two events were responsible for the vastly selective and intense extinctions of the Eurasian large mammal species mentioned previously.[67] The megafauna extinctions that occurred towards the end of the Pleistocene is believed to be largely due to human hunting and overkill. Overkill models that incorporate prey availability for Homo Sapiens have provided solid backing to that theory.

Hunters of the Upper Paleolithic had crafted tools and projectile weapons that were able to bring down prey as large as Mammoths. With the population of humans rapidly increasing, the consumption and hunting of meat grew just as rapidly. In addition to the growing numbers of human hunters, large terrestrial mammals in Eurasia had to combat detrimental climatic changes.

Northern Eurasia during the Middle and Upper Pleistocene (ca. 700000-10000 BP) was continuously facing a changing climate. The landscape and habitats of mammals say phases ranging from extensive glaciation and cold stages to temperate climates and interglacials.

A majority of extinctions occurred during the Lateglacial (ca. 15000-10000 BP) periods. This period was characterized by a major reformation of vegetation, mainly the replacement of open vegetation by forests. These changes were more profound than earlier in the Last Cold Stage and are believed to have played a critical role in the extinction of the Pleistocene megafauna. [68]

Australia[edit]

The most recent Ice Age occurred during the Pleistocene, and caused lower global sea levels.[69][70] The lower sea level revealed the entire Sahul Shelf, connecting Australia with New Guinea and Tasmania.[70] Most literature about Australian megafauna during the Pleistocene refers to the entirety of Sahul.

Australia was characterized by marsupials, monotremes, crocodilians, testudines, monitors and numerous large flightless birds. Pleistocene Australia also supported the giant short-faced kangaroo (Procoptodon goliah), Diprotodon (a giant wombat relative), the marsupial lion (Thylacoleo carnifex), the flightless bird Genyornis, the five-meter long snake Wonambi and the giant monitor lizard Megalania.[71][72] Since 450 Ka, 88 Australian megafauna species have gone extinct.[73]

There are several hypotheses that attempt to explain why Pleistocene Australian megafauna went extinct. Most studies point to either climate change or human activity as reasons for the die off, but there is not yet a consensus among scientists about which factor had a larger impact. A scarcity of reliably dated megafaunal bone deposits has made it difficult to construct timelines for megafaunal extinctions in certain areas, leading to a divide among researches about when and how megafaunal species went extinct.[74][75]

Several studies provide evidence that climate change caused megafaunal extinction during the Pleistocene in Australia. One group of researchers analyzed fossilized teeth found at Cuddie Springs in southeastern Australia. By analyzing oxygen isotopes, they measured aridity, and by analyzing carbon isotopes and dental microwear texture analysis, they assessed megafaunal diets and vegetation.[73] During the middle Pleistocene, southeastern Australia was dominated by browsers, including fauna that consumed C4 plants.[73] By the late Pleistocene, the C4 plant dietary component had decreased considerably. This shift may have been caused by increasingly arid conditions, which may have caused dietary restrictions. Other isotopic analyses of eggshells and wombat teeth also point to a decline of C4 vegetation after 45 Ka. This decline in C4 vegetation is coincident with increasing aridity. Increasingly arid conditions in southeastern Australia during the late Pleistocene may have stressed megafauna, and contributed to their decline.[73]

Human activity may have caused Australian megafaunal extinction during the Pleistocene, although this idea is hotly debated. In order to determine whether humans caused an extinction, three criteria must be met: (1) if megafauna species went extinct before a significant climate event but after human colonization, researchers can infer that the extinction was probably caused by humans; (2) if climate change during the studied epoch was not more significant than climate change during previous epochs, then any extinctions during that time were probably not caused by climate change; and (3) if all or most megafauna was still extant when humans arrived, then it is possible that human activity caused the extinction.[76]

Some researchers believe that humans were probably not responsible for the megafaunal extinctions in Sahul. They contribute the extinctions to climate change, and argue that most megafaunal species do not appear in the fossil record within 95 Ka of human arrival.[76] Additionally, they claim that long-term aridification of the continent resulted in staggered losses beginning by 130 Ka, and continued range contractions and extinctions throughout the rest of the Pleistocene.[76] Researchers who do not believe that human actions were the primary cause of Pleistocene megafaunal extinctions in Australia do not exclude anthropogenic influence entirely. One article cites evidence of human interactions with megafauna at Cuddie Springs, but further explains that humans can only be held accountable for declines in the populations of the 13% of species that can be placed at that location. They argue that it will remain futile to determine the primary cause of megafaunal extinctions.[76] Other researchers argue that, for most species, archaeological evidence of human hunting activity is rare and questionable.[77] The major exception to this is the giant bird, Genyornis. Between 54 and 47 Ka, distinct charring patterns on Genyornis eggshells indicate that humans heated the eggs over campfires. This time period also corresponds to the decline and extinction of Genyornis. Similar charring patterns were found on emu eggs from widespread locations, also dating to this time period. These widespread charred eggshells indicate the arrival and fast spread of humans in Sahul.[77] Despite the evidence of interactions between humans and Genyornis, there is not much evidence to indicate that there were significant interactions between humans and other megafaunal species. Many scientists interpret this lack of evidence of interaction as evidence that humans did not cause most megafaunal extinctions in Australia.

Other researchers disagree, and argue that there is sufficient evidence to determine that human activity was the primary cause for many of the megafaunal extinctions. They argue that the lack of evidence of hunting does not indicate that hunting during the Pleistocene was negligible. Rather, archaeological evidence of hunting of animals that went extinct soon after human arrival should be negligible, even if that hunting had an ecological impact.[77] Because humans arrived on the continent so early, the period of interaction between humans and megafauna is very small relative to the entire archaeological record of Sahul. Furthermore, hunting rates would have been highest soon after the arrival of humans, when megafaunal populations were very large. Human populations would have been small during this time, and as a result, would not be as visible in the archaeological record.[77] Researchers who believe that human activity was the primary cause of megafaunal extinction in Australia argue that the lack of evidence should not rule out human-megafauna interactions.

Insular[edit]

Skull of Canariomys bravoi (Tenerife giant rat). It was an endemic species that is now extinct.

Many islands had a unique megafauna that became extinct upon the arrival of humans more recently (over the last few millennia and continuing into recent centuries). These included dwarf woolly mammoths on Wrangel Island, St. Paul Island and the Channel Islands of California;[78] giant birds in New Zealand such as the moas and Hieraaetus moorei (a giant eagle); numerous species in Madagascar: giant ground-dwelling lemurs, including Megaladapis, Palaeopropithecus and the gorilla-sized Archaeoindris, three species of hippopotamuses, two species of giant tortoises, the Voay-crocodile and the giant bird Aepyornis; five species of giant tortoises from the Mascarenes; a dwarf Stegodon on Flores and a number of other islands; land turtles and crocodiles in New Caledonia; giant flightless owls and dwarf ground sloths in the Caribbean;[79][80] giant flightless geese and moa-nalo (giant flightless ducks) in Hawaii; and dwarf elephants and dwarf hippos from the Mediterranean islands. The Canary Islands were also inhabited by an endemic megafauna which are now extinct: giant lizards (Gallotia goliath), giant rats (Canariomys bravoi and Canariomys tamarani)[81] and giant tortoises (Geochelone burchardi and Geochelone vulcanica),[82] among others.

See also[edit]

References[edit]

  1. ^ Pavelková Řičánková, Věra; Robovský, Jan; Riegert, Jan (2014). "Ecological Structure of Recent and Last Glacial Mammalian Faunas in Northern Eurasia: The Case of Altai-Sayan Refugium". PLOS ONE. 9 (1): e85056. Bibcode:2014PLoSO...985056P. doi:10.1371/journal.pone.0085056. PMC 3890305. PMID 24454791.
  2. ^ a b Intergovernmental Panel on Climate Change (UN). "IPCC Fourth Assessment Report: Climate Change 2007 - Palaeoclimatic Perspective". The Nobel Foundation. Archived from the original on 2015-10-30. Retrieved 2015-08-09.
  3. ^ a b Clark, P. U.; Dyke, A. S.; Shakun, J. D.; Carlson, A. E.; Clark, J.; Wohlfarth, B.; Mitrovica, J. X.; Hostetler, S. W.; McCabe, A. M. (2009). "The Last Glacial Maximum". Science. 325 (5941): 710-4. Bibcode:2009Sci...325..710C. doi:10.1126/science.1172873. PMID 19661421. S2CID 1324559.
  4. ^ Elias, Scott A.; Short, Susan K.; Nelson, C. Hans; Birks, Hilary H. (1996). "Life and times of the Bering land bridge". Nature. 382 (6586): 60. Bibcode:1996Natur.382...60E. doi:10.1038/382060a0.
  5. ^ Jonathan Adams. "Europe during the last 150,000 years". Oak Ridge National Laboratory, Oak Ridge, USA. Archived from the original on 2005-11-26.
  6. ^ Meltzer, David J. (2015-10-21). "Pleistocene Overkill and North American Mammalian Extinctions". Annual Review of Anthropology. 44 (1): 33-53. doi:10.1146/annurev-anthro-102214-013854. ISSN 0084-6570.
  7. ^ Stuart, Anthony John (1999). "Late Pleistocene Megafaunal Extinctions". Extinctions in Near Time. pp. 257-269. doi:10.1007/978-1-4757-5202-1_11. ISBN 978-1-4419-3315-7.
  8. ^ Dale Guthrie, R. (2004). "Radiocarbon evidence of mid-Holocene mammoths stranded on an Alaskan Bering Sea island". Nature. 429 (6993): 746-749. Bibcode:2004Natur.429..746D. doi:10.1038/nature02612. PMID 15201907.
  9. ^ Reumer, Jelle W. F.; Rook, Lorenzo; Van Der Borg, Klaas; Post, Klaas; Mol, Dick; De Vos, John (2003). "Late Pleistocene survival of the saber-toothed cat Homotheriumin northwestern Europe". Journal of Vertebrate Paleontology. 23: 260-262. doi:10.1671/0272-4634(2003)23[260:LPSOTS]2.0.CO;2.
  10. ^ Barnett, R.; Shapiro, B.; Barnes, I. A. N.; Ho, S. Y. W.; Burger, J.; Yamaguchi, N.; Higham, T. F. G.; Wheeler, H. T.; Rosendahl, W.; Sher, A. V.; Sotnikova, M.; Kuznetsova, T.; Baryshnikov, G. F.; Martin, L. D.; Harington, C. R.; Burns, J. A.; Cooper, A. (2009). "Phylogeography of lions (Panthera leo ssp.) reveals three distinct taxa and a late Pleistocene reduction in genetic diversity". Molecular Ecology. 18 (8): 1668-1677. doi:10.1111/j.1365-294X.2009.04134.x. PMID 19302360. S2CID 46716748.
  11. ^ Ghezzo, Elena; Rook, Lorenzo (2015). "The remarkable Panthera pardus (Felidae, Mammalia) record from Equi (Massa, Italy): Taphonomy, morphology, and paleoecology". Quaternary Science Reviews. 110: 131-151. doi:10.1016/j.quascirev.2014.12.020.
  12. ^ Cooper, A.; Turney, C.; Hughen, K. A.; Brook, B. W.; McDonald, H. G.; Bradshaw, C. J. A. (2015). "Abrupt warming events drove Late Pleistocene Holarctic megafaunal turnover". Science. 349 (6248): 602-6. Bibcode:2015Sci...349..602C. doi:10.1126/science.aac4315. PMID 26250679.
  13. ^ White, T. D.; Asfaw, B.; Degusta, D.; Gilbert, H.; Richards, G. D.; Suwa, G.; Clark Howell, F. (2003). "Pleistocene Homo sapiens from Middle Awash, Ethiopia". Nature. 423 (6941): 742-7. Bibcode:2003Natur.423..742W. doi:10.1038/nature01669. PMID 12802332.
  14. ^ "A Human Journey:Migration Routes". The genographic project. National Geographic Society. 2015. Retrieved 12 August 2015.
  15. ^ Benazzi, S.; Douka, K.; Fornai, C.; Bauer, C. C.; Kullmer, O.; Svoboda, J. Í.; Pap, I.; Mallegni, F.; Bayle, P.; Coquerelle, M.; Condemi, S.; Ronchitelli, A.; Harvati, K.; Weber, G. W. (2011). "Early dispersal of modern humans in Europe and implications for Neanderthal behaviour". Nature. 479 (7374): 525-8. Bibcode:2011Natur.479..525B. doi:10.1038/nature10617. PMID 22048311.
  16. ^ Higham, T.; Compton, T.; Stringer, C.; Jacobi, R.; Shapiro, B.; Trinkaus, E.; Chandler, B.; Gröning, F.; Collins, C.; Hillson, S.; o'Higgins, P.; Fitzgerald, C.; Fagan, M. (2011). "The earliest evidence for anatomically modern humans in northwestern Europe". Nature. 479 (7374): 521-4. Bibcode:2011Natur.479..521H. doi:10.1038/nature10484. PMID 22048314.
  17. ^ Pavlov, Pavel; Svendsen, John Inge; Indrelid, Svein (2001). "Human presence in the European Arctic nearly 40,000 years ago". Nature. 413 (6851): 64-7. Bibcode:2001Natur.413...64P. doi:10.1038/35092552. PMID 11544525.
  18. ^ "Mamontovaya Kurya:an enigmatic, nearly 40000 years old Paleolithic site in the Russian Arctic" (PDF).
  19. ^ Pitulko, V. V.; Nikolsky, P. A.; Girya, E. Y.; Basilyan, A. E.; Tumskoy, V. E.; Koulakov, S. A.; Astakhov, S. N.; Pavlova, E. Y.; Anisimov, M. A. (2004). "The Yana RHS Site: Humans in the Arctic Before the Last Glacial Maximum". Science. 303 (5654): 52-6. Bibcode:2004Sci...303...52P. doi:10.1126/science.1085219. PMID 14704419.
  20. ^ Pitulko, V. V.; Tikhonov, A. N.; Pavlova, E. Y.; Nikolskiy, P. A.; Kuper, K. E.; Polozov, R. N. (2016). "Early human presence in the Arctic: Evidence from 45,000-year-old mammoth remains". Science. 351 (6270): 260-3. Bibcode:2016Sci...351..260P. doi:10.1126/science.aad0554. PMID 26816376.
  21. ^ Tamm, E.; Kivisild, T.; Reidla, M.; Metspalu, M.; Smith, D. G.; Mulligan, C. J.; Bravi, C. M.; Rickards, O.; Martinez-Labarga, C.; Khusnutdinova, E. K.; Fedorova, S. A.; Golubenko, M. V.; Stepanov, V. A.; Gubina, M. A.; Zhadanov, S. I.; Ossipova, L. P.; Damba, L.; Voevoda, M. I.; Dipierri, J. E.; Villems, R.; Malhi, R. S. (2007). Carter, Dee (ed.). "Beringian Standstill and Spread of Native American Founders". PLOS ONE. 2 (9): e829. Bibcode:2007PLoSO...2..829T. doi:10.1371/journal.pone.0000829. PMC 1952074. PMID 17786201.
  22. ^ Balter, M (4 July 2013). "Farming Was So Nice, It Was Invented at Least Twice". Science.
  23. ^ Marc A. Carrasco, Anthony D. Barnosky, Russell W. Graham Quantifying the Extent of North American Mammal Extinction Relative to the Pre-Anthropogenic Baseline plosone.org December 16, 2009
  24. ^ Nickerson, Colin (September 25, 2007), "Cosmic blast may have killed off megafauna Scientists say early humans doomed, too", Boston.com, Boston, MA: The Boston Globe, p. A2
  25. ^ a b Boissoneault, Lorraine. ""Are Humans to Blame for the Disappearance of Earth's Fantastic Beasts?"". Smithsonian. Retrieved 2019-11-24.
  26. ^ MacDonald, James (2018-05-14). "What Really Happened to the Megafauna". JSTOR Daily. Retrieved 2019-11-24.
  27. ^ a b Vignieri, S. (25 July 2014). "Vanishing fauna (Special issue)". Science. 345 (6195): 392-412. Bibcode:2014Sci...345..392V. doi:10.1126/science.345.6195.392. PMID 25061199. Although some debate persists, most of the evidence suggests that humans were responsible for extinction of this Pleistocene fauna, and we continue to drive animal extinctions today through the destruction of wild lands, consumption of animals as a resource or a luxury, and persecution of species we see as threats or competitors.
  28. ^ a b Cooper, Alan; Turney, Chris; Hughen, Konrad A.; Brook, Barry W.; McDonald, H. Gregory; Bradshaw, Corey J. A. (2015-08-07). "Abrupt warming events drove Late Pleistocene Holarctic megafaunal turnover". Science. 349 (6248): 602-606. Bibcode:2015Sci...349..602C. doi:10.1126/science.aac4315. ISSN 0036-8075. PMID 26250679.
  29. ^ Sandom, Christopher; Faurby, Søren; Sandel, Brody; Svenning, Jens-Christian (4 June 2014). "Global late Quaternary megafauna extinctions linked to humans, not climate change". Proceedings of the Royal Society B. 281 (1787): 20133254. doi:10.1098/rspb.2013.3254. PMC 4071532. PMID 24898370.
  30. ^ Faurby, Søren; Svenning, Jens-Christian (2015). "Historic and prehistoric human‐driven extinctions have reshaped global mammal diversity patterns". Diversity and Distributions. 21 (10): 1155-1166. doi:10.1111/ddi.12369. hdl:10261/123512.
  31. ^ Smith, Felisa A.; et al. (April 20, 2018). "Body size downgrading of mammals over the late Quaternary". Science. 360 (6386): 310-313. doi:10.1126/science.aao5987. PMID 29674591.
  32. ^ Koch, Paul L.; Barnosky, Anthony D. (2006). "Late Quaternary Extinctions: State of the Debate". Annual Review of Ecology, Evolution, and Systematics. 37: 215-250. doi:10.1146/annurev.ecolsys.34.011802.132415. ISSN 1543-592X. JSTOR 30033832. S2CID 16590668.
  33. ^ Miller, Gifford; Magee, John; Smith, Mike; Spooner, Nigel; Baynes, Alexander; Lehman, Scott; Fogel, Marilyn; Johnston, Harvey; Williams, Doug; Clark, Peter; Florian, Christopher (2016-01-29). "Human predation contributed to the extinction of the Australian megafaunal bird Genyornis newtoni ∼47 ka". Nature Communications. 7 (1): 10496. Bibcode:2016NatCo...710496M. doi:10.1038/ncomms10496. ISSN 2041-1723. PMC 4740177. PMID 26823193.
  34. ^ van der Kaars, Sander; Miller, Gifford H.; et al. (January 20, 2017). "Humans rather than climate the primary cause of Pleistocene megafaunal extinction in Australia". Nature Communications. 8: 14142. Bibcode:2017NatCo...814142V. doi:10.1038/ncomms14142. PMC 5263868. PMID 28106043.
  35. ^ a b c d e "Oldowan and Acheulean Stone Tools | Museum of Anthropology". anthromuseum.missouri.edu. Retrieved 2021-05-07.
  36. ^ Hoag, Colin; Svenning, Jens-Christian (2017-10-17). "African Environmental Change from the Pleistocene to the Anthropocene". Annual Review of Environment and Resources. 42 (1): 27-54. doi:10.1146/annurev-environ-102016-060653. ISSN 1543-5938.
  37. ^ a b Faith, J. Tyler; Rowan, John; Du, Andrew; Barr, W. Andrew (July 2020). "The uncertain case for human-driven extinctions prior to Homo sapiens". Quaternary Research. 96: 88-104. Bibcode:2020QuRes..96...88F. doi:10.1017/qua.2020.51. ISSN 0033-5894.
  38. ^ Faith, J. Tyler (2014). "Late Pleistocene and Holocene mammal extinctions on continental Africa". Earth-Science Reviews. 128: 105-121. Bibcode:2014ESRv..128..105F. doi:10.1016/j.earscirev.2013.10.009.
  39. ^ "Palaeontology and geological context of a Middle Pleistocene faunal assemblage from the Gladysvale Cave, South Africa". Palaeontologia Africana. 38: 99-114. Retrieved 2021-05-07.
  40. ^ a b Rowland, Teisha (19 December 2009). "Ancient American Giants Extinct Megafauna of North and South America". Santa Barbara Independent. Retrieved December 19, 2009.
  41. ^ Martin, Paul S (22 October 1966). "Africa and Pleistocene overkill" (PDF). Nature. 212 (5060): 339-342. Bibcode:1966Natur.212..339M. doi:10.1038/212339a0. Retrieved 15 May 2021.
  42. ^ a b c d Stuart, Anthony John (May 2015). "Late Quaternary megafaunal extinctions on the continents: a short review: LATE QUATERNARY MEGAFAUNAL EXTINCTIONS". Geological Journal. 50 (3): 338-363. doi:10.1002/gj.2633.
  43. ^ Stuart, Anthony J. (1991). "Mammalian Extinctions in the Late Pleistocene of Northern Eurasia and North America". Biological Reviews. 66 (4): 453-562. doi:10.1111/j.1469-185X.1991.tb01149.x. ISSN 1469-185X. PMID 1801948.
  44. ^ a b G., Martin, Paul S. (Paul Schultz), 1928- Klein, Richard (1995). Quaternary extinctions : a prehistoric revolution. University of Arizona Press. ISBN 0-8165-1100-4. OCLC 851043302.
  45. ^ Barnosky, A. D. (2004-10-01). "Assessing the Causes of Late Pleistocene Extinctions on the Continents". Science. 306 (5693): 70-75. Bibcode:2004Sci...306...70B. doi:10.1126/science.1101476. ISSN 0036-8075. PMID 15459379.
  46. ^ Turvey, Samuel T. (2009-05-28), "Holocene mammal extinctions", Holocene Extinctions, Oxford University Press, pp. 41-62, doi:10.1093/acprof:oso/9780199535095.003.0003, ISBN 978-0-19-953509-5, retrieved 2021-05-07
  47. ^ Churcher, C. S. (January 2006). "Distribution and history of the Cape zebra ( Equus capensis ) in the Quarternary of Africa". Transactions of the Royal Society of South Africa. 61 (2): 89-95. doi:10.1080/00359190609519957. ISSN 0035-919X.
  48. ^ Kerley, Graham I. H.; Sims-Castley, Rebecca; Boshoff, André F.; Cowling, Richard M. (2009-04-28). "Extinction of the blue antelope Hippotragus leucophaeus: modeling predicts non-viable global population size as the primary driver". Biodiversity and Conservation. 18 (12): 3235-3242. doi:10.1007/s10531-009-9639-x. ISSN 0960-3115.
  49. ^ O'Keefe FR, Fet EV, Harris JM. 2009. Compilation, calibration, and synthesis of faunal and floral radiocarbon dates, Rancho La Brea, California. Contrib Sci 518: 1-16
  50. ^ O'Keefe, F. Robin, Binder, Wendy J., Frost, Stephen R., Sadlier, Rudyard W., and Van Valkenburgh, Blaire 2014. Cranial morphometrics of the dire wolf, Canis dirus, at Rancho La Brea: temporal variability and its links to nutrient stress and climate. Palaeontologia Electronica Vol. 17, Issue 1;17A; 24p; [1]
  51. ^ L. D. Martin. 1998. Felidae. In C. M. Janis, K. M. Scott, and L. L. Jacobs (eds.), Evolution of Tertiary Mammals of North America 1:236-242
  52. ^ R. M. Nowak. 1991. Walker's Mammals of the World. Maryland, Johns Hopkins University Press (edited volume) II
  53. ^ "North American Glyptodon". Archived from the original on June 24, 2006. Retrieved July 2, 2014.
  54. ^ Ice Age Animals
  55. ^ Lambert, W. David; Holling, Crawford S. (March 1998). "Causes of Ecosystem Transformation at the End of the Pleistocene: Evidence from Mammal Body-Mass Distributions". Ecosystems. 1: 157-175. doi:10.1007/s100219900012. Retrieved 4 February 2021.
  56. ^ a b c d e Broughton, Jack M.; Weitzel, Elic M. (2018). "Population reconstructions for humans and megafauna suggest mixed causes for North American Pleistocene extinctions". Nature Communications. 9 (1): 5441. Bibcode:2018NatCo...9.5441B. doi:10.1038/s41467-018-07897-1. PMC 6303330. PMID 30575758.
  57. ^ a b c d Emery-Wetherell, Meaghan M.; McHorse, Brianna K.; Byrd Davis, Edward (2017). "Spatially explicit analysis sheds new light on the Pleistocene megafaunal extinction in North America". Paleobiology. 43 (4): 642-655. doi:10.1017/pab.2017.15.
  58. ^ a b Barnosky, A. D.; Koch, P. L.; Feranec, R. S.; Wing, S. L.; Shabel, A. B. (2004). "Assessing the Causes of Late Pleistocene Extinctions on the Continents". Science. 306 (5693): 70-75. Bibcode:2004Sci...306...70B. doi:10.1126/science.1101476. PMID 15459379.
  59. ^ a b Samonds, Karen E. (2014-12-01). "Megafauna: Giant Beasts of Pleistocene South America". Journal of Mammalogy. 95 (6): 1308-1309. doi:10.1644/14-MAMM-R-132. ISSN 0022-2372.
  60. ^ Webb, S. David (August 2006). "The Great American Biotic Interchange: Patterns and Processes1". Annals of the Missouri Botanical Garden. 93 (2): 245-257. doi:10.3417/0026-6493(2006)93[245:TGABIP]2.0.CO;2. ISSN 0026-6493.
  61. ^ A. E. Zurita, A. A. Carlini, G. J. Scillato-Yané and E. P. Tonni. (2004). Mamíferos extintos del Cuaternario de la Provincia del Chaco (Argentina) y su relación con aquéllos del este de la región pampeana y de Chile. Revista geológica de Chile 31(1):65-87
  62. ^ O. P. Recabarren, M. Pino, M. T. Alberdi. (2014). La Familia Gomphotheriidae en América del Sur: evidencia de molares al norte de la Patagonia chilena. Estudios Geológicos, Vol 70, No 1.
  63. ^ Gunz, Philipp; Harvati, Katerina; Benazzi, Stefano; Cabec, Adeline Le; Bergmann, Inga; Skinner, Matthew M.; Neubauer, Simon; Freidline, Sarah E.; Bailey, Shara E. (June 2017). "New fossils from Jebel Irhoud, Morocco and the pan-African origin of Homo sapiens" (PDF). Nature. 546 (7657): 289-292. Bibcode:2017Natur.546..289H. doi:10.1038/nature22336. ISSN 1476-4687. PMID 28593953.
  64. ^ Hublin, Jean-Jacques; Ben-Ncer, Abdelouahed; Bailey, Shara E.; Freidline, Sarah E.; Neubauer, Simon; Skinner, Matthew M.; Bergmann, Inga; Le Cabec, Adeline; Benazzi, Stefano (2017-06-07). "New fossils from Jebel Irhoud, Morocco and the pan-African origin of Homo sapiens" (PDF). Nature. 546 (7657): 289-292. Bibcode:2017Natur.546..289H. doi:10.1038/nature22336. ISSN 0028-0836. PMID 28593953.
  65. ^ "These Early Humans Lived 300,000 Years Ago—But Had Modern Faces". 2017-06-07. Retrieved 2017-10-13.
  66. ^ Kaifu, Yousuke (2017). "Archaic Hominin Populations in Asia before the Arrival of Modern Humans: Their Phylogeny and Implications for the Southern Denisovans". Current Anthropology. 58 (17): 418-433. doi:10.1086/694318 - via University of Chicago Press.
  67. ^ Carotenuto, F. (July 1, 2018). "The well-behaved killer: Late Pleistocene humans in Eurasia were significantly associated with living megafauna only". Palaeogeography, Palaeoclimatology, Palaeoecology. 500: 24-32. Bibcode:2018PPP...500...24C. doi:10.1016/j.palaeo.2018.03.036. PMC 5263868. PMID 28106043.
  68. ^ Stuart, Anthony (November 1991). "Mammalian Extinctions in the Late Pleistocene of Northern Eurasia and North America". Biological Reviews. 66 (4): 453-566. doi:10.1111/j.1469-185X.1991.tb01149.x. PMID 1801948.
  69. ^ August 2017, Kim Ann Zimmermann-Live Science Contributor 29. "Pleistocene Epoch: Facts About the Last Ice Age". livescience.com. Retrieved 2021-05-05.
  70. ^ a b M. A., Anthropology; B. Ed., Illinois State University; Twitter, Twitter. "What Did Australia Look Like When the First People Arrived?". ThoughtCo. Retrieved 2021-05-05.
  71. ^ "Australia's Megafauna". Archived from the original on 2018-03-24. Retrieved 2008-12-17.
  72. ^ Death of the Megafauna
  73. ^ a b c d DeSantis, Larisa R. G.; Field, Judith H.; Wroe, Stephen; Dodson, John R. (2017-01-26). "Dietary responses of Sahul (Pleistocene Australia-New Guinea) megafauna to climate and environmental change". Paleobiology. 43 (2): 181-195. doi:10.1017/pab.2016.50. ISSN 0094-8373.
  74. ^ David, Bruno; Arnold, Lee J.; Delannoy, Jean-Jacques; Fresløv, Joanna; Urwin, Chris; Petchey, Fiona; McDowell, Matthew C.; Mullett, Russell; Mialanes, Jerome; Wood, Rachel; Crouch, Joe; Berthet, Johan; Wong, Vanessa N.L.; Green, Helen; Hellstrom, John; GunaiKurnai Land; Waters Aboriginal Corporation (2021-02-01). "Late survival of megafauna refuted for Cloggs Cave, SE Australia: Implications for the Australian Late Pleistocene megafauna extinction debate". Quaternary Science Reviews. 253: 106781. Bibcode:2021QSRv..25306781D. doi:10.1016/j.quascirev.2020.106781. ISSN 0277-3791.
  75. ^ Price, Gilbert J.; Zhao, Jian-xin; Feng, Yue-Xing; Hocknull, Scott A. (2009-02-01). "New U/Th ages for Pleistocene megafauna deposits of southeastern Queensland, Australia". Journal of Asian Earth Sciences. 34 (2): 190-197. Bibcode:2009JAESc..34..190P. doi:10.1016/j.jseaes.2008.04.008. ISSN 1367-9120.
  76. ^ a b c d Wroe, Stephen; Field, Judith (2006-11-01). "A review of the evidence for a human role in the extinction of Australian megafauna and an alternative interpretation". Quaternary Science Reviews. 25 (21-22): 2692-2703. Bibcode:2006QSRv...25.2692W. doi:10.1016/j.quascirev.2006.03.005. ISSN 0277-3791.
  77. ^ a b c d Johnson, C. N.; Alroy, J.; Beeton, N. J.; Bird, M. I.; Brook, B. W.; Cooper, A.; Gillespie, R.; Herrando-Pérez, S.; Jacobs, Z.; Miller, G. H.; Prideaux, G. J. (2016-02-10). "What caused extinction of the Pleistocene megafauna of Sahul?". Proceedings of the Royal Society B: Biological Sciences. 283 (1824): 20152399. doi:10.1098/rspb.2015.2399. ISSN 0962-8452. PMC 4760161. PMID 26865301.
  78. ^ Extinct dwarf elephants from the Mediterranean islands Archived 2009-01-23 at the Wayback Machine;
  79. ^ North American Extinctions v. World
  80. ^ Mammoths and Humans as late Pleistocene contemporaries on Santa Rosa Island, Institute for Wildlife Studies 6th California Islands Symposium, Larry D. Agenbroad, et al, December 2003. Retrieved 8 November 2015
  81. ^ Algunas extinciones en Canarias Archived 2009-12-28 at the Wayback Machine Consejería de Medio Ambiente y Ordenación Territorial del Gobierno de Canarias
  82. ^ «La Paleontología de vertebrados en Canarias.» Spanish Journal of Palaeontology (antes Revista Española de Paleontología). Consultado el 17 de junio de 2016.

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