The Late Pleistocene to the beginning of the Holocene saw the extinction of the majority of the world's megafauna, typically defined as animal species having body masses of or more, which resulted in a collapse in faunal density and diversity across the globe. The extinctions during the Late Pleistocene are differentiated from previous extinctions by their extreme size bias towards large animals (with small animals being largely unaffected), the widespread absence of ecological succession to replace these extinct megafaunal species, and the regime shift of previously established faunal relationships and habitats as a consequence. The timing and severity of the extinctions varied by region and are generally thought to have been driven by the globally expanding population of modern humans, climatic change, or a combination of both. Human impact on megafauna populations is thought to have been driven by hunting ("overkill"), as well as possibly environmental alteration. The relative importance of human versus climatic factors in the extinctions has been the subject of long-running controversy, though most scholars support at least a contributory role of humans in the extinctions.
Major extinctions occurred in Australia-New Guinea (Sahul) beginning around 50,000 years ago and in the Americas about 13,000 years ago, coinciding in time with the migration of modern humans into these regions. Extinctions in northern Eurasia were staggered over tens of thousands of years between 50,000 and 10,000 years ago, while extinctions in the Americas were virtually simultaneous, spanning only 3,000 years at most. Overall, during the Late Pleistocene about 65% of all megafaunal species worldwide became extinct, rising to 72% in North America, 83% in South America and 88% in Australia, with all mammals over becoming extinct in Australia and the Americas, and around 80% globally. Africa, South Asia, and Southeast Asia experienced more moderate extinctions than other regions.
The Late Pleistocene-early Holocene megafauna extinctions have often been seen as part of a single extinction event with later, widely agreed to be human-caused extinctions in the mid-late Holocene, such as those on Madagascar and New Zealand, as the Late Quaternary extinction event.
Extinctions by biogeographic realm Summary
+ Extinctions range of the continental large and medium-sized mammals from 40,000 to 4,000 years BP in different biogeographic realmsBiogeographicrealmGiants(over 1,000 kg)Very large(400–1,000 kg)Large(150–400 kg)Moderately large(50–150 kg)Medium(10–50 kg)TotalRegions includedAfrotropic 6 −1 16.6% 4 −1 25% 25 −3 12% 32 0 0% 69 −2 2.9% 136 -7 5.1% Trans-Saharan Africa and ArabiaIndomalaya 5 −2 40% 6 −1 16.7% 10 −1 10% 20 −3 15% 56 −1 1.8% 97 -8 8.2% Indian subcontinent, Southeast Asia, and southern ChinaPalearctic 8 −8 100% 10 −5 50% 14 −5 35.7% 23 −3 15% 41 −1 2.4% 96 -22 22.9% Eurasia and North AfricaNearctic 5 −5 100% 10 −8 80% 26 −22 84.6% 20 −13 65% 25 −9 36% 86 -57 66% North AmericaNeotropic 9 −9 100% 12 −12 100% 17 −14 82% 20 −11 55% 35 −5 14.3% 93 -51 54% South America, Central America, South Florida, and the CaribbeanAustralasia 4 −4 100% 5 −5 100% 6 −6 100% 16 −13 81.2% 25 −10 40% 56 -38 67% Australia, New Guinea, New Zealand, and neighbouring islands.Global 33 −26 78.8% 46 −31 67.4% 86 −47 54.7% 113 −41 36.3% 215 −23 10.7% 493 -168 34%
Introduction
The Late Pleistocene saw the extinction of many mammals weighing or more, including around 80% of mammals weighing or more. The proportion of megafauna extinctions is progressively larger the further the human migratory distance from Africa, with the highest extinction rates in Australia, and North and South America.
The increased extent of extinction mirrors the migration pattern of modern humans: the further away from Africa, the more recently humans inhabited the area, the less time those environments (including its megafauna) had to become accustomed to humans (and vice versa).
There are two main hypotheses to explain this extinction: Climate change associated with the advance and retreat of major ice caps or ice sheets causing reduction in favorable habitat. Human hunting causing attrition of megafauna populations, commonly known as "overkill". There are some inconsistencies between the current available data and the prehistoric overkill hypothesis. For instance, there are ambiguities around the timing of Australian megafauna extinctions. Evidence supporting the prehistoric overkill hypothesis includes the persistence of megafauna on some islands for millennia past the disappearance of their continental cousins. For instance, ground sloths survived on the Antilles long after North and South American ground sloths were extinct, woolly mammoths died out on remote Wrangel Island 6,000 years after their extinction on the mainland, and Steller's sea cows persisted off the isolated and uninhabited Commander Islands for thousands of years after they had vanished from the continental shores of the north Pacific. The later disappearance of these island species correlates with the later colonization of these islands by humans.
Still, there are some arguments that species responded differently to environmental changes, and no one factor by itself explains the large variety of extinctions. The causes may involve the interplay of climate change, competition between species, unstable population dynamics, and hunting as well as competition by humans.
The original debates as to whether human arrival times or climate change constituted the primary cause of megafaunal extinctions necessarily were based on paleontological evidence coupled with geological dating techniques. Recently, genetic analyses of surviving megafaunal populations have contributed new evidence, leading to the conclusion: "The inability of climate to predict the observed population decline of megafauna, especially during the past 75,000 years, implies that human impact became the main driver of megafauna dynamics around this date."
Africa Although Africa was one of the least affected regions, the region still suffered extinctions, particularly around the Late Pleistocene-Holocene transition. These extinctions were likely predominantly climatically driven by changes to grassland habitats.
Ungulates Even-Toed Ungulates Suidae (swine) Metridiochoerus (ssp.) Kolpochoerus (ssp.) Bovidae (bovines, antelope) Giant buffalo (Syncerus antiquus) Megalotragus Rusingoryx Southern springbok (Antidorcas australis) Bond's springbok (Antidorcas bondi) Damaliscus hypsodon Damaliscus niro Gazella atlantica Gazella tingitana Caprinae Makapania? Deer (Cervidae) Megaceroides algericus (North Africa) Odd-toed Ungulates Rhinoceros (Rhinocerotidae). Narrow-nosed rhinoceros (Stephanorhinus hemitoechus, North Africa) Ceratotherium mauritanicum Wild Equus spp. Caballine horses Equus algericus (North Africa) Subgenus Asinus (asses) Equus melkiensis (North Africa) Subgenis Hippotigris (Zebras) Cape zebra (Equus capensis) Equus mauritanicus (North Africa). Proboscidea Elephantidae (elephants) Palaeoloxodon jolensis? (other authors suggest that this taxon went extinct at the latest Middle Pleistocene) Rodentia Paraethomys filfilae? Crocodilia Crocodylus sudani
South Asia and Southeast Asia
The timing of extinctions on the Indian subcontinent is uncertain due to a lack of reliable dating. Similar issues have been reported for Chinese sites, though there is no evidence for any of the megafaunal taxa having survived into the Holocene in that region. Extinctions in Southeast Asia and Southern China have been proposed to be the result of environmental shift from open to closed forested habitats.
Ungulates Even-Toed Ungulates Several Bovidae spp. Bos palaesondaicus (ancestor to the banteng) Cebu tamaraw (Bubalus cebuensis) Bubalus grovesi Short-horned water buffalo (Bubalus mephistopheles) Bubalus palaeokerabau Hippopotamidae Hexaprotodon (Indian subcontinent and Southeast Asia) Odd-toed Ungulates Equus spp. Equus namadicus (Indian subcontinent) Yunnan horse (Equus yunanensis) Giant tapir (Tapirus augustus, Southeast Asia and Southern China) Pholidota (pangolins) Manis palaeojavanica Carnivora Ursidae (bears) Ailuropoda baconi (ancestor to the giant panda, which it is often considered a subspecies of distinctiveness from the living species has been disputed) Hyaenidae (hyenas) Cave hyena (Crocuta (Crocuta) ultima East Asia and Mainland Southeast Asia) Afrotheria Proboscideans Stegodontidae Stegodon spp. (including Stegodon florensis on Flores, Stegodon orientalis in East and Southeast Asia, and Stegodon sp. in the Indian subcontinent) Elephantidae Palaeoloxodon spp. Palaeoloxodon namadicus (Indian subcontinent, possibly also Southeast Asia) Birds Shiriyanetta hasegawai (a flightless duck native to Japan) Leptoptilos robustus Ostriches (Struthio) (Indian subcontinent) Reptiles Crocodylia Alligator munensis? Testudines (turtles and tortoises) Manouria oyamai Primates Several simian (Simiiformes) spp. Pongo (orangutans) Pongo weidenreichi (South China) Various Homo spp. (archaic humans) Homo erectus soloensis (Java) Homo floresiensis (Flores) Homo luzonensis (Luzon, Philippines) Denisovans (Homo sp.)
Europe, Northern and East Asia
The Palearctic realm spans the entirety of the European continent and stretches into northern Asia, through the Caucasus and central Asia to northern China, Siberia and Beringia. Extinctions were more severe in Northern Eurasia than in Africa or South and Southeast Asia. These extinctions were staggered over tens of thousands of years, spanning from around 50,000 years Before Present (BP) to around 10,000 years BP, with temperate adapted species like the straight-tusked elephant and the narrow-nosed rhinoceros generally going extinct earlier than cold adapted species like the woolly mammoth and woolly rhinoceros. Climate change has been considered a probable major factor in the extinctions, possibly in combination with human hunting.
Ungulates Even-Toed Hoofed Mammals Various Bovidae spp. Steppe bison (Bison priscus) Baikal yak (Bos baikalensis) European water buffalo (Bubalus murrensis) Bubalus wansjocki (extinct buffalo native to North China) Bubalus teilhardi European tahr (Hemitragus cedrensis) Praeovibos priscus Northern saiga antelope (Saiga borealis), distinctiveness Spirocerus kiakhtensis Parabubalis capricornis) Various deer (Cervidae) spp. Giant deer/Irish elk (Megaloceros giganteus) Candiacervus spp. (Crete) Haploidoceros mediterraneus Sinomegaceros spp. (including Sinomegaceros yabei in Japan, and Sinomegaceros ordosianus and possibly Sinomegaceros pachyosteus in China). Cervus astylodon (Ryukyu Islands) All native Hippopotamus spp. Hippopotamus amphibius (known as the Europe European range, still extant in Africa) Maltese dwarf hippopotamus (Hippopotamus melitensis) Cypriot pygmy hippopotamus (Hippopotamus minor) Sicilian dwarf hippopotamus (Hippopotamus pentlandi) Camelus knoblochi and other Camelus spp. Odd-Toed Hoofed Mammals Various Equus spp. e.g. Various wild horse subspecies (e.g. Equus c. gallicus, Equus c. latipes, Equus c. uralensis) Equus dalianensis (wild horse species known from North China) European wild ass (Equus hydruntinus) (survived in refugia in Anatolia until the Late Holocene) Equus ovodovi (survived in refugia in North China until the Late Holocene) All native Rhinoceros (Rhinocerotidae) spp. Elasmotherium sibiricum Woolly rhinoceros (Coelodonta antiquitatis) Stephanorhinus spp. Merck's rhinoceros (Stephanorhinus kirchbergensis) Narrow-nosed rhinoceros (Stephanorhinus hemiotoechus) Carnivora Caniformia Canidae Caninae Wolves Cave wolf (Canis lupus spelaeus) Dire wolf? (Aenocyon dirus) Dholes European dhole (Cuon alpinus europaeus) Sardinian dhole (Cynotherium sardous) Arctoidea Various Ursus spp. Ursus kanivetz