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 45 kg (99 lb) 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 1,000 kg (2,200 lb) 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
Introduction
The Late Pleistocene saw the extinction of many mammals weighing 40 kilograms (88 lb) or more, including around 80% of mammals weighing 1,000 kilograms (2,200 lb) 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
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