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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 South China have been proposed to be the result of environmental shift from open to closed forested habitats.
*
The
North American extinctions (noted as
South America suffered among the worst losses of the continents, with around 83% of its megafauna going extinct. These extinctions postdate the arrival of modern humans in South America around 15,000 years ago. Both human and climatic factors have been attributed as factors in the extinctions by various authors. Although some megafauna has been historically suggested to have survived into the early Holocene based on radiocarbon dates this may be the result of dating errors due to contamination. The extinctions are coincident with the end of the Antarctic Cold Reversal (a cooling period earlier and less severe than the Northern Hemisphere Younger Dryas) and the emergence of Fishtail projectile points, which became widespread across South America. Fishtail projectile points are thought to have been used in big game hunting, though direct evidence of exploitation of extinct megafauna by humans is rare, though megafauna exploitation has been documented at a number of sites. Fishtail points rapidly disappeared after the extinction of the megafauna, and were replaced by other styles more suited to hunting smaller prey. Some authors have proposed the "Broken Zig-Zag" model, where human hunting and climate change causing a reduction in open habitats preferred by megafauna were synergistic factors in megafauna extinction in South America.
* Ungulates
** ''Even-Toed Hoofed Mammals''
*** Several Cervidae (deer) spp.
**** '' Morenelaphus''
**** '' Antifer''
**** '' Agalmaceros blicki'' (potentially synonym of modern
* 
*** '' Ikanogavialis'' (the last fully marine crocodilian)
*** '' Paludirex'' (Australian freshwater mekosuchine crocodiian)
*** '' Quinkana'' (Australian terrestrial mekosuchine crocodilian,
A 2020 study published in ''Science Advances'' found that human population size and/or specific human activities, not climate change, caused rapidly rising global mammal extinction rates during the past 126,000 years. Around 96% of all mammalian extinctions over this time period are attributable to human impacts. According to Tobias Andermann, lead author of the study, "these extinctions did not happen continuously and at constant pace. Instead, bursts of extinctions are detected across different continents at times when humans first reached them. More recently, the magnitude of human driven extinctions has picked up the pace again, this time on a global scale." Text and images are available under a creativecommons:by/4.0/, Creative Commons Attribution 4.0 International License. On a related note, the population declines of still extant megafauna during the Pleistocene have also been shown to correlate with human expansion rather than climate change.
The extinction's extreme bias towards larger animals further supports a relationship with human activity rather than climate change. There is evidence that the average size of mammalian fauna declined over the course of the Quaternary, a phenomenon that was likely linked to disproportionate hunting of large animals by humans.
Extinction through human hunting has been supported by archaeological finds of mammoths with projectile points embedded in their skeletons, by observations of modern naive animals allowing hunters to approach easily and by computer models by Mosimann and Martin, and Whittington and Dyke, and most recently by Alroy.
In 2024 a paper was published in ''Science Advances'' that added additional support to the overkill hypothesis in North America when the skull of an 18 month old child, dated to 12,800 years ago, was analyzed for chemical signatures attributable to both maternal milk and solid food. Specific isotopes of carbon and nitrogen most closely matched those that would have been found in the mammoth genus and secondarily elk or bison.
A number of objections have been raised regarding the hunting hypothesis. Notable among them is the sparsity of evidence of human hunting of megafauna. There is no archeological evidence that in North America megafauna other than mammoths, mastodons, gomphotheres and bison were hunted, despite the fact that, for example, camels and horses are very frequently reported in fossil history. Overkill proponents, however, say this is due to the fast extinction process in North America and the low probability of animals with signs of butchery to be preserved. The majority of North American taxa have too sparse a fossil record to accurately assess the frequency of human hunting of them. A study by Surovell and Grund concluded "archaeological sites dating to the time of the coexistence of humans and extinct fauna are rare. Those that preserve bone are considerably more rare, and of those, only a very few show unambiguous evidence of human hunting of any type of prey whatsoever." Eugene S. Hunn suggests that the birthrate in hunter-gatherer societies is generally too low, that too much effort is involved in the bringing down of a large animal by a hunting party, and that in order for hunter-gatherers to have brought about the extinction of megafauna simply by hunting them to death, an extraordinary amount of meat would have had to have been wasted. Proponents of hunting as a cause of the extinctions argue that statistical modelling validates that relatively low-level hunting can have significant effect on megafauna populations due to their slow life cycles, and that hunting can cause top-down forcing trophic cascade events that destabilize ecosystems.
The Second-Order Predation Hypothesis says that as humans entered the New World they continued their policy of killing predators, which had been successful in the Old World but because they were more efficient and because the fauna, both herbivores and carnivores, were more naive, they killed off enough carnivores to upset the Ecological equilibrium, ecological balance of the continent, causing overpopulation (biology), overpopulation, environmental exhaustion, and environmental collapse. The hypothesis accounts for changes in animal, plant, and human populations.
The scenario is as follows:
* After the arrival of ''H. sapiens'' in the New World, existing predators must share the prey populations with this new predator. Because of this competition, populations of original, or first-order, predators cannot find enough food; they are in direct competition with humans.
* Second-order predation begins as humans begin to kill predators.
* Prey populations are no longer well controlled by predation. Killing of nonhuman predators by ''H. sapiens'' reduces their numbers to a point where these predators no longer regulate the size of the prey populations.
* Lack of regulation by first-order predators triggers boom-and-bust cycles in prey populations. Prey populations expand and consequently overgraze and over-browse the land. Soon the environment is no longer able to support them. As a result, many herbivores starve. Species that rely on the slowest recruiting food become extinct, followed by species that cannot extract the maximum benefit from every bit of their food.
* Boom-bust cycles in herbivore populations change the nature of the vegetative environment, with consequent climatic impacts on relative humidity and continentality. Through overgrazing and overbrowsing, mixed parkland becomes grassland, and climatic continentality increases.
The second-order predation hypothesis has been supported by a computer model, the Pleistocene extinction model (PEM), which, using the same assumptions and values for all variables (herbivore population, herbivore recruitment rates, food needed per human, herbivore hunting rates, etc.) other than those for hunting of predators. It compares the overkill hypothesis (predator hunting = 0) with second-order predation (predator hunting varied between 0.01 and 0.05 for different runs). The findings are that second-order predation is more consistent with extinction than is overkill (results graph at left). The Pleistocene extinction model is the only test of multiple hypotheses and is the only model to specifically test combination hypotheses by artificially introducing sufficient climate change to cause extinction. When overkill and climate change are combined they balance each other out. Climate change reduces the number of plants, overkill removes animals, therefore fewer plants are eaten. Second-order predation combined with climate change exacerbates the effect of climate change. (results graph at right). The second-order predation hypothesis is further supported by the observation above that there was a massive increase in bison populations.
However, this hypothesis has been criticised on the grounds that the multispecies model produces a mass extinction through indirect competition between herbivore species: small species with high reproductive rates subsidize predation on large species with low reproductive rates. All prey species are lumped in the Pleistocene extinction model. Also, the control of population sizes by predators is not fully supported by observations of modern ecosystems. The hypothesis further assumes decreases in vegetation due to climate change, but deglaciation doubled the habitable area of North America. Any vegetational changes that did occur failed to cause almost any extinctions of small vertebrates, and they are more narrowly distributed on average, which detractors cite as evidence against the hypothesis.
However, more recent authors have viewed it as more likely that the collapse of the mammoth steppe was driven by climatic warming, which in turn impacted the megafauna, rather than the other way around.
Megafauna play a significant role in the lateral transport of mineral nutrients in an ecosystem, tending to translocate them from areas of high to those of lower abundance. They do so by their movement between the time they consume the nutrient and the time they release it through elimination (or, to a much lesser extent, through decomposition after death). In South America's Amazon Basin, it is estimated that such lateral diffusion was reduced over 98% following the megafaunal extinctions that occurred roughly 12,500 years ago. Given that phosphorus availability is thought to limit productivity in much of the region, the decrease in its transport from the western part of the basin and from floodplains (both of which derive their supply from the uplift of the Andes) to other areas is thought to have significantly impacted the region's ecology, and the effects may not yet have reached their limits. The extinction of the mammoths allowed grasslands they had maintained through grazing habits to become birch forests. The new forest and the resulting forest fires may have induced
Late Pleistocene
The Late Pleistocene is an unofficial Age (geology), age in the international geologic timescale in chronostratigraphy, also known as the Upper Pleistocene from a Stratigraphy, stratigraphic perspective. It is intended to be the fourth division ...
to the beginning of the Holocene
The Holocene () is the current geologic time scale, geological epoch, beginning approximately 11,700 years ago. It follows the Last Glacial Period, which concluded with the Holocene glacial retreat. The Holocene and the preceding Pleistocene to ...
saw the extinction of the majority of the world's megafauna
In zoology, megafauna (from Ancient Greek, Greek μέγας ''megas'' "large" and Neo-Latin ''fauna'' "animal life") are large animals. The precise definition of the term varies widely, though a common threshold is approximately , this lower en ...
, typically defined as animal species having body masses over , 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), and widespread absence of ecological succession
Ecological succession is the process of how species compositions change in an Community (ecology), ecological community over time.
The two main categories of ecological succession are primary succession and secondary succession. Primary successi ...
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 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 vs 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
__NOTOC__
Sahul (), also called Sahul-land, Meganesia, Papualand and Greater Australia, was a paleocontinent that encompassed the modern-day landmasses of mainland Australia, Tasmania, New Guinea, and the Aru Islands.
Sahul was in the south- ...
) beginning around 50,000 years ago and in the Americas
The Americas, sometimes collectively called America, are a landmass comprising the totality of North America and South America.''Webster's New World College Dictionary'', 2010 by Wiley Publishing, Inc., Cleveland, Ohio. When viewed as a sing ...
about 13,000 years ago, coinciding in time with the early human migrations
Early human migrations are the earliest migrations and expansions of archaic and modern humans across continents. They are believed to have begun approximately 2 million years ago with the early expansions out of Africa by ''Homo erectu ...
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 3000 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
Madagascar, officially the Republic of Madagascar, is an island country that includes the island of Madagascar and numerous smaller peripheral islands. Lying off the southeastern coast of Africa, it is the world's List of islands by area, f ...
and New Zealand
New Zealand () is an island country in the southwestern Pacific Ocean. It consists of two main landmasses—the North Island () and the South Island ()—and List of islands of New Zealand, over 600 smaller islands. It is the List of isla ...
, as the Late Quaternary extinction event.
Extinctions by biogeographic realm
Summary
Introduction
The Late Pleistocene saw the extinction of many mammals weighing more than , including around 80% of mammals over 1 tonne. 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
Present-day climate change includes both global warming—the ongoing increase in Global surface temperature, global average temperature—and its wider effects on Earth's climate system. Climate variability and change, Climate change in ...
associated with the advance and retreat of major ice caps
In glaciology, an ice cap is a mass of ice that covers less than of land
Land, also known as dry land, ground, or earth, is the solid terrestrial surface of Earth not submerged by the ocean or another body of water. It makes up 29.2% ...
or ice sheets
In glaciology, an ice sheet, also known as a continental glacier, is a mass of glacial ice that covers surrounding terrain and is greater than . The only current ice sheets are the Antarctic ice sheet and the Greenland ice sheet. 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
The term Australian megafauna refers to the megafauna in Australia (continent), Australia during the Pleistocene, Pleistocene Epoch. Most of these species became extinct during the latter half of the Pleistocene, as part of the broader global L ...
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
The Antilles is an archipelago bordered by the Caribbean Sea to the south and west, the Gulf of Mexico to the northwest, and the Atlantic Ocean to the north and east.
The Antillean islands are divided into two smaller groupings: the Greater An ...
long after North and South American ground sloths were extinct, woolly mammoths died out on remote Wrangel Island
Wrangel Island (, ; , , ) is an island of the Chukotka Autonomous Okrug, Russia. It is the List of islands by area, 92nd-largest island in the world and roughly the size of Crete. Located in the Arctic Ocean between the Chukchi Sea and East Si ...
6,000 years after their extinction on the mainland, and Steller's sea cow
Steller's sea cow (''Hydrodamalis gigas'') is an extinction, extinct sirenian described by Georg Wilhelm Steller in 1741. At that time, it was found only around the Commander Islands in the Bering Sea between Alaska and Russia; its range exte ...
s persisted off the isolated and uninhabited Commander Islands
The Commander Islands, Komandorski Islands, or Komandorskie Islands (, ''Komandorskiye ostrova'') are a series of islands in the Russian Far East, a part of the Aleutian Islands, located about east of the Kamchatka Peninsula in the Bering Sea. ...
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
Present-day climate change includes both global warming—the ongoing increase in Global surface temperature, global average temperature—and its wider effects on Earth's climate system. Climate variability and change, Climate change in ...
, competition between species, unstable population dynamics
Population dynamics is the type of mathematics used to model and study the size and age composition of populations as dynamical systems. Population dynamics is a branch of mathematical biology, and uses mathematical techniques such as differenti ...
, 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. *Ungulate
Ungulates ( ) are members of the diverse clade Euungulata ("true ungulates"), which primarily consists of large mammals with Hoof, hooves. Once part of the clade "Ungulata" along with the clade Paenungulata, "Ungulata" has since been determined ...
s
** '' Even-Toed Ungulates''
*** Suidae
Suidae is a family (biology), family of Even-toed ungulate, artiodactyl mammals which are commonly called pigs, hogs, or swine. In addition to numerous fossil species, 18 Extant taxon, extant species are currently recognized (or 19 counting domes ...
(swine)
**** '' Metridiochoerus '' (ssp.)
**** '' Kolpochoerus'' (ssp.)
***Bovidae
The Bovidae comprise the family (biology), biological family of cloven-hoofed, ruminant mammals that includes Bos, cattle, bison, Bubalina, buffalo, antelopes (including Caprinae, goat-antelopes), Ovis, sheep and Capra (genus), goats. A member o ...
(bovines, antelope)
**** Giant buffalo (''Syncerus antiquus'')
**** '' Megalotragus''
**** '' Rusingoryx''
**** Southern springbok (''Antidorcas australis'')
**** Bond's springbok (''Antidorcas bondi'')
**** '' Damaliscus hypsodon''
**** '' Damaliscus niro''
**** Atlantic gazelle (''Gazella atlantica'')
**** '' Gazella tingitana''
**** Caprinae
The subfamily Caprinae, also sometimes referred to as the tribe Caprini, is part of the ruminant family Bovidae, and consists of mostly medium-sized bovids. A member of this subfamily is called a caprine.
Prominent members include sheep and g ...
***** '' Makapania?''
*** Cervidae (deer)
****'' Megaceroides algericus'' (North Africa)
**'' Odd-toed Ungulates''
***Rhinoceros
A rhinoceros ( ; ; ; : rhinoceros or rhinoceroses), commonly abbreviated to rhino, is a member of any of the five extant taxon, extant species (or numerous extinct species) of odd-toed ungulates (perissodactyls) in the family (biology), famil ...
(Rhinocerotidae).
**** Narrow-nosed rhinoceros
The narrow-nosed rhinoceros (''Stephanorhinus hemitoechus''), also known as the steppe rhinoceros is an extinct species of rhinoceros belonging to the genus '' Stephanorhinus'' that lived in western Eurasia, including Europe, and West Asia, as ...
(''Stephanorhinus hemitoechus'', North Africa)
**** '' Ceratotherium mauritanicum''
***Wild ''Equus'' spp.
**** Caballine horses
*****''Equus algericus'' (North Africa)
****Subgenus ''Asinus
''Asinus'' is a subgenus of ''Equus (genus), Equus'' that encompasses several subspecies of the Equidae commonly known as wild asses, characterized by long ears, a lean, straight-backed build, lack of a true withers, a coarse mane and tail, and a ...
'' (asses)
*****''Equus melkiensis'' (North Africa)
**** Zebras
***** Giant zebra (''Equus capensis'')
***** Saharan zebra (''Equus mauritanicus'')
*Proboscidea
Proboscidea (; , ) is a taxonomic order of afrotherian mammals containing one living family (Elephantidae) and several extinct families. First described by J. Illiger in 1811, it encompasses the elephants and their close relatives. Three l ...
**Elephantidae
Elephantidae is a family (biology), family of large, herbivorous proboscidean mammals which includes the living Elephant, elephants (belonging to the genera ''Elephas'' and ''Loxodonta''), as well as a number of extinct genera like ''Mammuthus'' ...
(elephants)
***'' Palaeoloxodon iolensis''? (other authors suggest that this taxon went extinct at the end of the Middle Pleistocene)
* Rodentia
Rodents (from Latin , 'to gnaw') are mammals of the order Rodentia ( ), which are characterized by a single pair of continuously growing incisors in each of the upper and lower jaws. About 40% of all mammal species are rodents. They are na ...
** ''Paraethomys filfilae''?
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 South China have been proposed to be the result of environmental shift from open to closed forested habitats.
* Ungulate
Ungulates ( ) are members of the diverse clade Euungulata ("true ungulates"), which primarily consists of large mammals with Hoof, hooves. Once part of the clade "Ungulata" along with the clade Paenungulata, "Ungulata" has since been determined ...
s
** '' Even-Toed Ungulates''
*** Several Bovidae
The Bovidae comprise the family (biology), biological family of cloven-hoofed, ruminant mammals that includes Bos, cattle, bison, Bubalina, buffalo, antelopes (including Caprinae, goat-antelopes), Ovis, sheep and Capra (genus), goats. A member o ...
spp.
**** '' Bos palaesondaicus'' (ancestor to the banteng
The banteng (''Bos javanicus''; ), also known as tembadau, is a species of wild Bovinae, bovine found in Southeast Asia.
The head-and-body length is between . Wild banteng are typically larger and heavier than their Bali cattle, domesticated ...
)
**** Cebu tamaraw (''Bubalus cebuensis'')
**** '' Bubalus grovesi''
**** Short-horned water buffalo (''Bubalus mephistopheles'')
**** '' Bubalus palaeokerabau''
*** Hippopotamidae
Hippopotamidae is a family of stout, naked-skinned, and semiaquatic artiodactyl mammals, possessing three-chambered stomachs and walking on four toes on each foot. While they resemble pigs physiologically, their closest living relatives are th ...
**** '' 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)
*** '' Taprus sinensis''
* Pholidota
Pangolins, sometimes known as scaly anteaters, are mammals of the order Pholidota (). The one Neontology, extant family, the Manidae, has three genera: ''Manis'', ''Phataginus'', and ''Smutsia''. ''Manis'' comprises four species found in Asia, ...
** Giant Asian pangolin ('' Manis palaeojavanica'')
* Carnivora
Carnivora ( ) is an order of placental mammals specialized primarily in eating flesh, whose members are formally referred to as carnivorans. The order Carnivora is the sixth largest order of mammals, comprising at least 279 species. Carnivor ...
** Ursidae
Bears are carnivoran mammals of the family (biology), family Ursidae (). They are classified as caniforms, or doglike carnivorans. Although only eight species of bears are extant, they are widespread, appearing in a wide variety of habitats ...
(bears)
*** '' Ailuropoda baconi'' (ancestor to the giant panda
The giant panda (''Ailuropoda melanoleuca''), also known as the panda bear or simply panda, is a bear species endemic to China. It is characterised by its white animal coat, coat with black patches around the eyes, ears, legs and shoulders. ...
, 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
Afrotheria ( from Latin ''Afro-'' "of Africa" + ''theria'' "wild beast") is a superorder of placental mammals, the living members of which belong to groups that are either currently living in Africa or of African origin: golden moles, elephan ...
** Proboscidea
Proboscidea (; , ) is a taxonomic order of afrotherian mammals containing one living family (Elephantidae) and several extinct families. First described by J. Illiger in 1811, it encompasses the elephants and their close relatives. Three l ...
ns
*** Stegodontidae
**** ''Stegodon
''Stegodon'' (from the Ancient Greek στέγω (''stégō''), meaning "to cover", and ὀδούς (''odoús''), meaning "tooth", named for the distinctive ridges on the animal's molars) is an extinct genus of proboscidean, related to elephants ...
'' spp''.'' (including ''Stegodon florensis'' on Flores, ''Stegodon orientalis'' in East and Southeast Asia, and ''Stegodon'' sp. in the Indian subcontinent)
***Elephantidae
Elephantidae is a family (biology), family of large, herbivorous proboscidean mammals which includes the living Elephant, elephants (belonging to the genera ''Elephas'' and ''Loxodonta''), as well as a number of extinct genera like ''Mammuthus'' ...
**** ''Palaeoloxodon
''Palaeoloxodon'' is an extinct genus of elephant. The genus originated in Africa during the Early Pleistocene, and expanded into Eurasia at the beginning of the Middle Pleistocene. The genus contains the largest known species of elephants, with ...
'' spp.
***** '' Palaeoloxodon namadicus'' (Indian subcontinent, possibly also Southeast Asia)
* Birds
** Japanese flightless duck (''Shiriyanetta hasegawai'')
** '' Leptoptilos robustus''
** Ostrich
Ostriches are large flightless birds. Two living species are recognised, the common ostrich, native to large parts of sub-Saharan Africa, and the Somali ostrich, native to the Horn of Africa.
They are the heaviest and largest living birds, w ...
es (''Struthio'') (Indian subcontinent)
*Reptiles
**Crocodilia
Crocodilia () is an order of semiaquatic, predatory reptiles that are known as crocodilians. They first appeared during the Late Cretaceous and are the closest living relatives of birds. Crocodilians are a type of crocodylomorph pseudosuchia ...
***'' Alligator munensis''?
**Testudines
Turtles are reptiles of the order (biology), order Testudines, characterized by a special turtle shell, shell developed mainly from their ribs. Modern turtles are divided into two major groups, the Pleurodira (side necked turtles) and Crypt ...
(turtles and tortoises)
***'' Manouria oyamai''
* Primates
** Several simian
The simians, anthropoids, or higher primates are an infraorder (Simiiformes ) of primates containing all animals traditionally called monkeys and apes. More precisely, they consist of the parvorders New World monkey, Platyrrhini (New World mon ...
(Simiiformes) spp.
*** ''Pongo'' ( orangutans)
**** ''Pongo weidenreichi
The Chinese orangutan (''Pongo weidenreichi'') is an extinct species of orangutan from the Pleistocene of South China and possibly Southeast Asia. It is known from fossil teeth found in the Sanhe Cave, and Baikong, Juyuan and Queque Caves in Ch ...
'' (South China)
*** Various ''Homo
''Homo'' () is a genus of great ape (family Hominidae) that emerged from the genus ''Australopithecus'' and encompasses only a single extant species, ''Homo sapiens'' (modern humans), along with a number of extinct species (collectively called ...
'' spp. (archaic humans)
**** '' Homo erectus soloensis'' (Java)
**** ''Homo floresiensis
''Homo floresiensis'' , also known as "Flores Man" or "Hobbit" (after Hobbit, the fictional species), is an Extinction, extinct species of small archaic humans that inhabited the island of Flores, Indonesia, until the arrival of Homo sapiens, ...
'' (Flores)
**** '' Homo luzonensis'' (Luzon, Philippines)
**** Denisovans
The Denisovans or Denisova hominins ( ) are an extinct species or subspecies of archaic human that ranged across Asia during the Lower Paleolithic, Lower and Middle Paleolithic, and lived, based on current evidence, from 285 thousand to 25 thou ...
(''Homo'' sp.)
Europe, Northern and East Asia
The Palearctic realm
The Palearctic or Palaearctic is a biogeographic realm of the Earth, the largest of eight. Confined almost entirely to the Eastern Hemisphere, it stretches across Europe and Asia, north of the foothills of the Himalayas, and North Africa.
The ...
spans the entirety of the European continent
Europe is a continent located entirely in the Northern Hemisphere and mostly in the Eastern Hemisphere. It is bordered by the Arctic Ocean to the north, the Atlantic Ocean to the west, the Mediterranean Sea to the south, and Asia to the eas ...
and stretches into northern Asia
North Asia or Northern Asia () is the northern region of Asia, which is defined in geographical terms and consists of three federal districts of Russia: Ural, Siberian, and the Far Eastern. North Asia is bordered by the Arctic Ocean to its n ...
, through the Caucasus
The Caucasus () or Caucasia (), is a region spanning Eastern Europe and Western Asia. It is situated between the Black Sea and the Caspian Sea, comprising parts of Southern Russia, Georgia, Armenia, and Azerbaijan. The Caucasus Mountains, i ...
and central Asia
Central Asia is a region of Asia consisting of Kazakhstan, Kyrgyzstan, Tajikistan, Turkmenistan, and Uzbekistan. The countries as a group are also colloquially referred to as the "-stans" as all have names ending with the Persian language, Pers ...
to northern China
Northern China () and Southern China () are two approximate regions that display certain differences in terms of their geography, demographics, economy, and culture.
Extent
The Qinling, Qinling–Daba Mountains serve as the transition zone ...
, Siberia
Siberia ( ; , ) is an extensive geographical region comprising all of North Asia, from the Ural Mountains in the west to the Pacific Ocean in the east. It has formed a part of the sovereign territory of Russia and its predecessor states ...
and Beringia
Beringia is defined today as the land and maritime area bounded on the west by the Lena River in Russia; on the east by the Mackenzie River in Canada; on the north by 70th parallel north, 72° north latitude in the Chukchi Sea; and on the south ...
. 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
Before Present (BP) or "years before present (YBP)" is a time scale used mainly in archaeology, geology, and other scientific disciplines to specify when events occurred relative to the origin of practical radiocarbon dating in the 1950s. Because ...
(BP) to around 10,000 years BP, with temperate adapted species like the straight-tusked elephant
The straight-tusked elephant (''Palaeoloxodon antiquus'') is an extinct species of elephant that inhabited Europe and Western Asia during the Middle Pleistocene, Middle and Late Pleistocene. One of the largest known elephant species, mature full ...
and the narrow-nosed rhinoceros
The narrow-nosed rhinoceros (''Stephanorhinus hemitoechus''), also known as the steppe rhinoceros is an extinct species of rhinoceros belonging to the genus '' Stephanorhinus'' that lived in western Eurasia, including Europe, and West Asia, as ...
generally going extinct earlier than cold adapted species like the woolly mammoth
The woolly mammoth (''Mammuthus primigenius'') is an extinct species of mammoth that lived from the Middle Pleistocene until its extinction in the Holocene epoch. It was one of the last in a line of mammoth species, beginning with the African ...
and woolly rhinoceros
The woolly rhinoceros (''Coelodonta antiquitatis'') is an extinct species of rhinoceros that inhabited northern Eurasia during the Pleistocene epoch. The woolly rhinoceros was a member of the Pleistocene megafauna. The woolly rhinoceros was larg ...
. 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
The Bovidae comprise the family (biology), biological family of cloven-hoofed, ruminant mammals that includes Bos, cattle, bison, Bubalina, buffalo, antelopes (including Caprinae, goat-antelopes), Ovis, sheep and Capra (genus), goats. A member o ...
spp.
**** Steppe bison
The steppe bison (''Bison'' ''priscus'', also less commonly known as the steppe wisent and the primeval bison) is an extinct species of bison which lived from the Middle Pleistocene to the Holocene. During the Late Pleistocene, it was widely dist ...
(''Bison priscus'')
**** Baikal yak (''Bos baikalensis'')
**** European water buffalo (''Bubalus murrensis'')
**** '' Bubalus wansijocki'' (extinct buffalo native to North China)
**** '' Bubalus teilhardi''
**** European tahr (''Hemitragus cedrensis'')
**** Giant muskox (''Praeovibos priscus'')
**** Northern saiga antelope (''Saiga borealis'')
**** Twisted-horned antelope ('' Spirocerus kiakhtensis'')
**** Goat-horned antelope ('' Parabubalis capricornis'')
*** Various deer
A deer (: deer) or true deer is a hoofed ruminant ungulate of the family Cervidae (informally the deer family). Cervidae is divided into subfamilies Cervinae (which includes, among others, muntjac, elk (wapiti), red deer, and fallow deer) ...
(Cervidae) spp.
**** Giant deer/Irish elk (''Megaloceros giganteus'')
**** Cretan deer (''Candiacervus'' spp.)
**** '' Haploidoceros mediterraneus''
**** ''Sinomegaceros
''Sinomegaceros'' is an extinct genus of deer known from the Late Pliocene/Early Pleistocene to Late Pleistocene of Central and East Asia. It is considered to be part of the group of "giant deer" (often referred to collectively as members of the ...
'' spp. (including ''Sinomegaceros yabei'' in Japan, and ''Sinomegaceros ordosianus'' and possibly ''Sinomegaceros pachyosteus'' in China).
**** Dwarf Ryukyu deer (''Cervus astylodon'')
*** All native ''Hippopotamus
The hippopotamus (''Hippopotamus amphibius;'' ; : hippopotamuses), often shortened to hippo (: hippos), further qualified as the common hippopotamus, Nile hippopotamus and river hippopotamus, is a large semiaquatic mammal native to sub-Sahar ...
'' spp.
**** '' Hippopotamus amphibius'' (European range, still extant in Africa)
**** Maltese dwarf hippopotamus (''Hippopotamus melitensis'')
**** Cyprus dwarf hippopotamus (''Hippopotamus minor'')
**** Sicilian dwarf hippopotamus (''Hippopotamus pentlandi'')
*** ''Camelus knoblochi
''Camelus knoblochi'' is an extinct species of camel that inhabited Eurasia during the Pleistocene epoch. One of the largest known camel species, its range spanned from Eastern Europe to Northern China.
History of discovery
The earliest remain ...
'' and other ''Camel
A camel (from and () from Ancient Semitic: ''gāmāl'') is an even-toed ungulate in the genus ''Camelus'' that bears distinctive fatty deposits known as "humps" on its back. Camels have long been domesticated and, as livestock, they provid ...
us'' spp.
** ''Odd-Toed Hoofed Mammals''
*** Various ''Equus'' spp. e.g.
**** Various wild horse
The wild horse (''Equus ferus'') is a species of the genus Equus (genus), ''Equus'', which includes as subspecies the modern domestication of the horse, domesticated horse (''Equus ferus caballus'') as well as the Endangered species, endangered ...
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 late Holocene)
**** '' Equus ovodovi'' (survived in refugia in North China until late Holocene)
*** All native Rhinoceros
A rhinoceros ( ; ; ; : rhinoceros or rhinoceroses), commonly abbreviated to rhino, is a member of any of the five extant taxon, extant species (or numerous extinct species) of odd-toed ungulates (perissodactyls) in the family (biology), famil ...
(Rhinocerotidae) spp.
**** '' Elasmotherium''
**** Woolly rhinoceros
The woolly rhinoceros (''Coelodonta antiquitatis'') is an extinct species of rhinoceros that inhabited northern Eurasia during the Pleistocene epoch. The woolly rhinoceros was a member of the Pleistocene megafauna. The woolly rhinoceros was larg ...
(''Coelodonta antiquitatis'')
**** ''Stephanorhinus
''Stephanorhinus'' is an extinct genus of two-horned rhinoceros native to Eurasia and North Africa that lived during the Late Pliocene to Late Pleistocene. Species of ''Stephanorhinus'' were the predominant and often only species of rhinoceros in ...
'' spp.
***** Merck's rhinoceros
''Stephanorhinus kirchbergensis'', also known as Merck's rhinoceros (or the less commonly, the forest rhinoceros) is an extinct species of rhinoceros belonging to the genus ''Stephanorhinus'' that lived from the end of the Early Pleistocene (arou ...
(''Stephanorhinus kirchbergensis'')
***** Narrow-nosed rhinoceros
The narrow-nosed rhinoceros (''Stephanorhinus hemitoechus''), also known as the steppe rhinoceros is an extinct species of rhinoceros belonging to the genus '' Stephanorhinus'' that lived in western Eurasia, including Europe, and West Asia, as ...
(''Stephanorhinus hemiotoechus'')
* Carnivora
** ''Caniformia
Caniformia is a suborder within the order Carnivora consisting of "dog-like" carnivorans. They include Canidae, dogs (Wolf, wolves, foxes, etc.), bears, raccoons, and Mustelidae, mustelids. The Pinnipedia (pinniped, seals, walruses and sea lions) ...
''
*** ''Canidae
Canidae (; from Latin, ''canis'', "dog") is a family (biology), biological family of caniform carnivorans, constituting a clade. A member of this family is also called a canid (). The family includes three subfamily, subfamilies: the Caninae, a ...
''
**** Caninae
Caninae (whose members are known as canines () is the only living subfamily within Canidae, alongside the extinct Borophaginae and Hesperocyoninae. They first appeared in North America, during the Oligocene around 35 million years ago, subsequent ...
***** Wolves
The wolf (''Canis lupus''; : wolves), also known as the grey wolf or gray wolf, is a canine native to Eurasia and North America. More than thirty subspecies of ''Canis lupus'' have been recognized, including the dog and dingo, though gr ...
****** Cave wolf (''Canis lupus spelaeus'')
****** Dire wolf
The dire wolf (''Aenocyon dirus'' ) is an Extinction, extinct species of Caninae, canine which was native to the Americas during the Late Pleistocene and Early Holocene epochs (125,000–10,000 years ago). The species was named in 1858, four y ...
(''Aenocyon dirus'')
***** Dhole
The dhole ( ; ''Cuon alpinus'') is a canid native to South, East and Southeast Asia. It is anatomically distinguished from members of the genus ''Canis'' in several aspects: its skull is convex rather than concave in profile, it lacks a third ...
s
****** European dhole (''Cuon alpinus europaeus'')
***** Sardinian dhole (''Cynotherium sardous'')
*** Arctoidea
Arctoidea is an Order (biology), infraorder of mostly Carnivore, carnivorous mammals which include the extinct Hemicyoninae, Hemicyonidae (dog-bears), and the extant Musteloidea (weasels, raccoons, skunks, red pandas), Pinniped, Pinnipedia (seals ...
**** Various ''Ursus'' spp.
***** Steppe brown bear (''Ursus arctos'' "''priscus''")
***** Gamssulzen cave bear (''Ursus ingressus'')
***** Pleistocene small cave bear (''Ursus rossicus'')
***** Cave bear
The cave bear (''Ursus spelaeus'') is a prehistoric species of bear that lived in Europe and Asia during the Pleistocene and became extinct about 24,000 years ago during the Last Glacial Maximum.
Both the word ''cave'' and the scientific name '' ...
(''Ursus spelaeus'')
***** Giant polar bear (''Ursus maritimus tyrannus'')
**** Musteloidea
Musteloidea is a superfamily (taxonomy), superfamily of carnivoran mammals united by shared characteristics of the skull and teeth. Musteloids are the sister group of pinnipeds, the group which includes seals.
Musteloidea comprises the following ...
***** Mustelidae
The Mustelidae (; from Latin , weasel) are a diverse family of carnivora, carnivoran mammals, including weasels, badgers, otters, polecats, martens, grisons, and wolverines. Otherwise known as mustelids (), they form the largest family in the s ...
****** Several otter
Otters are carnivorous mammals in the subfamily Lutrinae. The 13 extant otter species are all semiaquatic, aquatic, or marine. Lutrinae is a branch of the Mustelidae family, which includes weasels, badgers, mink, and wolverines, among ...
(Lutrinae) spp.
******* Robust Pleistocene European otter (''Cyrnaonyx'')
******* '' Algarolutra''
******* Sardinian giant otter (''Megalenhydris barbaricina'')
******* Sardinian dwarf otter (''Sardolutra'')
******* Cretan otter (''Lutrogale cretensis'')
** ''Feliformia
Feliformia is a suborder within the order Carnivora consisting of "cat-like" carnivorans, including Felidae, cats (large and small), hyenas, mongooses, viverrids, and related taxa. Feliformia stands in contrast to the other suborder of Carnivora, ...
''
*** Various Felidae
Felidae ( ) is the Family (biology), family of mammals in the Order (biology), order Carnivora colloquially referred to as cats. A member of this family is also called a felid ( ).
The 41 extant taxon, extant Felidae species exhibit the gre ...
(cats) spp.
**** '' Homotherium latidens'' (sometimes called the scimitar-toothed cat)
**** Cave lynx (''Lynx pardinus spelaeus'')
**** Issoire lynx (''Lynx issiodorensis'')
**** ''Panthera
''Panthera'' is a genus within the family (biology), family Felidae, and one of two extant genera in the subfamily Pantherinae. It contains the largest living members of the cat family. There are five living species: the jaguar, leopard, lion, ...
'' spp.
***** Cave lion (''Panthera spelaea'')
***** European ice age leopard Leopards have a long history in Europe, spanning from the Early-Middle Pleistocene transition, around 1.2-0.6 million years ago, until the end of the Late Pleistocene, around 12,000 years ago, and possibly later into the early Holocene. Remains of ...
(''Panthera pardus spelaea'')
*** Hyaenidae (hyenas)
**** Cave hyena (''Crocuta crocuta spelaea'' and ''Crocuta crocuta ultima'')
****'' "Hyaena" prisca''
* All native Elephant
Elephants are the largest living land animals. Three living species are currently recognised: the African bush elephant ('' Loxodonta africana''), the African forest elephant (''L. cyclotis''), and the Asian elephant ('' Elephas maximus ...
(Elephantidae) spp.
** ''Mammoth
A mammoth is any species of the extinct elephantid genus ''Mammuthus.'' They lived from the late Miocene epoch (from around 6.2 million years ago) into the Holocene until about 4,000 years ago, with mammoth species at various times inhabi ...
s''
*** Woolly mammoth
The woolly mammoth (''Mammuthus primigenius'') is an extinct species of mammoth that lived from the Middle Pleistocene until its extinction in the Holocene epoch. It was one of the last in a line of mammoth species, beginning with the African ...
(''Mammuthus primigenius'')
*** Dwarf Sardinian mammoth (''Mammuthus lamarmorai'')
** Straight-tusked elephant
The straight-tusked elephant (''Palaeoloxodon antiquus'') is an extinct species of elephant that inhabited Europe and Western Asia during the Middle Pleistocene, Middle and Late Pleistocene. One of the largest known elephant species, mature full ...
(''Palaeoloxodon antiquus'') (Europe)
** '' Palaeoloxodon naumanni'' (Japan, possibly also Korea and northern China)
** '' Palaeoloxodon huaihoensis'' (China)
** Dwarf elephant
Dwarf elephants are prehistoric members of the order Proboscidea which, through the process of allopatric speciation on islands, evolved much smaller body sizes (around shoulder height) in comparison with their immediate ancestors. Dwarf elephant ...
*** '' Palaeoloxodon creutzburgi'' (Crete)
*** Cyprus dwarf elephant (''Palaeoloxodon cypriotes'')
*** '' Palaeoloxodon mnaidriensis'' (Sicily)
* Rodent
Rodents (from Latin , 'to gnaw') are mammals of the Order (biology), order Rodentia ( ), which are characterized by a single pair of continuously growing incisors in each of the upper and Mandible, lower jaws. About 40% of all mammal specie ...
s
** ''Allocricetus bursae''
** '' Cricetus major'' (alternatively ''Cricetus cricetus major'')
** '' Dicrostonyx gulielmi'' (ancestor to the Arctic lemming
The Arctic lemming (''Dicrostonyx torquatus'') is a species of rodent in the family Cricetidae.
Although generally classified as a "least concern" species, the Novaya Zemlya subspecies ''(Dicrostonyx torquatus ungulatus)'' is considered a vulne ...
)
** Giant Eurasian porcupine (''Hystrix refossa'')
** ''Leithia
''Leithia'' is an extinct genus of giant dormice from the Pleistocene of the Mediterranean islands of Malta and Sicily. It is considered an example of island gigantism. ''Leithia melitensis'' is the largest known species of dormouse, living or e ...
'' spp. (Maltese and Sicilian giant dormouse)
** '' Marmota paleocaucasica''
** '' Microtus grafi''
** ''Mimomys
''Mimomys'' is an extinct genus of voles that lived in Eurasia and North America during the Plio-Pleistocene. It is believed that one of the many species belonging to this genus gave rise to the modern water voles ''(Arvicola)''. Several other pr ...
'' spp.
*** ''M. pyrenaicus''
*** ''M. chandolensis''
** '' Pliomys lenki''
** '' Spermophilus citelloides''
** '' Spermophilus severskensis''
** '' Spermophilus superciliosus''
** '' Trogontherium cuvieri'' (large beaver)
** ''Lagomorpha
The lagomorphs () are the members of the taxonomic order Lagomorpha, of which there are two living families: the Leporidae (rabbits and hares) and the Ochotonidae ( pikas). There are 110 recent species of lagomorph, of which 109 species in t ...
''
*** '' Lepus tanaiticus'' (alternatively ''Lepus timidus tanaiticus'')
*** Pika
A pika ( , or ) is a small, mountain-dwelling mammal native to Asia and North America. With short limbs, a very round body, an even coat of fur, and no external tail, they resemble their close relative the rabbit, but with short, rounded ears. ...
(''Ochotona'') spp. e.g.
**** Giant pika (''Ochotona whartoni'')
*** ''Tonomochota'' spp.
**** ''T. khasanensis''
**** ''T. sikhotana''
**** ''T. major''
* Birds
** Yakutian goose (''Anser djuktaiensis'')
** East Asian Ostrich ('' Struthio anderssoni'')
** Various European crane spp. (Genus '' Grus'')
*** ''Grus primigenia''
*** ''Grus melitensis''
** Cretan owl (''Athene cretensis'')
*Primates
** ''Homo
''Homo'' () is a genus of great ape (family Hominidae) that emerged from the genus ''Australopithecus'' and encompasses only a single extant species, ''Homo sapiens'' (modern humans), along with a number of extinct species (collectively called ...
''
*** Denisovan
The Denisovans or Denisova hominins ( ) are an extinct species or subspecies of archaic human that ranged across Asia during the Lower and Middle Paleolithic, and lived, based on current evidence, from 285 thousand to 25 thousand years ago. D ...
s (''Homo'' sp.)
*** Neanderthals
Neanderthals ( ; ''Homo neanderthalensis'' or sometimes ''H. sapiens neanderthalensis'') are an extinction, extinct group of archaic humans who inhabited Europe and Western and Central Asia during the Middle Pleistocene, Middle to Late Plei ...
(''Homo'' (''sapiens'') ''neanderthalensis''; survived until about 40,000 years ago on the Iberian peninsula)
* Reptiles
** '' Solitudo sicula''; survived in Sicily
Sicily (Italian language, Italian and ), officially the Sicilian Region (), is an island in the central Mediterranean Sea, south of the Italian Peninsula in continental Europe and is one of the 20 regions of Italy, regions of Italy. With 4. ...
until about 12,500 years ago.
** '' Lacerta siculimelitensis''; from Malta
Malta, officially the Republic of Malta, is an island country in Southern Europe located in the Mediterranean Sea, between Sicily and North Africa. It consists of an archipelago south of Italy, east of Tunisia, and north of Libya. The two ...
.
Extinctions in North America were concentrated at the end of the Late Pleistocene, around 13,800–11,400 years Before Present, which were coincident with the onset of the
Younger Dryas
The Younger Dryas (YD, Greenland Stadial GS-1) was a period in Earth's geologic history that occurred circa 12,900 to 11,700 years Before Present (BP). It is primarily known for the sudden or "abrupt" cooling in the Northern Hemisphere, when the ...
cooling period, as well as the emergence of the hunter-gatherer Clovis culture
The Clovis culture is an archaeological culture from the Paleoindian period of North America, spanning around 13,050 to 12,750 years Before Present (BP). The type site is Blackwater Draw locality No. 1 near Clovis, New Mexico, where stone too ...
. The relative importance of human and climactic factors in the North American extinctions has been the subject of significant controversy. Extinctions totalled around 35 genera. The radiocarbon record for North America south of the Alaska-Yukon region has been described as "inadequate" to construct a reliable chronology.
North American extinctions (noted as herbivores
A herbivore is an animal anatomically and physiologically evolved to feed on plants, especially upon vascular tissues such as foliage, fruits or seeds, as the main component of its diet. These more broadly also encompass animals that eat ...
(H) or carnivores
A carnivore , or meat-eater (Latin, ''caro'', genitive ''carnis'', meaning meat or "flesh" and ''vorare'' meaning "to devour"), is an animal or plant whose nutrition and energy requirements are met by consumption of animal tissues (mainly mu ...
(C)) included:
* Ungulates
** ''Even-Toed Hoofed Mammals''
*** Various Bovidae
The Bovidae comprise the family (biology), biological family of cloven-hoofed, ruminant mammals that includes Bos, cattle, bison, Bubalina, buffalo, antelopes (including Caprinae, goat-antelopes), Ovis, sheep and Capra (genus), goats. A member o ...
spp.
**** Most forms of Pleistocene bison
A bison (: bison) is a large bovine in the genus ''Bison'' (from Greek, meaning 'wild ox') within the tribe Bovini. Two extant taxon, extant and numerous extinction, extinct species are recognised.
Of the two surviving species, the American ...
(only ''Bison bison'' in North America, and ''Bison bonasus'' in Eurasia, survived)
***** Ancient bison (''Bison antiquus'') (H)
***** Long-horned/Giant bison (''Bison latifrons'') (H)
***** Steppe bison
The steppe bison (''Bison'' ''priscus'', also less commonly known as the steppe wisent and the primeval bison) is an extinct species of bison which lived from the Middle Pleistocene to the Holocene. During the Late Pleistocene, it was widely dist ...
(''Bison priscus'') (H)
***** ''Bison occidentalis
''Bison occidentalis'' is an extinct species of bison that lived in North America, from about 11,700 to 5,000 years ago, spanning the end of the Pleistocene to the mid-Holocene.
Evolution
Some authors consider ''Bison occidentalis'' to be an i ...
'' (H)
**** Several members of ''Caprinae
The subfamily Caprinae, also sometimes referred to as the tribe Caprini, is part of the ruminant family Bovidae, and consists of mostly medium-sized bovids. A member of this subfamily is called a caprine.
Prominent members include sheep and g ...
'' (the muskox
The muskox (''Ovibos moschatus'') is a hoofed mammal of the family Bovidae. Native to the Arctic, it is noted for its thick coat and for the strong odor emitted by males during the seasonal rut, from which its name derives. This musky odor ha ...
survived)
***** Giant muskox (''Praeovibos priscus'') (H)
***** Shrub-ox (''Euceratherium collinum'') (H)
***** Harlan's muskox (''Bootherium bombifrons'') (H)
***** Soergel's ox (''Soergelia mayfieldi'') (H)
***** Harrington's mountain goat (''Oreamnos harringtoni''; smaller and more southern distribution than its surviving relative) (H)
**** Saiga antelope (''Saiga tatarica''; extirpated) (H)
*** Deer
**** Stag-moose (''Cervalces scotti'') (H)
**** American mountain deer (''Odocoileus lucasi'') (H)
**** '' Torontoceros hypnogeos'' (H)
*** Various Antilocapridae
The Antilocapridae are a family of ruminant artiodactyls endemic to North America. Their closest extant relatives are the giraffids. Only one species, the pronghorn (''Antilocapra americana''), is living today; all other members of the family ...
genera (pronghorn
The pronghorn (, ) (''Antilocapra americana'') is a species of artiodactyl (even-toed, hoofed) mammal indigenous to interior western and central North America. Though not an antelope, it is known colloquially in North America as the American ante ...
s survived)
**** ''Capromeryx'' (H)
**** ''Stockoceros
''Stockoceros'' is an extinct genus of the North American artiodactyl family Antilocapridae (pronghorns), known from what is now Mexico and the southwestern United States. The genus survived until about 12,000 years ago, and was present when Pale ...
'' (H)
**** ''Tetrameryx
''Tetrameryx'' is an extinct genus of the North American artiodactyl family Antilocapridae, known from Mexico, the western United States, and Saskatchewan in Canada.
Taxonomy
The name means "four ornedruminant", referring to the division of e ...
'' (H)
**** Pacific pronghorn (''Antilocapra pacifica'') (H)
*** Several peccary
Peccaries (also javelinas or skunk pigs) are pig-like ungulates of the family Tayassuidae (New World pigs). They are found throughout Central and South America, Trinidad in the Caribbean, and in the southwestern area of North America. Peccari ...
(Tayassuidae) spp.
**** Flat-headed peccary (''Platygonus'') (H)
**** Long-nosed peccary (''Mylohyus'') (H)
**** Collared peccary
The collared peccary (''Dicotyles tajacu'') is a peccary, a species of artiodactyl (even-toed) mammal in the family Peccary, Tayassuidae found in North America, North, Central America, Central, and South America. It is the only member of the gen ...
(''Dicotyles tajacu''; extirpated, range semi-recolonised) (H) (''Muknalia minimus'' is a junior synonym)
*** Various members of Camelidae
Camelids are members of the biological family Camelidae, the only currently living family in the suborder Tylopoda. The seven extant members of this group are: dromedary camels, Bactrian camels, wild Bactrian camels, llamas, alpacas, vicuñas ...
**** Western camel (''Camelops hesternus'') (H)
**** Stilt legged llamas (''Hemiauchenia'' ssp.) (H)
**** Stout legged llamas (''Palaeolama'' ssp.) (H)
** ''Odd-Toed Hoofed Mammals''
*** All native forms of Equidae
Equidae (commonly known as the horse family) is the Taxonomy (biology), taxonomic Family (biology), family of Wild horse, horses and related animals, including Asinus, asses, zebra, zebras, and many extinct species known only from fossils. The fa ...
**** Caballine true horses (''Equus cf. ferus'') from the Late Pleistocene of North America have historically been assigned to many different species, including '' Equus fraternus'', '' Equus scotti'' and '' Equus lambei,'' but the taxonomy of these horses is unclear, and many of these species may be synonymous with each other, perhaps only representing a single species.
**** Stilt-legged horse (''Haringtonhippus francisci'' / ''Equus francisci''; (H)
*** Tapirs (''Tapirus
''Tapirus'' is a genus of tapir which contains the living tapir species. The Malayan tapir is usually included in ''Tapirus'' as well, although some authorities have moved it into its own genus, ''Acrocodia''.
Extant species
The Kabomani tapir ...
''; three species)
**** California tapir
''Tapirus californicus'', the California tapir, is an extinct species of tapir that inhabited North America during the Pleistocene. It became extinct about 13,000 years ago.
Like other Perissodactyla, perissodactyls, tapirs originated in North A ...
(''Tapirus californicus'') (H)
**** Merriam's tapir (''Tapirus merriami'') (H)
**** Vero tapir (''Tapirus veroensis'') (H)
**Order Notoungulata
Notoungulata is an extinct order of ungulates that inhabited South America from the early Paleocene to the end of the Pleistocene, living from approximately 61 million to 11,000 years ago. Notoungulates were morphologically diverse, with forms re ...
*** '' Mixotoxodon'' (H)
* Carnivora
** ''Feliformia''
*** Several Felidae
Felidae ( ) is the Family (biology), family of mammals in the Order (biology), order Carnivora colloquially referred to as cats. A member of this family is also called a felid ( ).
The 41 extant taxon, extant Felidae species exhibit the gre ...
spp.
**** Sabertooths (Machairodontinae
Machairodontinae (from Ancient Greek μάχαιρα ''Makhaira, machaira,'' a type of Ancient Greek sword and ὀδόντος ''odontos'' meaning tooth) is an extinct subfamily of carnivoran mammals of the cat family Felidae, representing the ...
)
***** ''Smilodon fatalis
''Smilodon'' is an extinct genus of felids. It is one of the best known saber-toothed predators and prehistoric mammals. Although commonly known as the saber-toothed tiger, it was not closely related to the tiger or other modern cats, belon ...
'' (sabertooth cat) (C)
***** '' Homotherium serum'' scimitar-toothed cat (C)
**** American cheetah (''Miracinonyx trumani''; not true cheetah)
**** Cougar
The cougar (''Puma concolor'') (, ''Help:Pronunciation respelling key, KOO-gər''), also called puma, mountain lion, catamount and panther is a large small cat native to the Americas. It inhabits North America, North, Central America, Cent ...
(''Puma concolor''; megafaunal ecomorph
Ecomorphology or ecological morphology is the study of the relationship between the ecological role of an individual and its morphological adaptations. The term "morphological" here is in the anatomical context. Both the morphology and ecology ex ...
extirpated from North America, South American populations recolonised former range) (C)
**** Jaguarundi
The jaguarundi (''Herpailurus yagouaroundi''; or ) is a wild felidae, cat native to the Americas. Its range extends from central Argentina in the south to northern Mexico, through Central America, Central and South America east of the Andes. T ...
(''Herpailurus yagouaroundi''; extirpated, range semi-recolonised) (C)
**** Margay
The margay (''Leopardus wiedii'') is a small wild cat native to Mexico, Central and South America. A solitary and nocturnal felid, it lives mainly in primary evergreen and deciduous forest.
Until the 1990s, margays were hunted for the wildl ...
(''Leopardus weidii''; extirpated) (C)
**** Ocelot
The ocelot (''Leopardus pardalis'') is a medium-sized spotted Felidae, wild cat that reaches at the shoulders and weighs between on average. It is native to the southwestern United States, Mexico, Central America, Central and South America, ...
(''Leopardus pardalis''; extirpated, range marginally recolonised) (C)
**** Jaguar
The jaguar (''Panthera onca'') is a large felidae, cat species and the only extant taxon, living member of the genus ''Panthera'' that is native to the Americas. With a body length of up to and a weight of up to , it is the biggest cat spe ...
s
***** Pleistocene North American jaguar (''Panthera onca augusta''; range semi-recolonised by other subspecies) (C)
***** '' North America Jaguar''
***** '' Panthera balamoides'' (dubious, suggested to be a junior synonym of the short faced bear ''Arctotherium
''Arctotherium'' ("bear beast") is an extinct genus of the Pleistocene Tremarctinae, short-faced bears endemic to Central America, Central and South America. ''Arctotherium'' migrated from North America to South America during the Great American In ...
'')
**** Lion
The lion (''Panthera leo'') is a large Felidae, cat of the genus ''Panthera'', native to Sub-Saharan Africa and India. It has a muscular, broad-chested body (biology), body; a short, rounded head; round ears; and a dark, hairy tuft at the ...
s
***** American lion
The American lion (''Panthera atrox'' (), with the species name meaning "savage" or "cruel", also called the North American lion) is an extinct pantherine cat native to North America during the Late Pleistocene from around 129,000 to 12,800 y ...
(''Panthera atrox'') (C)
***** Cave lion (''Panthera spelaea''; present only in Alaska and Yukon) (C)
** ''Caniformia''
*** Canidae
**** Dire wolf
The dire wolf (''Aenocyon dirus'' ) is an Extinction, extinct species of Caninae, canine which was native to the Americas during the Late Pleistocene and Early Holocene epochs (125,000–10,000 years ago). The species was named in 1858, four y ...
(''Aenocyon dirus'') (C)
**** Pleistocene coyote (''Canis latrans orcutti'') (C)
**** Megafaunal wolf e.g.
***** Beringian wolf (''Canis lupus'' ssp.) (C)
**** Dhole
The dhole ( ; ''Cuon alpinus'') is a canid native to South, East and Southeast Asia. It is anatomically distinguished from members of the genus ''Canis'' in several aspects: its skull is convex rather than concave in profile, it lacks a third ...
(''Cuon alpinus''; extirpated) (C)
**** '' Protocyon troglodytes'' (C)
*** Arctoidea
**** Musteloidea
***** Mephitidae
****** Short-faced skunk (''Brachyprotoma obtusata'') (C)
***** Mustelidae
The Mustelidae (; from Latin , weasel) are a diverse family of carnivora, carnivoran mammals, including weasels, badgers, otters, polecats, martens, grisons, and wolverines. Otherwise known as mustelids (), they form the largest family in the s ...
****** Steppe polecat (''Mustela eversmanii''; extirpated) (C)
**** Various bear
Bears are carnivoran mammals of the family (biology), family Ursidae (). They are classified as caniforms, or doglike carnivorans. Although only eight species of bears are extant, they are widespread, appearing in a wide variety of habitats ...
(Ursidae) spp.
***** Arctodus simus'' (C)''
***** Florida spectacled bear (''Tremarctos floridanus'') (C)
***** South American short-faced bear (''Arctotherium wingei'') (C)
***** Giant polar bear (''Ursus maritimus tyrannus''; a possible inhabitant) (C)
* Afrotheria
** Paenungulata
*** Tethytheria
**** ''All native spp. of Proboscidea
Proboscidea (; , ) is a taxonomic order of afrotherian mammals containing one living family (Elephantidae) and several extinct families. First described by J. Illiger in 1811, it encompasses the elephants and their close relatives. Three l ...
''
***** Mastodons
****** American mastodon (''Mammut americanum'') (H)
****** Pacific mastodon (''Mammut pacificus'') (H) (validity uncertain)
***** Gomphotheriidae
Gomphotheres are an extinct group of proboscideans related to modern elephants. First appearing in Africa during the Oligocene, they dispersed into Eurasia and North America during the Miocene and arrived in South America during the Pleistocene ...
spp.
****** ''Cuvieronius
''Cuvieronius'' is an extinct New World genus of gomphothere which ranged from southern North America to western South America during the Pleistocene epoch. Reaching a shoulder height of and a body mass of , it was on average shorter but compara ...
'' (H)
***** Mammoth
A mammoth is any species of the extinct elephantid genus ''Mammuthus.'' They lived from the late Miocene epoch (from around 6.2 million years ago) into the Holocene until about 4,000 years ago, with mammoth species at various times inhabi ...
(''Mammuthus'') spp.
****** Columbian mammoth (''Mammuthus columbi'') (H)
****** Pygmy mammoth (''Mammuthus exilis'') (H)
****** Woolly mammoth
The woolly mammoth (''Mammuthus primigenius'') is an extinct species of mammoth that lived from the Middle Pleistocene until its extinction in the Holocene epoch. It was one of the last in a line of mammoth species, beginning with the African ...
(''Mammuthus primigenius'') (H)
**** ''Sirenia
The Sirenia (), commonly referred to as sea cows or sirenians, are an order of fully aquatic, herbivorous mammals that inhabit swamps, rivers, estuaries, marine wetlands, and coastal marine waters. The extant Sirenia comprise two distinct famili ...
''
***** Dugongidae
Dugongidae is a Family (biology), family in the Order (biology), order of Sirenia. The family has one surviving species, the dugong (''Dugong dugon''), one recently Extinction, extinct species, Steller's sea cow (''Hydrodamalis gigas''), and a n ...
****** Steller's sea cow
Steller's sea cow (''Hydrodamalis gigas'') is an extinction, extinct sirenian described by Georg Wilhelm Steller in 1741. At that time, it was found only around the Commander Islands in the Bering Sea between Alaska and Russia; its range exte ...
(''Hydrodamalis gigas''; extirpated from North America, survived in Beringia into 18th century) (H)
* Euarchontoglires
** Bat
Bats are flying mammals of the order Chiroptera (). With their forelimbs adapted as wings, they are the only mammals capable of true and sustained flight. Bats are more agile in flight than most birds, flying with their very long spread-out ...
s
*** Stock's vampire bat (''Desmodus stocki'') (C)
*** Pristine mustached bat (''Pteronotus'' (''Phyllodia'') ''pristinus'') (C)
** Rodents
*** Giant beaver (''Castoroides'') spp.
**** '' Castoroides ohioensis'' (H)
**** '' Castoroides leiseyorum'' (H)
*** Klein's porcupine (''Erethizon kleini'') (H)
*** Giant island deer mouse (''Peromyscus nesodytes'') (C)
*** '' Neochoerus'' spp. e.g.
**** Pinckney's capybara (''Neochoerus pinckneyi'') (H)
**** '' Neochoerus aesopi'' (H)
*** '' Neotoma findleyi''
*** '' Neotoma pygmaea''
*** '' Synaptomys australis''
*** All giant hutia ''(Heptaxodontidae) spp.''
**** Blunt-toothed giant hutia (''Amblyrhiza inundata''; could grow as large as an American black bear
The American black bear (''Ursus americanus''), or simply black bear, is a species of medium-sized bear which is Endemism, endemic to North America. It is the continent's smallest and most widely distributed bear species. It is an omnivore, with ...
) (H)
**** Plate-toothed giant hutia (''Elasmodontomys obliquus'') (H)
**** Twisted-toothed mouse (''Quemisia gravis'') (H)
**** Osborn's key mouse (''Clidomys osborn's'') (H)
**** ''Xaymaca fulvopulvis'' (H)
** Lagomorphs
*** Aztlan rabbit (''Aztlanolagus'' sp.) (H)
*** Giant pika (''Ochotona whartoni'') (H)
* Eulipotyphla
** '' Notiosorex dalquesti''
** '' Notiosorex harrisi''
* Xenarthra
Xenarthra (; from Ancient Greek ξένος, xénos, "foreign, alien" + ἄρθρον, árthron, "joint") is a superorder and major clade of placental mammals native to the Americas. There are 31 living species: the anteaters, tree sloths, and ...
** Pilosa
The Order (biology), order Pilosa is a clade of xenarthran placental mammals, native to the Americas. It includes anteaters and sloths (which include the extinct ground sloths). The name comes from the Latin word for "hairy".
Origins and taxon ...
*** Giant anteater
The giant anteater (''Myrmecophaga tridactyla'') is an Insectivore, insectivorous mammal native to Central America, Central and South America. It is the largest of the four living species of anteaters, which are classified with sloths in the or ...
(''Myrmecophaga tridactyla''; extirpated, range partially recolonised) (C)
*** All remaining ground sloth
Ground sloths are a diverse group of extinct sloths in the mammalian superorder Xenarthra. They varied widely in size with the largest, belonging to genera '' Lestodon'', ''Eremotherium'' and ''Megatherium'', being around the size of elephants. ...
spp.
**** ''Eremotherium
''Eremotherium'' (from Greek for "steppe" or "desert" "beast": ἔρημος "steppe or desert" and θηρίον "beast") is an extinct genus of giant ground sloth in the family Megatheriidae. ''Eremotherium'' lived in southern North America, Cen ...
'' ( megatheriid giant ground sloth) (H)
**** '' Nothrotheriops'' ( nothrotheriid ground sloth) (H)
**** Megalonychid ground sloth spp.
***** '' Megalonyx'' (H)
***** '' Nohochichak'' (H)
***** '' Xibalbaonyx'' (H)
***** '' Meizonyx''
**** Mylodontid ground sloth spp.
***** '' Paramylodon'' (H)
** Cingulata
*** All members of '' Glyptodontinae''
**** '' Glyptotherium'' (H)
*** Beautiful armadillo (''Dasypus bellus'') (H)
*** '' Pachyarmatherium''
*** All '' Pampatheriidae'' spp.
**** '' Holmesina'' (H)
**** '' Pampatherium'' (H)
* Birds
** ''Water Fowl''
*** Ducks
**** Bermuda flightless duck (''Anas pachyscelus'') (H)
**** Californian flightless sea duck (''Chendytes lawi'') (C)
**** Mexican stiff-tailed duck (''Oxyura zapatima'') (H)
*** '' Neochen barbadiana'' (H)
** ''Turkey
Turkey, officially the Republic of Türkiye, is a country mainly located in Anatolia in West Asia, with a relatively small part called East Thrace in Southeast Europe. It borders the Black Sea to the north; Georgia (country), Georgia, Armen ...
(''Meleagris'') spp.''
*** Californian turkey (''Meleagris californica'') (H)
*** ''Meleagris crassipes'' (H)
** ''Various Gruiformes
The Gruiformes ( ) are an order containing a considerable number of living and extinct bird families, with a widespread geographical diversity. Gruiform means "crane-like".
Traditionally, a number of wading and terrestrial bird families that ...
spp.''
*** All cave rail (''Nesotrochis'') spp. e.g.
**** Antillean cave rail (''Nesotrochis debooyi'') (C)
*** Barbados rail (Incertae sedis
or is a term used for a taxonomy (biology), taxonomic group where its broader relationships are unknown or undefined. Alternatively, such groups are frequently referred to as "enigmatic taxa". In the system of open nomenclature, uncertainty ...
) (C)
*** Cuban flightless crane (''Antigone cubensis'') (H)
*** La Brea crane (''Grus pagei'') (H)
** ''Various flamingo
Flamingos or flamingoes () are a type of wading bird in the family Phoenicopteridae, which is the only extant family in the order Phoenicopteriformes. There are four flamingo species distributed throughout the Americas (including the Caribbe ...
(Phoenicopteridae) spp.''
*** Minute flamingo (''Phoenicopterus minutus'') (C)
*** Cope's flamingo (''Phoenicopterus copei'') (C)
** Dow's puffin (''Fratercula dowi'') (C)
** Pleistocene Mexican diver spp.
***''Plyolimbus baryosteus'' (C)
*** ''Podiceps
''Podiceps'' is a genus of birds in the grebe family. The genus name comes from Latin , "rear-end" and ', "foot", and is a reference to the placement of a grebe's legs towards the rear of its body.
It has representatives breeding in all contine ...
'' spp.
****''Podiceps parvus'' (C)
** Stork
Storks are large, long-legged, long-necked wading birds with long, stout bills. They belong to the family Ciconiidae, and make up the order Ciconiiformes . Ciconiiformes previously included a number of other families, such as herons and ibise ...
s
*** La Brea/Asphalt stork (''Ciconia maltha'') (C)
*** Wetmore's stork (''Mycteria wetmorei'') (C)
** Pleistocene Mexican cormorant
Phalacrocoracidae is a family of approximately 40 species of aquatic birds commonly known as cormorants and shags. Several different classifications of the family have been proposed, but in 2021 the International Ornithologists' Union (IOU) ado ...
s spp. (genus '' Phalacrocorax'')
***''Phalacrocorax goletensis'' (C)
*** ''Phalacrocorax chapalensis'' (C)
** All remaining teratorn (Teratornithidae) spp.
*** ''Aiolornis incredibilis'' (C)
*** ''Cathartornis gracilis'' (C)
*** ''Oscaravis olsoni'' (C)
*** ''Teratornis merriami'' (C)
*** ''Teratornis woodburnensis'' (C)
** Several New World vultures (Cathartidae) spp.
*** Pleistocene black vulture (''Coragyps occidentalis'' ssp.) (C)
*** Megafaunal Californian condor (''Gymnogyps amplus'') (C)
*** Clark's condor (''Breagyps clarki'') (C)
*** Cuban condor (''Gymnogyps varonai'') (C)
** Several Accipitridae
The Accipitridae () is one of the four families within the order Accipitriformes, and is a family of small to large birds of prey with strongly hooked bills and variable morphology based on diet. They feed on a range of prey items from insects ...
spp.
*** American neophrone vulture (''Neophrontops americanus'') (C)
*** Woodward's eagle (''Amplibuteo woodwardi'') (C)
*** Cuban great hawk (''Buteogallus borrasi'') (C)
*** Daggett's eagle (''Buteogallus daggetti'') (C)
*** Fragile eagle (''Buteogallus fragilis'') (C)
*** Cuban giant hawk (''Gigantohierax suarezi'') (C)
*** Errant eagle (''Neogyps errans'') (C)
*** Grinnell's crested eagle (''Spizaetus grinnelli'') (C)
*** Willett's hawk-eagle (''Spizaetus willetti'') (C)
*** Caribbean titan hawk (''Titanohierax'') (C)
** Several owl
Owls are birds from the order Strigiformes (), which includes over 200 species of mostly solitary and nocturnal birds of prey typified by an upright stance, a large, broad head, binocular vision, binaural hearing, sharp talons, and feathers a ...
(Strigiformes) spp.
*** Brea miniature owl (''Asphaltoglaux'') (C)
*** Kurochkin's pygmy owl (''Glaucidium kurochkini'') (C)
*** Brea owl (''Oraristix brea'') (C)
*** Cuban giant owl (''Ornimegalonyx'') (C)
** Bermuda flicker (''Colaptes oceanicus'') (C)
** Several caracara (Caracarinae) spp.
*** Bahaman terrestrial caracara ('' Caracara'' sp.) (C)
*** Puerto Rican terrestrial caracara ('' Caracara'' sp.) (C)
*** Jamaican caracara (''Carcara tellustris'') (C)
*** Cuban caracara ('' Milvago'' sp.) (C)
*** Hispaniolan caracara ('' Milvago'' sp.) (C)
** Psittacopasserae
*** Psittaciformes
**** Mexican thick-billed parrot (''Rhynchopsitta phillipsi'') (H)
* Several giant tortoise
Giant tortoises are any of several species of various large land tortoises, which include a number of extinct species, as well as two extant species with multiple subspecies formerly common on the islands of the western Indian Ocean and on the ...
spp.
** '' Hesperotestudo'' (H)
** ''Gopherus
''Gopherus'' is a genus of fossorial tortoises commonly referred to as gopher tortoises. The gopher tortoise is grouped with land tortoises that originated 60 million years ago, in North America. A genetic study has shown that their closest relat ...
'' spp.
*** '' Gopherus donlaloi'' (H)
** '' Chelonoidis'' spp.
*** '' Chelonoidis marcanoi'' (H)
*** '' Chelonoidis alburyorum'' (H)
The survivors are in some ways as significant as the losses: bison
A bison (: bison) is a large bovine in the genus ''Bison'' (from Greek, meaning 'wild ox') within the tribe Bovini. Two extant taxon, extant and numerous extinction, extinct species are recognised.
Of the two surviving species, the American ...
(H), grey wolf
The wolf (''Canis lupus''; : wolves), also known as the grey wolf or gray wolf, is a canine native to Eurasia and North America. More than thirty subspecies of ''Canis lupus'' have been recognized, including the dog and dingo, though gr ...
(C), lynx
A lynx ( ; : lynx or lynxes) is any of the four wikt:extant, extant species (the Canada lynx, Iberian lynx, Eurasian lynx and the bobcat) within the medium-sized wild Felidae, cat genus ''Lynx''. The name originated in Middle Engl ...
(C), grizzly bear
The grizzly bear (''Ursus arctos horribilis''), also known as the North American brown bear or simply grizzly, is a population or subspecies of the brown bear inhabiting North America.
In addition to the mainland grizzly (''Ursus arctos horr ...
(C), American black bear
The American black bear (''Ursus americanus''), or simply black bear, is a species of medium-sized bear which is Endemism, endemic to North America. It is the continent's smallest and most widely distributed bear species. It is an omnivore, with ...
(C), deer
A deer (: deer) or true deer is a hoofed ruminant ungulate of the family Cervidae (informally the deer family). Cervidae is divided into subfamilies Cervinae (which includes, among others, muntjac, elk (wapiti), red deer, and fallow deer) ...
(e.g. caribou
The reindeer or caribou (''Rangifer tarandus'') is a species of deer with circumpolar distribution, native to Arctic, subarctic, tundra, boreal, and mountainous regions of Northern Europe, Siberia, and North America. It is the only represe ...
, moose
The moose (: 'moose'; used in North America) or elk (: 'elk' or 'elks'; used in Eurasia) (''Alces alces'') is the world's tallest, largest and heaviest extant species of deer and the only species in the genus ''Alces''. It is also the tal ...
, wapiti (elk), '' Odocoileus'' spp.) (H), pronghorn
The pronghorn (, ) (''Antilocapra americana'') is a species of artiodactyl (even-toed, hoofed) mammal indigenous to interior western and central North America. Though not an antelope, it is known colloquially in North America as the American ante ...
(H), white-lipped peccary (H), muskox
The muskox (''Ovibos moschatus'') is a hoofed mammal of the family Bovidae. Native to the Arctic, it is noted for its thick coat and for the strong odor emitted by males during the seasonal rut, from which its name derives. This musky odor ha ...
(H), bighorn sheep
The bighorn sheep (''Ovis canadensis'') is a species of Ovis, sheep native to North America. It is named for its large Horn (anatomy), horns. A pair of horns may weigh up to ; the sheep typically weigh up to . Recent genetic testing indicates th ...
(H), and mountain goat
The mountain goat (''Oreamnos americanus''), also known as the Rocky Mountain goat, is a cloven-footed mammal that is endemic to the remote and rugged mountainous areas of western North America. A subalpine to truly alpine species, it is a s ...
(H); the list of survivors also include species which were extirpated during the Quaternary extinction event, but recolonised at least part of their ranges during the mid-Holocene from South American relict populations, such as the cougar
The cougar (''Puma concolor'') (, ''Help:Pronunciation respelling key, KOO-gər''), also called puma, mountain lion, catamount and panther is a large small cat native to the Americas. It inhabits North America, North, Central America, Cent ...
(C), jaguar
The jaguar (''Panthera onca'') is a large felidae, cat species and the only extant taxon, living member of the genus ''Panthera'' that is native to the Americas. With a body length of up to and a weight of up to , it is the biggest cat spe ...
(C), giant anteater
The giant anteater (''Myrmecophaga tridactyla'') is an Insectivore, insectivorous mammal native to Central America, Central and South America. It is the largest of the four living species of anteaters, which are classified with sloths in the or ...
(C), collared peccary
The collared peccary (''Dicotyles tajacu'') is a peccary, a species of artiodactyl (even-toed) mammal in the family Peccary, Tayassuidae found in North America, North, Central America, Central, and South America. It is the only member of the gen ...
(H), ocelot
The ocelot (''Leopardus pardalis'') is a medium-sized spotted Felidae, wild cat that reaches at the shoulders and weighs between on average. It is native to the southwestern United States, Mexico, Central America, Central and South America, ...
(C) and jaguarundi
The jaguarundi (''Herpailurus yagouaroundi''; or ) is a wild felidae, cat native to the Americas. Its range extends from central Argentina in the south to northern Mexico, through Central America, Central and South America east of the Andes. T ...
(C). All save the pronghorns and giant anteaters were descended from Asian ancestors that had evolved with human predators. Pronghorns are the second-fastest land mammal (after the cheetah
The cheetah (''Acinonyx jubatus'') is a large Felidae, cat and the Fastest animals, fastest land animal. It has a tawny to creamy white or pale buff fur that is marked with evenly spaced, solid black spots. The head is small and rounded, wit ...
), which may have helped them elude hunters. More difficult to explain in the context of overkill is the survival of bison, since these animals first appeared in North America less than 240,000 years ago and so were geographically removed from human predators for a sizeable period of time. Because ancient bison evolved into living bison, there was no continent-wide extinction of bison at the end of the Pleistocene (although the genus was regionally extirpated in many areas). The survival of bison into the Holocene and recent times is therefore inconsistent with the overkill scenario. By the end of the Pleistocene, when humans first entered North America, these large animals had been geographically separated from intensive human hunting for more than 200,000 years. Given this enormous span of geologic time, bison would almost certainly have been very nearly as naive as native North American large mammals.
The culture that has been connected with the wave of extinctions in North America is the paleo-American culture associated with the Clovis people (''q.v.''), who were thought to use spear throwers to kill large animals. The chief criticism of the "prehistoric overkill hypothesis" has been that the human population at the time was too small and/or not sufficiently widespread geographically to have been capable of such ecologically significant impacts. This criticism does not mean that climate change scenario
A climate change scenario is a hypothetical future based on a "set of key driving forces".IPCC, 2022Annex I: Glossary an Diemen, R., J.B.R. Matthews, V. Möller, J.S. Fuglestvedt, V. Masson-Delmotte, C. Méndez, A. Reisinger, S. Semenov (eds) In ...
s explaining the extinction are automatically to be preferred by default, however, any more than weaknesses in climate change arguments can be taken as supporting overkill. Some form of a combination of both factors could be plausible, and overkill would be a lot easier to achieve large-scale extinction with an already stressed population due to climate change.
South America
South America suffered among the worst losses of the continents, with around 83% of its megafauna going extinct. These extinctions postdate the arrival of modern humans in South America around 15,000 years ago. Both human and climatic factors have been attributed as factors in the extinctions by various authors. Although some megafauna has been historically suggested to have survived into the early Holocene based on radiocarbon dates this may be the result of dating errors due to contamination. The extinctions are coincident with the end of the Antarctic Cold Reversal (a cooling period earlier and less severe than the Northern Hemisphere Younger Dryas) and the emergence of Fishtail projectile points, which became widespread across South America. Fishtail projectile points are thought to have been used in big game hunting, though direct evidence of exploitation of extinct megafauna by humans is rare, though megafauna exploitation has been documented at a number of sites. Fishtail points rapidly disappeared after the extinction of the megafauna, and were replaced by other styles more suited to hunting smaller prey. Some authors have proposed the "Broken Zig-Zag" model, where human hunting and climate change causing a reduction in open habitats preferred by megafauna were synergistic factors in megafauna extinction in South America.
* Ungulates
** ''Even-Toed Hoofed Mammals''
*** Several Cervidae (deer) spp.
**** '' Morenelaphus''
**** '' Antifer''
**** '' Agalmaceros blicki'' (potentially synonym of modern white-tailed deer
The white-tailed deer (''Odocoileus virginianus''), also known Common name, commonly as the whitetail and the Virginia deer, is a medium-sized species of deer native to North America, North, Central America, Central and South America. It is the ...
)
**** '' Odocoileus salinae''
*** Various Camelidae
Camelids are members of the biological family Camelidae, the only currently living family in the suborder Tylopoda. The seven extant members of this group are: dromedary camels, Bactrian camels, wild Bactrian camels, llamas, alpacas, vicuñas ...
spp.
**** '' Eulamaops''
**** Stilt legged llama '' Hemiauchenia''
**** Stout legged llama '' Palaeolama''
** ''Odd-Toed Hoofed Mammals''
*** Several species of tapirs (Tapir
Tapirs ( ) are large, herbivorous mammals belonging to the family Tapiridae. They are similar in shape to a Suidae, pig, with a short, prehensile nose trunk (proboscis). Tapirs inhabit jungle and forest regions of South America, South and Centr ...
idae)
**** ''Tapirus cristatellus''
*** All Pleistocene wild horse genera (Equidae
Equidae (commonly known as the horse family) is the Taxonomy (biology), taxonomic Family (biology), family of Wild horse, horses and related animals, including Asinus, asses, zebra, zebras, and many extinct species known only from fossils. The fa ...
)
**** '' Equus neogeus''
**** ''Hippidion
''Hippidion'' (meaning ''little horse'') is an extinct genus of equine that lived in South America from the Late Pliocene to the end of the Late Pleistocene (Lujanian), between 2.5 million and 11,000 years ago. They were one of two lineages of eq ...
''
***** ''Hippidion devillei''
***** ''Hippidion principale''
***** ''Hippidion saldiasi''
** ''All remaining Meridiungulata
South American native ungulates, commonly abbreviated as SANUs, are extinct ungulate-like mammals that were indigenous to South America from the Paleocene (from at least 63 million years ago) until the end of the Late Pleistocene (~12,000 years a ...
genera''
*** Order Litopterna
Litopterna (from "smooth heel") is an extinction, extinct order of South American native ungulates that lived from the Paleocene to the Pleistocene-Holocene around 62.5 million to 12,000 years ago (or possibly as late as 3,500 years ago), and we ...
**** Macraucheniidae
Macraucheniidae is a family in the extinct South American ungulate order Litopterna, that resembled camelids. They had three functional digits on the fore and hind feet, as well as elongate necks. The family is generally divided up into two sub ...
***** ''Macrauchenia
''Macrauchenia'' ("long llama", based on the now-invalid llama genus, ''Auchenia'', from Greek "big neck") is an extinct genus of large ungulate native to South America from the Pliocene or Middle Pleistocene to the end of the Late Pleistocene. I ...
''
***** '' Macraucheniopsis''
***** ''Xenorhinotherium
''Xenorhinotherium'' is an extinct genus of macraucheniine macraucheniids, native to northern South America during the Pleistocene and Holocene epoch, closely related to ''Macrauchenia'' of Patagonia. The type species is ''X. bahiense''.
''
**** Proterotheriidae
Proterotheriidae is an extinction, extinct family of Litopterna, litoptern ungulates known from the Eocene-Late Pleistocene of South America. Members of the group were small-medium sized cursorial Herbivore, herbivores with brachydont Tooth, teet ...
***** '' Neolicaphrium recens''
*** Order Notoungulata
Notoungulata is an extinct order of ungulates that inhabited South America from the early Paleocene to the end of the Pleistocene, living from approximately 61 million to 11,000 years ago. Notoungulates were morphologically diverse, with forms re ...
**** Toxodontidae
Toxodontidae is an extinct family of notoungulate mammals, known from the Oligocene to the Holocene (11,000 BP) of South America, with one genus, '' Mixotoxodon'', also known from the Pleistocene of Central America and southern North America (a ...
***** '' Piauhytherium'' (Some authors regard this taxon as synonym
A synonym is a word, morpheme, or phrase that means precisely or nearly the same as another word, morpheme, or phrase in a given language. For example, in the English language, the words ''begin'', ''start'', ''commence'', and ''initiate'' are a ...
of '' Trigodonops'')
***** '' Mixotoxodon''
***** '' Toxodon''
***** '' Trigodonops''
* Primates
** Platyrrhini (New World monkeys)
*** Atelidae
The Atelidae are one of the five families of New World monkeys now recognised. It was formerly included in the family Cebidae. Atelids are generally larger monkeys; the family includes the howler, spider, woolly, and woolly spider monkeys (t ...
**** '' Protopithecus''
**** '' Caipora''
**** '' Cartelles''
**** '' Alouatta mauroi''
* Carnivora
** ''Feliformia''
*** Several ''Felidae
Felidae ( ) is the Family (biology), family of mammals in the Order (biology), order Carnivora colloquially referred to as cats. A member of this family is also called a felid ( ).
The 41 extant taxon, extant Felidae species exhibit the gre ...
'' spp.
**** Saber-toothed cat
Machairodontinae (from Ancient Greek μάχαιρα '' machaira,'' a type of Ancient Greek sword and ὀδόντος ''odontos'' meaning tooth) is an extinct subfamily of carnivoran mammals of the cat family Felidae, representing the earliest ...
(''Smilodon'') spp.
***** ''Smilodon fatalis'' (northwestern South America)
***** ''Smilodon populator'' (eastern and southern South America)
**** Patagonian jaguar ('' Panthera onca mesembrina'') (some authors have suggested that these remains actually belong to the American lion
The American lion (''Panthera atrox'' (), with the species name meaning "savage" or "cruel", also called the North American lion) is an extinct pantherine cat native to North America during the Late Pleistocene from around 129,000 to 12,800 y ...
instead)
** ''Caniformia''
*** Canidae
**** Dire wolf ('' Aenocyon dirus'')
**** Nehring's wolf ('' Canis nehringi'')
**** '' Protocyon''
**** Pleistocene bush dog ('' Speothos pacivorus'')
*** Ursidae (bears)
**** South American short-faced bear (''Arctotherium
''Arctotherium'' ("bear beast") is an extinct genus of the Pleistocene Tremarctinae, short-faced bears endemic to Central America, Central and South America. ''Arctotherium'' migrated from North America to South America during the Great American In ...
'' spp.)
***** '' Arctotherium bonairense''
***** '' Arctotherium tarijense''
***** '' Arctotherium wingei''
* Rodents
** '' Neochoerus''
* Bats
** Giant vampire bat ('' Desmodus draculae'')
*Proboscidea (elephants and relatives)
** Gomphotheridae
*** ''Cuvieronius
''Cuvieronius'' is an extinct New World genus of gomphothere which ranged from southern North America to western South America during the Pleistocene epoch. Reaching a shoulder height of and a body mass of , it was on average shorter but compara ...
''
*** ''Notiomastodon
''Notiomastodon'' is an extinct genus of gomphothere proboscidean (related to modern elephants), endemic to South America from the Pleistocene to the early Holocene. ''Notiomastodon'' specimens reached a size similar to that of the modern Asian ...
''
* Xenarthrans
** All remaining ground sloth
Ground sloths are a diverse group of extinct sloths in the mammalian superorder Xenarthra. They varied widely in size with the largest, belonging to genera '' Lestodon'', ''Eremotherium'' and ''Megatherium'', being around the size of elephants. ...
genera
*** Megatheriidae
Megatheriidae is a family of Extinction, extinct ground sloths that lived from approximately 23 Annum, mya—11,000 years ago.
Megatheriids appeared during the Oligocene, Late Oligocene (Deseadan in the South American land mammal age, SALMA cl ...
spp.
**** ''Eremotherium
''Eremotherium'' (from Greek for "steppe" or "desert" "beast": ἔρημος "steppe or desert" and θηρίον "beast") is an extinct genus of giant ground sloth in the family Megatheriidae. ''Eremotherium'' lived in southern North America, Cen ...
''
**** ''Megatherium
''Megatherium'' ( ; from Greek () 'great' + () 'beast') is an extinct genus of ground sloths endemic to South America that lived from the Early Pliocene through the end of the Late Pleistocene. It is best known for the elephant-sized type spe ...
''
*** Nothrotheriidae
Nothrotheriidae is a family of extinct ground sloths that lived from approximately 17.5 mya—10,000 years ago, existing for approximately . Previously placed within the tribe Nothrotheriini or subfamily Nothrotheriinae within Megatheriidae, they ...
spp.
**** '' Nothropus''
**** '' Nothrotherium''
*** Megalonychidae spp.
**** '' Ahytherium''
**** '' Australonyx''
**** '' Diabolotherium''
**** '' Megistonyx''
*** Mylodontidae
Mylodontidae is a family of extinct South American and North American ground sloths within the suborder Folivora of order Pilosa, living from around 23 million years ago (Mya) to 11,000 years ago. This family is most closely related to another fa ...
spp. (including Scelidotheriinae)
**** '' Catonyx''
**** '' Glossotherium''
**** '' Lestodon''
**** '' Mylodon''
**** '' Scelidotherium''
**** '' Scelidodon''
**** '' Mylodonopsis''
**** '' Ocnotherium''
**** '' Valgipes''
** All remaining Glyptodontinae spp.
*** '' Doedicurus''
*** '' Glyptodon''
*** '' Hoplophorus''
*** '' Lomaphorus''
*** '' Neosclerocalyptus''
*** ''Neuryurus
''Neuryurus'' is an extinct genus of glyptodont. It lived from the Late Pliocene to the Early Holocene, and its fossilized remains were discovered in South America.
Description
This genus, like all glyptodonts, had a heavy armor formed by oste ...
''
*** '' Panochthus''
*** '' Parapanochthus''? (has been described as "doubtful")
*** ''Plaxhaplous
''Plaxhaplous'' was a genus of glyptodont, an extinct relative of the modern armadillo. It lived in the Pleistocene epoch. The type species is ''Plaxhaplous canaliculatus''. ''Plaxhaplous canaliculatus'' fossils were found in Argentina, near Luj ...
''
*** '' Sclerocalyptus''
** Several Dasypodidae spp.
*** Beautiful armadillo ('' Dasypus bellus'')
*** '' Eutatus''
*** '' Pachyarmatherium''
*** '' Propaopus''
** All Pampatheriidae spp.
*** '' Holmesina'' (et ''Chlamytherium occidentale'')
*** '' Pampatherium''
*** '' Tonnicinctus''
* Birds
** Various Caracarinae spp.
*** Venezuelan caracara ('' Caracara major'')
*** Seymour's caracara ('' Caracara seymouri'')
*** Peruvian caracara ('' Milvago brodkorbi'')
** Various ''Cathartidae
Cathartidae, known commonly as New World vultures or condors, are a family of birds of prey consisting of seven extant species in five genera. It includes five extant vultures and two extant condors found in the Americas. They are known as "New W ...
spp.''
*** '' Pampagyps imperator''
*** '' Geronogyps reliquus''
*** '' Wingegyps cartellei''
*** '' Pleistovultur nevesi''
** Various Tadorninae
The Tadornini is a biological tribe that includes the shelducks and sheldgeese, which is placed in subfamily Anatinae of family Anatinae, which includes the ducks and most duck-like waterfowl such as the geese and swans. It has been treated a ...
spp.
*** '' Neochen pugil''
** '' Psilopterus'' (small terror bird remains dated to the Late Pleistocene, but these are disputed)
* Reptiles
* Crocs & Gators
** '' Caiman venezuelensis''
* Testudines
Turtles are reptiles of the order (biology), order Testudines, characterized by a special turtle shell, shell developed mainly from their ribs. Modern turtles are divided into two major groups, the Pleurodira (side necked turtles) and Crypt ...
** '' Chelonoidis lutzae'' (Argentina)
** '' Peltocephalus maturin''
Sahul (Australia-New Guinea) and the Pacific
Extinction of Australian megafauna appears to have taken place earlier than in the Americas or the extinction of the Eurasian mammoth steppe fauna, with an estimated peak of extinction of around 42,000 years ago. Debate on megafaunal extinction in Australia has historically centred on whether the extinctions were caused by humans (which most sources estimate arrived in Australia at least 50,000 years ago, spreading to Tasmania later around 42-41,000 years ago), or whether many megafauna species had already gone extinct prior to human arrival due to climatic change. Resolution of this debate has been hampered by the rare and poorly dated nature of Australian megafauna remains. Studies from the late 2010s onward suggested that many megafauna species survived later than previously assumed by some authors, and were contemporaneous with humans in Australia, though some studies still argue that climate change was the primary cause of their extinction. There is little evidence of human interaction with extinct Australian megafauna, with one notable exception being the burning of ''Genyornis
''Genyornis newtoni'' is an extinct species of large, flightless bird that lived in Australia during the Pleistocene Epoch until around 50,000 years ago. Over two metres in height, they were likely herbivorous. Many other species of Austral ...
'' (a type of giant dromornithid bird related to ducks) eggshells. Megafauna species may have survived considerably later in New Guinea, until the Last Glacial Maximum
The Last Glacial Maximum (LGM), also referred to as the Last Glacial Coldest Period, was the most recent time during the Last Glacial Period where ice sheets were at their greatest extent between 26,000 and 20,000 years ago.
Ice sheets covered m ...
.
* Marsupial
Marsupials are a diverse group of mammals belonging to the infraclass Marsupialia. They are natively found in Australasia, Wallacea, and the Americas. One of marsupials' unique features is their reproductive strategy: the young are born in a r ...
s
** All remaining members of Diprotodontidae
Diprotodontidae is an extinct family of large herbivorous marsupials, endemic to Australia and New Guinea during the Oligocene through Pleistocene periods from 28.4 million to 40,000 years ago.
Description
The family primarily consisted of lar ...
*** '' Diprotodon'' (largest known marsupial)
*** '' Hulitherium tomasetti''
*** '' Maokopia ronaldi''
*** ''Zygomaturus
''Zygomaturus'' is an extinct genus of giant marsupial belonging to the family Diprotodontidae which inhabited Australia from the Late Miocene to Late Pleistocene.
Description
It was a large animal, weighing 500 kg (1100 lbs) or o ...
''
** '' Palorchestes'' ("marsupial tapir
Tapirs ( ) are large, herbivorous mammals belonging to the family Tapiridae. They are similar in shape to a Suidae, pig, with a short, prehensile nose trunk (proboscis). Tapirs inhabit jungle and forest regions of South America, South and Centr ...
")
** Various members of '' Vombatidae''
*** '' Lasiorhinus angustidens'' (giant wombat)
*** '' Phascolonus'' (giant wombat)
*** '' Ramasayia magna'' (giant wombat)
*** '' Vombatus hacketti'' (Hackett's wombat)
*** '' Warendja wakefieldi'' (dwarf wombat)
*** '' Sedophascolomys'' (giant wombat)
** '' Phascolarctos stirtoni'' (giant koala)
** Marsupial lion (''Thylacoleo carnifex)''
** ''Borungaboodie
''Borungaboodie'' is an extinct genus of potoroo that lived in Southwest Australia during the Pleistocene. The genus is represented by a single species known as ''Borungaboodie hatcheri'', or more informally, the giant potoroo.
Discovery and n ...
'' (giant potoroo)
** Various members of ''Macropodidae
Macropodidae is a Family (biology), family of marsupials that includes kangaroos, Wallaby, wallabies, tree-kangaroos, wallaroos, pademelons, quokkas, and several other groups. These genera are allied to the suborder Macropodiformes, containing ...
'' (kangaroos, wallabies, etc.)
*** '' Procoptodon'' (short-faced kangaroos) e.g.
**** '' Procoptodon goliah''
*** '' Sthenurus'' (giant kangaroo)
*** '' Simosthenurus'' (giant kangaroo)
*** Various '' Macropus'' (giant kangaroo
Kangaroos are marsupials from the family Macropodidae (macropods, meaning "large foot"). In common use, the term is used to describe the largest species from this family, the red kangaroo, as well as the antilopine kangaroo, eastern gre ...
) spp. e.g.
**** '' Macropus ferragus''
**** '' Macropus titan''
**** '' Macropus pearsoni''
*** '' Protemnodon'' spp. (giant wallaby)
*** Troposodon (wallaby
A wallaby () is a small or middle-sized Macropodidae, macropod native to Australia and New Guinea, with introduced populations in New Zealand, Hawaii, the United Kingdom and other countries. They belong to the same Taxonomy (biology), taxon ...
)
*** '' Bohra'' (giant tree kangaroo)
*** '' Propleopus oscillans'' (omnivorous, giant musky rat-kangaroo)
*** '' Nombe''
*** '' Congruus''
** Various forms of '' Sarcophilus'' (Tasmanian devil
The Tasmanian devil (''Sarcophilus harrisii''; palawa kani: ''purinina'') is a carnivorous marsupial of the family Dasyuridae. It was formerly present across mainland Australia, but became extinct there around 3,500 years ago; it is now con ...
)
*** '' Sarcophilus laniarius'' (25% larger than modern species, unclear if it is actually a distinct species from living Tasmanian devil)
*** '' Sarcophilus moornaensis''
* Monotreme
Monotremes () are mammals of the order Monotremata. They are the only group of living mammals that lay eggs, rather than bearing live young. The extant monotreme species are the platypus and the four species of echidnas. Monotremes are typified ...
s: egg-laying mammals.
** Echidna
Echidnas (), sometimes known as spiny anteaters, are quill-covered monotremes (egg-laying mammals) belonging to the Family (biology), family Tachyglossidae , living in Australia and New Guinea. The four Extant taxon, extant species of echidnas ...
*** '' Murrayglossus hacketti'' (giant echidna)
*** '' Megalibgwilia ramsayi''
* Birds
** Pygmy Cassowary ('' Casuarius lydekkeri'')
** ''Genyornis
''Genyornis newtoni'' is an extinct species of large, flightless bird that lived in Australia during the Pleistocene Epoch until around 50,000 years ago. Over two metres in height, they were likely herbivorous. Many other species of Austral ...
'' (a dromornithid
** Giant malleefowl
''Progura'' is an extinct genus of megapode that was native to Australia. It was described from Plio-Pleistocene deposits at the Darling Downs and Chinchilla, Queensland, Chinchilla in southeastern Queensland by Charles De Vis.
Taxonomy
Compa ...
(''Progura gallinacea'')
** '' Cryptogyps lacertosus''
** '' Dynatoaetus gaffae''
** Several Phoenicopteridae spp.
*** '' Xenorhynchopsis'' spp. (Australian flamingo)
*** ''Xenorhynchopsis minor''
*** ''Xenorhynchopsis tibialis''
* Reptiles
** Crocs & Gators
*** '' Ikanogavialis'' (the last fully marine crocodilian)
*** '' Paludirex'' (Australian freshwater mekosuchine crocodiian)
*** '' Quinkana'' (Australian terrestrial mekosuchine crocodilian, apex predator
An apex predator, also known as a top predator or superpredator, is a predator at the top of a food chain, without natural predators of its own.
Apex predators are usually defined in terms of trophic dynamics, meaning that they occupy the hig ...
)
*** '' Volia'' (a two-to-three meter long mekosuchine crocodylian, apex predator of Pleistocene Fiji)
***'' Mekosuchus''
****'' Mekosuchus inexpectatus'' (New Caledonian land crocodile)
****''Mekosuchus kalpokasi'' (Vanuatu land crocodile)
** '' Varanus sp.'' (Pleistocene and Holocene New Caledonia)
** Megalania (''Varanus pricus'') (a giant predatory monitor lizard comparable or larger than the Komodo dragon)
** Snakes
*** '' Wonambi'' (a five-to-six-metre-long Australian constrictor snake
Snakes are elongated limbless reptiles of the suborder Serpentes (). Cladistically squamates, snakes are ectothermic, amniote vertebrates covered in overlapping scales much like other members of the group. Many species of snakes have s ...
)
** Several spp. of Meiolaniidae
Meiolaniidae is an extinct family of large, probably herbivorous stem group, stem-group turtles with heavily armored heads and tail club, clubbed tails known from South America and Australasia. Though once believed to be cryptodires, they are not ...
(giant armoured turtles)
*** '' Meiolania''
*** '' Ninjemys''
Causes
History of research
The megafaunal extinctions were already recognized as a distinct phenomenon by some scientists in the 19th century: Several decades later in his 1911 book ''The World of Life'' (published 2 years before his death), Wallace revisited the issue of the Pleistocene megafauna extinctions, concluding that the extinctons were at least in part the result of human agency in combination with other factors. Discussion of the topic became more widespread during the 20th century, particularly following the proposal of the "overkill hypothesis" byPaul Schultz Martin
Paul Schultz Martin (born in Allentown, Pennsylvania in 1928, died in Tucson, Arizona September 13, 2010)Mari N. Jensen. '. University of Arizona. Retrieved 2010-09-17. was an American geoscientist at the University of Arizona who developed t ...
during the 1960s. By the end of the 20th century, two "camps" of researchers had emerged on the topic, one supporting climate change, the other supporting human hunting as the primary cause of the extinctions.
Hunting
The hunting hypothesis suggests that humans hunted megaherbivores to extinction, which in turn caused the extinction of carnivores and scavengers which had preyed upon those animals. This hypothesis holds Pleistocene humans responsible for the megafaunal extinction. One variant, known as ''blitzkrieg'', portrays this process as relatively quick. Some of the direct evidence for this includes: fossils of some megafauna found in conjunction with human remains, embedded arrows and tool cut marks found in megafaunal bones, and European cave paintings that depict such hunting. biogeography, Biogeographical evidence is also suggestive: the areas of the world where humans evolved currently have more of their Pleistocene megafaunal diversity (the elephants and Rhinoceros, rhinos of Asia and Africa) compared to other areas such as Australia, theAmericas
The Americas, sometimes collectively called America, are a landmass comprising the totality of North America and South America.''Webster's New World College Dictionary'', 2010 by Wiley Publishing, Inc., Cleveland, Ohio. When viewed as a sing ...
, Madagascar
Madagascar, officially the Republic of Madagascar, is an island country that includes the island of Madagascar and numerous smaller peripheral islands. Lying off the southeastern coast of Africa, it is the world's List of islands by area, f ...
and New Zealand
New Zealand () is an island country in the southwestern Pacific Ocean. It consists of two main landmasses—the North Island () and the South Island ()—and List of islands of New Zealand, over 600 smaller islands. It is the List of isla ...
without the earliest humans. The overkill hypothesis, a variant of the hunting hypothesis, was proposed in 1966 by Paul S. Martin, Professor of Geosciences Emeritus at the Desert Laboratory of the University of Arizona.
Circumstantially, the close correlation in time between the appearance of humans in an area and extinction there provides weight for this scenario. Radiocarbon dating has supported the plausibility of this correlation being reflective of causation. The megafaunal extinctions covered a vast period of time and highly variable climatic situations. The earliest extinctions in Australia were complete approximately 50,000 BP, well before the Last Glacial Maximum and before rises in temperature. The most recent extinction in New Zealand was complete no earlier than 500 BP and during a period of cooling. In between these extremes megafaunal extinctions have occurred progressively in such places as North America, South America and Madagascar with no climatic commonality. The only common factor that can be ascertained is the arrival of humans. This phenomenon appears even within regions. The mammal extinction wave in Australia about 50,000 years ago coincides not with known climatic changes, but with the arrival of humans. In addition, large mammal species like the giant kangaroo '' Protemnodon'' appear to have succumbed sooner on the Australian mainland than on Tasmania, which was colonised by humans a few thousand years later. A study published in 2015 supported the hypothesis further by running several thousand scenarios that correlated the time windows in which each species is known to have become extinct with the arrival of humans on different continents or islands. This was compared against climate reconstructions for the last 90,000 years. The researchers found correlations of human spread and species extinction indicating that the Human impact on the environment, human impact was the main cause of the extinction, while climate change exacerbated the frequency of extinctions. The study, however, found an apparently low extinction rate in the fossil record of mainland Asia.
A 2020 study published in ''Science Advances'' found that human population size and/or specific human activities, not climate change, caused rapidly rising global mammal extinction rates during the past 126,000 years. Around 96% of all mammalian extinctions over this time period are attributable to human impacts. According to Tobias Andermann, lead author of the study, "these extinctions did not happen continuously and at constant pace. Instead, bursts of extinctions are detected across different continents at times when humans first reached them. More recently, the magnitude of human driven extinctions has picked up the pace again, this time on a global scale." Text and images are available under a creativecommons:by/4.0/, Creative Commons Attribution 4.0 International License. On a related note, the population declines of still extant megafauna during the Pleistocene have also been shown to correlate with human expansion rather than climate change.
The extinction's extreme bias towards larger animals further supports a relationship with human activity rather than climate change. There is evidence that the average size of mammalian fauna declined over the course of the Quaternary, a phenomenon that was likely linked to disproportionate hunting of large animals by humans.
Extinction through human hunting has been supported by archaeological finds of mammoths with projectile points embedded in their skeletons, by observations of modern naive animals allowing hunters to approach easily and by computer models by Mosimann and Martin, and Whittington and Dyke, and most recently by Alroy.
In 2024 a paper was published in ''Science Advances'' that added additional support to the overkill hypothesis in North America when the skull of an 18 month old child, dated to 12,800 years ago, was analyzed for chemical signatures attributable to both maternal milk and solid food. Specific isotopes of carbon and nitrogen most closely matched those that would have been found in the mammoth genus and secondarily elk or bison.
A number of objections have been raised regarding the hunting hypothesis. Notable among them is the sparsity of evidence of human hunting of megafauna. There is no archeological evidence that in North America megafauna other than mammoths, mastodons, gomphotheres and bison were hunted, despite the fact that, for example, camels and horses are very frequently reported in fossil history. Overkill proponents, however, say this is due to the fast extinction process in North America and the low probability of animals with signs of butchery to be preserved. The majority of North American taxa have too sparse a fossil record to accurately assess the frequency of human hunting of them. A study by Surovell and Grund concluded "archaeological sites dating to the time of the coexistence of humans and extinct fauna are rare. Those that preserve bone are considerably more rare, and of those, only a very few show unambiguous evidence of human hunting of any type of prey whatsoever." Eugene S. Hunn suggests that the birthrate in hunter-gatherer societies is generally too low, that too much effort is involved in the bringing down of a large animal by a hunting party, and that in order for hunter-gatherers to have brought about the extinction of megafauna simply by hunting them to death, an extraordinary amount of meat would have had to have been wasted. Proponents of hunting as a cause of the extinctions argue that statistical modelling validates that relatively low-level hunting can have significant effect on megafauna populations due to their slow life cycles, and that hunting can cause top-down forcing trophic cascade events that destabilize ecosystems.
Second-order predation
The Second-Order Predation Hypothesis says that as humans entered the New World they continued their policy of killing predators, which had been successful in the Old World but because they were more efficient and because the fauna, both herbivores and carnivores, were more naive, they killed off enough carnivores to upset the Ecological equilibrium, ecological balance of the continent, causing overpopulation (biology), overpopulation, environmental exhaustion, and environmental collapse. The hypothesis accounts for changes in animal, plant, and human populations.
The scenario is as follows:
* After the arrival of ''H. sapiens'' in the New World, existing predators must share the prey populations with this new predator. Because of this competition, populations of original, or first-order, predators cannot find enough food; they are in direct competition with humans.
* Second-order predation begins as humans begin to kill predators.
* Prey populations are no longer well controlled by predation. Killing of nonhuman predators by ''H. sapiens'' reduces their numbers to a point where these predators no longer regulate the size of the prey populations.
* Lack of regulation by first-order predators triggers boom-and-bust cycles in prey populations. Prey populations expand and consequently overgraze and over-browse the land. Soon the environment is no longer able to support them. As a result, many herbivores starve. Species that rely on the slowest recruiting food become extinct, followed by species that cannot extract the maximum benefit from every bit of their food.
* Boom-bust cycles in herbivore populations change the nature of the vegetative environment, with consequent climatic impacts on relative humidity and continentality. Through overgrazing and overbrowsing, mixed parkland becomes grassland, and climatic continentality increases.
The second-order predation hypothesis has been supported by a computer model, the Pleistocene extinction model (PEM), which, using the same assumptions and values for all variables (herbivore population, herbivore recruitment rates, food needed per human, herbivore hunting rates, etc.) other than those for hunting of predators. It compares the overkill hypothesis (predator hunting = 0) with second-order predation (predator hunting varied between 0.01 and 0.05 for different runs). The findings are that second-order predation is more consistent with extinction than is overkill (results graph at left). The Pleistocene extinction model is the only test of multiple hypotheses and is the only model to specifically test combination hypotheses by artificially introducing sufficient climate change to cause extinction. When overkill and climate change are combined they balance each other out. Climate change reduces the number of plants, overkill removes animals, therefore fewer plants are eaten. Second-order predation combined with climate change exacerbates the effect of climate change. (results graph at right). The second-order predation hypothesis is further supported by the observation above that there was a massive increase in bison populations.
However, this hypothesis has been criticised on the grounds that the multispecies model produces a mass extinction through indirect competition between herbivore species: small species with high reproductive rates subsidize predation on large species with low reproductive rates. All prey species are lumped in the Pleistocene extinction model. Also, the control of population sizes by predators is not fully supported by observations of modern ecosystems. The hypothesis further assumes decreases in vegetation due to climate change, but deglaciation doubled the habitable area of North America. Any vegetational changes that did occur failed to cause almost any extinctions of small vertebrates, and they are more narrowly distributed on average, which detractors cite as evidence against the hypothesis.
Competition for water
In southeastern Australia, the scarcity of water during the interval in which humans arrived in Australia suggests that human competition with megafauna for precious water sources may have played a role in the extinction of the latter.Landscape alteration
One consequence of the colonisation by humans of lands previously uninhabited by them may have been the introduction of new fire regimes because of extensive fire use by humans. There is evidence that anthropogenic fire use had major impacts on the local environments in both Australia and North America.Climate change
At the end of the 19th and beginning of the 20th centuries, when scientists first realized that there had been glacial and interglacial ages, and that they were somehow associated with the prevalence or disappearance of certain animals, they surmised that the termination of the Pleistocene ice age might be an explanation for the extinctions. The most obvious change associated with the termination of an ice age is the increase in temperature. Between 15,000 Before Present, BP and 10,000 BP, a 6 °C increase in global mean annual temperatures occurred. This was generally thought to be the cause of the extinctions. According to this hypothesis, a temperature increase sufficient to melt the Wisconsin glaciation, Wisconsin ice sheet could have placed enough thermal stress on cold-adapted mammals to cause them to die. Their heavy fur, which helps conserve body heat in the glacial cold, might have prevented the dumping of excess heat, causing the mammals to die of heat exhaustion. Large mammals, with their reduced Surface area to volume ratio, surface area-to-volume ratio, would have fared worse than small mammals. A study covering the past 56,000 years indicates that rapid warming events with temperature changes of up to had an important impact on the extinction of megafauna. Ancient DNA and radiocarbon data indicates that local genetic populations were replaced by others within the same species or by others within the same genus. Survival of populations was dependent on the existence of Refugium (population biology), refugia and long distance dispersals, which may have been disrupted by human hunters. Other scientists have proposed that increasingly extreme weather—hotter summers and colder winters—referred to as "continentality", or related changes in rainfall caused the extinctions. It has been shown that vegetation changed from mixed woodland-aspen parkland, parkland to separate prairie and woodland. This may have affected the kinds of food available. Shorter growing seasons may have caused the extinction of large herbivores and the dwarfing of many others. In this case, as observed, bison and other large ruminants would have fared better than horses, elephants and other monogastrics, because ruminants are able to extract more nutrition from limited quantities of high-Dietary fiber, fiber food and better able to deal with anti-herbivory toxins. So, in general, when vegetation becomes more specialized, herbivores with less diet flexibility may be less able to find the mix of vegetation they need to sustain life and reproduce, within a given area. Increased continentality resulted in reduced and less predictable rainfall limiting the availability of plants necessary for energy and nutrition. It has been suggested that this change in rainfall restricted the amount of time favorable for reproduction. This could disproportionately harm large animals, since they have longer, more inflexible mating periods, and so may have produced young at unfavorable seasons (i.e., when sufficient food, water, or shelter was unavailable because of shifts in the growing season). In contrast, small mammals, with their shorter Biological life cycle, life cycles, shorter reproductive cycles, and shorter gestation periods, could have adjusted to the increased unpredictability of the climate, both as individuals and as species which allowed them to synchronize their reproductive efforts with conditions favorable for offspring survival. If so, smaller mammals would have lost fewer offspring and would have been better able to repeat the reproductive effort when circumstances once more favored offspring survival. A study looking at the environmental conditions across Europe, Siberia and the Americas from 25,000 to 10,000 YBP found that prolonged warming events leading to deglaciation and maximum rainfall occurred just prior to the transformation of the rangelands that supported megaherbivores into widespread wetlands that supported herbivore-resistant plants. The study proposes that moisture-driven environmental change led to the megafaunal extinctions and that Africa's trans-equatorial position allowed rangeland to continue to exist between the deserts and the central forests, therefore fewer megafauna species became extinct there. Evidence in Southeast Asia, in contrast to Europe, Australia, and the Americas, suggests that climate change and an increasing sea level were significant factors in the extinction of several herbivorous species. Alterations in vegetation growth and new access routes for early humans and mammals to previously isolated, localized ecosystems were detrimental to select groups of fauna. Some evidence from Europe also suggests climatic changes were responsible for extinctions there, as the individuals extinctions tended to occur during times of environmental change and did not correlate particularly well with human migrations. In Australia, some studies have suggested that extinctions of megafauna began before the peopling of the continent, favouring climate change as the driver. In Beringia, megafauna may have gone extinct because of particularly intense paludification and because the land connection between Eurasia and North America flooded before the Cordilleran Ice Sheet retreated far enough to reopen the corridor between Beringia and the remainder of North America. Woolly mammoths became extirpated from Beringia because of climatic factors, although human activity also played a synergistic role in their decline. In North America, a Radiocarbon-dated Event-Count (REC) modelling study found that megafaunal declines in North America correlated with climatic changes instead of human population expansion. In the North American Great Lakes region, the population declines of mastodons and mammoths have been found to correlate with climatic fluctuations during the Younger Dryas rather than human activity. In the Argentine Pampas, the flooding of vast swathes of the once much larger Pampas grasslands may have played a role in the extinctions of its megafaunal assemblages. Critics object that since there were :Image:Five Myr Climate Change.png, multiple glacial :Image:Atmospheric CO2 with glaciers cycles.gif, advances and withdrawals in the evolutionary history of many of the megafauna, it is rather implausible that only after the last glacial maximum would there be such extinctions. Proponents of climate change as the extinction event's cause like David J. Meltzer suggest that the last deglaciation may have been markedly different from previous ones. Also, one study suggests that the Pleistocene megafaunal composition may have differed markedly from that of earlier interglacials, making the Pleistocene populations particularly vulnerable to changes in their environment. Studies propose that the annual mean temperature of the current interglacial that we have seen for the last 10,000 years is no higher than that of previous interglacials, yet most of the same large mammals survived similar temperature increases. In addition, numerous species such as mammoths onWrangel Island
Wrangel Island (, ; , , ) is an island of the Chukotka Autonomous Okrug, Russia. It is the List of islands by area, 92nd-largest island in the world and roughly the size of Crete. Located in the Arctic Ocean between the Chukchi Sea and East Si ...
and Saint Paul Island (Alaska), St. Paul Island survived in human-free Refugium (population biology), refugia despite changes in climate. This would not be expected if climate change were responsible (unless their maritime climates offered some protection against climate change not afforded to coastal populations on the mainland). Under normal ecological assumptions island populations should be more vulnerable to extinction due to climate change because of small populations and an inability to migrate to more favorable climes.
Critics have also identified a number of problems with the continentality hypotheses. Megaherbivores have prospered at other times of continental climate. For example, megaherbivores thrived in Pleistocene Siberia
Siberia ( ; , ) is an extensive geographical region comprising all of North Asia, from the Ural Mountains in the west to the Pacific Ocean in the east. It has formed a part of the sovereign territory of Russia and its predecessor states ...
, which had and has a more continental climate than Pleistocene or modern (post-Pleistocene, interglacial) North America. The animals that became extinct actually should have prospered during the shift from mixed woodland-parkland to prairie, because their primary food source, grass, was increasing rather than decreasing. Although the vegetation did become more spatially specialized, the amount of prairie and grass available increased, which would have been good for horses and for mammoths, and yet they became extinct. This criticism ignores the increased abundance and broad geographic extent of Pleistocene bison at the end of the Pleistocene, which would have increased competition for these resources in a manner not seen in any earlier interglacials. Although horses became extinct in the New World, they were successfully reintroduced by the Spanish in the 16th century—into a modern post-Pleistocene, interglacial climate. Today there are feral horses still living in those same environments. They find a sufficient mix of food to avoid toxins, they extract enough nutrition from forage to reproduce effectively and the timing of their gestation is not an issue. This criticism ignores the fact that present-day horses are not competing for resources with ground sloths, mammoths, mastodons, camels, llamas, and bison. Similarly, mammoths survived the Pleistocene Holocene transition on isolated, uninhabited islands in the Mediterranean Sea until 4,000 to 7,000 years ago, as well as on Wrangel Island in the Siberian Arctic. Additionally, large mammals should have been able to migrate, permanently or seasonally, if they found the temperature too extreme, the breeding season too short, or the rainfall too sparse or unpredictable. Seasons vary geographically. By migrating away from the equator, herbivores could have found areas with growing seasons more favorable for finding food and breeding successfully. Modern-day African elephants migrate during periods of drought to places where there is apt to be water. Large animals also store more fat in their bodies than do medium-sized animals and this should have allowed them to compensate for extreme seasonal fluctuations in food availability.
Some evidence weighs against climate change as a valid hypothesis as applied to Australia. It has been shown that the prevailing climate at the time of extinction (40,000–50,000 BP) was similar to that of today, and that the extinct animals were strongly adapted to an arid climate. The evidence indicates that all of the extinctions took place in the same short time period, which was the time when humans entered the landscape. The main mechanism for extinction was probably fire (started by humans) in a then much less fire-adapted landscape. Isotopic evidence shows sudden changes in the diet of surviving species, which could correspond to the stress they experienced before extinction.
Some evidence obtained from analysis of the tusks of American mastodon, mastodons from the Great Lakes region (North America), American Great Lakes region appears inconsistent with the climate change hypothesis. Over a span of several thousand years prior to their extinction in the area, the mastodons show a trend of declining age at maturation. This is the opposite of what one would expect if they were experiencing stresses from deteriorating environmental conditions, but is consistent with a reduction in intraspecific competition that would result from a population being reduced by human hunting.
It may be observed that neither the overkill nor the climate change hypotheses can fully explain events: Browser (herbivore), browsers, mixed feeders and non-ruminant grazer species suffered most, while relatively more ruminant grazers survived. However, a broader variation of the overkill hypothesis may predict this, because changes in vegetation wrought by either Second Order Predation (see below) or Human impact on the environment, anthropogenic fire preferentially selects against browse species.
Disease
The hyperdisease hypothesis, as advanced by Ross D. E. MacFee and Preston A. Marx, attributes the extinction of large mammals during the late Pleistocene to indirect effects of the newly arrived Indigenous peoples, aboriginal humans. In more recent times, disease has driven many vulnerable species to extinction; the introduction of avian malaria and avipoxvirus, for example, has greatly decreased the populations of the endemic birds of Hawaii, with some going extinct. The hyperdisease hypothesis proposes that humans or animals traveling with them (e.g., chickens or domestic dogs) introduced one or more highly virulent diseases into vulnerable populations of native mammals, eventually causing extinctions. The extinction was biased toward larger-sized species because smaller species have greater resilience because of their life history traits (e.g., shorter gestation time, greater population sizes, etc.). Humans are thought to be the cause because other earlier immigrations of mammals into North America from Eurasia did not cause extinctions. A similar suggestion is that pathogens were transmitted by the expanding humans via the domesticated dogs they brought with them. A related theory proposes that a highly contagious prion disease similar to chronic wasting disease or scrapie that was capable of infecting a large number of species was the culprit. Animals weakened by this "superprion" would also have easily become reservoirs of viral and bacterial diseases as they succumbed to neurological degeneration from the prion, causing a cascade of different diseases to spread among various mammal species. This theory could potentially explain the prevalence of heterozygosity at codon 129 of the prion protein gene in humans, which has been speculated to be the result of natural selection against homozygous genotypes that were more susceptible to prion disease and thus potentially a tell-tale of a major prion pandemic that affected humans of or younger than reproductive age far in the past and disproportionately killed before they could reproduce those with homozygous genotypes at codon 129. If a disease was indeed responsible for the end-Pleistocene extinctions, then there are several criteria it must satisfy (see Table 7.3 in MacPhee & Marx 1997). First, the pathogen must have a stable Asymptomatic carrier, carrier state in a reservoir species. That is, it must be able to sustain itself in the environment when there are no susceptible Host (biology), hosts available to infect. Second, the pathogen must have a high infection rate, such that it is able to infect virtually all individuals of all ages and sexes encountered. Third, it must be extremely lethal, with a mortality rate of c. 50–75%. Finally, it must have the ability to infect multiple host species without posing a serious threat to humans. Humans may be infected, but the disease must not be highly lethal or able to cause an epidemic. As with other hypotheses, a number of counterarguments to the hyperdisease hypothesis have been put forth. Generally speaking, disease has to be very virulent to kill off all the individuals in a genus or species. Even such a virulent disease as West Nile fever is unlikely to have caused extinction. The disease would need to be implausibly selective while being simultaneously implausibly broad. Such a disease needs to be capable of killing off wolves such as ''Canis dirus'' or goats such as ''Oreamnos harringtoni'' while leaving other very similar species (''Canis lupus'' and ''Oreamnos americanus'', respectively) unaffected. It would need to be capable of killing off flightless birds while leaving closely related flighted species unaffected. Yet while remaining sufficiently selective to afflict only individual species within genera it must be capable of fatally infecting across such clades as birds, marsupials, placentals, testudines, and crocodilians. No disease with such a broad scope of fatal infectivity is known, much less one that remains simultaneously incapable of infecting numerous closely related species within those disparate clades. On the other hand, this objection does not account for the possibility of a variety of different diseases being introduced around the same era. Numerous species including wolves, mammoths, camelids, and horses had emigrated continually between Asia and North America over the past 100,000 years. For the disease hypothesis to be applicable there it would require that the population remain immunologically naive despite this constant transmission of genetic and pathogenic material. The dog-specific hypothesis in particular cannot account for several major extinction events, notably the Americas (for reasons already covered) and Australia. Dogs did not arrive in Australia until approximately 35,000 years after the first humans arrived there, and approximately 30,000 years after the Australian megafaunal extinction was complete.Extraterrestrial impact
An extraterrestrial impact, which has occasionally been proposed as a cause of the Younger Dryas, has been suggested by some authors as a potential cause of the extinction of North America's megafauna due to the temporal proximity between a proposed date for such an impact and the following megafaunal extinctions. However, the Younger Dryas impact hypothesis lacks widespread support among scholars due to various inconsistencies in the hypothesis, and another group of researchers has published a review contesting the arguments for it point by point.Geomagnetic field weakening
Around 41,500 years ago, the Earth's magnetic field weakened in an event known as the Laschamp event. This weakening may have caused increased flux of UVB radiation, UV-B radiation and has been suggested by a few authors as a cause of megafaunal extinctions in the Late Quaternary. The full effects of such events on the biosphere are poorly understood, however these explanations have been criticized as they do not account for the population bottlenecks seen in many megafaunal species and nor is there evidence for extreme radio-isotopic changes during the event. Considering these factors, causation is unlikely.Effects
The extinction of the megafauna has been argued by some authors to have caused disappearance of the mammoth steppe rather than the other way around. Alaska now has low nutrient soil unable to support bison, mammoths, and horses. R. Dale Guthrie has claimed this as a cause of the extinction of the megafauna there; however, he may be interpreting it backwards. The loss of large herbivores to break up the permafrost allows the cold soils that are unable to support large herbivores today. Today, in the arctic, where trucks have broken the permafrost, grasses and diverse flora and fauna can be supported. In addition, Chapin (Chapin 1980) showed that simply adding fertilizer to the soil in Alaska could make grasses grow again like they did in the era of the mammoth steppe. Possibly, the extinction of the megafauna and the corresponding loss of dung is what led to low nutrient levels in modern-day soil and therefore is why the landscape can no longer support megafauna.
However, more recent authors have viewed it as more likely that the collapse of the mammoth steppe was driven by climatic warming, which in turn impacted the megafauna, rather than the other way around.
Megafauna play a significant role in the lateral transport of mineral nutrients in an ecosystem, tending to translocate them from areas of high to those of lower abundance. They do so by their movement between the time they consume the nutrient and the time they release it through elimination (or, to a much lesser extent, through decomposition after death). In South America's Amazon Basin, it is estimated that such lateral diffusion was reduced over 98% following the megafaunal extinctions that occurred roughly 12,500 years ago. Given that phosphorus availability is thought to limit productivity in much of the region, the decrease in its transport from the western part of the basin and from floodplains (both of which derive their supply from the uplift of the Andes) to other areas is thought to have significantly impacted the region's ecology, and the effects may not yet have reached their limits. The extinction of the mammoths allowed grasslands they had maintained through grazing habits to become birch forests. The new forest and the resulting forest fires may have induced climate change
Present-day climate change includes both global warming—the ongoing increase in Global surface temperature, global average temperature—and its wider effects on Earth's climate system. Climate variability and change, Climate change in ...
. Such disappearances might be the result of the proliferation of modern humans.
Large populations of megaherbivores have the potential to contribute greatly to the atmospheric concentration of methane, which is an important greenhouse gas. Modern ruminant herbivores
A herbivore is an animal anatomically and physiologically evolved to feed on plants, especially upon vascular tissues such as foliage, fruits or seeds, as the main component of its diet. These more broadly also encompass animals that eat ...
produce methane as a byproduct of foregut fermentation in digestion, and release it through belching or flatulence. Today, around 20% of annual methane emissions come from livestock methane release. In the Mesozoic, it has been estimated that sauropods could have emitted 520 million tons of methane to the atmosphere annually, contributing to the warmer climate of the time (up to 10 °C warmer than at present). This large emission follows from the enormous estimated biomass of sauropods, and because methane production of individual herbivores is believed to be almost proportional to their mass.
Recent studies have indicated that the extinction of megafaunal herbivores may have caused a reduction in atmospheric methane. One study examined the methane emissions from the American bison, bison that occupied the Great Plains of North America before contact with European settlers. The study estimated that the removal of the bison caused a decrease of as much as 2.2 million tons per year. Another study examined the change in the methane concentration in the atmosphere at the end of the Pleistocene epoch after the extinction of megafauna in the Americas. After early humans migrated to the Americas about 13,000 Before Present, BP, their hunting and other associated ecological impacts led to the extinction of many megafaunal species there. Calculations suggest that this extinction decreased methane production by about 9.6 million tons per year. This suggests that the absence of megafaunal methane emissions may have contributed to the abrupt climatic cooling at the onset of the Younger Dryas
The Younger Dryas (YD, Greenland Stadial GS-1) was a period in Earth's geologic history that occurred circa 12,900 to 11,700 years Before Present (BP). It is primarily known for the sudden or "abrupt" cooling in the Northern Hemisphere, when the ...
. The decrease in atmospheric methane that occurred at that time, as recorded in ice cores, was 2–4 times more rapid than any other decrease in the last half million years, suggesting that an unusual mechanism was at work.
The extermination of megafauna left many niches vacant, which has been cited as an explanation for the vulnerability and fragility of many ecosystems to destruction in the later Holocene extinction. The comparative lack of megafauna in modern ecosystems has reduced high-order interactions among surviving species, reducing ecological complexity. This depauperate, post-megafaunal ecological state has been associated with diminished ecological resilience to stressors. Many extant species of plants have adaptations that were advantageous in the presence of megafauna but are now useless in their absence. The demise of megafaunal ecosystem engineers in the Arctic that maintained open grassland environments has been highly detrimental to shorebirds of the genus ''Numenius (bird), Numenius.''
Relationship to later extinctions
There is no general agreement on where the Quaternary extinction event ends, and theHolocene
The Holocene () is the current geologic time scale, geological epoch, beginning approximately 11,700 years ago. It follows the Last Glacial Period, which concluded with the Holocene glacial retreat. The Holocene and the preceding Pleistocene to ...
, or Human impact on the environment, anthropogenic, extinction begins, or if they should be considered separate events at all. Some authors have argued that the activities of earlier archaic humans have also resulted in extinctions, though the evidence for this is equivocal.
This hypothesis is supported by rapid megafaunal extinction following recent human colonisation in Australian megafauna, Australia, List of extinct animals of New Zealand, New Zealand and List of African animals extinct in the Holocene, Madagascar, in a similar way that any Invasive species, large, adaptable predator moving into a new ecosystem would. In many cases, it is suggested even minimal hunting pressure was enough to wipe out large fauna, particularly on Geographical isolation, geographically isolated islands. Only during the most recent parts of the extinction have Effect of climate change on plant biodiversity, plants also suffered large losses.
See also
* * * * List of Ice Age species preserved as permafrost mummies * * *References
External links
Hyperdisease hypothesis
* *Second-order predation
*Other links
* * * * * {{DEFAULTSORT:Quaternary Extinction Event Extinction events Pleistocene Quaternary extinctions, Younger Dryas impact hypothesis Megafauna