Megafauna
Overview
In terrestrial zoology, megafauna (Ancient Greek
Ancient Greek
Ancient Greek is the stage of the Greek language in the periods spanning the times c. 9th–6th centuries BC, , c. 5th–4th centuries BC , and the c. 3rd century BC – 6th century AD of ancient Greece and the ancient world; being predated in the 2nd millennium BC by Mycenaean Greek...

 megas "large" + New Latin
New Latin
The term New Latin, or Neo-Latin, is used to describe the Latin language used in original works created between c. 1500 and c. 1900. Among other uses, Latin during this period was employed in scholarly and scientific publications...

 fauna "animal") are "giant", "very large" or "large" animals. The most common thresholds used are 44 kilograms (97 lb) or 100 kilograms (220 lb). This thus includes many species not popularly thought of as overly large, such as white-tailed deer
White-tailed Deer
The white-tailed deer , also known as the Virginia deer or simply as the whitetail, is a medium-sized deer native to the United States , Canada, Mexico, Central America, and South America as far south as Peru...

 and red kangaroo
Red Kangaroo
The Red Kangaroo is the largest of all kangaroos, the largest mammal native to Australia, and the largest surviving marsupial. It is found across mainland Australia, avoiding only the more fertile areas in the south, the east coast, and the northern rainforests.-Description:This species is a very...

, and for the lower figure, even human
Human
Humans are the only living species in the Homo genus...

s.

In practice the most common usage encountered in academic and popular writing describes land animals roughly larger than a human which are not (solely) domesticated.
Encyclopedia
In terrestrial zoology, megafauna (Ancient Greek
Ancient Greek
Ancient Greek is the stage of the Greek language in the periods spanning the times c. 9th–6th centuries BC, , c. 5th–4th centuries BC , and the c. 3rd century BC – 6th century AD of ancient Greece and the ancient world; being predated in the 2nd millennium BC by Mycenaean Greek...

 megas "large" + New Latin
New Latin
The term New Latin, or Neo-Latin, is used to describe the Latin language used in original works created between c. 1500 and c. 1900. Among other uses, Latin during this period was employed in scholarly and scientific publications...

 fauna "animal") are "giant", "very large" or "large" animals. The most common thresholds used are 44 kilograms (97 lb) or 100 kilograms (220 lb). This thus includes many species not popularly thought of as overly large, such as white-tailed deer
White-tailed Deer
The white-tailed deer , also known as the Virginia deer or simply as the whitetail, is a medium-sized deer native to the United States , Canada, Mexico, Central America, and South America as far south as Peru...

 and red kangaroo
Red Kangaroo
The Red Kangaroo is the largest of all kangaroos, the largest mammal native to Australia, and the largest surviving marsupial. It is found across mainland Australia, avoiding only the more fertile areas in the south, the east coast, and the northern rainforests.-Description:This species is a very...

, and for the lower figure, even human
Human
Humans are the only living species in the Homo genus...

s.

In practice the most common usage encountered in academic and popular writing describes land animals roughly larger than a human which are not (solely) domesticated. The term is especially associated with the Pleistocene megafauna
Pleistocene megafauna
Pleistocene megafauna is the set of species of large animals — mammals, birds and reptiles — that lived on Earth during the Pleistocene epoch and became extinct in a Quaternary extinction event. These species appear to have died off as humans expanded out of Africa and southern Asia,...

 — the giant and very large land animals considered archetypical of the last ice age such as mammoth
Mammoth
A mammoth is any species of the extinct genus Mammuthus. These proboscideans are members of Elephantidae, the family of elephants and mammoths, and close relatives of modern elephants. They were often equipped with long curved tusks and, in northern species, a covering of long hair...

s. It is also commonly used for the largest extant wild land animals, especially elephant
Elephant
Elephants are large land mammals in two extant genera of the family Elephantidae: Elephas and Loxodonta, with the third genus Mammuthus extinct...

s, giraffe
Giraffe
The giraffe is an African even-toed ungulate mammal, the tallest of all extant land-living animal species, and the largest ruminant...

s, hippopotamus
Hippopotamus
The hippopotamus , or hippo, from the ancient Greek for "river horse" , is a large, mostly herbivorous mammal in sub-Saharan Africa, and one of only two extant species in the family Hippopotamidae After the elephant and rhinoceros, the hippopotamus is the third largest land mammal and the heaviest...

es, rhinoceros
Rhinoceros
Rhinoceros , also known as rhino, is a group of five extant species of odd-toed ungulates in the family Rhinocerotidae. Two of these species are native to Africa and three to southern Asia....

es, elk
Elk
The Elk is the large deer, also called Cervus canadensis or wapiti, of North America and eastern Asia.Elk may also refer to:Other antlered mammals:...

, condor
Condor
Condor is the name for two species of New World vultures, each in a monotypic genus. They are the largest flying land birds in the Western Hemisphere.They are:* The Andean Condor which inhabits the Andean mountains....

s, etc. Megafauna may be subcategorized by their trophic
Trophic species
A trophic species is a group of species that are aggregated according to their common trophic positions in a food web or food chain. Trophic species have identical prey and a shared set of predators in the food web. This means that members of a trophic species share many of the same kinds of...

 position into megaherbivores (e.g. elk
Elk
The Elk is the large deer, also called Cervus canadensis or wapiti, of North America and eastern Asia.Elk may also refer to:Other antlered mammals:...

), megacarnivores (e.g. lion
Lion
The lion is one of the four big cats in the genus Panthera, and a member of the family Felidae. With some males exceeding 250 kg in weight, it is the second-largest living cat after the tiger...

s), and more rarely, megaomnivores (e.g. bear
Bear
Bears are mammals of the family Ursidae. Bears are classified as caniforms, or doglike carnivorans, with the pinnipeds being their closest living relatives. Although there are only eight living species of bear, they are widespread, appearing in a wide variety of habitats throughout the Northern...

s).

Other common uses are for giant aquatic species, especially whales, any larger wild or domesticated land animals such as larger antelope
Antelope
Antelope is a term referring to many even-toed ungulate species indigenous to various regions in Africa and Eurasia. Antelopes comprise a miscellaneous group within the family Bovidae, encompassing those old-world species that are neither cattle, sheep, buffalo, bison, nor goats...

 and cattle
Cattle
Cattle are the most common type of large domesticated ungulates. They are a prominent modern member of the subfamily Bovinae, are the most widespread species of the genus Bos, and are most commonly classified collectively as Bos primigenius...

, and dinosaur
Dinosaur
Dinosaurs are a diverse group of animals of the clade and superorder Dinosauria. They were the dominant terrestrial vertebrates for over 160 million years, from the late Triassic period until the end of the Cretaceous , when the Cretaceous–Paleogene extinction event led to the extinction of...

s and other extinct giant reptilians.

The term is also sometimes applied to animals (usually extinct
Extinction
In biology and ecology, extinction is the end of an organism or of a group of organisms , normally a species. The moment of extinction is generally considered to be the death of the last individual of the species, although the capacity to breed and recover may have been lost before this point...

) of great size relative to a more common or surviving type of the animal, for example the 1 m (3 ft) dragonflies
Dragonfly
A dragonfly is a winged insect belonging to the order Odonata, the suborder Epiprocta or, in the strict sense, the infraorder Anisoptera . It is characterized by large multifaceted eyes, two pairs of strong transparent wings, and an elongated body...

 of the Carboniferous
Carboniferous
The Carboniferous is a geologic period and system that extends from the end of the Devonian Period, about 359.2 ± 2.5 Mya , to the beginning of the Permian Period, about 299.0 ± 0.8 Mya . The name is derived from the Latin word for coal, carbo. Carboniferous means "coal-bearing"...

 period.

Ecological strategy

Megafauna — in the sense of the largest mammals and birds — are generally K-strategist
R/K selection theory
In ecology, r/K selection theory relates to the selection of combinations of traits in an organism that trade off between quantity or quality of offspring...

s, with great longevity, slow population growth rates, low death rates, and few or no natural predators capable of killing adults. These characteristics, although not exclusive to such megafauna, make them highly vulnerable to human overexploitation
Overexploitation
Overexploitation, also called overharvesting, refers to harvesting a renewable resource to the point of diminishing returns. Sustained overexploitation can lead to the destruction of the resource...

.

Mass extinctions

A well-known mass extinction of megafauna, the Holocene extinction (see also Quaternary extinction event
Quaternary extinction event
The Quaternary period saw the extinctions of numerous predominantly larger, especially megafaunal, species, many of which occurred during the transition from the Pleistocene to the Holocene epoch. However, the extinction wave did not stop at the end of the Pleistocene, but continued especially on...

), occurred at the end of the last ice age glacial period (a.k.a. the Würm glaciation) and wiped out many giant ice age animals, such as woolly mammoth
Woolly mammoth
The woolly mammoth , also called the tundra mammoth, is a species of mammoth. This animal is known from bones and frozen carcasses from northern North America and northern Eurasia with the best preserved carcasses in Siberia...

s, in the Americas
Americas
The Americas, or America , are lands in the Western hemisphere, also known as the New World. In English, the plural form the Americas is often used to refer to the landmasses of North America and South America with their associated islands and regions, while the singular form America is primarily...

 and northern Eurasia
Eurasia
Eurasia is a continent or supercontinent comprising the traditional continents of Europe and Asia ; covering about 52,990,000 km2 or about 10.6% of the Earth's surface located primarily in the eastern and northern hemispheres...

. Various theories have attributed the wave of extinctions to human hunting, climate change, disease, a putative extraterrestrial impact, or other causes. However, this extinction pulse
Quaternary extinction event
The Quaternary period saw the extinctions of numerous predominantly larger, especially megafaunal, species, many of which occurred during the transition from the Pleistocene to the Holocene epoch. However, the extinction wave did not stop at the end of the Pleistocene, but continued especially on...

 near the end of the Pleistocene
Pleistocene
The Pleistocene is the epoch from 2,588,000 to 11,700 years BP that spans the world's recent period of repeated glaciations. The name pleistocene is derived from the Greek and ....

 was just one of a series of megafaunal extinction pulses that have occurred during the last 50,000 years over much of the Earth's surface, with Africa
Africa
Africa is the world's second largest and second most populous continent, after Asia. At about 30.2 million km² including adjacent islands, it covers 6% of the Earth's total surface area and 20.4% of the total land area...

 and southern Asia
Asia
Asia is the world's largest and most populous continent, located primarily in the eastern and northern hemispheres. It covers 8.7% of the Earth's total surface area and with approximately 3.879 billion people, it hosts 60% of the world's current human population...

 being largely spared. (The latter areas did suffer a gradual attrition of megafauna, particularly of the slower-moving species, over the last several million years.) Outside the mainland of Afro-Eurasia
Afro-Eurasia
Afro-Eurasia or less commonly Afrasia or Eurafrasia is the term used to describe the largest landmass on earth. It may be defined as a supercontinent, consisting of Africa and Eurasia...

, these megafaunal extinctions followed a distinctive landmass-by-landmass pattern that closely parallels the spread of humans into previously uninhabited regions of the world, and which shows no correlation with climate. Australia
Australia
Australia , officially the Commonwealth of Australia, is a country in the Southern Hemisphere comprising the mainland of the Australian continent, the island of Tasmania, and numerous smaller islands in the Indian and Pacific Oceans. It is the world's sixth-largest country by total area...

 was struck first around 46,000 years ago, followed by Tasmania
Tasmania
Tasmania is an Australian island and state. It is south of the continent, separated by Bass Strait. The state includes the island of Tasmania—the 26th largest island in the world—and the surrounding islands. The state has a population of 507,626 , of whom almost half reside in the greater Hobart...

 about 41,000 years ago (after formation of a land bridge to Australia about 43,000 years ago), Japan
Japan
Japan is an island nation in East Asia. Located in the Pacific Ocean, it lies to the east of the Sea of Japan, China, North Korea, South Korea and Russia, stretching from the Sea of Okhotsk in the north to the East China Sea and Taiwan in the south...

 apparently about 30,000 years ago, North America
North America
North America is a continent wholly within the Northern Hemisphere and almost wholly within the Western Hemisphere. It is also considered a northern subcontinent of the Americas...

 13,000 years ago, South America
South America
South America is a continent situated in the Western Hemisphere, mostly in the Southern Hemisphere, with a relatively small portion in the Northern Hemisphere. The continent is also considered a subcontinent of the Americas. It is bordered on the west by the Pacific Ocean and on the north and east...

 about 500 years later, Cyprus
Prehistoric Cyprus
The Prehistoric Period is the oldest part of Cypriot history.This article covers the period 10,000 to 800 BC and ends immediately before written records of civilizations, such as the first mention of Cyprus by the Romans.-Epipalaeolithic:...

 10,000 years ago, the Antilles
Antilles
The Antilles islands form the greater part of the West Indies in the Caribbean Sea. The Antilles are divided into two major groups: the "Greater Antilles" to the north and west, including the larger islands of Cuba, Jamaica, Hispaniola , and Puerto Rico; and the smaller "Lesser Antilles" on the...

 6000 years ago, New Caledonia and nearby islands 3000 years ago, Madagascar
Madagascar
The Republic of Madagascar is an island country located in the Indian Ocean off the southeastern coast of Africa...

 2000 years ago, New Zealand
New Zealand
New Zealand is an island country in the south-western Pacific Ocean comprising two main landmasses and numerous smaller islands. The country is situated some east of Australia across the Tasman Sea, and roughly south of the Pacific island nations of New Caledonia, Fiji, and Tonga...

 700 years ago, the Mascarenes
Mascarene Islands
The Mascarene Islands is a group of islands in the Indian Ocean east of Madagascar comprising Mauritius, Réunion, Rodrigues, Cargados Carajos shoals, plus the former islands of the Saya de Malha, Nazareth and Soudan banks...

 400 years ago, and the Commander Islands 250 years ago. Nearly all of the world's isolated islands could furnish similar examples of extinctions occurring shortly after the arrival of Homo sapiens, though most of these islands, such as the Hawaiian Islands
Hawaiian Islands
The Hawaiian Islands are an archipelago of eight major islands, several atolls, numerous smaller islets, and undersea seamounts in the North Pacific Ocean, extending some 1,500 miles from the island of Hawaii in the south to northernmost Kure Atoll...

, never had terrestrial megafauna, so their extinct fauna were smaller.

Continuing human hunting and environmental disturbance has led to additional megafaunal extinctions in the recent past, and has created a serious danger of further extinctions in the near future (see examples below).

A number of other mass extinction
Extinction event
An extinction event is a sharp decrease in the diversity and abundance of macroscopic life. They occur when the rate of extinction increases with respect to the rate of speciation...

s occurred earlier in Earth's geologic history, in which some or all of the megafauna of the time also died out. Famously, in the Cretaceous–Tertiary extinction event the dinosaurs and most other giant reptilians were eliminated. However, the earlier mass extinctions were more global and not so selective for megafauna; i.e., many species of other types, including plants, marine invertebrates and plankton, went extinct as well. Thus, the earlier events must have been caused by more generalized types of disturbances to the biosphere
Biosphere
The biosphere is the global sum of all ecosystems. It can also be called the zone of life on Earth, a closed and self-regulating system...

.

Effect of megafaunal extinctions on methane emissions

Many herbivores produce methane
Methane
Methane is a chemical compound with the chemical formula . It is the simplest alkane, the principal component of natural gas, and probably the most abundant organic compound on earth. The relative abundance of methane makes it an attractive fuel...

 as a byproduct of foregut fermentation
Foregut fermentation
Foregut fermentation is a form of digestion that occurs in the foregut of some animals. It has evolved independently in several groups of mammals, and also in the hoatzin bird. All ruminants use foregut fermentation, whereas only some rodents and marsupials do. It has also evolved in colobine...

 in digestion, and release it through belching. Large populations of herbivore megafauna have the potential to contribute greatly to the atmospheric concentration of methane, which is an important greenhouse gas
Greenhouse gas
A greenhouse gas is a gas in an atmosphere that absorbs and emits radiation within the thermal infrared range. This process is the fundamental cause of the greenhouse effect. The primary greenhouse gases in the Earth's atmosphere are water vapor, carbon dioxide, methane, nitrous oxide, and ozone...

. Today, around 20% of annual methane emissions come from livestock methane release. Recent studies have indicated that the extinction of megafaunal herbivores may have caused a reduction in atmospheric methane
Atmospheric methane
Atmospheric methane levels are of interest due to its impact on climate change. Atmospheric methane is one of the most potent and influential greenhouse gases on Earth. The 100-year global warming potential of methane is 25, i.e...

. This hypothesis is relatively new.

Several studies have examined the effect of elimination of megaherbivorous mammals on methane emissions. One study examined the methane emissions from the bison
American Bison
The American bison , also commonly known as the American buffalo, is a North American species of bison that once roamed the grasslands of North America in massive herds...

 that occupied the Great Plains
Great Plains
The Great Plains are a broad expanse of flat land, much of it covered in prairie, steppe and grassland, which lies west of the Mississippi River and east of the Rocky Mountains in the United States and Canada. This area covers parts of the U.S...

 of North America before contact with European settlers. The study estimated that the removal of the bison caused a decrease of 2.2 Tg/yr. This is a proportionally large change for the time period.

Another study examined the change of 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 ~13,000 BP
Before Present
Before Present years is a time scale used in archaeology, geology, and other scientific disciplines to specify when events in the past occurred. Because the "present" time changes, standard practice is to use AD 1950 as the origin of the age scale, reflecting the fact that radiocarbon...

, their hunting and other associated ecological impacts led to the extinction of many megafaunal species in the region. Calculations suggest that this extinction decreased methane production by ~9.6 Tg/yr. Ice core
Ice core
An ice core is a core sample that is typically removed from an ice sheet, most commonly from the polar ice caps of Antarctica, Greenland or from high mountain glaciers elsewhere. As the ice forms from the incremental build up of annual layers of snow, lower layers are older than upper, and an ice...

 records support this hypothesis of rapid methane decrease during the time period. This suggests that the absence of megafaunal methane emissions may have contributed to the abrupt climatic cooling at the onset of the Younger Dryas
Younger Dryas
The Younger Dryas stadial, also referred to as the Big Freeze, was a geologically brief period of cold climatic conditions and drought between approximately 12.8 and 11.5 ka BP, or 12,800 and 11,500 years before present...

.

Examples

The following are some notable examples of animals often considered as megafauna (in the sense of the "large animal" definition). This list is not intended to be exhaustive:
  • class Mammalia
    • infraclass Metatheria
      Metatheria
      Metatheria is a grouping within the animal class Mammalia. First proposed by Thomas Henry Huxley in 1880, it is nearly synonymous with the earlier taxon Marsupialia though it is slightly wider since it also contains the nearest fossil relatives of marsupial mammals.The earliest known...

      • order Diprotodontia
        Diprotodontia
        Diprotodontia is a large order of about 120 marsupial mammals including the kangaroos, wallabies, possums, koala, wombats, and many others. Extinct diprotodonts include the rhinoceros-sized Diprotodon, and Thylacoleo, the so-called "marsupial lion"....

        • The red kangaroo
          Red Kangaroo
          The Red Kangaroo is the largest of all kangaroos, the largest mammal native to Australia, and the largest surviving marsupial. It is found across mainland Australia, avoiding only the more fertile areas in the south, the east coast, and the northern rainforests.-Description:This species is a very...

           (Macropus rufus) is the largest living Australia
          Australia
          Australia , officially the Commonwealth of Australia, is a country in the Southern Hemisphere comprising the mainland of the Australian continent, the island of Tasmania, and numerous smaller islands in the Indian and Pacific Oceans. It is the world's sixth-largest country by total area...

          n mammal and marsupial
          Marsupial
          Marsupials are an infraclass of mammals, characterized by giving birth to relatively undeveloped young. Close to 70% of the 334 extant species occur in Australia, New Guinea, and nearby islands, with the remaining 100 found in the Americas, primarily in South America, but with thirteen in Central...

           at a weight of up to 85 kg (187.4 lb). However, its extinct relative, the giant short-faced kangaroo
          Procoptodon
          Procoptodon was a genus of giant short-faced kangaroo living in Australia during the Pleistocene epoch. P. goliah, the largest known kangaroo that ever existed, stood approximately 2 meters tall. They weighed about ....

           Procoptodon goliah reached 230 kg (507.1 lb), while extinct diprotodon
          Diprotodon
          Diprotodon, meaning "two forward teeth", sometimes known as the Giant Wombat or the Rhinoceros Wombat, was the largest known marsupial that ever lived...

          ts attained the largest size of any marsupial in history, up to an estimated 2750 kg (6,062.7 lb). The extinct marsupial lion
          Marsupial Lion
          The Marsupial Lion is an extinct species of carnivorous marsupial mammal that lived in Australia from the early to the late Pleistocene...

           (Thylacleo carnifex), at up to 160 kg (350 lb) was much larger than any extant carnivorous marsupial.
    • infraclass Eutheria
      Eutheria
      Eutheria is a group of mammals consisting of placental mammals plus all extinct mammals that are more closely related to living placentals than to living marsupials . They are distinguished from noneutherians by various features of the feet, ankles, jaws and teeth...

      • superorder Afrotheria
        Afrotheria
        Afrotheria is a clade of mammals, the living members of which belong to groups from Africa or of African origin: golden moles, sengis , tenrecs, aardvarks, hyraxes, elephants and sea cows. The common ancestry of these animals was not recognized until the late 1990s...

        • order Proboscidea
          Proboscidea
          Proboscidea is a taxonomic order containing one living family, Elephantidae, and several extinct families. This order was first described by J. Illiger in 1881 and encompasses the trunked mammals...

          • Elephants are the largest living land animals. They and their relatives arose in Africa
            Africa
            Africa is the world's second largest and second most populous continent, after Asia. At about 30.2 million km² including adjacent islands, it covers 6% of the Earth's total surface area and 20.4% of the total land area...

            , but until recently had a nearly worldwide distribution. The African bush elephant
            African Bush Elephant
            The African Bush Elephant or African Savanna Elephant is the larger of the two species of African elephant. Both it and the African Forest Elephant have usually been classified as a single species, known simply as the African Elephant...

             (Loxodonta africana) has a shoulder height of up to 4.3 m (14 ft) and weighs up to 13 tons. Among recently extinct proboscideans, mammoth
            Mammoth
            A mammoth is any species of the extinct genus Mammuthus. These proboscideans are members of Elephantidae, the family of elephants and mammoths, and close relatives of modern elephants. They were often equipped with long curved tusks and, in northern species, a covering of long hair...

            s (Mammuthus) were close relatives of elephants, while mastodon
            Mastodon
            Mastodons were large tusked mammal species of the extinct genus Mammut which inhabited Asia, Africa, Europe, North America and Central America from the Oligocene through Pleistocene, 33.9 mya to 11,000 years ago. The American mastodon is the most recent and best known species of the group...

            s (Mammut) were much more distantly related. The Songhua River mammoth
            Mammuthus sungari
            Mammuthus sungari, sometimes called the Songhua River Mammoth, evolved from smaller Siberian mammoths and occurred in Northern China during the middle Pleistocene...

             (M. sungari) is estimated to have weighed 17 tonnes, making it the largest proboscid
            Proboscidea
            Proboscidea is a taxonomic order containing one living family, Elephantidae, and several extinct families. This order was first described by J. Illiger in 1881 and encompasses the trunked mammals...

             and second largest land mammal after indricotherines
            Indricotheriinae
            Indricotheriinae is a subfamily of Hyracodontidae, a group of long-limbed, hornless rhinoceroses that evolved in the Eocene epoch and continued through to the early Miocene. The earlier hyracodontid species, such as Hyracodon were modest-sized, fast-running, lightly built animals with little...

            .
        • order Sirenia
          Sirenia
          Sirenia is an order of fully aquatic, herbivorous mammals that inhabit swamps, rivers, estuaries, marine wetlands, and coastal marine waters. Four species are living, in two families and genera. These are the dugong and manatees...

          • The largest sirenian at up to 1500 kg is the West Indian manatee
            West Indian Manatee
            The West Indian Manatee is a manatee, and the largest surviving member of the aquatic mammal order Sirenia . The West Indian Manatee, Trichechus manatus, is a species distinct from the Amazonian Manatee, T. inunguis, and the West African Manatee, T. senegalensis...

             (Trichechus manatus). Steller's sea cow
            Steller's Sea Cow
            Steller's sea cow was a large herbivorous marine mammal. In historical times, it was the largest member of the order Sirenia, which includes its closest living relative, the dugong , and the manatees...

             (Hydrodamalis gigas) was probably around five times as massive, but unfortunately was exterminated by humans within 27 years of its discovery off the remote Commander Islands in 1741. In prehistoric times this sea cow also lived along the coasts of northeastern Asia
            Asia
            Asia is the world's largest and most populous continent, located primarily in the eastern and northern hemispheres. It covers 8.7% of the Earth's total surface area and with approximately 3.879 billion people, it hosts 60% of the world's current human population...

             and northwestern North America
            North America
            North America is a continent wholly within the Northern Hemisphere and almost wholly within the Western Hemisphere. It is also considered a northern subcontinent of the Americas...

            ; it was apparently eliminated from these more accessible locations by aboriginal hunters.
      • superorder Xenarthra
        Xenarthra
        The superorder Xenarthra is a group of placental mammals , existent today only in the Americas and represented by anteaters, tree sloths, and armadillos. The origins of the order can be traced back as far as the Paleogene in South America...

        • order Cingulata
          • The glyptodonts
            Glyptodontidae
            Glyptodonts were large, more heavily armored relatives of extinct pampatheres and modern armadillos.They first evolved during the Miocene in South America, which remained their center of species diversity...

             were a group of large, heavily armored ankylosaur
            Ankylosauria
            Ankylosauria is a group of herbivorous dinosaurs of the order Ornithischia. It includes the great majority of dinosaurs with armor in the form of bony osteoderms. Ankylosaurs were bulky quadrupeds, with short, powerful limbs. They are first known to have appeared in the early Jurassic Period of...

            -like xenarthra
            Xenarthra
            The superorder Xenarthra is a group of placental mammals , existent today only in the Americas and represented by anteaters, tree sloths, and armadillos. The origins of the order can be traced back as far as the Paleogene in South America...

            ns related to living armadillos. They originated in South America
            South America
            South America is a continent situated in the Western Hemisphere, mostly in the Southern Hemisphere, with a relatively small portion in the Northern Hemisphere. The continent is also considered a subcontinent of the Americas. It is bordered on the west by the Pacific Ocean and on the north and east...

            , invaded North America during the Great American Interchange
            Great American Interchange
            The Great American Interchange was an important paleozoogeographic event in which land and freshwater fauna migrated from North America via Central America to South America and vice versa, as the volcanic Isthmus of Panama rose up from the sea floor and bridged the formerly separated continents...

            , and went extinct at the end of the Pleistocene
            Pleistocene
            The Pleistocene is the epoch from 2,588,000 to 11,700 years BP that spans the world's recent period of repeated glaciations. The name pleistocene is derived from the Greek and ....

             epoch
            Series (stratigraphy)
            Series are subdivisions of rock layers made based on the age of the rock and corresponding to the dating system unit called an epoch, both being formally defined international conventions of the geological timescale. A series is therefore a sequence of rock depositions defining a...

            .
        • order Pilosa
          Pilosa
          The order Pilosa is a group of placental mammals, extant today only in the Americas. It includes the anteaters and sloths, including the recently extinct ground sloths....

          • Ground sloth
            Ground sloth
            Ground sloths are a diverse group of extinct sloths, in the mammalian superorder Xenarthra. Their most recent survivors lived in the Antilles, where it has been proposed they may have survived until 1550 CE; however, the youngest AMS radiocarbon date reported is 4190 BP, calibrated to c. 4700 BP...

            s were another group of slow, terrestrial xenarthrans, related to modern tree sloth
            Sloth
            Sloths are the six species of medium-sized mammals belonging to the families Megalonychidae and Bradypodidae , part of the order Pilosa and therefore related to armadillos and anteaters, which sport a similar set of specialized claws.They are arboreal residents of the jungles of Central and South...

            s. They had a similar history, although they reached North America earlier, and spread farther north
            Megalonyx
            Megalonyx is an extinct genus of giant ground sloths of the family Megalonychidae endemic to North America from the Hemphillian of the Late Miocene through to the Rancholabrean of the Pleistocene, living from ~10.3 Mya—11,000 years ago, existing for approximately .-Taxonomy:The generic name...

            . The largest genera, Megatherium
            Megatherium
            Megatherium was a genus of elephant-sized ground sloths endemic to Central America and South America that lived from the Pliocene through Pleistocene existing approximately...

            and Eremotherium
            Eremotherium
            Eremotherium is an extinct genus of actively mobile ground sloth of the family Megatheriidae, endemic to North America and South America during the Pleistocene epoch...

            , reached sizes comparable to elephants.
      • superorder Euarchontoglires
        Euarchontoglires
        Euarchontoglires is a clade of mammals, the living members of which are rodents, lagomorphs, treeshrews, colugos and primates .-Evolutionary relationships:...

        • order Primates
          • The largest living primate, at up to 266 kg (586.4 lb), is the gorilla
            Gorilla
            Gorillas are the largest extant species of primates. They are ground-dwelling, predominantly herbivorous apes that inhabit the forests of central Africa. Gorillas are divided into two species and either four or five subspecies...

             (Gorilla beringei and Gorilla gorilla, with three of four subspecies being critically endangered
            Critically endangered
            Version 2010.3 of the IUCN Red List of Threatened Species identified 3744 Critically Endangered species, subspecies and varieties, stocks and subpopulations.Critically Endangered by kingdom:*1993 Animalia*2 Fungi*1745 Plantae*4 Protista-References:...

            ). The extinct Malagasy sloth lemur Archaeoindris
            Archaeoindris
            Archaeoindris fontoynonti is an extinct species of Malagasy lemur that was the largest primate to evolve on Madagascar. It weighed about and measured around 1.5m in height, more than a silverback gorilla. Archaeoindris is one of eight known members of the Palaeopropithecinae subfamily...

            reached a similar size, while the extinct Gigantopithecus blacki of Southeast Asia
            Southeast Asia
            Southeast Asia, South-East Asia, South East Asia or Southeastern Asia is a subregion of Asia, consisting of the countries that are geographically south of China, east of India, west of New Guinea and north of Australia. The region lies on the intersection of geological plates, with heavy seismic...

             is believed to have been several times larger. Some populations of archaic Homo
            Archaic Homo sapiens
            Archaic Homo sapiens is a loosely defined term used to describe a number of varieties of Homo, as opposed to anatomically modern humans , in the period beginning 500,000 years ago....

             were significantly larger than recent Homo sapiens; for example, Homo heidelbergensis
            Homo heidelbergensis
            Homo heidelbergensis is an extinct species of the genus Homo which may be the direct ancestor of both Homo neanderthalensis in Europe and Homo sapiens. The best evidence found for these hominins date between 600,000 and 400,000 years ago. H...

            in southern Africa may have commonly reached 7 feet (2.1 m) in height, while Neanderthal
            Neanderthal
            The Neanderthal is an extinct member of the Homo genus known from Pleistocene specimens found in Europe and parts of western and central Asia...

            s were about 30% more massive.
        • order Rodent
          Rodent
          Rodentia is an order of mammals also known as rodents, characterised by two continuously growing incisors in the upper and lower jaws which must be kept short by gnawing....

          ia
          • The extant capybara
            Capybara
            The capybara , also known as capivara in Portuguese, and capibara, chigüire in Venezuela, Colombia, and Ecuador ronsoco in Peru, chigüiro, and carpincho in Spanish, is the largest living rodent in the world. Its closest relatives are agouti, chinchillas, coyphillas, and guinea pigs...

             (Hydrochoerus hydrochaeris) of South America, the largest living rodent, weighs up to 65 kg (143.3 lb). Several recently extinct North American forms were larger: the capybara Neochoerus pinckneyi
            Neochoerus pinckneyi
            Neochoerus pinckneyi was a North American species of capybara. While capybaras originated in South America, formation of the Isthmus of Panama three million years ago allowed some of them to migrate north as part of the Great American Interchange...

            (another neotropic migrant) was about 40% heavier; the giant beaver
            Giant Beaver
            Castoroides ohioensis was a species of giant beaver, huge members of the family Castoridae , endemic to North America during the Pleistocene epoch .-Morphology:...

             (Castoroides ohioensis) was similar. The extinct blunt-toothed giant hutia
            Blunt-toothed Giant Hutia
            The Blunt-toothed Giant Hutia is an extinct species of giant hutia from Anguilla and Saint Martin that is estimated to have weighed between 50 and 200 kg ....

             (Amblyrhiza inundata) of several Caribbean
            Caribbean
            The Caribbean is a crescent-shaped group of islands more than 2,000 miles long separating the Gulf of Mexico and the Caribbean Sea, to the west and south, from the Atlantic Ocean, to the east and north...

             islands may have been larger still. However, several million years ago South America harbored much more massive rodents. Phoberomys pattersoni
            Phoberomys pattersoni
            Phoberomys pattersoni is an extinct rodent that lived in the ancient Orinoco River delta approximately 8 million years ago. It was the second-largest of the roughly 7 species of its genus. Like many other rodents, Phoberomys was a herbivore with high-crowned premolars and molars...

            , known from a nearly full skeleton, probably reached 700 kg (1,543.2 lb). Fragmentary remains suggest that Josephoartigasia monesi
            Josephoartigasia monesi
            Josephoartigasia monesi, an extinct species of South American caviomorph rodent, is the largest rodent known, and lived approximately 4 to 2 million years ago during the Pliocene to early Pleistocene. The species may have weighed , considerably larger than its closest living relative, the pacarana...

            grew to upwards of 1000 kg (2,204.6 lb).
      • superorder Laurasiatheria
        Laurasiatheria
        Laurasiatheria is a large group of placental mammals believed to have originated on the northern supercontinent of Laurasia. It includes shrews, hedgehogs, pangolins, bats, whales, most hoofed mammals, and carnivorans, among others....

        • order Carnivora
          Carnivora
          The diverse order Carnivora |Latin]] carō "flesh", + vorāre "to devour") includes over 260 species of placental mammals. Its members are formally referred to as carnivorans, while the word "carnivore" can refer to any meat-eating animal...

          • Big cats include the tiger
            Tiger
            The tiger is the largest cat species, reaching a total body length of up to and weighing up to . Their most recognizable feature is a pattern of dark vertical stripes on reddish-orange fur with lighter underparts...

             (Panthera tigris) and lion
            Lion
            The lion is one of the four big cats in the genus Panthera, and a member of the family Felidae. With some males exceeding 250 kg in weight, it is the second-largest living cat after the tiger...

             (Panthera leo). The largest subspecies, at up to 306 kg, is the Siberian tiger (P. tigris altaica), in accord with Bergmann's rule
            Bergmann's Rule
            Bergmann's rule is an ecogeographic principle that states that within a broadly distributed genus, species of larger size are found in colder environments, and species of smaller size are found in warmer regions. Although originally formulated in terms of species within a genus, it has often been...

            . Members of Panthera
            Panthera
            Panthera is a genus of the family Felidae , which contains four well-known living species: the tiger, the lion, the jaguar, and the leopard. The genus comprises about half of the Pantherinae subfamily, the big cats...

            are distinguished by morphological
            Morphology (biology)
            In biology, morphology is a branch of bioscience dealing with the study of the form and structure of organisms and their specific structural features....

             features which enable them to roar. Larger extinct felids include the American lion
            American lion
            The American lion — also known as the North American lion, Naegele’s giant jaguar or American cave lion — is an extinct lion of the family Felidae, endemic to North America during the Pleistocene epoch , existing for approximately...

             (Panthera leo atrox) and the South American saber-toothed cat
            Saber-toothed cat
            Saber-toothed cat or Sabre-toothed cat refers to the extinct subfamilies of Machairodontinae , Barbourofelidae , and Nimravidae as well as two families related to marsupials that were found worldwide from the Eocene Epoch to the end of the Pleistocene Epoch ,...

             Smilodon populator.
          • Bears are large carnivorans of the caniform suborder
            Caniformia
            Caniformia, or Canoidea , is a suborder within the order Carnivora. They typically possess a long snout and non-retractile claws . The Pinnipedia evolved from caniform ancestors and are accordingly assigned to this group...

            . The largest living forms are the polar bear
            Polar Bear
            The polar bear is a bear native largely within the Arctic Circle encompassing the Arctic Ocean, its surrounding seas and surrounding land masses. It is the world's largest land carnivore and also the largest bear, together with the omnivorous Kodiak Bear, which is approximately the same size...

             (Ursus maritimus), with a body weight of up to 680 kg (1,499.1 lb), and the similarly sized Kodiak bear
            Kodiak Bear
            The Kodiak bear , also known as the Kodiak brown bear or the Alaskan grizzly bear or American brown bear, occupies the islands of the Kodiak Archipelago in South-Western Alaska. Its name in the Alutiiq language is Taquka-aq. It is the largest subspecies of brown bear.- Taxonomy :Taxonomist C.H...

             (Ursus arctos middendorffi), again consistent with Bergmann's rule. Arctotherium
            Arctotherium
            Arctotherium is an extinct genus of South American short-faced bears within Ursidae of the late Pliocene through the end of the Pleistocene. Their ancestors migrated from North America to South America during the Great American Interchange, following the formation of the Isthmus of Panama. They...

             augustans
            , an extinct short-faced bear from South America, was the largest predatory land mammal ever with an estimated average weight of 1,600 kg (3,500 lb).
          • Seals, sea lions, and walruses
            Pinniped
            Pinnipeds or fin-footed mammals are a widely distributed and diverse group of semiaquatic marine mammals comprising the families Odobenidae , Otariidae , and Phocidae .-Overview: Pinnipeds are typically sleek-bodied and barrel-shaped...

             are amphibious marine carnivorans that evolved from bearlike ancestors. The southern elephant seal
            Southern Elephant Seal
            The Southern Elephant Seal is one of the two extant species of elephant seal. It is both the most massive pinniped and member of the order Carnivora living today...

             (Mirounga leonina) of Antarctic
            Antarctic
            The Antarctic is the region around the Earth's South Pole, opposite the Arctic region around the North Pole. The Antarctic comprises the continent of Antarctica and the ice shelves, waters and island territories in the Southern Ocean situated south of the Antarctic Convergence...

             and subantarctic
            Subantarctic
            The Subantarctic is a region in the southern hemisphere, located immediately north of the Antarctic region. This translates roughly to a latitude of between 46° – 60° south of the Equator. The subantarctic region includes many islands in the southern parts of the Indian Ocean, Atlantic Ocean and...

             waters is the largest carnivoran of all time, with bull males reaching a maximum length of 6–7 m (19.7–23 ft) and maximum weight of 5,000 kilograms.
        • order Perissodactyla
          • Tapir
            Tapir
            A Tapir is a large browsing mammal, similar in shape to a pig, with a short, prehensile snout. Tapirs inhabit jungle and forest regions of South America, Central America, and Southeast Asia. There are four species of Tapirs: the Brazilian Tapir, the Malayan Tapir, Baird's Tapir and the Mountain...

            s are browsing animals, with a short prehensile snout and pig-like form that appears to have changed little in 20 million years. They inhabit tropical forests
            Tropical rainforest
            A tropical rainforest is an ecosystem type that occurs roughly within the latitudes 28 degrees north or south of the equator . This ecosystem experiences high average temperatures and a significant amount of rainfall...

             of Southeast Asia and South and Central America, and include the largest surviving land animals of the latter two regions. There are four species.
          • Rhinoceros
            Rhinoceros
            Rhinoceros , also known as rhino, is a group of five extant species of odd-toed ungulates in the family Rhinocerotidae. Two of these species are native to Africa and three to southern Asia....

            es are odd-toed ungulates with horns made of keratin
            Keratin
            Keratin refers to a family of fibrous structural proteins. Keratin is the key of structural material making up the outer layer of human skin. It is also the key structural component of hair and nails...

            , the same type of protein
            Protein
            Proteins are biochemical compounds consisting of one or more polypeptides typically folded into a globular or fibrous form, facilitating a biological function. A polypeptide is a single linear polymer chain of amino acids bonded together by peptide bonds between the carboxyl and amino groups of...

             composing hair. They are among the largest living land mammals after elephants (hippos attain a similar size). Three of five extant species are critically endangered. Their extinct central Asia
            Central Asia
            Central Asia is a core region of the Asian continent from the Caspian Sea in the west, China in the east, Afghanistan in the south, and Russia in the north...

            n relatives the indricotherines
            Indricotheriinae
            Indricotheriinae is a subfamily of Hyracodontidae, a group of long-limbed, hornless rhinoceroses that evolved in the Eocene epoch and continued through to the early Miocene. The earlier hyracodontid species, such as Hyracodon were modest-sized, fast-running, lightly built animals with little...

             were the largest terrestrial mammals of all time.
        • order Artiodactyla (or cladistically
          Cladistics
          Cladistics is a method of classifying species of organisms into groups called clades, which consist of an ancestor organism and all its descendants . For example, birds, dinosaurs, crocodiles, and all descendants of their most recent common ancestor form a clade...

          , Cetartiodactyla
          Cetartiodactyla
          Cetartiodactyla is the clade in which whales and even-toed ungulates have currently been placed. The term was coined by merging the name for the two orders, Cetacea and Artiodactyla, into a single word. The term Cetartiodactyla reflects the idea that whales evolved within the artiodactyls...

          )
          • Giraffes (Giraffa camelopardalis) are the tallest living land animals, reaching heights of up to nearly 6 m (20 ft).
          • Bovine ungulates
            Bovinae
            The biological subfamily Bovinae includes a diverse group of 10 genera of medium to large sized ungulates, including domestic cattle, the bison, African buffalo, the water buffalo, the yak, and the four-horned and spiral-horned antelopes...

             include the largest surviving land animals of Europe
            Europe
            Europe is, by convention, one of the world's seven continents. Comprising the westernmost peninsula of Eurasia, Europe is generally 'divided' from Asia to its east by the watershed divides of the Ural and Caucasus Mountains, the Ural River, the Caspian and Black Seas, and the waterways connecting...

             and North America. The water buffalo (Bubalis arnee), bison
            Bison
            Members of the genus Bison are large, even-toed ungulates within the subfamily Bovinae. Two extant and four extinct species are recognized...

             (Bison bison and B. bonasus
            Wisent
            The wisent , Bison bonasus, also known as the European bison or European wood bison, is a species of Eurasian bison. It is the heaviest surviving land animal in Europe; a typical wisent is about long, not counting a tail of long, and tall. Weight typically can range from , with an occasional big...

            ), and gaur
            Gaur
            The gaur , also called Indian bison, is a large bovine native to South Asia and Southeast Asia. The species is listed as vulnerable on the IUCN Red List since 1986 as the population decline in parts of the species' range is likely to be well over 70% over the last three generations...

             (Bos gaurus) can all grow to weights of over 900 kg (1,984.2 lb).
          • The semiaquatic  hippopotamus
            Hippopotamus
            The hippopotamus , or hippo, from the ancient Greek for "river horse" , is a large, mostly herbivorous mammal in sub-Saharan Africa, and one of only two extant species in the family Hippopotamidae After the elephant and rhinoceros, the hippopotamus is the third largest land mammal and the heaviest...

             (Hippopotamus amphibius) is the heaviest living even-toed ungulate
            Even-toed ungulate
            The even-toed ungulates are ungulates whose weight is borne about equally by the third and fourth toes, rather than mostly or entirely by the third as in odd-toed ungulates such as horses....

            ; it and the critically endangered pygmy hippo
            Pygmy Hippopotamus
            The pygmy hippopotamus is a large mammal native to the forests and swamps of western Africa . The pygmy hippo is reclusive and nocturnal...

             (Choeropsis liberiensis) are believed to be the closest extant relatives of cetaceans. Hippos are among the megafaunal species most dangerous to humans.
        • order Cetacea
          Cetacea
          The order Cetacea includes the marine mammals commonly known as whales, dolphins, and porpoises. Cetus is Latin and is used in biological names to mean "whale"; its original meaning, "large sea animal", was more general. It comes from Ancient Greek , meaning "whale" or "any huge fish or sea...

           (or cladistically, Cetartiodactyla)
          • Whales, dolphins, and porpoises
            Cetacea
            The order Cetacea includes the marine mammals commonly known as whales, dolphins, and porpoises. Cetus is Latin and is used in biological names to mean "whale"; its original meaning, "large sea animal", was more general. It comes from Ancient Greek , meaning "whale" or "any huge fish or sea...

             are marine mammals. The blue whale
            Blue Whale
            The blue whale is a marine mammal belonging to the suborder of baleen whales . At in length and or more in weight, it is the largest known animal to have ever existed....

             (Balaenoptera musculus) is the largest baleen whale
            Baleen whale
            The Baleen whales, also called whalebone whales or great whales, form the Mysticeti, one of two suborders of the Cetacea . Baleen whales are characterized by having baleen plates for filtering food from water, rather than having teeth. This distinguishes them from the other suborder of cetaceans,...

             and the largest animal that has ever lived. The sperm whale
            Sperm Whale
            The sperm whale, Physeter macrocephalus, is a marine mammal species, order Cetacea, a toothed whale having the largest brain of any animal. The name comes from the milky-white waxy substance, spermaceti, found in the animal's head. The sperm whale is the only living member of genus Physeter...

             (Physeter macrocephalus) is the largest toothed whale
            Toothed whale
            The toothed whales form a suborder of the cetaceans, including sperm whales, beaked whales, dolphins, and others. As the name suggests, the suborder is characterized by the presence of teeth rather than the baleen of other whales.-Anatomy:Toothed whales have a single blowhole on the top of the head...

            , as well as the planet's loudest and brainiest animal (with a brain
            Brain
            The brain is the center of the nervous system in all vertebrate and most invertebrate animals—only a few primitive invertebrates such as sponges, jellyfish, sea squirts and starfishes do not have one. It is located in the head, usually close to primary sensory apparatus such as vision, hearing,...

             about five times as massive as a human's
            Human brain
            The human brain has the same general structure as the brains of other mammals, but is over three times larger than the brain of a typical mammal with an equivalent body size. Estimates for the number of neurons in the human brain range from 80 to 120 billion...

            ). The killer whale (Orcinus orca) is the largest dolphin.
  • class Aves (phylogenetically
    Phylogenetic nomenclature
    Phylogenetic nomenclature or phylogenetic taxonomy is an alternative to rank-based nomenclature, applying definitions from cladistics . Its two defining features are the use of phylogenetic definitions of biological taxon names, and the lack of obligatory ranks...

    , a clade
    Clade
    A clade is a group consisting of a species and all its descendants. In the terms of biological systematics, a clade is a single "branch" on the "tree of life". The idea that such a "natural group" of organisms should be grouped together and given a taxonomic name is central to biological...

     within Coelurosauria
    Coelurosauria
    Coelurosauria is the clade containing all theropod dinosaurs more closely related to birds than to carnosaurs. In the past, it was used to refer to all small theropods, although this classification has been abolished...

    , a taxon
    Taxon
    |thumb|270px|[[African elephants]] form a widely-accepted taxon, the [[genus]] LoxodontaA taxon is a group of organisms, which a taxonomist adjudges to be a unit. Usually a taxon is given a name and a rank, although neither is a requirement...

     within the order Saurischia of the clade Sauropsida
    Sauropsida
    Sauropsida is a group of amniotes that includes all existing reptiles and birds and their fossil ancestors, including the dinosaurs, the immediate ancestors of birds...

    ; see below)
    • order Struthioniformes
      • The ratite
        Ratite
        A ratite is any of a diverse group of large, flightless birds of Gondwanan origin, most of them now extinct. Unlike other flightless birds, the ratites have no keel on their sternum—hence the name from the Latin ratis...

        s are an ancient and diverse group of flightless bird
        Flightless bird
        Flightless birds are birds which lack the ability to fly, relying instead on their ability to run or swim. They are thought to have evolved from flying ancestors. There are about forty species in existence today, the best known being the ostrich, emu, cassowary, rhea, kiwi, and penguin...

        s that are found on fragments of the former supercontinent
        Supercontinent
        In geology, a supercontinent is a landmass comprising more than one continental core, or craton. The assembly of cratons and accreted terranes that form Eurasia qualifies as a supercontinent today.-History:...

         Gondwana
        Gondwana
        In paleogeography, Gondwana , originally Gondwanaland, was the southernmost of two supercontinents that later became parts of the Pangaea supercontinent. It existed from approximately 510 to 180 million years ago . Gondwana is believed to have sutured between ca. 570 and 510 Mya,...

        . The largest living bird, the Ostrich
        Ostrich
        The Ostrich is one or two species of large flightless birds native to Africa, the only living member of the genus Struthio. Some analyses indicate that the Somali Ostrich may be better considered a full species apart from the Common Ostrich, but most taxonomists consider it to be a...

         (Struthio camelus) was surpassed by the extinct Aepyornis
        Aepyornis
        Aepyornis is a genus of aepyornithid, one of two genera of ratite birds endemic to Madagascar known as elephant birds. This animal was the world's largest bird until its extinction, about 1000 years ago.-Description:...

        of Madagascar
        Madagascar
        The Republic of Madagascar is an island country located in the Indian Ocean off the southeastern coast of Africa...

        , the heaviest of the group, and the extinct giant moa (Dinornis) of New Zealand
        New Zealand
        New Zealand is an island country in the south-western Pacific Ocean comprising two main landmasses and numerous smaller islands. The country is situated some east of Australia across the Tasman Sea, and roughly south of the Pacific island nations of New Caledonia, Fiji, and Tonga...

        , the tallest, growing to heights of 3.4 m (11 ft). The latter two are examples of island gigantism
        Island gigantism
        Island gigantism or insular giantism is a biological phenomenon in which the size of animals isolated on an island increases dramatically in comparison to their mainland relatives....

        .
    • order Anseriformes
      Anseriformes
      The order Anseriformes contains about 150 living species of birds in three extant families: the Anhimidae , Anseranatidae , and the Anatidae, which includes over 140 species of waterfowl, among them the ducks, geese, and swans.All species in the order are highly adapted for an aquatic existence at...

      • Extinct dromornithid
        Dromornithidae
        Dromornithidae — the dromornithids — were a family of large, flightless Australian birds of the Oligocene through Pleistocene epochs. All are now extinct. They were long classified in the order Struthioniformes, but are now usually classified as a family of Anseriformes1...

        s of Australia such as Dromornis
        Dromornis
        Dromornis is a genus of prehistoric birds. They stood 3 meters tall and weighed half a ton. Dromornis lived in Australia from the late Miocene to the early Pliocene, meaning that early humans never encountered this genus....

        may have exceeded the largest ratites in size. (Due to its small size for a continent and its isolation, Australia is sometimes viewed as the world's largest island; thus, these species could also be considered insular giants.)
  • class Reptilia (or cladistically, Sauropsida)
    • order Crocodilia
      Crocodilia
      Crocodilia is an order of large reptiles that appeared about 84 million years ago in the late Cretaceous Period . They are the closest living relatives of birds, as the two groups are the only known survivors of the Archosauria...

      • Alligators and crocodiles are large semiaquatic reptiles, the largest of which, the saltwater crocodile
        Saltwater Crocodile
        The saltwater crocodile, also known as estuarine or Indo-Pacific crocodile, is the largest of all living reptiles...

         (Crocodylus porosus), can grow to a weight of 1360 kg (2,998.3 lb). Crocodilians' distant ancestors and their kin, the crurotarsans, dominated the world in the late Triassic
        Triassic
        The Triassic is a geologic period and system that extends from about 250 to 200 Mya . As the first period of the Mesozoic Era, the Triassic follows the Permian and is followed by the Jurassic. Both the start and end of the Triassic are marked by major extinction events...

        , until the Triassic–Jurassic extinction event allowed dinosaurs to overtake them. They remained diverse during the later Mesozoic
        Mesozoic
        The Mesozoic era is an interval of geological time from about 250 million years ago to about 65 million years ago. It is often referred to as the age of reptiles because reptiles, namely dinosaurs, were the dominant terrestrial and marine vertebrates of the time...

        , when crocodyliforms
        Crocodyliformes
        Crocodyliformes is a clade of crurotarsan archosaurs, the group often traditionally referred to as "crocodilians."In 1988, Michael J. Benton and James M. Clark argued that all traditional names for well-known groups of animals should be restricted to their crown clades, that is, used only for...

         such as Deinosuchus
        Deinosuchus
        Deinosuchus is an extinct genus related to the alligator that lived 73 to 80 Ma , during the late Cretaceous period. The name translates as "terrible crocodile" and is derived from the Greek deinos , "terrible", and soukhos , "crocodile"...

        and Sarcosuchus
        Sarcosuchus
        Sarcosuchus is an extinct genus of crocodyliform and distant relative of the crocodile that lived 112 million years ago. It dates from the early Cretaceous Period of what is now Africa and is one of the largest giant crocodile-like reptiles that ever lived...

        reached lengths of 12 m. Similarly large crocodilians, such as Mourasuchus
        Mourasuchus
        Mourasuchus is an extinct genus of giant crocodilian from the Miocene of South America. It was similar in length and weight to Rhamphosuchus...

        and Purussaurus
        Purussaurus
        Purussaurus is an extinct genus of giant caiman that lived in South America during the Miocene epoch, 8 million years ago. It is known from skull material found in the Brazilian, Colombian and Peruvian Amazonia, and northern Venezuela. The estimated skull length for one large individual of the type...

        , were present as recently as the Miocene
        Miocene
        The Miocene is a geological epoch of the Neogene Period and extends from about . The Miocene was named by Sir Charles Lyell. Its name comes from the Greek words and and means "less recent" because it has 18% fewer modern sea invertebrates than the Pliocene. The Miocene follows the Oligocene...

         in South America.
    • order Saurischia
      Saurischia
      Saurischia meaning 'lizard' and ischion meaning 'hip joint') is one of the two orders, or basic divisions, of dinosaurs. In 1888, Harry Seeley classified dinosaurs into two orders, based on their hip structure...

      • Saurischian dinosaur
        Dinosaur
        Dinosaurs are a diverse group of animals of the clade and superorder Dinosauria. They were the dominant terrestrial vertebrates for over 160 million years, from the late Triassic period until the end of the Cretaceous , when the Cretaceous–Paleogene extinction event led to the extinction of...

        s of the Jurassic
        Jurassic
        The Jurassic is a geologic period and system that extends from about Mya to  Mya, that is, from the end of the Triassic to the beginning of the Cretaceous. The Jurassic constitutes the middle period of the Mesozoic era, also known as the age of reptiles. The start of the period is marked by...

         and Cretaceous
        Cretaceous
        The Cretaceous , derived from the Latin "creta" , usually abbreviated K for its German translation Kreide , is a geologic period and system from circa to million years ago. In the geologic timescale, the Cretaceous follows the Jurassic period and is followed by the Paleogene period of the...

         include sauropod
        Sauropoda
        Sauropoda , or the sauropods , are an infraorder of saurischian dinosaurs. They had long necks, long tails, small heads , and thick, pillar-like legs. They are notable for the enormous sizes attained by some species, and the group includes the largest animals to have ever lived on land...

        s, the longest (at up to 40 m or 131.2 ft) and most massive terrestrial animals known (Argentinosaurus
        Argentinosaurus
        Argentinosaurus is a genus of titanosaur sauropod dinosaur first discovered by Guillermo Heredia in Argentina. The generic name refers to the country in which it was discovered...

        reached 80–100 metric tonnes, or 90–110 ton
        Short ton
        The short ton is a unit of mass equal to . In the United States it is often called simply ton without distinguishing it from the metric ton or the long ton ; rather, the other two are specifically noted. There are, however, some U.S...

        s), as well as theropod
        Theropoda
        Theropoda is both a suborder of bipedal saurischian dinosaurs, and a clade consisting of that suborder and its descendants . Dinosaurs belonging to the suborder theropoda were primarily carnivorous, although a number of theropod groups evolved herbivory, omnivory, and insectivory...

        s, the largest terrestrial carnivores (Spinosaurus
        Spinosaurus
        Spinosaurus is a genus of theropod dinosaur which lived in what is now North Africa, from the lower Albian to lower Cenomanian stages of the Cretaceous period, about 112 to 97 million years ago. This genus was first known from Egyptian remains discovered in 1912 and described by German...

        grew to 7–9 tonnes).
    • order Squamata
      Squamata
      Squamata, or the scaled reptiles, is the largest recent order of reptiles, including lizards and snakes. Members of the order are distinguished by their skins, which bear horny scales or shields. They also possess movable quadrate bones, making it possible to move the upper jaw relative to the...

      • While the largest extant lizard
        Lizard
        Lizards are a widespread group of squamate reptiles, with nearly 3800 species, ranging across all continents except Antarctica as well as most oceanic island chains...

        , the Komodo dragon
        Komodo dragon
        The Komodo dragon , also known as the Komodo monitor, is a large species of lizard found in the Indonesian islands of Komodo, Rinca, Flores, Gili Motang and Gili Dasami. A member of the monitor lizard family , it is the largest living species of lizard, growing to a maximum length of in rare cases...

         (Varanus komodoensis), another island giant, can reach 3 m (10 ft) in length, its extinct Australian relative Megalania
        Megalania
        Megalania is a giant extinct goanna or monitor lizard. It was part of a megafaunal assemblage that inhabited southern Australia during the Pleistocene, and appears to have disappeared around 40,000 years ago...

        may have reached more than twice that size. These monitor lizard
        Monitor lizard
        Monitor lizards are usually large reptiles, although some can be as small as in length. They have long necks, powerful tails and claws, and well-developed limbs. Most species are terrestrial, but arboreal and semiaquatic monitors are also known...

        s' marine relatives, the mosasaur
        Mosasaur
        Mosasaurs are large extinct marine lizards. The first fossil remains were discovered in a limestone quarry at Maastricht on the Meuse in 1764...

        s, were apex predator
        Apex predator
        Apex predators are predators that have no predators of their own, residing at the top of their food chain. Zoologists define predation as the killing and consumption of another organism...

        s in late Cretaceous seas.
      • The heaviest extant snake
        Snake
        Snakes are elongate, legless, carnivorous reptiles of the suborder Serpentes that can be distinguished from legless lizards by their lack of eyelids and external ears. Like all squamates, snakes are ectothermic, amniote vertebrates covered in overlapping scales...

         is considered to be the green anaconda (Eunectes murinus), while the reticulated python (Python reticulatus), at up to 8.7 m or more, is considered the longest. An extinct Australian Pliocene
        Pliocene
        The Pliocene Epoch is the period in the geologic timescale that extends from 5.332 million to 2.588 million years before present. It is the second and youngest epoch of the Neogene Period in the Cenozoic Era. The Pliocene follows the Miocene Epoch and is followed by the Pleistocene Epoch...

         species of Liasis
        Liasis
        Liasis is a genus of non-venomous pythons found in Indonesia, New Guinea and Australia. Currently, 3 extant species are recognized and one fossil species L. dubudingala -Geographic range:...

        , the Bluff Downs giant python
        Bluff Downs Giant Python
        The Bluff Downs Giant Python is an extinct genus of snake from Queensland, Australia, that lived during the Pliocene.The Bluff Downs Giant Python hunted mammals, birds and reptiles in the woodlands and vine thickets bordering Australian watercourses during Pliocene times...

        , reached 10 m, while the Paleocene
        Paleocene
        The Paleocene or Palaeocene, the "early recent", is a geologic epoch that lasted from about . It is the first epoch of the Palaeogene Period in the modern Cenozoic Era...

         Titanoboa
        Titanoboa
        Titanoboa, , meaning "titanic boa," is a genus of snake that lived approximately 58 to 60 million years ago, in the Paleocene epoch, a 10-million-year period immediately following the dinosaur extinction event...

        of South America reached lengths of 12–15 m and an estimated weight of about 1135 kilograms (2500 lb).
    • order Testudines
      • The largest turtle is the critically endangered
        Critically endangered
        Version 2010.3 of the IUCN Red List of Threatened Species identified 3744 Critically Endangered species, subspecies and varieties, stocks and subpopulations.Critically Endangered by kingdom:*1993 Animalia*2 Fungi*1745 Plantae*4 Protista-References:...

         marine leatherback turtle (Dermochelys coriacea), weighing up to 900 kg (1,984.2 lb). It is distinguished from other sea turtle
        Sea turtle
        Sea turtles are marine reptiles that inhabit all of the world's oceans except the Arctic.-Distribution:...

        s by its lack of a bony
        Bone
        Bones are rigid organs that constitute part of the endoskeleton of vertebrates. They support, and protect the various organs of the body, produce red and white blood cells and store minerals. Bone tissue is a type of dense connective tissue...

         shell
        Exoskeleton
        An exoskeleton is the external skeleton that supports and protects an animal's body, in contrast to the internal skeleton of, for example, a human. In popular usage, some of the larger kinds of exoskeletons are known as "shells". Examples of exoskeleton animals include insects such as grasshoppers...

        . The most massive terrestrial chelonians are the giant tortoise
        Giant tortoise
        Giant tortoises are characteristic reptiles of certain tropical islands. Often reaching enormous size—they can weigh as much as 300 kg and can grow to be 1.3 m long—they live, or lived , in the Seychelles, the Mascarenes and the Galapagos...

        s of the Galápagos Islands
        Galápagos Islands
        The Galápagos Islands are an archipelago of volcanic islands distributed around the equator in the Pacific Ocean, west of continental Ecuador, of which they are a part.The Galápagos Islands and its surrounding waters form an Ecuadorian province, a national park, and a...

          (Chelonoidis nigra) and Aldabra Atoll
        Aldabra
        Aldabra, the world's second largest coral atoll, is in the Aldabra Group of islands in the Indian Ocean that form part of the Seychelles. Uninhabited and extremely isolated, Aldabra is virtually untouched by humans, has distinctive island fauna including the Aldabra Giant Tortoise, and is...

         (Aldabrachelys gigantea), at up to 300 kg (661.4 lb). These tortoises are the biggest survivors of an assortment of giant tortoise species that were widely present on continental landmasses and additional islands during the Pleistocene.
  • class Amphibia
    • order Temnospondyli
      Temnospondyli
      Temnospondyli is a diverse order of small to giant tetrapods—often considered primitive amphibians—that flourished worldwide during the Carboniferous, Permian, and Triassic periods. A few species continued into the Cretaceous. Fossils have been found on every continent...

      • The Permian
        Permian
        The PermianThe term "Permian" was introduced into geology in 1841 by Sir Sir R. I. Murchison, president of the Geological Society of London, who identified typical strata in extensive Russian explorations undertaken with Edouard de Verneuil; Murchison asserted in 1841 that he named his "Permian...

         temnospondyl Prionosuchus
        Prionosuchus
        Prionosuchus is a genus of extremely large temnospondyl amphibians from the Late Permian which was found in an area of what is now Brazil.-Description:...

        , the largest amphibian known, reached 9 m in length and was an aquatic predator resembling a crocodilian. After the appearance of real crocodilians, temnospondyls such as Koolasuchus
        Koolasuchus
        Koolasuchus is an extinct genus of brachyopoid temnospondyl in the family Chigutisauridae. Fossils have been found from Victoria, Australia and date back 120 Ma to the Aptian stage of the Early Cretaceous. Koolasuchus is the latest known temnospondyl. Koolasuchus is known from several fragments of...

        (5 m long) had retreated to the Antarctic region by the Cretaceous, before going extinct.
  • class Actinopterygii
    Actinopterygii
    The Actinopterygii or ray-finned fishes constitute a class or sub-class of the bony fishes.The ray-finned fishes are so called because they possess lepidotrichia or "fin rays", their fins being webs of skin supported by bony or horny spines , as opposed to the fleshy, lobed fins that characterize...

    • order Tetraodontiformes
      Tetraodontiformes
      The Tetraodontiformes are an order of highly derived ray-finned fish, also called the Plectognathi. Sometimes these are classified as a suborder of the Perciformes...

      • The largest extant bony fish is the ocean sunfish
        Ocean sunfish
        The ocean sunfish, Mola mola, or common mola, is the heaviest known bony fish in the world. It has an average adult weight of . The species is native to tropical and temperate waters around the globe. It resembles a fish head with a tail, and its main body is flattened laterally...

         (Mola mola), whose average adult weight is 1000 kg (2,204.6 lb). While phylogenetically a "bony fish", its skeleton is primarily cartilage
        Cartilage
        Cartilage is a flexible connective tissue found in many areas in the bodies of humans and other animals, including the joints between bones, the rib cage, the ear, the nose, the elbow, the knee, the ankle, the bronchial tubes and the intervertebral discs...

         (which is lighter than bone
        Bone
        Bones are rigid organs that constitute part of the endoskeleton of vertebrates. They support, and protect the various organs of the body, produce red and white blood cells and store minerals. Bone tissue is a type of dense connective tissue...

        ). It has a disk-shaped body, and propels itself with its long, thin dorsal
        Dorsal fin
        A dorsal fin is a fin located on the backs of various unrelated marine and freshwater vertebrates, including most fishes, marine mammals , and the ichthyosaurs...

         and anal fins; it feeds primarily on jellyfish
        Jellyfish
        Jellyfish are free-swimming members of the phylum Cnidaria. Medusa is another word for jellyfish, and refers to any free-swimming jellyfish stages in the phylum Cnidaria...

        . In these three respects (as well as in its size and diving habits), it resembles a leatherback turtle.
    • order Acipenseriformes
      Acipenseriformes
      Acipenseriformes are an order of primitive ray-finned fishes that includes the sturgeons and paddlefishes, as well as some extinct families.Notable characteristics of Acipenseriformes include:* Cartilaginous endoskeleton* Lack of vertebral centrum...

      • The critically endangered beluga (European sturgeon, Huso huso) at up to 1476 kg (3250 lb) is the largest sturgeon
        Sturgeon
        Sturgeon is the common name used for some 26 species of fish in the family Acipenseridae, including the genera Acipenser, Huso, Scaphirhynchus and Pseudoscaphirhynchus. The term includes over 20 species commonly referred to as sturgeon and several closely related species that have distinct common...

         (which are also mostly cartilaginous) and is considered the largest anadromous fish.
    • order Siluriformes
      • The critically endangered Mekong giant catfish
        Mekong giant catfish
        The Mekong giant catfish, Pangasianodon gigas, is a species of catfish in the shark catfish family , native to the Mekong basin in Southeast Asia.-Species characteristics:...

         (Pangasianodon gigas), at up to 293 kg (646 lb), is often viewed as the largest freshwater fish
        Freshwater fish
        Freshwater fish are fish that spend some or all of their lives in freshwater, such as rivers and lakes, with a salinity of less than 0.05%. These environments differ from marine conditions in many ways, the most obvious being the difference in levels of salinity...

        .
  • class Chondrichthyes
    Chondrichthyes
    Chondrichthyes or cartilaginous fishes are jawed fish with paired fins, paired nares, scales, two-chambered hearts, and skeletons made of cartilage rather than bone...

    • order Lamniformes
      Lamniformes
      Lamniformes is an order of sharks commonly known as mackerel sharks . It includes some of the most familiar species of sharks, such as the great white shark, as well as more unusual representatives, such as the goblin shark and the megamouth shark.Members of the order are distinguished by...

      • The largest living predatory fish, the great white shark
        Great white shark
        The great white shark, scientific name Carcharodon carcharias, also known as the great white, white pointer, white shark, or white death, is a large lamniform shark found in coastal surface waters in all major oceans. It is known for its size, with the largest individuals known to have approached...

         (Carcharodon carcharias), reaches weights up to 2240 kg (4,938.4 lb). Its extinct relative C. megalodon
        Megalodon
        The megalodon and ὀδούς ) is an extinct species of shark that lived roughly from 28 to 1.5 million years ago, during the Cenozoic Era .The taxonomic assignment of C...

        (the disputed genus being either Carcharodon or Carcharocles) was more than an order of magnitude
        Order of magnitude
        An order of magnitude is the class of scale or magnitude of any amount, where each class contains values of a fixed ratio to the class preceding it. In its most common usage, the amount being scaled is 10 and the scale is the exponent being applied to this amount...

         larger, and is the largest predatory shark or fish of all time; it preyed on whales and other marine mammal
        Marine mammal
        Marine mammals, which include seals, whales, dolphins, and walruses, form a diverse group of 128 species that rely on the ocean for their existence. They do not represent a distinct biological grouping, but rather are unified by their reliance on the marine environment for feeding. The level of...

        s.
    • order Orectolobiformes
      • The largest extant shark
        Shark
        Sharks are a type of fish with a full cartilaginous skeleton and a highly streamlined body. The earliest known sharks date from more than 420 million years ago....

        , cartilaginous fish
        Chondrichthyes
        Chondrichthyes or cartilaginous fishes are jawed fish with paired fins, paired nares, scales, two-chambered hearts, and skeletons made of cartilage rather than bone...

        , and fish
        Fish
        Fish are a paraphyletic group of organisms that consist of all gill-bearing aquatic vertebrate animals that lack limbs with digits. Included in this definition are the living hagfish, lampreys, and cartilaginous and bony fish, as well as various extinct related groups...

         overall is the whale shark
        Whale shark
        The whale shark, Rhincodon typus, is a slow-moving filter feeding shark, the largest extant fish species. The largest confirmed individual had a length of and a weight of more than , but unconfirmed claims report considerably larger whale sharks...

         (Rhincodon typus), which reaches weights in excess of 21.5 tonnes (47,000 lb). Like baleen whales, it is a filter feeder
        Filter feeder
        Filter feeders are animals that feed by straining suspended matter and food particles from water, typically by passing the water over a specialized filtering structure. Some animals that use this method of feeding are clams, krill, sponges, baleen whales, and many fish and some sharks. Some birds,...

         and primarily consumes plankton
        Plankton
        Plankton are any drifting organisms that inhabit the pelagic zone of oceans, seas, or bodies of fresh water. That is, plankton are defined by their ecological niche rather than phylogenetic or taxonomic classification...

        .
    • order Rajiformes
      Rajiformes
      Rajiformes is one of the four orders of batoids, flattened cartilaginous fishes related to sharks.Rajiforms are distinguished by the presence of greatly enlarged pectoral fins, which reach as far forward as the sides of the head, with a generally flattened body. The undulatory pectoral fin motion...

      • The manta ray
        Manta ray
        The manta ray is the largest species of the rays. The largest known specimen was more than across, with a weight of about . It ranges throughout waters of the world, typically around coral reefs...

          (Manta birostris) is another filter feeder and the largest ray
        Batoidea
        Batoidea is a superorder of cartilaginous fish commonly known as rays and skates, containing more than 500 described species in thirteen families...

        , growing to up to 2300 kg.
  • class Cephalopoda
    • order Teuthida
      • A number of deep ocean creatures exhibit abyssal gigantism
        Deep-sea gigantism
        In zoology, deep-sea gigantism, also known as abyssal gigantism, is the tendency for species of crustaceans, invertebrates and other deep-sea-dwelling animals to display a larger size than their shallow-water counterparts...

        . These include the giant squid
        Giant squid
        The giant squid is a deep-ocean dwelling squid in the family Architeuthidae, represented by as many as eight species...

         (Architeuthis) and colossal squid
        Colossal Squid
        The colossal squid , sometimes called the Antarctic or giant cranch squid, is believed to be the largest squid species in terms of mass. It is the only known member of the genus Mesonychoteuthis...

         (Mesonychoteuthis hamiltoni); both (although rarely seen) are believed to attain lengths of 12 m (39 ft) or more. The latter is the world's largest invertebrate
        Invertebrate
        An invertebrate is an animal without a backbone. The group includes 97% of all animal species – all animals except those in the chordate subphylum Vertebrata .Invertebrates form a paraphyletic group...

        , and has the largest eye
        Eye
        Eyes are organs that detect light and convert it into electro-chemical impulses in neurons. The simplest photoreceptors in conscious vision connect light to movement...

        s of any animal. Both are preyed upon by sperm whales.

See also

  • Australian megafauna
    Australian megafauna
    Australian megafauna are a number of large animal species in Australia, often defined as species with body mass estimates of greater than 30 kilograms, or equal to or greater than 30% greater body mass than their closest living relatives...

  • Bergmann's rule
    Bergmann's Rule
    Bergmann's rule is an ecogeographic principle that states that within a broadly distributed genus, species of larger size are found in colder environments, and species of smaller size are found in warmer regions. Although originally formulated in terms of species within a genus, it has often been...

  • Charismatic megafauna
    Charismatic megafauna
    Charismatic megafauna are large animal species with widespread popular appeal that environmental activists use to achieve conservation goals well beyond just those species...

  • Cope's rule
    Cope's rule
    Cope's rule states that population lineages tend to increase in body size over evolutionary time. While the rule has been demonstrated in many instances, it does not hold true at all taxonomic levels, or in all clades...

  • Deep-sea gigantism
    Deep-sea gigantism
    In zoology, deep-sea gigantism, also known as abyssal gigantism, is the tendency for species of crustaceans, invertebrates and other deep-sea-dwelling animals to display a larger size than their shallow-water counterparts...

  • Fauna
    Fauna
    Fauna or faunæ is all of the animal life of any particular region or time. The corresponding term for plants is flora.Zoologists and paleontologists use fauna to refer to a typical collection of animals found in a specific time or place, e.g. the "Sonoran Desert fauna" or the "Burgess shale fauna"...

  • Giant animals in fiction and mythology
  • Island dwarfism
  • Island gigantism
    Island gigantism
    Island gigantism or insular giantism is a biological phenomenon in which the size of animals isolated on an island increases dramatically in comparison to their mainland relatives....

  • Largest organisms
    Largest organisms
    The largest organism found on Earth can be measured using a variety of methods. It could be defined as the largest by volume, mass, height or length. Some organisms group together to form a superorganism, though this cannot truly be classed as one large organism...

  • Largest prehistoric organisms
    Largest prehistoric organisms
    The largest prehistoric organisms include both vertebrate and invertebrate species. Many are described below, along with their typical range of size...

  • List of megafauna discovered in modern times
  • Megafauna (categories)
    • Africa
    • Australia
    • Eurasia
    • North America
    • South America
  • New World Pleistocene extinctions
  • Pleistocene megafauna
    Pleistocene megafauna
    Pleistocene megafauna is the set of species of large animals — mammals, birds and reptiles — that lived on Earth during the Pleistocene epoch and became extinct in a Quaternary extinction event. These species appear to have died off as humans expanded out of Africa and southern Asia,...

  • Quaternary extinction event
    Quaternary extinction event
    The Quaternary period saw the extinctions of numerous predominantly larger, especially megafaunal, species, many of which occurred during the transition from the Pleistocene to the Holocene epoch. However, the extinction wave did not stop at the end of the Pleistocene, but continued especially on...



External links

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