In terrestrial

zoology Zoology ()The pronunciation of zoology as is usually regarded as nonstandard, though it is not uncommon. is the branch of biology that studies the animal kingdom, including the structure, embryology, evolution, classification, habits, and ...

, the megafauna (from

Greek Greek may refer to: Greece Anything of, from, or related to Greece, a country in Southern Europe: *Greeks, an ethnic group. *Greek language, a branch of the Indo-European language family. **Proto-Greek language, the assumed last common ancestor ...

μέγας ''megas'' "large" and

New Latin New Latin (also called Neo-Latin or Modern Latin) is the revival of Literary Latin used in original, scholarly, and scientific works since about 1500. Modern scholarly and technical nomenclature, such as in zoological and botanical taxonomy ...

fauna Fauna is all of the animal life present in a particular region or time. The corresponding term for plants is ''flora'', and for fungi, it is '' funga''. Flora, fauna, funga and other forms of life are collectively referred to as ''biota''. Zoo ...

'' "animal life") comprises the large or giant animals of an area, habitat, or geological period, extinct and/or extant. The most common thresholds used are weight over see page 17 (i.e., having a mass comparable to or larger than a

human Humans (''Homo sapiens'') are the most abundant and widespread species of primate, characterized by bipedalism and exceptional cognitive skills due to a large and complex brain. This has enabled the development of advanced tools, culture, ...

) or over a

tonne The tonne ( or ; symbol: t) is a unit of mass equal to 1000 kilograms. It is a non-SI unit accepted for use with SI. It is also referred to as a metric ton to distinguish it from the non-metric units of the short ton ( United State ...

, (i.e., having a mass comparable to or larger than an ox). The first of these include many species not popularly thought of as overly large, and being the only few large animals left in a given range/area, such as

white-tailed deer The white-tailed deer (''Odocoileus virginianus''), also known as the whitetail or Virginia deer, is a medium-sized deer native to North America, Central America, and South America as far south as Peru and Bolivia. It has also been introduced t ...

Thomson's gazelle Thomson's gazelle (''Eudorcas thomsonii'') is one of the best known species of gazelles. It is named after explorer Joseph Thomson (explorer), Joseph Thomson and is sometimes referred to as a "tommie". It is considered by some to be a subspecies o ...

, and

red kangaroo The red kangaroo (''Osphranter rufus'') is the largest of all kangaroos, the largest terrestrial mammal native to Australia, and the largest extant marsupial. It is found across mainland Australia, except for the more fertile areas, such as ...

. In practice, the most common usage encountered in academic and popular writing describes land mammals roughly larger than a human that are not (solely) domesticated. The term is especially associated with the

Pleistocene megafauna Pleistocene megafauna is the set of large animals that lived on Earth during the Pleistocene epoch. Pleistocene megafauna became extinct during the Quaternary extinction event resulting in substantial changes to ecosystems globally. The role of hu ...

– the land animals often larger than their extant counterparts that are considered archetypical of the last ice age, such as

mammoth A mammoth is any species of the extinct elephantid genus ''Mammuthus'', one of the many genera that make up the order of trunked mammals called proboscideans. The various species of mammoth were commonly equipped with long, curved tusks and ...

s, the majority of which in northern Eurasia, the Americas and Australia became extinct within the last forty thousand years. Among living animals, the term megafauna is most commonly used for the largest

extant Extant is the opposite of the word extinct. It may refer to: * Extant hereditary titles * Extant literature, surviving literature, such as ''Beowulf'', the oldest extant manuscript written in English * Extant taxon, a taxon which is not extinct, ...

terrestrial mammals, which includes (but is not limited to)

elephant Elephants are the largest existing land animals. Three living species are currently recognised: the African bush elephant, the African forest elephant, and the Asian elephant. They are the only surviving members of the family Elephantidae ...

giraffe The giraffe is a large African hoofed mammal belonging to the genus ''Giraffa''. It is the tallest living terrestrial animal and the largest ruminant on Earth. Traditionally, giraffes were thought to be one species, '' Giraffa cameloparda ...

zebra Zebras (, ) (subgenus ''Hippotigris'') are African equines with distinctive black-and-white striped coats. There are three living species: the Grévy's zebra (''Equus grevyi''), plains zebra (''E. quagga''), and the mountain zebra (''E. ...

hippopotamus The hippopotamus ( ; : hippopotamuses or hippopotami; ''Hippopotamus amphibius''), also called the hippo, common hippopotamus, or river hippopotamus, is a large semiaquatic mammal native to sub-Saharan Africa. It is one of only two exta ...

es,

rhinoceros A rhinoceros (; ; ), commonly abbreviated to rhino, is a member of any of the five extant taxon, extant species (or numerous extinct species) of odd-toed ungulates in the family (biology), family Rhinocerotidae. (It can also refer to a member ...

es, and large

bovines Bovines ( subfamily Bovinae) comprise a diverse group of 10 genera of medium to large-sized ungulates, including cattle, bison, African buffalo, water buffalos, and the four-horned and spiral-horned antelopes. The evolutionary relationship betw ...

. Of these five categories of large herbivores, only bovines are presently found outside of

Africa Africa is the world's second-largest and second-most populous continent, after Asia in both cases. At about 30.3 million km2 (11.7 million square miles) including adjacent islands, it covers 6% of Earth's total surface area ...

and southern

Asia Asia (, ) is one of the world's most notable geographical regions, which is either considered a continent in its own right or a subcontinent of Eurasia, which shares the continental landmass of Afro-Eurasia with Africa. Asia covers an ...

, but all the others were formerly more wide-ranging, with their ranges and populations continually shrinking and decreasing over time. Wild

equines ''Equus'' , is a genus of mammals in the family Equidae, which includes horses, donkeys, and zebras. Within the Equidae, ''Equus'' is the only recognized extant genus, comprising seven living species. Like Equidae more broadly, ''Equus'' has n ...

are another example of megafauna, but their current ranges are largely restricted to the

old world The "Old World" is a term for Afro-Eurasia that originated in Europe , after Europeans became aware of the existence of the Americas. It is used to contrast the continents of Africa, Europe, and Asia, which were previously thought of by th ...

, specifically Africa and Asia. Megafaunal species may be categorized according to their dietary type: megaherbivores (e.g.,

elephants Elephants are the largest existing land animals. Three living species are currently recognised: the African bush elephant, the African forest elephant, and the Asian elephant. They are the only surviving members of the family Elephantidae ...

), megacarnivores (e.g.,

lion The lion (''Panthera leo'') is a large Felidae, cat of the genus ''Panthera'' native to Africa and India. It has a muscular, broad-chested body; short, rounded head; round ears; and a hairy tuft at the end of its tail. It is sexually dimorphi ...

s), and, more rarely, megaomnivores (e.g.,

bear Bears are carnivoran mammals of the 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 throughout the N ...

s). The megafauna is also categorized by the

class Class or The Class may refer to: Common uses not otherwise categorized * Class (biology), a taxonomic rank * Class (knowledge representation), a collection of individuals or objects * Class (philosophy), an analytical concept used differently ...

of animals that it belongs to, which are mammals, birds, reptiles, amphibians, fish, and invertebrates. Other common uses are for giant aquatic species, especially

whales Whales are a widely distributed and diverse group of fully aquatic placental marine mammals. As an informal and colloquial grouping, they correspond to large members of the infraorder Cetacea, i.e. all cetaceans apart from dolphins a ...

, as well as any of the larger wild or domesticated land animals such as larger

antelope The term antelope is used to refer to many species of even-toed ruminant that are indigenous to various regions in Africa and Eurasia. Antelope comprise a wastebasket taxon defined as any of numerous Old World grazing and browsing hoofed mamm ...

deer Deer or true deer are hoofed ruminant mammals forming the family Cervidae. The two main groups of deer are the Cervinae, including the muntjac, the elk (wapiti), the red deer, and the fallow deer; and the Capreolinae, including the ...

horse The horse (''Equus ferus caballus'') is a domesticated, one-toed, hoofed mammal. It belongs to the taxonomic family Equidae and is one of two extant subspecies of ''Equus ferus''. The horse has evolved over the past 45 to 55 million ...

and

cattle Cattle (''Bos taurus'') are large, domesticated, cloven-hooved, herbivores. They are a prominent modern member of the subfamily Bovinae and the most widespread species of the genus '' Bos''. Adult females are referred to as cows and adult ...

, as well as

dinosaur Dinosaurs are a diverse group of reptiles of the clade Dinosauria. They first appeared during the Triassic period, between 243 and 233.23 million years ago (mya), although the exact origin and timing of the evolution of dinosaurs is t ...

s and other extinct giant reptilians. The term megafauna is very rarely used to describe invertebrates, though it has occasionally been used for some species of invertebrates such as

coconut crab The coconut crab (''Birgus latro'') is a species of terrestrial hermit crab, also known as the robber crab or palm thief. It is the largest terrestrial arthropod in the world, with a weight of up to . It can grow to up to in width from the tip ...

s and

Japanese spider crab The Japanese spider crab (''Macrocheira kaempferi'') is a species of marine crab that lives in the waters around Japan. It has the largest known leg-span of any arthropod. It goes through three main larval stages along with a prezoeal stage to ...

s, as well as extinct invertebrates that were much larger than all similar invertebrate species alive today, for example the dragonflies of the Carboniferous period.

Ecological strategy

Megafauna animals – in the sense of the largest mammals and birds – are generally ''K''-strategists, with high longevity, slow population growth rates, low mortality rates, and (at least for the largest) few or no natural predators capable of killing adults. These characteristics, although not exclusive to such megafauna, make them vulnerable to human

overexploitation Overexploitation, also called overharvesting, refers to harvesting a renewable resource to the point of diminishing returns. Continued overexploitation can lead to the destruction of the resource, as it will be unable to replenish. The term ap ...

, in part because of their slow population recovery rates.

Evolution of large body size

One observation that has been made about the evolution of larger body size is that rapid rates of increase that are often seen over relatively short time intervals are not sustainable over much longer time periods. In an examination of mammal body mass changes over time, the maximum increase possible in a given time interval was found to scale with the interval length raised to the 0.25 power. This is thought to reflect the emergence, during a trend of increasing maximum body size, of a series of anatomical, physiological, environmental, genetic and other constraints that must be overcome by evolutionary innovations before further size increases are possible. A strikingly faster rate of change was found for large decreases in body mass, such as may be associated with the phenomenon of

insular dwarfism Insular dwarfism, a form of phyletic dwarfism, is the process and condition of large animals evolving or having a reduced body size when their population's range is limited to a small environment, primarily islands. This natural process is dist ...

. When normalized to generation length, the maximum rate of body mass decrease was found to be over 30 times greater than the maximum rate of body mass increase for a ten-fold change.

In terrestrial mammals

Patagotitan vs Mammals Scale Diagram SVG Steveoc86

Subsequent to the

Cretaceous–Paleogene extinction event The Cretaceous–Paleogene (K–Pg) extinction event (also known as the Cretaceous–Tertiary extinction) was a sudden extinction event, mass extinction of three-quarters of the plant and animal species on Earth, approximately 66 million y ...

that eliminated the non-avian dinosaurs about Ma (million years) ago, terrestrial mammals underwent a nearly exponential increase in body size as they diversified to occupy the ecological niches left vacant. Starting from just a few kg before the event, maximum size had reached ~50 kg a few million years later, and ~750 kg by the end of the

Paleocene The Paleocene, ( ) or Palaeocene, is a geological epoch that lasted from about 66 to 56 million years ago (mya). It is the first epoch of the Paleogene Period in the modern Cenozoic Era. The name is a combination of the Ancient Greek ''pal ...

. This trend of increasing body mass appears to level off about 40 Ma ago (in the late

Eocene The Eocene ( ) Epoch is a geological epoch that lasted from about 56 to 33.9 million years ago (mya). It is the second epoch of the Paleogene Period in the modern Cenozoic Era. The name ''Eocene'' comes from the Ancient Greek (''ēṓs'', " ...

), suggesting that physiological or ecological constraints had been reached, after an increase in body mass of over three orders of magnitude. However, when considered from the standpoint of rate of size increase per generation, the exponential increase is found to have continued until the appearance of ''

Indricotherium ''Paraceratherium'' is an extinct genus of hornless rhinoceros. It is one of the largest terrestrial mammals that has existed and lived from the early to late Oligocene epoch (34–23 million years ago). The first fossils were discovered ...

'' 30 Ma ago. (Since generation time scales with ''body mass''^0.259, increasing generation times with increasing size cause the log mass vs. time plot to curve downward from a linear fit.) Megaherbivores eventually attained a body mass of over 10,000 kg. The largest of these,

indricothere Paraceratheriidae is an extinct family of long-limbed, hornless rhinocerotoids, commonly known as paraceratheres or indricotheres, that originated in the Eocene epoch and lived until the early Miocene. The first paraceratheres were only about th ...

s and

proboscid The Proboscidea (; , ) are 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. From ...

s, have been

hindgut fermenter Hindgut fermentation is a digestive process seen in monogastric herbivores, animals with a simple, single-chambered stomach. Cellulose is digested with the aid of symbiotic bacteria.foregut fermenters in terms of being able to accelerate gastrointestinal transit in order to accommodate very large food intakes. A similar trend emerges when rates of increase of maximum body mass per generation for different mammalian clades are compared (using rates averaged over

macroevolution Macroevolution usually means the evolution of large-scale structures and traits that go significantly beyond the intraspecific variation found in microevolution (including speciation). In other words, macroevolution is the evolution of taxa abov ...

ary time scales). Among terrestrial mammals, the fastest rates of increase of ''body mass''^0.259 vs. time (in Ma) occurred in

perissodactyl Odd-toed ungulates, mammals which constitute the taxonomic order Perissodactyla (, ), are animals—ungulates—who have reduced the weight-bearing toes to three (rhinoceroses and tapirs, with tapirs still using four toes on the front legs) ...

s (a slope of 2.1), followed by

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 lower jaws. About 40% of all mammal species are roden ...

s (1.2) and proboscids (1.1), all of which are hindgut fermenters. The rate of increase for

artiodactyl The even-toed ungulates (Artiodactyla , ) are ungulates—hoofed animals—which bear weight equally on two (an even number) of their five toes: the third and fourth. The other three toes are either present, absent, vestigial, or pointing poste ...

s (0.74) was about a third that of perissodactyls. The rate for

carnivora Carnivora is a monophyletic order of placental mammals consisting of the most recent common ancestor of all cat-like and dog-like animals, and all descendants of that ancestor. Members of this group are formally referred to as carnivorans, ...

ns (0.65) was slightly lower yet, while

primate Primates are a diverse order (biology), order of mammals. They are divided into the Strepsirrhini, strepsirrhines, which include the lemurs, galagos, and lorisids, and the Haplorhini, haplorhines, which include the Tarsiiformes, tarsiers and ...

s, perhaps constrained by their

arboreal Arboreal locomotion is the locomotion of animals in trees. In habitats in which trees are present, animals have evolved to move in them. Some animals may scale trees only occasionally, but others are exclusively arboreal. The habitats pose num ...

habits, had the lowest rate (0.39) among the mammalian groups studied. Terrestrial mammalian carnivores from several

eutheria Eutheria (; from Greek , 'good, right' and , 'beast'; ) is the clade consisting of all therian mammals that are more closely related to placentals than to marsupials. Eutherians are distinguished from noneutherians by various phenotypic t ...

n groups (the

Andrewsarchus ''Andrewsarchus'' () is an extinct genus of mammal that lived during the middle Eocene epoch in what is now Inner Mongolia, China. Only one species is usually recognized, ''A. mongoliensis'', known from a single skull of great size discovered ...

'' – formerly considered a

mesonychid Mesonychia ("middle claws") is an extinct taxon of small- to large-sized carnivorous ungulates related to artiodactyls. Mesonychids first appeared in the early Paleocene, went into a sharp decline at the end of the Eocene, and died out entirel ...

, the

oxyaenid Oxyaenidae ("sharp hyenas") is a family of extinct carnivorous placental mammals. Traditionally classified in order Creodonta, this group is now classified in its own order Oxyaenodonta ("sharp tooth hyenas") within clade Pan-Carnivora in mirorde ...

Sarkastodon ''Sarkastodon'' ("meaty tooth") is an extinction, extinct genus of mammal within the creodont family (biology), family Oxyaenidae that lived during the early to late Eocene, 48.6 to 37.2 million years ago. It was a large, carnivorous animal ...

'', and the carnivorans ''

Amphicyon ''Amphicyon'' ("ambiguous dog") is an extinct genus of large carnivorous bone-crushing mammals, popularly known as bear dogs, of the family Amphicyonidae, subfamily Amphicyoninae, from the Burdigalian Epoch until the late Pliocene, with the ...

'' and ''

Arctodus ''Arctodus'' is an extinct genus of short-faced bear that inhabited North America during the Pleistocene (~2.5 Mya until 12,000 years ago). There are two recognized species: the lesser short-faced bear (''Arctodus pristinus'') and the giant short- ...

'') all reached a maximum size of about 1000 kg (the carnivoran ''

Arctotherium ''Arctotherium'' ("''bear beast''") is an extinct genus of the Pleistocene short-faced bears endemic to Central and South America. ''Arctotherium'' migrated from North America to South America during the Great American Interchange, following the ...

'' and the

hyaenodontid Hyaenodontidae ("hyena teeth") is a family of extinct predatory mammals from extinct superfamily Hyaenodontoidea within extinct order Hyaenodonta. Hyaenodontids arose during the early Eocene and persisted well into the early Miocene. Fossils ...

Simbakubwa ''Simbakubwa'' ("great lion") is an extinct genus of hyainailourid hyaenodonts from paraphyletic subfamily Hyainailourinae that lived in Kenya during the early Miocene. Etymology The name of this genus comes from Swahili language for "great l ...

'' may have been somewhat larger). The largest known

metatheria Metatheria is a mammalian clade that includes all mammals more closely related to marsupials than to placentals. First proposed by Thomas Henry Huxley in 1880, it is a more inclusive group than the marsupials; it contains all marsupials as we ...

n carnivore, ''

Proborhyaena gigantea ''Proborhyaena'' is an extinct genus of proborhyaenid sparassodont that lived during the Oligocene of what is now South America. It is considered to be the largest of the sparassodonts. Description This animal was very large in size, with the s ...

'', apparently reached 600 kg, also close to this limit. A similar theoretical maximum size for mammalian carnivores has been predicted based on the metabolic rate of mammals, the energetic cost of obtaining prey, and the maximum estimated rate coefficient of prey intake. It has also been suggested that maximum size for mammalian carnivores is constrained by the stress the

humerus The humerus (; ) is a long bone in the arm that runs from the shoulder to the elbow. It connects the scapula and the two bones of the lower arm, the radius and ulna, and consists of three sections. The humeral upper extremity consists of a roun ...

can withstand at top running speed. Analysis of the variation of maximum body size over the last 40 Ma suggests that decreasing temperature and increasing continental land area are associated with increasing maximum body size. The former correlation would be consistent with

Bergmann's rule Bergmann's rule is an ecogeographical rule that states that within a broadly distributed taxonomic clade, populations and species of larger size are found in colder environments, while populations and species of smaller size are found in warmer ...

, and might be related to the

thermoregulatory Thermoregulation is the ability of an organism to keep its body temperature within certain boundaries, even when the surrounding temperature is very different. A thermoconforming organism, by contrast, simply adopts the surrounding temperature ...

advantage of large body mass in cool climates, better ability of larger organisms to cope with seasonality in food supply, or other factors; the latter correlation could be explained in terms of range and resource limitations. However, the two parameters are interrelated (due to sea level drops accompanying increased glaciation), making the driver of the trends in maximum size more difficult to identify.

In marine mammals

Since tetrapods (first

reptiles Reptiles, as most commonly defined are the animals in the class Reptilia ( ), a paraphyletic grouping comprising all sauropsids except birds. Living reptiles comprise turtles, crocodilians, squamates (lizards and snakes) and rhynchocephali ...

, later

mammals Mammals () are a group of vertebrate animals constituting the class Mammalia (), characterized by the presence of mammary glands which in females produce milk for feeding (nursing) their young, a neocortex (a region of the brain), fu ...

) returned to the sea in the

Late Permian Late may refer to: * LATE, an acronym which could stand for: ** Limbic-predominant age-related TDP-43 encephalopathy, a proposed form of dementia ** Local-authority trading enterprise, a New Zealand business law ** Local average treatment effect, ...

, they have dominated the top end of the marine body size range, due to the more efficient intake of oxygen possible using lungs. The ancestors of cetaceans are believed to have been the semiaquatic

pakicetid Pakicetidae ("Pakistani whales") is an extinct family of Archaeoceti (early whales) that lived during the Early Eocene in Pakistan. Description described the first pakicetid, '' Ichthyolestes'', but at the time they did not recognize it as a ce ...

s, no larger than dogs, of about 53 million years (Ma) ago. By 40 Ma ago, cetaceans had attained a length of 20 m or more in ''

Basilosaurus ''Basilosaurus'' (meaning "king lizard") is a genus of large, predatory, prehistoric archaeocete whale from the late Eocene, approximately 41.3 to 33.9 million years ago (mya). First described in 1834, it was the first archaeocete and prehistor ...

'', an elongated, serpentine whale that differed from modern whales in many respects and was not ancestral to them. Following this, the evolution of large body size in cetaceans appears to have come to a temporary halt, and then to have backtracked, although the available fossil records are limited. However, in the period from 31 Ma ago (in the

Oligocene The Oligocene ( ) is a geologic epoch of the Paleogene Period and extends from about 33.9 million to 23 million years before the present ( to ). As with other older geologic periods, the rock beds that define the epoch are well identified but ...

) to the present, cetaceans underwent a significantly more rapid sustained increase in body mass (a rate of increase in ''body mass''^0.259 of a factor of 3.2 per million years) than achieved by any group of terrestrial mammals. This trend led to the largest animal of all time, the modern

blue whale The blue whale (''Balaenoptera musculus'') is a marine mammal and a baleen whale. Reaching a maximum confirmed length of and weighing up to , it is the largest animal known to have ever existed. The blue whale's long and slender body can b ...

. Several reasons for the more rapid evolution of large body size in cetaceans are possible. Fewer biomechanical constraints on increases in body size may be associated with suspension in water as opposed to standing against the force of gravity, and with swimming movements as opposed to

terrestrial locomotion Terrestrial locomotion has evolved as animals adapted from aquatic to terrestrial environments. Locomotion on land raises different problems than that in water, with reduced friction being replaced by the increased effects of gravity. As view ...

. Also, the greater heat capacity and thermal conductivity of water compared to air may increase the

advantage of large body size in marine

endotherm An endotherm (from Greek ἔνδον ''endon'' "within" and θέρμη ''thermē'' "heat") is an organism that maintains its body at a metabolically favorable temperature, largely by the use of heat released by its internal bodily functions inste ...

s, although diminishing returns apply. Among toothed whales, maximum body size appears to be limited by food availability. Larger size, as in sperm and

beaked whale Beaked whales ( systematic name Ziphiidae) are a family of cetaceans noted as being one of the least known groups of mammals because of their deep-sea habitat and apparent low abundance. Only three or four of the 24 species are reasonably well- ...

s, facilitates deeper diving to access relatively easily-caught, large cephalopod prey in a less competitive environment. Compared to odontocetes, the efficiency of baleen whales'

filter feeding Filter feeders are a sub-group of suspension feeding 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 feedi ...

scales more favorably with increasing size when planktonic food is dense, making larger size more advantageous. The

lunge feeding Aquatic feeding mechanisms face a special difficulty as compared to feeding on land, because the density of water is about the same as that of the prey, so the prey tends to be pushed away when the mouth is closed. This problem was first identifi ...

technique of

rorqual Rorquals () are the largest group of baleen whales, which comprise the family Balaenopteridae, containing ten extant species in three genera. They include the largest animal that has ever lived, the blue whale, which can reach , and the fin ...

s appears to be more energy efficient than the

ram feeding Aquatic feeding mechanisms face a special difficulty as compared to feeding on land, because the density of water is about the same as that of the prey, so the prey tends to be pushed away when the mouth is closed. This problem was first identifi ...

balaenid Balaenidae () is a family of whales of the parvorder Mysticeti that contains two living genera: the right whales (genus '' Eubalaena''), and in a separate genus, the closely related bowhead whale (genus '' Balaena''). Evolutionary history Bal ...

whales; the latter technique is used with less dense and patchy plankton. The cooling trend in Earth's recent history may have generated more localities of high plankton abundance via wind-driven

upwelling Upwelling is an oceanographic phenomenon that involves wind-driven motion of dense, cooler, and usually nutrient-rich water from deep water towards the ocean surface. It replaces the warmer and usually nutrient-depleted surface water. The nut ...

s, facilitating the evolution of gigantic whales. Cetaceans are not the only marine mammals to reach tremendous sizes. The largest

ns of all time are marine

pinniped Pinnipeds (pronounced ), commonly known as seals, are a widely range (biology), distributed and diverse clade of carnivorous, fin-footed, semiaquatic, mostly marine mammal, marine mammals. They comprise the extant taxon, extant family (biology ...

s, the largest of which is the

southern elephant seal The southern elephant seal (''Mirounga leonina'') is one of two species of elephant seals. It is the largest member of the clade Pinnipedia and the order Carnivora, as well as the largest extant marine mammal that is not a cetacean. It gets it ...

, which can reach more than 6 meters in length and weigh up to . Other large pinnipeds include the

northern elephant seal The northern elephant seal (''Mirounga angustirostris'') is one of two species of elephant seal (the other is the southern elephant seal). It is a member of the family Phocidae (true seals). Elephant seals derive their name from their great si ...

at ,

walrus The walrus (''Odobenus rosmarus'') is a large flippered marine mammal with a discontinuous distribution about the North Pole in the Arctic Ocean and subarctic seas of the Northern Hemisphere. The walrus is the only living species in the f ...

at , and

Steller sea lion The Steller sea lion (''Eumetopias jubatus''), also known as the Steller's sea lion and northern sea lion, is a near-threatened species of sea lion in the northern Pacific. It is the sole member of the genus ''Eumetopias'' and the largest of ...

at . The

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 Sirenia currently comprise two distinct ...

ns are another group of marine mammals which adapted to fully aquatic life around the same time as the cetaceans did. Sirenians are closely related to elephants. The largest sirenian was the

Steller's sea cow Steller's sea cow (''Hydrodamalis gigas'') is an 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 extended across ...

, which reached up to 10 meters in length and weighed , and was hunted to extinction in the 18th century. The semi-aquatic

, which is the terrestrial mammal most closely related to cetaceans, can reach .

In flightless birds

Because of the small initial size of all mammals following the extinction of the non-avian dinosaurs, nonmammalian vertebrates had a roughly ten-million-year-long window of opportunity (during the Paleocene) for evolution of gigantism without much competition. During this interval,

apex predator An apex predator, also known as a top predator, 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 highest trophic le ...

niches were often occupied by reptiles, such as terrestrial

crocodilian Crocodilia (or Crocodylia, both ) is an order of mostly large, predatory, semiaquatic reptiles, known as crocodilians. They first appeared 95 million years ago in the Late Cretaceous period ( Cenomanian stage) and are the closest living ...

s (e.g. ''

Pristichampsus ''Pristichampsus'' ("saw crocodile") is a non-diagnostic extinct genus of crocodylian from France and possibly also Kazakhstan that is part of the monotypic Pristichampsidae family. As the type species, ''Pristichampsus rollinatii'', was based o ...

''), large snakes (e.g. ''

Titanoboa ''Titanoboa'' (; ) is an extinct genus of very large snakes that lived in what is now La Guajira in northeastern Colombia. They could grow up to , perhaps even long and reach a body mass of . This snake lived during the Middle to Late Pal ...

'') or

varanid lizard The Varanidae are a family of lizards in the superfamily Varanoidea within the Anguimorpha group. The family, a group of carnivorous and frugivorous lizards, includes the living genus '' Varanus'' and a number of extinct genera more closely relat ...

s, or by flightless birds (e.g. ''

Paleopsilopterus ''Paleopsilopterus'' is an extinct genus of giant flightless predatory birds within Cariamiformes. It is usually attributed to the subfamily Psilopterinae of the family Phorusrhacidae, or "terror birds", though doubts about such an identity hav ...

'' in South America). This is also the period when megafaunal flightless herbivorous

gastornithid ''Gastornis'' is an extinct genus of large flightless birds that lived during the mid Paleocene to mid Eocene epochs of the Paleogene period. Fossils have been found in Europe, Asia and North America, with the remains from North America origina ...

birds evolved in the Northern Hemisphere, while flightless

paleognath Palaeognathae (; ) is a infraclass of birds, called paleognaths, within the class Aves of the clade Archosauria. It is one of the two extant infraclasses of birds, the other being Neognathae, both of which form Neornithes. Palaeognathae conta ...

s evolved to large size on

Gondwana Gondwana () was a large landmass, often referred to as a supercontinent, that formed during the late Neoproterozoic (about 550 million years ago) and began to break up during the Jurassic period (about 180 million years ago). The final st ...

n land masses and

Europe Europe is a large peninsula conventionally considered a continent in its own right because of its great physical size and the weight of its history and traditions. Europe is also considered a subcontinent of Eurasia and it is located enti ...

. Gastornithids and at least one lineage of flightless paleognath birds originated in Europe, both lineages dominating niches for large herbivores while mammals remained below 45 kg (in contrast with other landmasses like North America and

, which saw the earlier evolution of larger mammals) and were the largest European tetrapods in the

. Flightless paleognaths, termed ratites, have traditionally been viewed as representing a lineage separate from that of their small flighted relatives, the

Neotropic The Neotropical realm is one of the eight biogeographic realms constituting Earth's land surface. Physically, it includes the tropical terrestrial ecoregions of the Americas and the entire South American temperate zone. Definition In bi ...

tinamou Tinamous () form an order of birds called Tinamiformes (), comprising a single family called Tinamidae (), divided into two distinct subfamilies, containing 46 species found in Mexico, Central America, and South America. The word "tinamou" comes ...

s. However, recent genetic studies have found that tinamous nest well within the ratite tree, and are the

sister group In phylogenetics, a sister group or sister taxon, also called an adelphotaxon, comprises the closest relative(s) of another given unit in an evolutionary tree. Definition The expression is most easily illustrated by a cladogram: Taxon A and ...

of the extinct

moa Moa are extinct giant flightless birds native to New Zealand. The term has also come to be used for chicken in many Polynesian cultures and is found in the names of many chicken recipes, such as Kale moa and Moa Samoa. Moa or MOA may also refe ...

of New Zealand. Similarly, the small

kiwi Kiwi most commonly refers to: * Kiwi (bird), a flightless bird native to New Zealand * Kiwi (nickname), a nickname for New Zealanders * Kiwifruit, an edible berry * Kiwi dollar or New Zealand dollar, a unit of currency Kiwi or KIWI may also ref ...

of New Zealand have been found to be the sister group of the extinct

elephant bird Elephant birds are members of the extinct ratite family Aepyornithidae, made up of flightless birds that once lived on the island of Madagascar. They are thought to have become extinct around 1000-1200 CE, probably as a result of human activit ...

s of Madagascar. These findings indicate that

flightlessness Flightless birds are birds that through evolution lost the ability to fly. There are over 60 extant species, including the well known ratites (ostriches, emu, cassowaries, rheas, and kiwi) and penguins. The smallest flightless bird is the Ina ...

and gigantism arose independently multiple times among ratites via

parallel evolution Parallel evolution is the similar development of a trait in distinct species that are not closely related, but share a similar original trait in response to similar evolutionary pressure.Zhang, J. and Kumar, S. 1997Detection of convergent and paral ...

. Predatory megafaunal flightless birds were often able to compete with mammals in the early

Cenozoic The Cenozoic ( ; ) is Earth's current geological era, representing the last 66million years of Earth's history. It is characterised by the dominance of mammals, birds and flowering plants, a cooling and drying climate, and the current configu ...

. Later in the Cenozoic, however, they were displaced by advanced carnivorans and died out. In North America, the

bathornithids Bathornithidae is an extinct family of birds from the Eocene to Miocene of North America. Part of Cariamiformes, they are related to the still extant seriemas and the also extinct Phorusrhacidae. They were likely similar in habits, being terr ...

Paracrax ''Paracrax'' ("near curassow") is a genus of extinct North American flightless birds, possibly related to modern seriemas and the extinct terror birds. Part of Bathornithidae (though some analysis recover it as closer to the living seriemas inst ...

'' and ''

Bathornis ''Bathornis'' ("tall bird") is an extinct lineage of birds related to modern day seriemas, that lived in North America about 37–20 million years ago. Like the closely related and also extinct phorusrhacids, it was a flightless predator, occup ...

'' were apex predators but became extinct by the

Early Miocene The Early Miocene (also known as Lower Miocene) is a sub-epoch of the Miocene Epoch made up of two stages: the Aquitanian and Burdigalian stages. The sub-epoch lasted from 23.03 ± 0.05 Ma to 15.97 ± 0.05 Ma (million years ago). It was p ...

. In South America, the related

phorusrhacid Phorusrhacids, colloquially known as terror birds, are an extinct clade of large carnivorous flightless birds that were one of the largest species of apex predators in South America during the Cenozoic era; their conventionally accepted temporal ...

s shared the dominant predatory niches with metatherian

sparassodont Sparassodonta (from Greek to tear, rend; and , gen. , ' tooth) is an extinct order of carnivorous metatherian mammals native to South America, related to modern marsupials. They were once considered to be true marsupials, but are now tho ...

s during most of the Cenozoic but declined and ultimately went extinct after eutherian predators arrived from North America (as part of the

Great American Interchange The Great American Biotic Interchange (commonly abbreviated as GABI), also known as the Great American Interchange and the Great American Faunal Interchange, was an important late Cenozoic paleozoogeographic biotic interchange event in which la ...

) during the

Pliocene The Pliocene ( ; also Pleiocene) is the epoch in the geologic time scale that extends from 5.333 million to 2.58Brontornis ''Brontornis'' is an extinct genus of giant bird that inhabited Argentina during the Early to Middle Miocene. Its taxonomic position is highly controversial, with authors alternatively considering it to be a cariamiform, typically a phorusrhaci ...

'', possibly omnivorous ''

Dromornis stirtoni ''Dromornis'' is a genus of large to enormous prehistoric birds. The species were flightless, possessing greatly reduced wing structures but with large legs, similar to the modern ostrich or emu. They were likely to have been predominantly, i ...

'' or herbivorous ''

Vorombe ''Vorombe'' is one of three genera of elephant birds, an extinct family of large ratite birds endemic to Madagascar. Originally considered to be large '' Aepyornis'' specimens, it is now thought ''Vorombe'' are the largest and heaviest birds k ...

'', ever grew to masses much above 500 kg, and thus never attained the size of the largest mammalian carnivores, let alone that of the largest mammalian herbivores. It has been suggested that the increasing thickness of avian eggshells in proportion to egg mass with increasing egg size places an upper limit on the size of birds. The largest species of ''Dromornis'', ''D. stirtoni'', may have gone extinct after it attained the maximum avian body mass and was then outcompeted by marsupial

diprotodon ''Diprotodon'' (Ancient Greek: "two protruding front teeth") is an extinct genus of marsupial from the Pleistocene of Australia, containing one species, ''D. optatum''. The earliest finds date to 1.77 million to 780,000 years ago, but most speci ...

ts that evolved to sizes several times larger.

In giant turtles

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 ...

s were important components of late

megafaunas, being present in every nonpolar continent until the arrival of

hominina Australopithecina or Hominina is a subtribe in the tribe Hominini. The members of the subtribe are generally ''Australopithecus'' ( cladistically including the genera ''Homo'', ''Paranthropus'', and '' Kenyanthropus''), and it typically include ...

ns. The largest known terrestrial tortoise was ''

Megalochelys atlas ''Megalochelys'' ("great turtle") is an extinct genus of cryptodiran tortoises that lived from the Miocene to Pleistocene. They are noted for their giant size, which is among the largest of any known testudine, with a maximum carapace length ove ...

'', an animal that probably weighed about 1,000 kg. Some earlier aquatic Testudines, e.g. the marine ''

Archelon ''Archelon'' is an extinct marine turtle from the Late Cretaceous, and is the largest turtle ever to have been documented, with the biggest specimen measuring from head to tail and in body mass. It is known only from the Dakota Pierre Shal ...

'' of the Cretaceous and freshwater ''

Stupendemys ''Stupendemys'' is an extinct genus of freshwater side-necked turtle, belonging to the family Podocnemididae. It is the largest freshwater turtle known to have existed, with a carapace over 2 meters long. Its fossils have been found in northe ...

'' of the Miocene, were considerably larger, weighing more than 2,000 kg.

Megafaunal mass extinctions

Timing and possible causes

Large Mammals Africa Australia NAmerica Madagascar

The

Holocene extinction The Holocene extinction, or Anthropocene extinction, is the ongoing extinction event during the Holocene epoch. The extinctions span numerous families of bacteria, fungi, plants, and animals, including mammals, birds, reptiles, amphibians, f ...

(see also

Quaternary extinction event The Quaternary period (from 2.588 ± 0.005 million years ago to the present) has seen the extinctions of numerous predominantly megafaunal species, which have resulted in a collapse in faunal density and diversity and the extinction of key ecolog ...

), occurred at the end of the last ice age glacial period (a.k.a. the

Würm glaciation The Würm glaciation or Würm stage (german: Würm-Kaltzeit or ''Würm-Glazial'', colloquially often also ''Würmeiszeit'' or ''Würmzeit''; cf. ice age), usually referred to in the literature as the Würm (often spelled "Wurm"), was the last g ...

) when many giant ice age mammals, such as

woolly mammoth The woolly mammoth (''Mammuthus primigenius'') is an extinct species of mammoth that lived during the Pleistocene until its extinction in the Holocene epoch. It was one of the last in a line of mammoth species, beginning with '' Mammuthus sub ...

s, went extinct in the Americas and northern

Eurasia Eurasia (, ) is the largest continental area on Earth, comprising all of Europe and Asia. Primarily in the Northern and Eastern Hemispheres, it spans from the British Isles and the Iberian Peninsula in the west to the Japanese archipelag ...

. An analysis of the extinction event in North America found it to be unique among Cenozoic extinction pulses in its selectivity for large animals. Various theories have attributed the wave of extinctions to

human hunting Human hunting refers to humans being hunted and killed for other persons' revenge, pleasure, entertainment, sports, or sustenance. Historically, incidents of the practice have occurred during times of social upheaval. Historical examples * In ...

climate change In common usage, climate change describes global warming—the ongoing increase in global average temperature—and its effects on Earth's climate system. Climate change in a broader sense also includes previous long-term changes to ...

disease A disease is a particular abnormal condition that negatively affects the structure or function of all or part of an organism, and that is not immediately due to any external injury. Diseases are often known to be medical conditions that a ...

, extraterrestrial impact, or other causes. However, this extinction near the end of the

Pleistocene The Pleistocene ( , often referred to as the '' Ice age'') is the geological epoch that lasted from about 2,580,000 to 11,700 years ago, spanning the Earth's most recent period of repeated glaciations. Before a change was finally confirmed ...

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

and southern

(where the local megafauna had a chance to evolve alongside modern humans) being comparatively less affected. The latter areas did suffer a gradual attrition of megafauna, particularly of the slower-moving species (a class of vulnerable megafauna epitomized by

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 ...

s), over the last several million years. Outside the mainland of

Afro-Eurasia Afro-Eurasia (also Afroeurasia, Eurafrasia or the Old World) is a landmass comprising the continents of Africa, Asia, and Europe. The terms are compound words of the names of its constituent parts. Its mainland is the largest and most populou ...

, these megafaunal extinctions followed a highly distinctive landmass-by-landmass pattern that closely parallels the spread of humans into previously uninhabited regions of the world, and which shows no overall correlation with climatic history (which can be visualized with plots over recent geological time periods of climate markers such as marine oxygen isotopes or atmospheric carbon dioxide levels). Australia and nearby islands (e.g., Flores) were struck first around 46,000 years ago, followed by

Tasmania ) , nickname = , image_map = Tasmania in Australia.svg , map_caption = Location of Tasmania in AustraliaCoordinates: , subdivision_type = Country , subdi ...

about 41,000 years ago (after formation of a land bridge to Australia about 43,000 years ago). The role of humans in the extinction of Australia and New Guinea's megafauna has been disputed, with multiple studies showing a decline in the number of species prior to the peopling of the continent and the absence of any evidence of human predation. The impact of climate change has instead been cited for their decline. Stepwise Japan apparently about 30,000 years ago, North America 13,000 years ago,

South America South America is a continent entirely in the Western Hemisphere and mostly in the Southern Hemisphere, with a relatively small portion in the Northern Hemisphere at the northern tip of the continent. It can also be described as the souther ...

about 500 years later,

Cyprus Cyprus ; tr, Kıbrıs (), officially the Republic of Cyprus,, , lit: Republic of Cyprus is an island country located south of the Anatolian Peninsula in the eastern Mediterranean Sea. Its continental position is disputed; while it is ...

10,000 years ago, the

Antilles The Antilles (; gcf, label=Antillean Creole, Antiy; es, Antillas; french: Antilles; nl, Antillen; ht, Antiy; pap, Antias; Jamaican Patois: ''Antiliiz'') is an archipelago bordered by the Caribbean Sea to the south and west, the Gulf of Mex ...

6,000 years ago, New Caledonia and nearby islands 3,000 years ago,

Madagascar Madagascar (; mg, Madagasikara, ), officially the Republic of Madagascar ( mg, Repoblikan'i Madagasikara, links=no, ; french: République de Madagascar), is an island country in the Indian Ocean, approximately off the coast of East Africa ...

2,000 years ago,

New Zealand New Zealand ( mi, Aotearoa ) is an island country in the southwestern Pacific Ocean. It consists of two main landmasses—the North Island () and the South Island ()—and over 700 List of islands of New Zealand, smaller islands. It is the ...

700 years ago, the

Mascarenes The Mascarene Islands (, ) or Mascarenes or Mascarenhas Archipelago is a group of islands in the Indian Ocean east of Madagascar consisting of the islands belonging to the Republic of Mauritius as well as the French department of Réunion. Thei ...

400 years ago, and the

Commander Islands The Commander Islands, Komandorski Islands, or Komandorskie Islands (russian: Командо́рские острова́, ''Komandorskiye ostrova'') are a series of treeless, sparsely populated Russian islands in the Bering Sea located about e ...

250 years ago. Nearly all of the world's isolated islands could furnish similar examples of extinctions occurring shortly after the arrival of

s, though most of these islands, such as the

Hawaiian Islands The Hawaiian Islands ( haw, Nā Mokupuni o Hawai‘i) are an archipelago of eight major islands, several atolls, and numerous smaller islets in the North Pacific Ocean, extending some from the island of Hawaii in the south to northernmost ...

, never had terrestrial megafauna, so their extinct fauna were smaller. An analysis of the timing of

Holarctic The Holarctic realm is a biogeographic realm that comprises the majority of habitats found throughout the continents in the Northern Hemisphere. It corresponds to the floristic Boreal Kingdom. It includes both the Nearctic zoogeographical regi ...

megafaunal extinctions and extirpations over the last 56,000 years has revealed a tendency for such events to cluster within

interstadial Stadials and interstadials are phases dividing the Quaternary period, or the last 2.6 million years. Stadials are periods of colder climate while interstadials are periods of warmer climate. Each Quaternary climate phase is associated with a M ...

s, periods of abrupt warming, but only when humans were also present. Humans may have impeded processes of migration and recolonization that would otherwise have allowed the megafaunal species to adapt to the climate shift. In at least some areas, interstadials were periods of expanding human populations. An analysis of ''

Sporormiella ''Sporormiella'' is a genus of fungi in the family Sporormiaceae. Species of the genus are obligately coprophilous, occurring on the dung of domestic livestock as well as wild herbivores. The genus is distributed across boreal and temperate reg ...

'' fungal spores (which derive mainly from the dung of megaherbivores) in swamp sediment cores spanning the last 130,000 years from

Lynch's Crater Lynch's Crater () formed about 230,000 years ago during an explosive volcanic eruption, creating a maar on the eastern edge of the Atherton Tableland in Queensland, Australia. Located at an altitude of about 760 m, the crater is about 80&nb ...

Queensland ) , nickname = Sunshine State , image_map = Queensland in Australia.svg , map_caption = Location of Queensland in Australia , subdivision_type = Country , subdivision_name = Australia , established_title = Before federation , established_ ...

, Australia, showed that the megafauna of that region virtually disappeared about 41,000 years ago, at a time when

s were minimal; the change was accompanied by an increase in charcoal, and was followed by a transition from rainforest to fire-tolerant

sclerophyll Sclerophyll is a type of vegetation that is adapted to long periods of dryness and heat. The plants feature hard leaves, short internodes (the distance between leaves along the stem) and leaf orientation which is parallel or oblique to direct ...

vegetation. The high-resolution chronology of the changes supports the hypothesis that human hunting alone eliminated the megafauna, and that the subsequent change in flora was most likely a consequence of the elimination of browsers and an increase in fire. The increase in fire lagged the disappearance of megafauna by about a century, and most likely resulted from accumulation of fuel once browsing stopped. Over the next several centuries grass increased; sclerophyll vegetation increased with a lag of another century, and a sclerophyll forest developed after about another thousand years. During two periods of climate change about 120,000 and 75,000 years ago, sclerophyll vegetation had also increased at the site in response to a shift to cooler, drier conditions; neither of these episodes had a significant impact on megafaunal abundance. Similar conclusions regarding the culpability of human hunters in the disappearance of Pleistocene megafauna were derived from high-resolution chronologies obtained via an analysis of a large collection of eggshell fragments of the flightless Australian bird ''

Genyornis newtoni ''Genyornis newtoni'', also known as thunder bird and mihirung paringmal (meaning "giant bird"), is an extinct species of large, flightless bird that lived in Australia during the Pleistocene epoch until around 50,000 years ago. Over two met ...

'', from analysis of ''Sporormiella'' fungal spores from a lake in eastern North America and from study of deposits of

Shasta ground sloth ''Nothrotheriops'' is a genus of Pleistocene ground sloth found in North America, from what is now central Mexico to the southern United States. This genus of bear-sized xenarthran was related to the much larger, and far more famous ''Megatheriu ...

dung left in over half a dozen caves in the American southwest. 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). Direct killing by humans, primarily for meat, is the most significant factor in contemporary megafaunal decline. A number of other

mass extinction An extinction event (also known as a mass extinction or biotic crisis) is a widespread and rapid decrease in the biodiversity on Earth. Such an event is identified by a sharp change in the diversity and abundance of multicellular organisms. I ...

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

the non-avian 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 The biosphere (from Greek βίος ''bíos'' "life" and σφαῖρα ''sphaira'' "sphere"), also known as the ecosphere (from Greek οἶκος ''oîkos'' "environment" and σφαῖρα), is the worldwide sum of all ecosystems. It can also be ...

Consequences of depletion of megafauna

Effect on nutrient transport

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 The Amazon basin is the part of South America drained by the Amazon River and its tributaries. The Amazon drainage basin covers an area of about , or about 35.5 percent of the South American continent. It is located in the countries of Boli ...

, 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 Phosphorus is a chemical element with the symbol P and atomic number 15. Elemental phosphorus exists in two major forms, white phosphorus and red phosphorus, but because it is highly reactive, phosphorus is never found as a free element on Ea ...

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 The Andes, Andes Mountains or Andean Mountains (; ) are the longest continental mountain range in the world, forming a continuous highland along the western edge of South America. The range is long, wide (widest between 18°S – 20°S ...

) to other areas is thought to have significantly impacted the region's ecology, and the effects may not yet have reached their limits. In the sea, cetaceans and pinnipeds that feed at depth are thought to translocate nitrogen from deep to shallow water, enhancing ocean productivity, and counteracting the activity of

zooplankton Zooplankton are the animal component of the planktonic community ("zoo" comes from the Greek word for ''animal''). Plankton are aquatic organisms that are unable to swim effectively against currents, and consequently drift or are carried along by ...

, which tend to do the opposite.

Effect on methane emissions

Large populations of megaherbivores have the potential to contribute greatly to the atmospheric concentration of

methane Methane ( , ) is a chemical compound with the chemical formula (one carbon atom bonded to four hydrogen atoms). It is a group-14 hydride, the simplest alkane, and the main constituent of natural gas. The relative abundance of methane on Ear ...

, which is an important

greenhouse gas A greenhouse gas (GHG or GhG) is a gas that absorbs and emits radiant energy within the thermal infrared range, causing the greenhouse effect. The primary greenhouse gases in Earth's atmosphere are water vapor (), carbon dioxide (), met ...

. Modern

ruminant Ruminants ( suborder Ruminantia) are hoofed herbivorous grazing or browsing mammals that are able to acquire nutrients from plant-based food by fermenting it in a specialized stomach prior to digestion, principally through microbial actions. Th ...

herbivores A herbivore is an animal anatomically and physiologically adapted to eating plant material, for example foliage or marine algae, for the main component of its diet. As a result of their plant diet, herbivorous animals typically have mouthpar ...

produce methane as a byproduct of

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. Foregut fermentation is employed by ruminants and pseudoruminants, som ...

in digestion, and release it through belching or flatulence. Today, around 20% of annual

methane emissions Increasing methane emissions are a major contributor to the rising concentration of greenhouse gases in Earth's atmosphere, and are responsible for up to one-third of near-term global heating. During 2019, about 60% (360 million tons) of methane ...

come from livestock methane release. In the

Mesozoic The Mesozoic Era ( ), also called the Age of Reptiles, the Age of Conifers, and colloquially as the Age of the Dinosaurs is the second-to-last era of Earth's geological history, lasting from about , comprising the Triassic, Jurassic and Creta ...

, it has been estimated that

sauropod Sauropoda (), whose members are known as sauropods (; from '' sauro-'' + '' -pod'', 'lizard-footed'), is a clade of saurischian ('lizard-hipped') dinosaurs. Sauropods had very long necks, long tails, small heads (relative to the rest of their ...

s 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 Atmospheric methane is the methane present in Earth's atmosphere. Atmospheric methane concentrations are of interest because it is one of the most potent greenhouse gases in Earth's atmosphere. Atmospheric methane is rising. The 20-year global ...

. This hypothesis is relatively new. One study examined the methane emissions from the

bison Bison are large bovines in the genus ''Bison'' (Greek: "wild ox" (bison)) within the tribe Bovini. Two extant and numerous extinct species are recognised. Of the two surviving species, the American bison, ''B. bison'', found only in North ...

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 The Pleistocene ( , often referred to as the ''Ice age'') is the geological epoch that lasted from about 2,580,000 to 11,700 years ago, spanning the Earth's most recent period of repeated glaciations. Before a change was finally confirmed in ...

after the extinction of megafauna in the Americas. After early humans migrated to the Americas about 13,000 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 (c. 12,900 to 11,700 years BP) was a return to glacial conditions which temporarily reversed the gradual climatic warming after the Last Glacial Maximum (LGM, c. 27,000 to 20,000 years BP). The Younger Dryas was the last stag ...

. The decrease in atmospheric methane that occurred at that time, as recorded in

ice core An ice core is a core sample that is typically removed from an ice sheet or a high mountain glacier. Since the ice forms from the incremental buildup of annual layers of snow, lower layers are older than upper ones, and an ice core contains ...

s, was 2-4 times more rapid than any other decrease in the last half million years, suggesting that an unusual mechanism was at work.

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: *Clade Synapsida **Class

Mammalia Mammals () are a group of vertebrate animals constituting the class Mammalia (), characterized by the presence of mammary glands which in females produce milk for feeding (nursing) their young, a neocortex (a region of the brain), fu ...

(

phylogenetically In biology, phylogenetics (; from Greek φυλή/ φῦλον [] "tribe, clan, race", and wikt:γενετικός, γενετικός [] "origin, source, birth") is the study of the evolutionary history and relationships among or within groups o ...

, a clade within

Therapsid Therapsida is a major group of eupelycosaurian synapsids that includes mammals, their ancestors and relatives. Many of the traits today seen as unique to mammals had their origin within early therapsids, including limbs that were oriented mor ...

a; see below) ***Infraclass

Metatheria Metatheria is a mammalian clade that includes all mammals more closely related to marsupials than to placentals. First proposed by Thomas Henry Huxley in 1880, it is a more inclusive group than the marsupials; it contains all marsupials as we ...

****Order

Diprotodontia Diprotodontia (, from Greek "two forward teeth") is the largest extant order of marsupials, with about 155 species, including the kangaroos, wallabies, possums, koala, wombats, and many others. Extinct diprotodonts include the hippopotamus-sized ...

*****The

(''Macropus rufus'') is the largest living Australian mammal and

marsupial Marsupials are any members of the mammalian infraclass Marsupialia. All extant marsupials are endemic to Australasia, Wallacea and the Americas. A distinctive characteristic common to most of these species is that the young are carried in a ...

at a weight of up to . However, its extinct relative, the giant short-faced kangaroo ''Procoptodon goliah'' reached , while extinct

ts attained the largest size of any marsupial in history, up to an estimated . The extinct marsupial lion (''

Thylacoleo carnifex ''Thylacoleo'' ("pouch lion") is an extinct genus of carnivorous marsupials that lived in Australia from the late Pliocene to the late Pleistocene (2 million to 46 thousand years ago). Some of these marsupial lions were the largest mammalian p ...

''), at up to was much larger than any extant carnivorous marsupial. ***Infraclass

Eutheria Eutheria (; from Greek , 'good, right' and , 'beast'; ) is the clade consisting of all therian mammals that are more closely related to placentals than to marsupials. Eutherians are distinguished from noneutherians by various phenotypic t ...

****Superorder

Afrotheria Afrotheria ( from Latin ''Afro-'' "of Africa" + ''theria'' "wild beast") is a clade of mammals, the living members of which belong to groups that are either currently living in Africa or of African origin: golden moles, elephant shrews (also ...

*****Order

Proboscidea The Proboscidea (; , ) are 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. Fr ...

******

Elephants Elephants are the largest existing land animals. Three living species are currently recognised: the African bush elephant, the African forest elephant, and the Asian elephant. They are the only surviving members of the family Elephantidae ...

are the largest living land animals. They and their relatives arose in

, but until recently had a nearly worldwide distribution. The African bush elephant (''Loxodonta africana'') has a shoulder height of up to and weighs up to . Among recently extinct proboscideans,

s (''Mammuthus'') were close relatives of elephants, while

mastodon A mastodon ( 'breast' + 'tooth') is any proboscidean belonging to the extinct genus ''Mammut'' (family Mammutidae). Mastodons inhabited North and Central America during the late Miocene or late Pliocene up to their extinction at the end of th ...

s (''Mammut'') were much more distantly related. The Palaeoloxodon namadicus may have reached 5.2 meters in height and 22 tones in weight. This makes it the largest known terrestrial mammal. *****Order

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 Sirenia currently comprise two distinct ...

******The largest sirenian at up to is the

West Indian manatee The West Indian manatee (''Trichechus manatus''), also known as the North American manatee, is a large, aquatic mammal native to warm coastal areas of the Caribbean, from the eastern US to northern Brazil. Living alone or in herds, it feeds on un ...

(''Trichechus manatus'').

(''Hydrodamalis gigas'') was probably around five times as massive, but was exterminated by humans within 27 years of its discovery off the remote

in 1741. In prehistoric times this sea cow also lived along the coasts of northeastern

and northwestern North America; it was apparently eliminated from these more accessible locations by aboriginal hunters. ****Superorder

Xenarthra Xenarthra (; from Ancient Greek ξένος, xénos, "foreign, alien" + ἄρθρον, árthron, "joint") is a major clade of placental mammals native to the Americas. There are 31 living species: the anteaters, tree sloths, and armadillos. Ex ...

*****Order

Cingulata Cingulata, part of the superorder Xenarthra, is an order of armored New World placental mammals. Dasypodids and chlamyphorids, the armadillos, are the only surviving families in the order. Two groups of cingulates much larger than extant arma ...

******The

glyptodonts Glyptodonts are an extinct subfamily of large, heavily armoured armadillos. They arose in South America around 48 million years ago and spread to southern North America after the continents became connected several million years ago. The best-k ...

were a group of large, heavily armored

ankylosaur 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, similar to turtles. Ankylosaurs were bulky quadrupeds, with short, powerful limbs. ...

-like

xenarthra Xenarthra (; from Ancient Greek ξένος, xénos, "foreign, alien" + ἄρθρον, árthron, "joint") is a major clade of placental mammals native to the Americas. There are 31 living species: the anteaters, tree sloths, and armadillos. Ex ...

ns related to living

armadillos Armadillos (meaning "little armored ones" in Spanish) are New World placental mammals in the order Cingulata. The Chlamyphoridae and Dasypodidae are the only surviving families in the order, which is part of the superorder Xenarthra, al ...

. They originated in

, invaded North America during the

, and went extinct at the end of the

epoch In chronology and periodization, an epoch or reference epoch is an instant in time chosen as the origin of a particular calendar era. The "epoch" serves as a reference point from which time is measured. The moment of epoch is usually decided by ...

. *****Order

Pilosa The order Pilosa is a clade of xenarthran placental mammals, native to the Americas. It includes the anteaters and sloths (which includes the extinct ground sloths). The name comes from the Latin word for "hairy". Origins and taxonomy ...

******

Ground sloth Ground sloths are a diverse group of extinct sloths in the mammalian superorder Xenarthra. The term is used to refer to all extinct sloths because of the large size of the earliest forms discovered, compared to existing tree sloths. The Cari ...

s were another group of slow, terrestrial xenarthrans, related to modern tree sloths. They had a similar history, although they reached North America earlier, and spread farther north (e.g., ''

Megalonyx ''Megalonyx'' (Greek, "large claw") is an extinct genus of ground sloths of the family Megalonychidae, native to North America during the Pliocene and Pleistocene epochs. It became extinct during the Quaternary extinction event at the end of the ...

''). The largest genera, ''

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 Pleistocene. It is best known for the elephant-sized type species ...

'' and ''

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, the largest and most heavily built family of sloths. ' ...

'', reached sizes comparable to elephants. ****Superorder

Euarchontoglires Euarchontoglires (synonymous with Supraprimates) is a clade and a superorder of mammals, the living members of which belong to one of the five following groups: rodents, lagomorphs, treeshrews, colugos, and primates. Evolutionary affinitie ...

*****Order

Primates Primates are a diverse order of mammals. They are divided into the strepsirrhines, which include the lemurs, galagos, and lorisids, and the haplorhines, which include the tarsiers and the simians (monkeys and apes, the latter includin ...

******The largest living primate, at up to , is the

gorilla Gorillas are herbivorous, predominantly ground-dwelling great apes that inhabit the tropical forests of equatorial Africa. The genus ''Gorilla'' is divided into two species: the eastern gorilla and the western gorilla, and either four ...

(''

Gorilla beringei The eastern gorilla (''Gorilla beringei'') is a critically endangered species of the genus ''Gorilla'' and the largest living primate. At present, the species is subdivided into two subspecies. There are 3,800 eastern lowland gorillas or Grau ...

'' and ''

Gorilla gorilla The western gorilla (''Gorilla gorilla'') is a great ape found in Africa, one of two species of the hominid genus '' Gorilla''. Large and robust with males weighing around , the hair is significantly lighter in color than the eastern gorilla, ' ...

'', with three of four subspecies being critically endangered). The extinct Malagasy

sloth lemur The sloth lemurs (Palaeopropithecidae) comprise an extinct family of lemurs that includes four genera. The common name can be misleading, as members of Palaeopropithecidae were not closely related to sloths. This clade has been dubbed the ‘� ...

Archaeoindris ''Archaeoindris fontoynontii'' is an extinct giant lemur and the largest primate known to have evolved on Madagascar, comparable in size to a male gorilla. It belonged to a family of extinct lemurs known as "sloth lemurs" (Palaeopropithecida ...

'' reached a similar size, while the extinct ''

Gigantopithecus blacki ''Gigantopithecus'' ( ; ) is an extinct genus of ape from roughly 2 million to 350,000 years ago during the Early Pleistocene, Early to Middle Pleistocene of southern China, represented by one species, ''Gigantopithecus blacki''. Potential identi ...

'' of

Southeast Asia Southeast Asia, also spelled South East Asia and South-East Asia, and also known as Southeastern Asia, South-eastern Asia or SEA, is the geographical United Nations geoscheme for Asia#South-eastern Asia, south-eastern region of Asia, consistin ...

is believed to have been larger yet, although probably less than twice as large, contrary to early estimates (the absence of postcranial remains makes its size difficult to judge). Some populations of archaic ''Homo'' were significantly larger on average than recent ''

Homo sapiens Humans (''Homo sapiens'') are the most abundant and widespread species of primate, characterized by bipedalism and exceptional cognitive skills due to a large and complex brain. This has enabled the development of advanced tools, culture, ...

''; for example, ''

Homo heidelbergensis ''Homo heidelbergensis'' (also ''H. sapiens heidelbergensis''), sometimes called Heidelbergs, is an extinct species or subspecies of archaic human which existed during the Middle Pleistocene. It was subsumed as a subspecies of '' H. erectus'' ...

'' in southern Africa may have commonly reached in height, while

Neanderthal Neanderthals (, also ''Homo neanderthalensis'' and erroneously ''Homo sapiens neanderthalensis''), also written as Neandertals, are an extinct species or subspecies of archaic humans who lived in Eurasia until about 40,000 years ago. While ...

s were about 30% more massive. *****Order

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 lower jaws. About 40% of all mammal species are roden ...

ia ******The extant

capybara The capybaraAlso called capivara (in Brazil), capiguara (in Bolivia), chigüire, chigüiro, or fercho (in Colombia and Venezuela), carpincho (in Argentina, Paraguay and Uruguay) and ronsoco (in Peru). or greater capybara (''Hydrochoerus hydro ...

(''Hydrochoerus hydrochaeris'') of South America, the largest living rodent, weighs up to . Several recently extinct North American forms were larger: the capybara ''

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 Interc ...

'' (another

migrant) was about 40% heavier on average; the giant beaver (''Castoroides ohioensis'') was similar. The extinct

blunt-toothed giant hutia The blunt-toothed giant hutia (''Amblyrhiza inundata'') is an extinct species of giant hutia from Anguilla and Saint Martin that is estimated to have weighed between 50 and 200 kg (110 and 440 lb). It was discovered by Edward Drinker ...

(''Amblyrhiza inundata'') of several Caribbean islands may have been larger still. However, several million years ago South America harbored much more massive rodents. ''

Phoberomys pattersoni ''Phoberomys pattersoni'' is an extinct rodent that lived in the ancient Orinoco River delta around 8 million years ago. It was the second-largest of the roughly seven species of its genus. Like many other rodents, ''Phoberomys'' was a herbivore ...

'', known from a nearly full skeleton, probably reached . Fragmentary remains suggest that ''

Josephoartigasia monesi ''Josephoartigasia'' is an extinct genus of enormous dinomyid rodent from the Early Pliocene to Early Pleistocene of Uruguay. The only living member of Dinomyidae is the pacarana. ''Josephoartigasia'' is named after Uruguayan national hero J ...

'' grew to upwards of . ****Superorder

Laurasiatheria Laurasiatheria ("laurasian beasts") is a superorder of placental mammals that groups together true insectivores ( eulipotyphlans), bats ( chiropterans), carnivorans, pangolins ( pholidotes), even-toed ungulates ( artiodactyls), odd-toed ungula ...

*****Order

Carnivora Carnivora is a monophyletic order of placental mammals consisting of the most recent common ancestor of all cat-like and dog-like animals, and all descendants of that ancestor. Members of this group are formally referred to as carnivorans, ...

******The largest extant cats are in genus ''

Panthera ''Panthera'' is a genus within the family Felidae that was named and described by Lorenz Oken in 1816 who placed all the spotted cats in this group. Reginald Innes Pocock revised the classification of this genus in 1916 as comprising the tiger ...

'', including the

tiger The tiger (''Panthera tigris'') is the largest living cat species and a member of the genus '' Panthera''. It is most recognisable for its dark vertical stripes on orange fur with a white underside. An apex predator, it primarily preys on ...

(''P. tigris'') and

(''P. leo''). The

Siberian tiger The Siberian tiger or Amur tiger is a population of the tiger subspecies ''Panthera tigris tigris'' native to the Russian Far East, Northeast China and possibly North Korea. It once ranged throughout the Korean Peninsula, but currently inhabi ...

(''P. t. altaica'') should be the biggest wild cat according to

, and has been regarded as such by some but this is disputable. Historically, wild Siberian tigers have declined in size, and they are now smaller than Bengal tigers (''P. t. tigris''); however, Siberian tigers do still tend to be the largest of tigers in captivity, reaching about in weight. ''Panthera'' species are distinguished by morphological features which enable them to roar. Larger extinct cats include the

American lion ''Panthera atrox'', better known as the American lion, also called the North American lion, or American cave lion, is an extinct pantherine cat that lived in North America during the Pleistocene epoch and the early Holocene epoch, about 340 ...

(''P. atrox'') and the South American

saber-toothed cat Machairodontinae is an extinct subfamily of carnivoran mammals of the family Felidae (true cats). They were found in Asia, Africa, North America, South America, and Europe from the Miocene to the Pleistocene, living from about 16 million until ...

(''

Smilodon populator ''Smilodon'' is a genus of the extinct machairodont subfamily of the felids. It is one of the most famous prehistoric mammals and the best known saber-toothed cat. Although commonly known as the saber-toothed tiger, it was not closely relate ...

''). ******

Bear Bears are carnivoran mammals of the 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 throughout the N ...

s are large carnivorans of the caniform suborder. The largest living forms are the polar bear (''Ursus maritimus''), with a body weight of up to , and the nearly as large

Kodiak bear The Kodiak bear (''Ursus arctos middendorffi''), also known as the Kodiak brown bear, sometimes the Alaskan brown bear, inhabits the islands of the Kodiak Archipelago in southwest Alaska. It is the largest recognized subspecies or population ...

(''Ursus arctos middendorffi''), consistent with Bergmann's rule. ''

augustans'', an extinct

short-faced bear The Tremarctinae or short-faced bears is a subfamily of Ursidae that contains one living representative, the spectacled bear (''Tremarctos ornatus'') of South America, and several extinct species from four genera: the Florida spectacled bear (' ...

from South America, was the largest predatory land mammal ever with an estimated average weight of . ****** Seals, sea lions, and walruses are amphibious marine carnivorans that evolved from bearlike ancestors. The

(''Mirounga leonina'') of

Antarctic The Antarctic ( or , American English also or ; commonly ) is a polar region around Earth's South Pole, opposite the Arctic region around the North Pole. The Antarctic comprises the continent of Antarctica, the Kerguelen Plateau and o ...

and

subantarctic The sub-Antarctic zone is a region in the Southern Hemisphere, located immediately north of the Antarctic region. This translates roughly to a latitude of between 46° and 60° south of the Equator. The subantarctic region includes many islands ...

waters is the largest carnivoran of all time, with bull males reaching a maximum length of and maximum weight of . *****Order Perissodactyla ******

Tapir Tapirs ( ) are large, herbivorous mammals belonging to the family Tapiridae. They are similar in shape to a pig, with a short, prehensile nose trunk. Tapirs inhabit jungle and forest regions of South and Central America, with one species inh ...

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 forests (a.k.a. jungle) are forested landscapes in tropical regions: ''i.e.'' land areas approximately bounded by the tropic of Cancer and Capricorn, but possibly affected by other factors such as prevailing winds. Some tropical fore ...

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 A rhinoceros (; ; ), commonly abbreviated to rhino, is a member of any of the five extant taxon, extant species (or numerous extinct species) of odd-toed ungulates in the family (biology), family Rhinocerotidae. (It can also refer to a member ...

es are

odd-toed ungulates Odd-toed ungulates, mammals which constitute the taxonomic order Perissodactyla (, ), are animals—ungulates—who have reduced the weight-bearing toes to three (rhinoceroses and tapirs, with tapirs still using four toes on the front legs) ...

with horns made of

keratin Keratin () is one of a family of structural fibrous proteins also known as ''scleroproteins''. Alpha-keratin (α-keratin) is a type of keratin found in vertebrates. It is the key structural material making up scales, hair, nails, feathers, ...

, the same type of

protein Proteins are large biomolecules and macromolecules that comprise one or more long chains of amino acid residues. Proteins perform a vast array of functions within organisms, including catalysing metabolic reactions, DNA replication, respon ...

composing hair. They are among the second-largest living land mammals at 850-3,800 kg. Three of five extant species are critically endangered. Their extinct

central Asia Central Asia, also known as Middle Asia, is a region of Asia that stretches from the Caspian Sea in the west to western China and Mongolia in the east, and from Afghanistan and Iran in the south to Russia in the north. It includes the former ...

n relatives the indricotherines were the largest terrestrial mammals of all time. Megafauna1

*****Order

Artiodactyla The even-toed ungulates (Artiodactyla , ) are ungulates—hoofed animals—which bear weight equally on two (an even number) of their five toes: the third and fourth. The other three toes are either present, absent, vestigial, or pointing poste ...

******

Giraffes The giraffe is a large African hoofed mammal belonging to the genus ''Giraffa''. It is the tallest living terrestrial animal and the largest ruminant on Earth. Traditionally, giraffes were thought to be one species, '' Giraffa camelopardali ...

(''Giraffa spp.'') are the tallest living land animals, reaching heights of up to nearly . The average weight is 1,192 kg (2,628 lb) for an adult male and 828 kg (1,825 lb) for an adult female with maximum weights of 1,930 kg (4,250 lb) and 1,180 kg (2,600 lb) recorded for males and females, respectively. ****** Bovine ungulates include the largest surviving land animals of

and North America. The

water buffalo The water buffalo (''Bubalus bubalis''), also called the domestic water buffalo or Asian water buffalo, is a large bovid originating in the Indian subcontinent and Southeast Asia. Today, it is also found in Europe, Australia, North America, S ...

(''Bubalis arnee''),

(''

Bison bison The American bison (''Bison bison'') is a species of bison native to North America. Sometimes colloquially referred to as American buffalo or simply buffalo (a different clade of bovine), it is one of two extant species of bison, alongside the ...

'' and '' B. bonasus''), and

gaur The gaur (''Bos gaurus''; ), also known as the Indian bison, is a bovine native to South Asia and Southeast Asia, and has been listed as Vulnerable on the IUCN Red List since 1986. The global population was estimated at a maximum of 21,000 ...

(''Bos gaurus'') can all grow to weights of over . ******The

semiaquatic In biology, semiaquatic can refer to various types of animals that spend part of their time in water, or plants that naturally grow partially submerged in water. Examples are given below. Semiaquatic animals Semi aquatic animals include: * Ve ...

(''Hippopotamus amphibius'') is the heaviest living member of the order

Cetartiodactyla The even-toed ungulates (Artiodactyla , ) are ungulates—hoofed animals—which bear weight equally on two (an even number) of their five toes: the third and fourth. The other three toes are either present, absent, vestigial, or pointing poster ...

after the cetaceans. Mean adult weight is around 1,500 kg (3,300 lb) and 1,300 kg (2,900 lb) for males and females respectively, with large males reaching over 3,200 kg (7,100 lb). The hippopotamus and the much smaller critically endangered

pygmy hippo The pygmy hippopotamus or pygmy hippo (''Choeropsis liberiensis'') is a small hippopotamid which is native to the forests and swamps of West Africa, primarily in Liberia, with small populations in Sierra Leone, Guinea, and Ivory Coast. It has ...

(''Choeropsis liberiensis'') are believed to be the closest extant relatives of cetaceans. Hippopotamuses are among the megafaunal species

most dangerous ''Most Dangerous: Daniel Ellsberg and the Secret History of the Vietnam War'' is a 2015 non-fiction book, aimed for young adolescent readers, written by Steve Sheinkin and published through Roaring Brook Press. The multi-award-winning book te ...

to humans. ******Infraorder Cetacea ******* Whales, dolphins, and porpoises are marine mammals. The

(''Balaenoptera musculus'') is the largest

baleen whale Baleen whales ( systematic name Mysticeti), also known as whalebone whales, are a parvorder of carnivorous marine mammals of the infraorder Cetacea ( whales, dolphins and porpoises) which use keratinaceous baleen plates (or "whalebone") in th ...

and the largest animal that has ever lived, at in length and 170 tonnes (190 short tons) or more in weight. The

sperm whale The sperm whale or cachalot (''Physeter macrocephalus'') is the largest of the toothed whales and the largest toothed predator. It is the only living member of the genus '' Physeter'' and one of three extant species in the sperm whale famil ...

(''Physeter macrocephalus'') is the largest

toothed whale The toothed whales (also called odontocetes, systematic name Odontoceti) are a parvorder of cetaceans that includes dolphins, porpoises, and all other whales possessing teeth, such as the beaked whales and sperm whales. Seventy-three species ...

and one of the largest predators in vertebrate history, as well as the planet's loudest and brainiest animal (with a

brain The brain is an organ that serves as the center of the nervous system in all vertebrate and most invertebrate animals. It consists of nervous tissue and is typically located in the head ( cephalization), usually near organs for special ...

about five times as massive as a human's). The

killer whale The orca or killer whale (''Orcinus orca'') is a toothed whale belonging to the oceanic dolphin family, of which it is the largest member. It is the only extant species in the genus '' Orcinus'' and is recognizable by its black-and-white ...

(''Orcinus orca'') is the largest dolphin, reaching up to and 10 tonnes. **Order

Pelycosauria Pelycosaur ( ) is an older term for basal or primitive Late Paleozoic synapsids, excluding the therapsids and their descendants. Previously, the term ''mammal-like reptile'' had been used, and pelycosaur was considered an order, but this is now ...

(traditional;

paraphyletic In taxonomy (general), taxonomy, a group is paraphyletic if it consists of the group's most recent common ancestor, last common ancestor and most of its descendants, excluding a few Monophyly, monophyletic subgroups. The group is said to be pa ...

) ***''

Cotylorhynchus ''Cotylorhynchus'' is an extinct genus of herbivorous caseid synapsids that lived during the late Lower Permian (Kungurian) and possibly the early Middle Permian (Roadian) in what is now Texas and Oklahoma in the United States. The large number o ...

'' was a large, big-clawed, herbivorous

caseid Caseidae are an extinct family of basal synapsids that lived from the Late Carboniferous to Middle Permian between about 300 and 265 million years ago. Fossils of these animals come from the south-central part of the United States (Texas, Oklah ...

of Early

Permian The Permian ( ) is a geologic period and stratigraphic system which spans 47 million years from the end of the Carboniferous Period million years ago (Mya), to the beginning of the Triassic Period 251.9 Mya. It is the last period of the Pale ...

North America, reaching and 2 tonnes. **Order Therapsida *** ''

Anteosaurus ''Anteosaurus'' (meaning "Antaeus reptile") is an extinct genus of large carnivorous dinocephalian synapsid. It lived at the end of the Guadalupian (= Middle Permian) during the Capitanian stage, about 265 to 260 million years ago in what is now ...

'' was a

headbutting A headbutt is a targeted strike with the head, typically (when intentional) involving the use of robust parts of the headbutter's cranium as the area of impact. The most effective headbutts strike the most sensitive areas of an opponent, such as ...

, semiaquatic, carnivorous

dinocephalia Dinocephalians (terrible heads) are a clade of large-bodied early therapsids that flourished in the Early and Middle Permian between 279.5 and 260 million years ago (Ma), but became extinct during the Capitanian mass extinction event. Dinoceph ...

n of

Middle Permian The Guadalupian is the second and middle series/ epoch of the Permian. The Guadalupian was preceded by the Cisuralian and followed by the Lopingian. It is named after the Guadalupe Mountains of New Mexico and Texas, and dates between 272.95 ...

South Africa. It reached long, and weighed about . *** ''

Lisowicia ''Lisowicia'' is an extinct genus of giant dicynodont synapsid that lived in what is now Poland during the late Norian or earliest Rhaetian age of the Late Triassic Period, about 210–205 million years ago. ''Lisowicia'' is the largest known d ...

'' was an elephant-sized (9 tonne) herbivorous

kannemeyeriiform Kannemeyeriiformes is a group of large-bodied Triassic dicynodonts. As a clade, Kannemeyeriiformes has been defined to include the species '' Kannemeyeria simocephalus'' and all dicynodonts more closely related to it than to the species '' Lystr ...

dicynodont Dicynodontia is an extinct clade of anomodonts, an extinct type of non-mammalian therapsid. Dicynodonts were herbivorous animals with a pair of tusks, hence their name, which means 'two dog tooth'. Members of the group possessed a horny, typica ...

of Late Triassic Europe. *Clade

Sauropsida Sauropsida ("lizard faces") is a clade of amniotes, broadly equivalent to the class Reptilia. Sauropsida is the sister taxon to Synapsida, the other clade of amniotes which includes mammals as its only modern representatives. Although early s ...

**Class

Aves Birds are a group of warm-blooded vertebrates constituting the class Aves (), characterised by feathers, toothless beaked jaws, the laying of hard-shelled eggs, a high metabolic rate, a four-chambered heart, and a strong yet lightweig ...

(phylogenetically, a clade within

Coelurosauria Coelurosauria (; from Greek, meaning "hollow tailed lizards") is the clade containing all theropod dinosaurs more closely related to birds than to carnosaurs. Coelurosauria is a subgroup of theropod dinosaurs that includes compsognathids, ty ...

, a

taxon In biology, a taxon ( back-formation from '' taxonomy''; plural taxa) is a group of one or more populations of an organism or organisms seen by taxonomists to form a unit. Although neither is required, a taxon is usually known by a particular n ...

within the order Saurischia; see below) ***Order

Struthioniformes Struthioniformes is an order of birds with only a single extant family, Struthionidae, containing the ostriches. Several other extinct families are known, spanning across the Northern Hemisphere, from the Early Eocene to the early Pliocene, includ ...

****The ratites are an ancient and diverse group of

flightless bird Flightless birds are birds that through evolution lost the ability to fly. There are over 60 extant species, including the well known ratites (ostriches, emu, cassowaries, rheas, and kiwi) and penguins. The smallest flightless bird is the ...

s that are found on fragments of the former

supercontinent In geology, a supercontinent is the assembly of most or all of Earth's continental blocks or cratons to form a single large landmass. However, some geologists use a different definition, "a grouping of formerly dispersed continents", which lea ...

. The largest living bird, the

ostrich Ostriches are large flightless birds of the genus ''Struthio'' in the order Struthioniformes, part of the infra-class Palaeognathae, a diverse group of flightless birds also known as ratites that includes the emus, rheas, and kiwis. There a ...

(''Struthio camelus'') was surpassed by the extinct ''

'' of

, the heaviest of the group at up to (), and the extinct

giant moa The giant moa (''Dinornis'') is an extinct genus of birds belonging to the moa family. As with other moa, it was a member of the order Dinornithiformes. It was endemic to New Zealand. Two species of ''Dinornis'' are considered valid, the North ...

(''Dinornis'') of

, the tallest, growing to heights of . The latter two are examples of

island gigantism Island gigantism, or insular gigantism, is a biological phenomenon in which the size of an animal species isolated on an island increases dramatically in comparison to its mainland relatives. Island gigantism is one aspect of the more general Fos ...

. ***Order

Gastornithiformes Gastornithiformes were an extinct order of giant flightless fowl with fossils found in North America, Eurasia, and possibly Australia. Members of Gastornithidae were long considered to be a part of the order Gruiformes. However, the traditional ...

****Extinct

dromornithid Dromornithidae, known as mihirungs and informally as thunder birds or demon ducks, were a clade of large, flightless Australian birds of the Oligocene through Pleistocene Epochs. All are now extinct. They were long classified in Struthioniform ...

s of Australia such as ''

Dromornis ''Dromornis'' is a genus of large to enormous prehistoric birds. The species were flightless, possessing greatly reduced wing structures but with large legs, similar to the modern ostrich or emu. They were likely to have been predominantly, i ...

'' approached 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.) ***Order

Cathartiformes The order Cathartiformes of raptors or birds of prey includes the New World vultures and the now-extinct Teratornithidae. These raptors are classified by most taxonomic authorities in the order Accipitriformes (which includes the eagles and h ...

****The extinct

condor Condor is the common name for two species of New World vultures, each in a monotypic genus. The name derives from the Quechua ''kuntur''. They are the largest flying land birds in the Western Hemisphere. They are: * The Andean condor (''V ...

-like

teratorn Teratornithidae is an extinct family of very large birds of prey that lived in North and South America from the Late Oligocene to the Late Pleistocene. They include some of the largest known flying birds. Taxonomy Teratornithidae are related t ...

Argentavis ''Argentavis magnificens'' was among the largest flying birds ever to exist. While it is still considered the heaviest flying bird of all time, ''Argentavis'' was likely surpassed in wingspan by '' Pelagornis sandersi'' which is estimated to have ...

'' of South America had an estimated wing span of and a mass of approximately , making it the best example of a megafaunal flying bird. **Class

Reptilia Reptiles, as most commonly defined are the animals in the class Reptilia ( ), a paraphyletic grouping comprising all sauropsids except birds. Living reptiles comprise turtles, crocodilians, squamates (lizards and snakes) and rhynchocephalian ...

(traditional;

) ***Order Saurischia ****Saurischian

s of the Jurassic and Cretaceous include Sauropoda, sauropods, the longest (at up to ) and most massive terrestrial animals known (''Argentinosaurus'' reached 80–100 metric tonnes, or 90–110 short ton, tons), as well as Theropoda, theropods, the largest terrestrial carnivores (''Spinosaurus'', the longest, grew to 15 meters; the more famous ''Tyrannosaurus'', to 8.4 tonnes in weight). ***Order Pterosauria ****The largest azhdarchid pterosaurs, such as ''Hatzegopteryx'' and ''Quetzalcoatlus'', attained wingspans around and weights probably in the range. The former is thought to have been the apex predator of its Hațeg Island, island ecosystem. ***Order Crocodilia ****Alligators and crocodiles are large semiaquatic reptiles and are among the largest extant predators, the largest of which, the Saltwater crocodile (''Crocodylus porosus''), reaches and can weigh up to , possibly up to in length and in weight. Several other larger species of crocodile such as Nile crocodile, Orinoco crocodile and American crocodile may reach or exceed sizes of and weigh up to or more. In the family Alligatoridae, the largest members are the Black caiman and the American alligator, both of which can reach at least , weighing up to , with unverified reports of sizes approaching and weights of over . Crocodilians' distant ancestors and their kin, the Pseudosuchia#Evolution, pseudosuchians (traditional crurotarsans), dominated the world in the late Triassic, until the Triassic–Jurassic extinction event allowed dinosaurs to overtake them. They remained diverse during the later

, when Crocodyliformes, crocodyliforms such as ''Deinosuchus'' and ''Sarcosuchus'' reached lengths of 12 m. Similarly large crocodilians, such as ''Mourasuchus'' and ''Purussaurus'', were present as recently as the Miocene in South America. ***Order Squamata ****While the largest extant lizard, the Komodo dragon (''Varanus komodoensis''), another island giant, can reach in length, its extinct Australian relative ''Megalania'' may have reached more than twice that size. These monitor lizards' marine relatives, the mosasaurs, were

s in late Cretaceous seas. ****The heaviest extant snake is considered to be the Eunectes murinus, green anaconda (''Eunectes murinus''), while the Python reticulatus, reticulated python (''Python reticulatus''), at up to 8.7 m or more, is considered the longest. An extinct Australian

Pliocene The Pliocene ( ; also Pleiocene) is the epoch in the geologic time scale that extends from 5.333 million to 2.58Paleocene The Paleocene, ( ) or Palaeocene, is a geological epoch that lasted from about 66 to 56 million years ago (mya). It is the first epoch of the Paleogene Period in the modern Cenozoic Era. The name is a combination of the Ancient Greek ''pal ...

'' of South America reached lengths of 12–15 m and an estimated weight of about . ***Order Testudines ****The largest turtle is the critically endangered marine leatherback turtle (''Dermochelys coriacea''), weighing up to . It is distinguished from other sea turtles by its lack of a bone, bony exoskeleton, shell. The most massive terrestrial chelonians are the

s of the Galápagos Islands (''Chelonoidis niger'') and Aldabra, Aldabra Atoll (''Aldabrachelys gigantea''), at up to . 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 (in the wide, probably paraphyletic, sense) **Order Temnospondyli (relationship to Lissamphibia, extant amphibians is unclear) ***The Permian temnospondyl ''Prionosuchus'', 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'' (5 m long) had retreated to the Antarctic region by the Cretaceous, before going extinct. *Class Actinopterygii **Order Tetraodontiformes ***The largest extant bony fish is the ocean sunfish (''Mola mola''), whose average adult weight is . While phylogenetically a "bony fish", its skeleton is primarily cartilage (which is lighter than bone). It has a disk-shaped body, and propels itself with its long, thin dorsal fin, dorsal and anal fins; it feeds primarily on jellyfish. In these three respects (as well as in its size and diving habits), it resembles a leatherback turtle. **Order Lampriformes ***The giant oarfish (''Regalecus glesne'') is the longest bony fish, reaching . **Order Acipenseriformes ***The critically endangered Beluga (sturgeon), beluga (European sturgeon, ''Huso huso'') at up to is the largest sturgeon (which are also mostly cartilaginous) and is considered the largest anadromous fish. **Order Siluriformes ***The critically endangered Mekong giant catfish (''Pangasianodon gigas''), at up to , is often viewed as the largest freshwater fish. *Class Chondrichthyes **Order Lamniformes ***The largest living predatory fish, the great white shark (''Carcharodon carcharias''), reaches weights up to . Its extinct relative ''megalodon, O. megalodon'' was more than an order of magnitude larger, and is the largest predatory shark or fish of all time (and one of the largest predators in vertebrate history); it preyed on whales and other marine mammals. **Order Orectolobiformes ***The largest extant shark, Chondrichthyes, cartilaginous fish, and fish overall is the whale shark (''Rhincodon typus''), which reaches weights in excess of . Like baleen whales, it is a filter feeder and primarily consumes plankton. **Order Rajiformes ***The manta ray (''Manta birostris'') is another filter feeder and the largest Batoidea, ray, growing to up to 2300 kg. *Class Placodermi **Order Arthrodira ***The largest armored fish, ''Dunkleosteus'', arose during the late Devonian. At up to in length and in mass, it was a hypercarnivore, hypercarnivorous

that employed Aquatic predation#Suction feeding, suction feeding. Its contemporary, ''Titanichthys'', apparently an early filter feeder, rivaled it in size. The arthrodires were eliminated by the environmental upheavals of the Late Devonian extinction, after existing for only about 50 million years. *Class Cephalopoda **Order Ammonitida ***The Late Cretaceous ammonite ''Parapuzosia seppenradensis'' reached a shell diameter of over 2 m. **Order Teuthida ***A number of deep ocean creatures exhibit Deep-sea gigantism, abyssal gigantism. These include the giant squid (''Architeuthis'') and colossal squid (''Mesonychoteuthis hamiltoni''); both (although rarely seen) are believed to attain lengths of or more. The latter is the world's largest invertebrate, and has the largest eyes of any animal. Both are preyed upon by sperm whales. *Stem-group Arthropoda **Order Radiodonta ***Anomalocarids were a group of very early legless marine arthropods that included the largest predators of the Cambrian, such as ''Anomalocaris''. By the early Ordovician they had evolved into giant (for the time) filter feeders, apparently in response to the proliferation of plankton during the Great Ordovician Biodiversification Event. ''Aegirocassis'' grew to over 2 m in length. **Order Eurypterida ***Eurypterids (sea scorpions) were a diverse group of aquatic and possibly amphibious predators that included the most massive arthropods to have existed. They survived over 200 million years, but finally died out in the Permian–Triassic extinction event along with trilobites and most other forms of life present at the time, including most of the dominant terrestrial therapsids. The Early Devonian'' Jaekelopterus'' reached an estimated length of , not including its raptorial chelicerae, and is thought to have been a freshwater species.

Gallery

Extinct

File:Eurypterus Paleoart.jpg, Some Paleozoic Eurypterid, sea scorpions (''Eurypterus'' shown) were larger than a human. File:Dunkleosteus BW.jpg, ''Dunkleosteus'' was a long toothless Armour (anatomy), armored predatory Devonian Placodermi, placoderm Prehistoric fish, fish. File:Dimetr eryopsDB.jpg, Sail-backed pelycosaur ''Dimetrodon'' and Temnospondyli, temnospondyl ''Eryops'' from North America's

. File:Leedsichtys092.jpg, ''Leedsichthys'', a mid-Jurassic filter feeder fish, may have reached sizes of . File:Macronaria scrubbed enh.jpg, Macronarian Sauropoda, sauropods; from left, ''Camarasaurus'', ''Brachiosaurus'', ''Giraffatitan'', ''Euhelopus''. File:Spinosaurus life restoration with Onchopristis.jpg, left, The ''Spinosaurus'' (left) was the largest terrestrial predator to ever live, at 12.6 to 18 meters (41 to 59 ft). File:Sues skeleton.jpg, ''Tyrannosaurus'' was a long theropod dinosaur, an

of Laramidia, west North America. File:Indricotherium11.jpg, Asian Indricotheriinae, indricothere rhino ''Paraceratherium'' was among the largest land mammals, about twice a bush elephant's mass. File:Argentavis magnificens.JPG, The Late Miocene Teratornithidae, teratorn ''

'' of South America had a wingspan. File:Megalodon jaws on display at the National Baltimore Aquarium.jpg, Reconstructed jaws of ''Megalodon, C. megalodon'' (National Aquarium (Baltimore), Baltimore). File:Deinotherium12.jpg, ''Deinotherium'' had downward-curving tusks and ranged widely over

. File:Life reconstruction of the terror bird Titanis walleri.jpg, ''Titanis, Titanis walleri'', the only Phorusrhacidae, terror bird known to have Great American Interchange, invaded North America, was tall. File:Diprotodon optatum (2).jpg, Hippo-sized ''Diprotodon'' of Australia, the largest

of all time, became extinct 40,000 years ago. File:Varanus priscus Melbourne Museum.jpg, ''Megalania'', a giant carnivorous goanna of Australia, might have grown to 7 metres long. File:Glyptodon (Riha2000).jpg, ''Glyptodon'', from South America's

, was an auto-sized Cingulata, cingulate, a relative of armadillos. File:Macrauchenia (reconstruction).jpg, ''Macrauchenia'', South America's last and largest litoptern, may have had a short saiga-like trunk or moose-like nostrils. File:Panthera leo atrox Sergiodlarosa.jpg,

s exceeded Extant taxon, extant

s in size and ranged over much of N. America until 11,000 BP. File:Woolly mammoth (Mammuthus primigenius) - Mauricio Antón.jpg, Woolly mammoths vanished after humans invaded their habitat in Eurasia and N. America. File:Archaeoindris fontoynonti.jpg, The subfossil lemur ''

'' was the largest lemur ever to exist, close in size to a

. File:Giant Haasts eagle attacking New Zealand moa.jpg, Haast's eagle, the largest eagle known, attacking

(a genus which included the Dinornis, tallest bird known).

Extant

Image:Kbnpsilverbackandchild 0.5.jpg, The eastern gorilla is the largest and one of the more IUCN Red List critically endangered species (Animalia)#Hominidae, endangered primates on the planet. Image:Hunting Tiger Ranthambore.jpg, The most common Tiger#Subspecies, tiger subspecies, Bengal tigers are endangered by poaching and habitat destruction. Image:Polar Bear 2004-11-15.jpg, Polar bears, among the largest

s (consistent with

), are Polar bear#Climate change, vulnerable to global warming. Image:Ngorongoro Spitzmaulnashorn edit1crop.jpg, The critically endangered black rhinoceros, up to long, is Black rhinoceros#Distribution, threatened by poaching. Image:Temee.jpg, Wild Bactrian camels are critically endangered. Their ancestors Camelid#Evolution, originated in North America. Image:Ovibos moschatus qtl3.jpg, Unlike woolly woolly rhinoceros, rhinos and woolly mammoth, mammoths, muskoxen narrowly survived the Quaternary extinction event, Quaternary extinctions. Image:Nijlpaard.jpg, Hippopotamuses, the heaviest and most aquatic even-toed ungulates, are cetacea, whales' Cetartiodactyla#Kin to hippos, closest living relatives. Image:Mother and baby sperm whale.jpg, The

, the largest

and toothed predator, has the biggest brain. Image:Killerwhales jumping.jpg, The orca, the largest dolphin and Pack hunter, pack predator, is Killer whale#Intelligence, highly intelligent and lives in Killer whale#Social structure, complex societies. Image:Helmkasuar3.jpg, The cassowary, the heaviest non-African bird, can run at 50 km/h through dense rainforest. Image:SaltwaterCrocodile('Maximo').jpg, The saltwater crocodile is the largest living reptile and a dangerous Crocodile attack, predator of humans. Image:Komodo dragon Varanus komodoensis Ragunan Zoo 2.JPG, The Komodo dragon, an Island gigantism, insular giant and the largest lizard, has serrated teeth and a Komodo dragon#Venom, venomous bite. Image:Anaconda Loreto Peru.jpg, The Eunectes murinus, green anaconda, an aquatic Constriction, constrictor, is the heaviest snake, weighing up to or more. Image:Sunfish2.jpg, The ocean sunfish#Range and behavior, deep-diving ocean sunfish is the largest Osteichthyes, bony fish, but its skeleton is mostly Cartilage, cartilaginous. Image:Lates niloticus 2.jpg, The Nile perch, one of the largest freshwater fish, is also a damaging invasive species. Image:White shark.jpg, The great white shark, great white, the largest macropredatory fish, is more endangered than the

. Image:Manta alfredi fushivaru thila.jpg, The manta ray, manta, a filter feeder, is the largest Batoidea, ray at up to 7.6 m across, yet can Whale surfacing behaviour#Breaching and lunging, breach clear of the water. Image:Giant squid Ranheim2.jpg, Examination of a 9 m giant squid, an Deep-sea gigantism, abyssal giant and the second largest cephalopod.

Notes

References

{{reflist , colwidth = 30em , refs = https://inauralist.ala.org.

External links

Megafauna – "First Victims of the Human-Caused Extinction"
Extinction Zoology Animal size

Ecological strategy

Evolution of large body size

In terrestrial mammals

In marine mammals

In flightless birds

In giant turtles

Megafaunal mass extinctions

Timing and possible causes

Consequences of depletion of megafauna

Effect on nutrient transport

Effect on methane emissions

Examples

Gallery

Extinct

Extant

See also

Notes

References

External links