Mammals are a group of vertebrate animals constituting the class Mammalia (/məˈmli.ə/), characterized by the presence of mammary glands which in females produce milk for feeding (nursing) their young, a neocortex (a region of the brain), fur or hair, and three middle ear bones. These characteristics distinguish them from reptiles (including birds) from which they diverged in the Carboniferous, over 300 million years ago. Around 6,400 extant species of mammals have been described divided into 29 orders. The largest orders, in terms of number of species, are the rodents, bats, and Eulipotyphla (hedgehogs, moles, shrews, and others). The next three are the Primates (including humans, apes, monkeys, and others), the Artiodactyla (cetaceans and even-toed ungulates), and the Carnivora (cats, dogs, seals, and others).

LifeDomainKingdomPhylumClassOrderFamilyGenusSpecies
The hierarchy of biological classification's eight major taxonomic ranks. Intermediate minor rankings are not shown.

Mammals are divided into three main groupings: the order Monotremata, containing egg-laying species; the infraclass Placentalia, containing the vast majority of extant mammals, for which the fetus is carried in the uterus; and the infraclass Marsupialia, containing the marsupial animals wherein the young are carried in a pouch. Placentalia and Marsupialia are subdivided into superorders, which then contain multiple orders of animals. These orders can contain between one and hundreds of species, grouped into genera and then into families. Orders and superorders are also sometimes grouped into named clades.

Monotremata edit

Monotremata is the smallest of the three main divisions of mammals, containing only five extant species. It is distinguished from the other two groups in that the monotremes are egg-laying rather than bearing live young, but, like all mammals, the female monotremes nurse their young with milk.

Infraclass Placentalia edit

Placentalia

Placentalia is one of the three main divisions of mammals, and contains the vast majority of extant species with around 5,500 species. It is distinguished from the other two groups in that the placental animals have fetuses that are carried in the uterus. It contains four superorders: Afrotheria, Euarchontoglires, Laurasiatheria, and Xenarthra; Afrotheria and Xenarthra make up the magnorder Atlantogenata, and the other two the magnorder Boreoeutheria.

Superorder Afrotheria edit

Afrosoricida edit

Suborder ChrysochlorideaBroom, 1915 – one families genera
Name Authority and species Range Size and ecology
Chrysochloridae
(Golden moles)

 

Gray, 1825

21 species in 10 genera
Sub-Saharan Africa Size range:

Habitats:

Diets:
Suborder TenrecomorphaButler, 1972 – two families genera
Name Authority and species Range Size and ecology
Potamogalidae
(Otter shrews)

 

Allmann, 1865

Three species in two genera
Sub-Saharan Africa Size range:

Habitats:

Diets:
Tenrecidae
(Tenrecs)

 

Gray, 1821

31 species in 8 genera
Madagascar
 
Size range:

Habitats:

Diets:

Hyracoidea edit

Macroscelidea edit

Not assigned to a named clade – one families genera
Name Authority and species Range Size and ecology
Macroscelididae
(Elephant shrews)

 

Bonaparte, 1838

Nineteen species in six genera
Africa Size range:

Habitats:

Diets:

Proboscidea edit

Sirenia edit

Tubulidentata edit

Superorder Euarchontoglires edit

Scandentia edit

Not assigned to a named clade – one families genera
Name Authority and species Range Size and ecology
Ptilocercidae
(Pen-tailed treeshrews)

 

Lyon, 1913

One species in one genera
Southeast Asia
 
Size range:

Habitats:

Diets:
Tupaiidae
(Treeshrews)

 

Gray, 1825

22 species in 3 genera
India and Southeast Asia Size range:

Habitats:

Diets:

Dermoptera edit

Lagomorpha edit

Not assigned to a named clade – two families genera
Name Authority and species Range Size and ecology
Leporidae
(Hares and rabbits)

 

G. Fischer von Waldheim, 1817

64 species in 11 genera (full list)
Worldwide Size range:

Habitats:

Diets:
Ochotonidae
(Pikas)

 

Thomas, 1897

29 species in 1 genera (full list)
Asia and western North America Size range:

Habitats:

Diets:

Primates edit

Rodentia edit

Superorder Laurasiatheria edit

Artiodactyla edit

Carnivora edit

Suborder CaniformiaKretzoi, 1943 – nine families genera
Name Authority and species Range Size and ecology
Ailuridae
(Red panda)

 

Gray, 1843

Two species in one genus
Eastern Himalayas and southwestern China
 
Size range: 50–64 cm (20–25 in) long, plus 28–59 cm (11–23 in) tail[1]

Habitats: Forest and shrubland[2]

Diets: Bamboo, as well as fruit, vegetation, lichen, bird eggs, and insects[2]
Canidae
(Wolves and foxes)

 

Waldheim, 1817

37 species in 14 genera (full list)
Worldwide Size range: 33 cm (13 in) long, plus 13 cm (5 in) tail (fennec fox) to 160 cm (63 in) long, plus 50 cm (20 in) tail (wolf)

Habitats: Shrubland, grassland, inland wetlands, forest, desert, rocky areas, savanna, desert, and coastal marine

Diets: Omnivorous
Mephitidae
(Skunks and stink badgers)

 

Geoffroy and Cuvier, 1795

Twelve species in four genera (full list)
North America, South America, Southeast Asia
 
Size range:

Habitats:

Diets: Omnivorous; primarily eats invertebrates, rodents, small reptiles, and eggs
Mustelidae
(Martens, polecats, otters, and badgers)

 

Geoffroy and Cuvier, 1795

63 species in 23 genera (full list)
All continents except Antarctica and Australia Size range:

Habitats:

Diets: Omnivorous
Odobenidae
(Walrus)

 

Allen, 1880

One species in one genus (full list)
Arctic Ocean and subarctic seas
 
Size range: Male: 270–356 cm (106–140 in) long; 800–1,700 kg (1,764–3,748 lb)
Female: 225–312 cm (89–123 in) long; 400–1,250 kg (882–2,756 lb)[3]

Habitats: Neritic marine, oceanic marine, intertidal marine, coastal marine, and other[4]

Diets: Bivalve molluscs, as well as other invertebrates, slow-moving fish, and occasionally birds, seals, and other marine mammals[4]
Otariidae
(Eared seals)

 

Gray, 1825

Sixteen species in seven genera (full list)
Antarctic Ocean, southern seas, and coasts of South America, Australia, Pacific Asia and Pacific North America Size range:

Habitats:

Diets:
Phocidae
(Earless seals)

 

Gray, 1821

Nineteen species in fourteen genera (full list)
Antarctic Ocean, Arctic Ocean, Northern Hemisphere coastlines, Caspian Sea, and Lake Baikal Size range:

Habitats:

Diets:
Procyonidae
(Raccoons, coatis, olingos, kinkajous, ring-tailed cats, and cacomistles)

 

Gray, 1825

Fourteen species in six genera (full list)
North and South America (common raccoon introduced to Europe, western Asia, and Japan) Size range:

Habitats:

Diets:
Ursidae
(Bears)

 

G. Fischer von Waldheim, 1817

Eight species in five genera (full list)
North and South America and Eurasia Size range:

Habitats:

Diets:
Suborder FeliformiaKretzoi, 1945 – seven families genera
Name Authority and species Range Size and ecology
Eupleridae
(Malagasy carnivorans)

 

Chenu, 1850

Ten species in seven genera
Madagascar
 
Size range:

Habitats:

Diets:
Felidae
(Cats)

 

G. Fischer von Waldheim, 1817

41 species in 14 genera (full list)
Worldwide (Felinae (excluding the domestic cat) in blue, Pantherinae in green
 
Size range:

Habitats:

Diets:
Herpestidae
(Mongooses)

 

Bonaparte, 1845

34 species in 14 genera (full list)
Southern Europe, Africa, and Asia
 
Size range:

Habitats:

Diets:
Hyaenidae
(Hyenas)

 

Gray, 1821

Four species in four genera
Africa and southern Asia
 
Size range:

Habitats:

Diets:
Nandiniidae
(African palm civet)

 

Pocock, 1929

One species in one genus
Sub-Saharan Africa
 
Size range:

Habitats:

Diets:
Prionodontidae
(Asiatic linsangs)

 

Gray, 1864

Two species in one genus
Southeast Asia Size range:

Habitats:

Diets:
Viverridae
(Civets and genets)

 

Gray, 1821

33 species in 14 genera (full list)
Southeast Asia Size range:

Habitats:

Diets:

Chiroptera edit

Eulipotyphla edit

Perissodactyla edit

Suborder CeratomorphaWood, 1937 – two families genera
Name Authority and species Range Size and ecology
Rhinocerotidae
(Rhinoceroses)

 

Owen, 1845

Five species in four genera
Sub-Saharan Africa, northern India, Southeast Asia Size range:

Habitats:

Diets:
Tapiridae
(Tapirs)

 

Brünnich, 1772

Four species in one genus
South America, Central America, scattered southeastern Asia Size range:

Habitats:

Diets:
Suborder HippomorphaWood, 1937 – one families genera
Name Authority and species Range Size and ecology
Equidae
(Horses, donkeys, zebras)

 

Brünnich, 1772

Nine species in one genus
Worldwide Size range:

Habitats:

Diets:

Pholidota edit

Superorder Xenarthra edit

Cingulata edit

Not assigned to a named clade – two families genera
Name Authority and species Range Size and ecology
Dasypodidae
(Armadillos)

 

Gray, 1821

Nine species in one genus
South America, and central, southern, and eastern North America Size range:

Habitats:

Diets:
Chlamyphoridae
(Armadillos)

 

Bonaparte, 1850

Thirteen species in eight genera
South America and Central America Size range:

Habitats:

Diets:

Pilosa edit

Infraclass Marsupialia edit

 
Distribution of marsupials

Marsupialia is one of the three main divisions of mammals, and contains around 300 extant species. It is distinguished from the other two groups in that marsupials give birth to relatively undeveloped young that often reside in a pouch located on their mothers' abdomen for a certain amount of time. It contains two superorders, Ameridelphia and Australidelphia.

Superorder Australidelphia edit

Dasyuromorphia edit

Not assigned to a named clade – three families genera
Name Authority and species Range Size and ecology
Dasyuridae
(Marsupial shrews)

 

Goldfuss, 1820

71 species in 13 genera
Australia and New Guinea Size range:

Habitats:

Diets:
Myrmecobiidae
(Numbat)

 

Waterhouse, 1841

One species in one genus
Scattered Australia
 
Size range:

Habitats:

Diets:
Thylacinidae
(Thylacine)

 

C. L. Bonaparte, 1838

One species in one genus
Tasmania
 
Size range:

Habitats:

Diets:

Diprotodontia edit

Suborder MacropodiformesAmeghino, 1889 – three families (full list) genera
Name Authority and species Range Size and ecology
Hypsiprymnodontidae
(musky rat-kangaroo)

 

Collett, 1877

1 species in 1 genera
Northeastern Australia
 
Size range:

Habitats:

Diets:
Macropodidae

 

Gray, 1821

64 species in 13 genera
Australia and New Guinea Size range:

Habitats:

Diets:
Potoroidae

 

Gray, 1821

Eight species in three genera
Australia Size range:

Habitats:

Diets:
Suborder PhalangeriformesSzalay, 1982 – six families (full list) genera
Name Authority and species Range Size and ecology
Acrobatidae

 

Aplin, 1987

Two species in two genera
Eastern Australia and New Guinea Size range:

Habitats:

Diets:
Burramyidae

 

Broom, 1989

Two species in two genera
New Guinea and southern and northeastern Australia Size range:

Habitats:

Diets:
Petauridae

 

C. L. Bonaparte, 1838

Eleven species in three genera
New Guinea and northern, eastern, and southern Australia Size range:

Habitats:

Diets:
Phalangeridae

 

Thomas, 1888

27 species in 6 genera
New Guinea, Sulawesi island and nearby islands in Indonesia, and scattered Australia Size range:

Habitats:

Diets:
Pseudocheiridae
(ringtail possum)

 

Winge, 1893

Eleven species in three genera
New Guinea and northern, eastern, and southern Australia Size range:

Habitats:

Diets:
Tarsipedidae
(ringtail possum)

 

Gervais, Verreaux, 1842

One species in one genus
Southwestern Australia
 
Size range:

Habitats:

Diets:
Suborder VombatiformesBurnett, 1830 – two families genera
Name Authority and species Range Size and ecology
Phascolarctidae
(koala)

 

Owen, 1839

One species in one genus
Southern and eastern Australia Size range:

Habitats:

Diets:
Vombatidae
(wombat)

 

Burnett, 1830

Three species in two genera
Eastern Australia
 
Size range:

Habitats:

Diets:

Microbiotheria edit

Notoryctemorphia edit

Paucituberculata edit

Peramelemorphia edit

Other edit

Didelphimorphia edit

Not assigned to a named clade – one families genera
Name Authority and species Range Size and ecology
Didelphidae
(Opossums)

 

Gray, 1821

93 species in 18 genera
North America and South America Size range:

Habitats:

Diets:

Paucituberculata edit

  1. ^ Cite error: The named reference Redpandasize was invoked but never defined (see the help page).
  2. ^ a b Cite error: The named reference IUCNRedpanda was invoked but never defined (see the help page).
  3. ^ Cite error: The named reference Walkers was invoked but never defined (see the help page).
  4. ^ a b Cite error: The named reference IUCNWalrus was invoked but never defined (see the help page).