Portal:Mammals

The Mammals portal

A mammal (from Latin mamma 'breast') is a vertebrate animal of the class Mammalia (/məˈmeɪli.ə/). Mammals are characterised by the presence of milk-producing mammary glands for feeding their young, a broad neocortex region of the brain, fur or hair, and three middle ear bones. These characteristics distinguish them from reptiles and birds, from which their ancestors diverged in the Carboniferous Period over 300 million years ago. Around 6,640 extant species of mammals have been described and divided into 27 orders. The study of mammals is called mammalogy.

The largest orders of mammals, by number of species, are the rodents, bats, and eulipotyphlans (including hedgehogs, moles and shrews). The next three are the primates (including humans, monkeys and lemurs), the even-toed ungulates (including pigs, camels, and whales), and the Carnivora (including cats, dogs, and seals).

Mammals are the only living members of Synapsida; this clade, together with Sauropsida (reptiles and birds), constitutes the larger Amniota clade. Early synapsids are referred to as "pelycosaurs." The more advanced therapsids became dominant during the Guadalupian. Mammals originated from cynodonts, an advanced group of therapsids, during the Late Triassic to Early Jurassic. Mammals achieved their modern diversity in the Paleogene and Neogene periods of the Cenozoic era, after the extinction of non-avian dinosaurs, and have been the dominant terrestrial animal group from 66 million years ago to the present.

The basic mammalian body type is quadrupedal, with most mammals using four limbs for terrestrial locomotion; but in some, the limbs are adapted for life at sea, in the air, in trees or underground. The bipeds have adapted to move using only the two lower limbs, while the rear limbs of cetaceans and the sea cows are mere internal vestiges. Mammals range in size from the 30–40 millimetres (1.2–1.6 in) bumblebee bat to the 30 metres (98 ft) blue whale—possibly the largest animal to have ever lived. Maximum lifespan varies from two years for the shrew to 211 years for the bowhead whale. All modern mammals give birth to live young, except the five species of monotremes, which lay eggs. The most species-rich group is the viviparous placental mammals, so named for the temporary organ (placenta) used by offspring to draw nutrition from the mother during gestation.

Most mammals are intelligent, with some possessing large brains, self-awareness, and tool use. Mammals can communicate and vocalise in several ways, including the production of ultrasound, scent marking, alarm signals, singing, echolocation; and, in the case of humans, complex language. Mammals can organise themselves into fission–fusion societies, harems, and hierarchies—but can also be solitary and territorial. Most mammals are polygynous, but some can be monogamous or polyandrous.

Domestication of many types of mammals by humans played a major role in the Neolithic Revolution, and resulted in farming replacing hunting and gathering as the primary source of food for humans. This led to a major restructuring of human societies from nomadic to sedentary, with more co-operation among larger and larger groups, and ultimately the development of the first civilisations. Domesticated mammals provided, and continue to provide, power for transport and agriculture, as well as food (meat and dairy products), fur, and leather. Mammals are also hunted and raced for sport, kept as pets and working animals of various types, and are used as model organisms in science. Mammals have been depicted in art since Paleolithic times, and appear in literature, film, mythology, and religion. Decline in numbers and extinction of many mammals is primarily driven by human poaching and habitat destruction, primarily deforestation. (Full article...)

Refresh with new selections below (purge)

Selected article

The elk, or wapiti (Cervus canadensis), is the second largest species of deer in the world and one of the largest mammals in North America and eastern Asia. In the deer family (Cervidae), only the moose, Alces alces (called an "elk" in Europe), is larger. Wapiti are almost identical to red deer found in Europe, of which they were long believed to be a subspecies; they have recently been determined to be a distinct species based on DNA evidence. Elk range in forest and forest-edge habitat, feeding on grasses, plants, leaves and bark. Although native to North America and eastern Asia, they have adapted well to countries where they have been introduced, including New Zealand and Argentina. Their high level of adaptability poses a threat to endemic species and ecosystems where they have been introduced. Male elk have large antlers which are shed each year. Males engage in ritualized mating behaviors during the rut, including posturing, antler wrestling and bugling, a loud series of screams which establishes dominance over other males and attracts females. The bugle call is one of the most distinctive calls in nature. Elk are susceptible to a number of infectious diseases, some of which can be transmitted to livestock. Efforts to eliminate infectious diseases from elk populations, largely through vaccination, have had mixed success. Some cultures revere the elk as a spiritual force. In parts of Asia, antlers and their velvet are used in traditional medicines. Elk are hunted as a game species; the meat is leaner and higher in protein than beef or chicken.

More selected articles

Read more...

Did you know?

...that one burrow of the eastern chipmunk (pictured) was found to contain 390 acorns?
.. that the Hare Indian dog, now extinct, was not known to bark, but puppies learned to imitate the barking of other dogs when the breed was introduced to Europe?
... that the rodents Thomasomys ucucha from Ecuador and Oxymycterus hucucha from Bolivia were both named after the local Quechua word for "mouse"?
...that the incisors of blesmols are visible even when their mouths are closed?
... that the pebble-mound mice of northern Australia construct mounds of stones around their burrows up to 10 m² in area?
... that the stationmaster of the Kinokawa train station in Kinokawa, Japan was a cat named Tama?

More did you know – Start a new article...

Related portals

edit

Selected images

Image 1
Javan slow loris
Photograph credit: Aprisonsan
The Javan slow loris (Nycticebus javanicus) is a species of primate native to western and central portions of the Indonesian island of Java. It is arboreal, feeding on fruit, gum, eggs, lizards, and the seeds of the cocoa tree. Weighing up to 680 g (24 oz), this small nocturnal mammal sleeps in the open on branches during the day and is easily poached for the exotic-pet trade. Populations are declining, and the animal is listed by the International Union for Conservation of Nature as a critically endangered species and included in a list of the world's 25 most endangered primates.
More selected pictures
Image 2
Cheetah
Photograph: William Warby
A portrait of a cheetah at Whipsnade Zoo in Bedfordshire. Cheetahs have small and streamlined heads. Their ears are small, short, and rounded, marked by black patches on the back and tawny edges. Their high-set eyes have round pupils, while their whiskers are fine and inconspicuous. Their faces have unique "tear streak" markings that may serve to reduce glare or define facial expressions.
More selected pictures
Image 3
Northern Elephant Seals
Photo credit: Helen Filatova
A group of female Northern Elephant Seals (Mirounga angustirostris) moulting on a beach near San Simeon, California. In the summer, elephant seals undergo a catastrophic moult, lasting about one month, during which they lose much of their fur and skin. They spend this time on beaches to preserve body heat, while they wait for the new fur to grow.
More selected pictures
Image 4
Indian elephant
Photograph: Yathin S Krishnappa
A male Indian elephant (Elephas maximus indicus) in Bandipur National Park, Karnataka. First described by Georges Cuvier in 1798, this subspecies of Asian elephant is considered endangered owing to large population declines since the mid-20th century.
More selected pictures
Image 5
Social grooming
Photo: Muhammad Mahdi Karim
Two olive baboons (Papio anubis) engaged in social grooming, an activity that social animals (including humans) engage in to clean or maintain one another's body or appearance. Grooming also reinforces social structures, family links, and builds relationships. It has been best studied among primates, but insects, birds, fish, and other mammals are known to engage in it as well.
More selected pictures
Image 6
Bennett's Wallaby
Photo: JJ Harrison
A juvenile Bennett's Wallaby (Macropus rufogriseus rufogriseus), a subspecies of the Red-necked Wallaby, on Maria Island, east of Tasmania. Red-necked Wallabies can be found in the more temperate and fertile parts of eastern Australia. They can weigh 13.8 to 18.6 kg (30 to 41 lb) and attain a head–body length of 90 cm (35 in), with the island version slightly smaller.
More selected pictures
Image 7
Eastern Gray Squirrel
Photo credit: Diliff
An Eastern Gray Squirrel (Sciurus carolinensis) eating a nut in St. James's Park, London. Although native to eastern North America, the species has been introduced into a variety of locations. In England, gray squirrels have mostly replaced native Red Squirrels and have no natural predators, which has added to their rapid population growth and has led to the species being classed as a pest.
More selected pictures
Image 8
Topi
Photograph: Charles J. Sharp
Female topi (Damaliscus lunatus jimela) in the Queen Elizabeth National Park in Uganda. A subspecies of the common tsessebe antelope, the topi is native to several countries in eastern Africa and lives primarily in grassland habitats, ranging from treeless plains to savannas. It is a tall species, with individuals ranging in height from 100 to 130 cm (39 to 51 in) at the shoulder. Predators of topi include lions and spotted hyenas, with jackals being predators of newborns.
More selected pictures
Image 9
European bison
Photo: Michael Gäbler
The European bison or wisent (Bison bonasus) is the heaviest of the surviving land animals in Europe, with males growing to around 1,000 kg (2,200 lb). European bison were hunted to extinction in the wild, but have since been reintroduced from captivity into several countries. This male is moulting, his winter coat coming off in clumps.
More selected pictures
Image 10
Cheetah
Photo: Muhammad Mahdi Karim
A close-up view of a cheetah (Acinonyx jubatus) cub. Unlike some other cats, the cheetah is born with its characteristic spots, as well as a downy underlying fur on their necks extending to mid-back, which gives the cub the appearance of the Honey Badger, to scare away potential aggressors. Despite this, up to 90% of cheetah cubs are killed by predators in the early weeks of life. Healthy adult cheetahs have few predators because of their speed.
More selected pictures
Image 11
Rothschild's Giraffe
Photo credit: Fir0002
The head of a Rothschild's Giraffe (Giraffa camelopardalis rothschildi), a subspecies of giraffe found in Uganda and north-central Kenya. It has deep brown, blotched or rectangular spots with poorly defined cream lines and its hocks may be spotted.
More selected pictures
Image 12
European wildcat
Photograph: Luc Viatour
The European wildcat (Felis silvestris silvestris) is a subspecies of the wildcat. It is native to the forests and grasslands of Europe, as well as Turkey and the Caucasus Mountains. Bulkier than both the African wildcat and the domestic cat, the European wildcat is also distinguished by its thick fur and non-tapered tail. Though it is predominantly nocturnal, the European wildcat may be active in the daytime in the absence of humans.
More selected pictures
Image 13
Eastern Grey Kangaroo
Photo credit: Fir0002
The Eastern Grey Kangaroo (Macropus giganteus), native to southern and eastern Australia, is the most commonly encountered kangaroo species, as it can be found in and around the major cities within its range. Although males can typically reach a height of 2 metres (6.6 ft) and weigh around 66 kilograms (146 lb), and the scientific name translates to "gigantic large-foot", the Red Kangaroo is actually larger.
More selected pictures
Image 14
Eastern chipmunk
Photo: Simon Pierre Barrette
The eastern chipmunk (Tamias striatus) is a chipmunk species native to eastern North America. Like other chipmunks, they transport food in pouches in their cheeks, as seen here. They eat bulbs, seeds, fruits, nuts, green plants, mushrooms, insects, worms, and bird eggs.
More selected pictures
Image 15
Virginia Opossum
Photo credit: Cody Pope
The Virginia Opossum (Didelphis virginiana) is the only marsupial found in North America. A solitary and nocturnal animal about the size of a domestic cat, it is a successful opportunist and is found throughout North America from coast to coast (introduced to California in 1910), and from Central America and Mexico to southern Canada.
More selected pictures

Scientific classification

Kingdom→ Animalia Phylum→ Chordata Subphylum→ Vertebrata Superclass→ Tetrapoda (unranked)→ Amniota Class→ Mammalia

Subclasses and Infraclasses

Subclass †Allotheria*
Subclass Prototheria
Subclass Theria
- Infraclass †Trituberculata
- Infraclass Metatheria
- Infraclass Eutheria

* Member of a haplogroup and not any of its subclades.
† Taxon is extinct.

Topics

Subcategories

Category puzzle

Select [►] to view subcategories

Quality content

This is a list of recognized content, updated weekly by JL-Bot (talk · contribs) (typically on Saturdays). There is no need to edit the list yourself. If an article is missing from the list, make sure it is tagged (e.g. {{WikiProject Mammals}}) or categorized correctly and wait for the next update. See WP:RECOG for configuration options.

Featured articles

Featured lists

Featured topics

Featured pictures

Good articles

WikiProjects

A complete list of scientific WikiProjects can be found here. See also Wikispecies, a Wikimedia project dedicated to classification of biological species.