Portal:Mammals

The Mammals portal

A mammal (from Latin mamma 'breast') is a vertebrate animal of the class Mammalia (/məˈmeɪli.ə/). Mammals are characterized 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, bovids 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 vocalize in several ways, including the production of ultrasound, scent marking, alarm signals, singing, echolocation; and, in the case of humans, complex language. Mammals can organize 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 civilizations. 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. The 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 Arabian horse is a breed of horse with a reputation for intelligence, spirit, and stamina. With a distinctive head shape and high tail carriage, the Arabian is one of the most easily recognizable horse breeds in the world. It is one of the oldest horse breeds, with archaeological evidence of horses that resemble modern Arabians dating back 4,500 years. Throughout history, Arabian horses from the Middle East spread around the world by both war and trade, used to improve other breeds by adding speed, refinement, endurance, and good bone. Today, Arabian bloodlines are found in almost every modern breed of riding horse. The Arabian developed in a desert climate and was prized by the nomadic Bedouin people, often being brought inside the family tent for shelter and protection. This close relationship with humans has created a horse breed that is good-natured, quick to learn, and willing to please. But the Arabian also developed the high spirit and alertness needed in a horse used for raiding and war. This combination of willingness and sensitivity requires modern Arabian horse owners to handle their horses with competence and respect. "The Versatile Arabian" is a slogan of the breed. Arabians dominate the discipline of endurance riding, and compete today in many other fields of equestrian activity. They are one of the top ten most popular horse breeds in the world. Arabian horses are now found worldwide, including the United States and Canada, the United Kingdom, Australia, continental Europe, South America (especially Brazil), and its land of origin, the Middle East.

More selected articles

Read more...

Did you know?

...that a polydactyl cat (pictured) is a cat that has more than the usual number of toes on one or all of its paws?
...that Unsinkable Sam was a ship's cat of both the Kriegsmarine and Royal Navy during the Second World War who survived the sinking of all three ships on which he served?
...that Able Seaman Just Nuisance is the only dog to have been officially enlisted in the Royal Navy?
...that the Moscow Water Dog, developed as a water rescue dog, preferred to bite drowning people instead of saving them?
...from its discovery by John Edward Gray in 1850 until a re-assessment in 1981, the Clymene Dolphin was regarded as sub-species of the Spinner Dolphin.
...the Australian Snubfin Dolphin (Orcaella heinsohni) is a recently recognised species of dolphin first described in 2005.

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

Related portals

edit

Selected images

Image 1
Mexican Wolf
Photo credit: Jim Clark, USFWS
A captive Mexican Wolf (Canis lupus baileyi) at the Sevilleta National Wildlife Refuge, New Mexico, USA. This critically endangered subspecies of the Gray Wolf once ranged from central Mexico to the Southwestern United States. In 1980, the last five known surviving members were captured to save the species. Now, over 300 wolves are taking part in a wolf reintroduction program, with at least fifty individuals in the wild.
More selected pictures
Image 2
Prairie dog
Photo credit: Aaron Siirila
A black-tailed prairie dog at the National Zoo in Washington, D.C., looks out from a system of burrows, characteristically scanning the horizon. On average, these rodents grow to between 12 and 16 inches (30 and 40 cm) long, including their short tails.
More selected pictures
Image 3
Babirusa skull
Photograph: Didier Descouens
Skull of a male North Sulawesi babirusa, a species from the pig family endemic to Indonesia. Babirusas are notable for the long upper canines in the males that emerge vertically from the alveolar process, penetrating though the skin and curving backward over the front of the face and towards the forehead.
More selected pictures
Image 4
Impala
Photo: Alchemist-hp
Several female black-faced impala drinking at a waterhole. Impalas are sexually dimorphic. Females can weigh 10 to 25 kilograms (22 to 55 lb) less than males and do not have horns.
More selected pictures
Image 5
Female proboscis monkey on Borneo
Photograph: Charles J. Sharp
A female proboscis monkey (Nasalis larvatus) at Labuk Bay, Sabah, Malaysia. This monkey is endemic to Borneo. Though the female has a large nose, it is smaller than that of the male.
More selected pictures
Image 6
Polar bear
Photograph credit: Andreas Weith
The polar bear (Ursus maritimus) is a hypercarnivorous bear whose native range lies largely within the Arctic Circle, encompassing the Arctic Ocean, its surrounding seas and surrounding land masses. A boar (adult male) weighs around 350–750 kilograms (770–1,650 lb), while a sow (adult female) is about half that size. Polar bears are the largest land carnivores currently in existence, rivalled only by the omnivorous Kodiak bear. Although it is the sister species of the brown bear, it has evolved to occupy a narrower ecological niche, with many body characteristics adapted for cold temperatures, for moving across snow, ice and open water, as well as for hunting seals, which make up most of its diet. Although most polar bears are born on land, they spend most of their time on sea ice. The species's scientific name, which is derived from this fact, means 'maritime bear'. Because of their dependence on sea ice, polar bears are categorized as marine mammals. Due to expected habitat loss caused by global warming, the polar bear is classified as a vulnerable species. For decades, large-scale hunting raised international concern for the future of the species, but populations have rebounded after controls and quotas began to take effect.

This picture shows a polar bear on an ice floe north of Svalbard, Norway, feeding on a bearded seal.
More selected pictures
Image 7
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 8
Yak
Photograph: Dennis Jarvis
A domesticated yak at Yamdrok Lake in Tibet. The animals are important to Tibetan culture, and have been kept for thousands of years. The yaks are a method of transportation and serve as beasts of burden. Their feces are a source of fuel, and their milk can be used for butter, which is then made into sculptures or consumed.
More selected pictures
Image 9
Braunvieh
Photo credit: Daniel Schwen
A Braunvieh cow wearing a cow bell below Fuorcla Sesvenna in the Engadin, Switzerland. Of Swiss origin, these cows were imported to the United States in the 19th century where they became the origin of the modern Brown Swiss cattle breed. Since the 1960s, Brown Swiss cattle have been crossed back into the Braunvieh stock of Europe. They are commonly various shades of brown in colour with lighter points.
More selected pictures
Image 10
Short-beaked Echidna
Photo credit: Fir0002
The Short-beaked Echidna (Tachyglossus aculeatus), also known as the Spiny Anteater because of its diet of ants and termites, is one of four living species of echidna. The species is found throughout Australia, where it is the most widespread native mammal, and in coastal and highland regions of southwestern New Guinea.
More selected pictures
Image 11
Proboscis monkey
Photograph credit: Charles James Sharp
The proboscis monkey (Nasalis larvatus) is endemic to the island of Borneo, where it is found predominantly in coastal areas, near rivers and in swamp forests. It is perhaps the most aquatic of the primates and is a fairly good swimmer, capable of swimming underwater; apart from this, it is largely arboreal. This image is a composite of three photographs and shows a proboscis monkey jumping between trees in Labuk Bay in the Malaysian state of Sabah.
More selected pictures
Image 12
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 13
Meerkat
Photo: Fir0002
The meerkat (Suricata suricatta) is a small member of the mongoose family native to the Kalahari Desert of southern Africa. They are social animals, living underground in groups of 20 to 50 members. Although the name means "lake cat" in Dutch, meerkats are not cats, nor are they attracted to lakes.
More selected pictures
Image 14
Yak
Photograph: travelwayoflife
A yak at Letdar on the Annapurna Circuit in the Annapurna mountain range of central Nepal. Mostly domesticated, these long-haired bovids are found throughout the Himalayan region of south Central Asia, the Tibetan Plateau and as far north as Mongolia and Russia.
More selected pictures
Image 15
African elephant
Photo: Ikiwaner
The term African elephant refers to elephants of the genus Loxodonta. Shown here is the African bush elephant (Loxodonta africana), one of two extant species and the largest living terrestrial animal, with males standing 3.2–4.0 m (10.5–13.1 ft) tall at the shoulder and weighing 4,700–6,048 kg (10,362–13,334 lb).
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.