In terms of cladistics, which reflects evolutionary history, mammals are the only living members of the Synapsida (synapsids); this clade, together with Sauropsida (reptiles and birds), constitutes the larger Amniota clade. The early synapsids were sphenacodonts, a group that included the famous Dimetrodon. The synapsids split into several diverse groups of non-mammalian synapsids — traditionally and incorrectly referred to as mammal-like reptiles or by the term pelycosaurs, and now known as stem mammals or protomammals — before giving rise to therapsids during the beginning of the Middle Permian period. Mammals originated from cynodonts, an advanced group of therapsids, during the Early Jurassic. The modern mammalian orders arose 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 body type is quadruped, and most mammals use their four extremities for terrestrial locomotion; but in some, the extremities are adapted for life at sea, in the air, in trees, underground, or on two legs. Mammals range in size from the 30–40 mm (1.2–1.6 in) bumblebee bat to the 30 m (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 are egg-laying mammals. The most species-rich group of mammals, the cohort called placentals, have a placenta, which enables the feeding of the fetus during gestation.
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, 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...)
The walrus (Odobenus rosmarus) is a large flipperedmarine mammal with a discontinuous circumpolar distribution in the Arctic Ocean and sub-Arctic seas of the Northern Hemisphere. The walrus is the only living species in the Odobenidae family. It is subdivided into two or three subspecies: the Atlantic walrus (O. rosmarus rosmarus) found in the Atlantic Ocean, the Pacific walrus (O. rosmarus divergens) found in the Pacific Ocean, and a possible third subspecies, O. rosmarus laptevi, found in the Laptev Sea. Walruses are immediately recognizable due to their prominent tusks, whiskers and great bulk. Adult Pacific males can weigh up to 4,500 pounds, and, among pinnipeds, are exceeded in size only by the elephant seals. They reside primarily in shallow oceanic shelf habitat, spending a significant proportion of their lives on sea ice in pursuit of their preferred diet of benthicbivalve mollusks. They are relatively long-lived, social animals and are considered a keystone species in Arctic marine ecosystems. Walruses have played a prominent role in the cultures of many indigenous Arctic peoples, who have hunted walruses for their meat, fat, skin, tusks and bone. In the 19th and early 20th centuries, walruses were the objects of heavy commercial exploitation for blubber and ivory and their numbers declined rapidly. Their global population has since rebounded, though the Atlantic and Laptev sub-population remain fragmented and at historically depressed levels.
...that Scarlett the cat is a former stray cat whose efforts to save her kittens from a fire, at serious harm to herself, attracted worldwide media attention and has been related in a number of nonfiction books?
...that Dr. Johnson's cat Hodge has his own statue in Gough Square, London?
The olive baboon (Papio anubis) is an Old World monkey found in 25 countries throughout Africa, making it the most widely ranging of all baboons. It is named for its coat, which, at a distance, is a shade of green-grey. At closer range, its coat is multi-colored, due to rings of yellow-brown and black on the hairs. It is omnivorous, finding nutrition in almost any environment, and able to adapt with different foraging tactics.
Off the coast of Juneau, Alaska, a group of 15 Humpback Whales works in tandem to catch herring using the bubble net feeding technique, in which they exhale through their blowholes, creating a ring of bubbles up to 30 m (100 ft) in diameter. The whales then suddenly swim upwards through the bubble net swallowing thousands of fish in each gulp.
The northern palm squirrel (Funambulus pennantii) is a species of rodent in the family Sciuridae. It has a wide distribution in the Indian subcontinent and Iran, being a semi-arboreal species found in dry deciduous forest and many other rural and urban habitats. It is a common species with a wide range and the International Union for Conservation of Nature has rated its conservation status as being of least concern. This northern palm squirrel was photographed in Keoladeo National Park in Bharatpur, in the Indian state of Rajasthan.
The llama (Lama glama) is a domesticated South American camelid, widely used as a meat and pack animal by Andean cultures since the pre-Columbian era. A full-grown llama can reach a height of 1.7 to 1.8 metres (5 ft 7 in to 5 ft 11 in) at the top of the head, and can weigh between 130 and 200 kilograms (290 and 440 lb). At birth, a baby llama (known as a cria) can weigh between 9 and 14 kilograms (20 and 31 lb). Llamas typically live for 15 to 25 years, with some individuals surviving 30 years or more. This photograph shows a dam (female llama) and her cria at Laguna Colorada in Eduardo Avaroa Andean Fauna National Reserve, Bolivia.
A female koala (Phascolarctos cinereus), an arborealherbivorousmarsupial native to coastal regions of eastern and southern Australia. The word "koala" comes from the Dharuk word gula. English-speaking settlers from the late 18th century first called it "koala bear" due to its similarity in appearance to bears, although they are not at all related. Instead, its closest living relative is the wombat.
A portrait of an African elephant, highlighting its trunk. The trunk, which contains some 150,000 muscle fascicles, is a fusion of the nose and upper lip with a unique nerve running along both sides. An elephant can use its trunk for power functions, such as lifting up to 350 kg (770 lb), or more delicate functions, such as wiping its eye.
A 2-month old domesticgoat (Capra aegagrus hircus) kid in a field of capeweed. Goats are one of the oldest domesticated species. For thousands of years, goats have been used for their milk, meat, hair, and skins over much of the world. Female goats are referred to as does or nannies, intact males as bucks or billies; their offspring are kids.
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.
The Zanzibar red colobus (Procolobus kirkii) is a species of red colobus monkey endemic to Unguja, the main island of the Zanzibar Archipelago. Brought to attention of Western science by Sir John Kirk, this colobus was first described by John Edward Gray in 1868. It is now considered an endangered species, and extensive conservation efforts have been undertaken since the mid-1990s.
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.
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.
The Nova Scotia Duck Tolling Retriever is a medium-sized retrieverdog breed that originated in southwestern Nova Scotia, Canada. It is named for its ability to lure waterfowl within gunshot range, called "tolling". It is particularly suited for retrieving in cold water climates because of its water-repellent double coat.
A 3-week-old donkey (Equus africanus asinus), in Kadzidłowo, Poland. A female donkey is normally pregnant for about 12 months, and usually gives birth to a single foal; twins are rare.
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