Portal:Mammals

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edit   Mammals Mammals (class Mammalia) are vertebrate animals characterized by the presence of sweat glands, including milk producing sweat glands, and by the presence of: hair, three middle ear bones used in hearing, and a neocortex region in the brain. Mammals, other than the monotremes, give birth to live young instead of laying eggs. They also possess specialized teeth and use a placenta in the ontogeny. The mammalian brain regulates endothermic and circulatory systems, including a four-chambered heart. Mammals encompass approximately 5,400 species, ranging in size from the Bumblebee Bat, (30-40mm), to the Blue Whale, (33,000mm), distributed in about 1,200 genera, 153 families, and 29 orders, though this varies by classification scheme. Most mammals belong to the placental group. The four largest orders within the placental mammals are Rodentia (mice, rats, and other small, gnawing mammals), Chiroptera (bats), Carnivora (dogs, cats, bears, and other mammals that primarily eat meat), and Cetartiodactyla (including numerous herbivore species, such as deer, sheep, goats, and buffalos, plus whales). Phylogenetically, Mammalia is defined as all descendants of the most recent common ancestor of monotremes (e.g., echidnas and platypuses) and therian mammals (marsupials and placentals). This means that some extinct groups of "mammals" are not members of the crown group Mammalia, even though most of them have all the characteristics that traditionally would have classified them as mammals. These "mammals" are now usually placed in the unranked clade Mammaliaformes. The mammalian line of descent diverged from the sauropsid line at the end of the Carboniferous period. The sauropsids would evolve into modern-day reptiles and birds, while the synapsid branch led to mammals. The first true mammals appeared in the Jurassic period. Modern mammalian orders appeared in the Palaeocene and Eocene epochs of the Palaeogene period. edit   Selected article The Fin Whale (Balaenoptera physalus), also called the Finback Whale or Razorback or Common Rorqual, is a marine mammal belonging to the suborder of baleen whales. It is the second largest whale and the second largest living animal after the Blue Whale, growing to nearly 27 meters (88 ft) long. Long and slender, the Fin Whale's body is brownish-grey with a paler underside. There are at least two distinct subspecies: the Northern Fin Whale of the North Atlantic, and the larger Antarctic Fin Whale of the Southern Ocean. It is found in all the world's major oceans, from polar to tropical waters. It is absent only from waters close to the ice pack at both the north and south poles and relatively small areas of water away from the open ocean. The highest population density occurs in temperate and cool waters. Its food consists of small schooling fish, squid and crustaceans including mysids and krill. edit   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 is a cat named Tama? ... that Dolphins and Whales are born with moustaches! edit   Selected picture 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. edit   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. edit   Topics Monotremata · Didelphimorphia · Paucituberculata · Microbiotheria · Notoryctemorphia · Dasyuromorphia · Peramelemorphia · Diprotodontia · Afrosoricida · Macroscelidea · Tubulidentata · Hyracoidea · Proboscidea · Sirenia · Cingulata · Pilosa · Scandentia · Dermoptera · Primates · Rodentia · Lagomorpha · Erinaceomorpha · Soricomorpha · Chiroptera · Pholidota · Carnivora · Perissodactyla · Artiodactyla · Cetacea edit   Quality content Babakotia Blue whale Beagle Bobcat Cougar Domestic sheep Elk Eremoryzomys Fin whale Giant Otter Gray Mouse Lemur Guinea pig Hippopotamus Homo floresiensis Humpback whale Island Fox Jaguar Javan Rhinoceros Killer whale Knut (polar bear) Lemur Lion List of lemur species Lundomys Marsh rice rat Meerkat Manor Meerkat Manor: The Story Begins Mindomys Noronhomys Oryzomys Oryzomys couesi Oryzomys dimidiatus Oryzomys gorgasi Platypus Primate Pseudoryzomys Pygmy Hippopotamus Raccoon Right whale Ring-tailed Lemur Ruffed lemur Sea otter Sei whale Short-beaked Echidna Sumatran Rhinoceros Tasmanian Devil Thylacine Transandinomys bolivaris Transandinomys talamancae Whale song ?Oryzomys pliocaenicus Arabian horse Carletonomys Central American Squirrel Monkey Ekbletomys Fancy rat Ferret legging Fossa (animal) Geoffroy's Spider Monkey Hadropithecus Herdwick Hipposideros besaoka Kitti's Hog-nosed Bat Labrador Retriever Malagasy Hippopotamus Mantled Howler Microgale macpheei North American River Otter Oecomys sydandersoni Oryzomys peninsulae Plesiorycteropus Pudú Red Panda Sperm whale Tamaraw Triaenops goodmani Triaenops menamena UA 8699 Walrus White-headed Capuchin William Windsor (goat) edit   WikiProjects Biology Tree of Life Prokaryotes and Protists Plants Arthropods Cephalopods Gastropods Fishes Amphibians and Reptiles Birds Mammals WikiProject Dogs WikiProject Dog breeds WikiProject Rodents WikiProject Cats WikiProject Equine WikiProject Horse breeds WikiProject Cetaceans WikiProject Primates WikiProject Monotremes and Marsupials Viruses A complete list of scientific WikiProjects can be found here. See also Wikispecies, a Wikimedia project dedicated to classification of biological species. edit   Things to do Articles needing attention Biology pages needing attention (cleanup, expansion, wikification, expert needed, etc.) Help Wikipedia by uploading required images Help Wikipedia by creating pages or redirects Help Wikipedia by expanding mammal-related stub articles. edit   Categories Mammals Mammals by geography • Lists of mammals • Mammal anatomy • Extinct mammals • Mammal hybrids • Mammalogy • Mammal stubs edit   Related portals Biology • Agriculture and Agronomy • Animals  • Arthropods • Amphibians and Reptiles • Biotechnology • Birds • Cats • Cetaceans • Dinosaurs • Dogs • Dentistry • Extinction • Evolutionary biology • Fish • Marine life • Medicine • Metabolism • Mind and Brain • Molecular and Cellular Biology • Neuroscience • Plants • Primates • Sharks • Turtles edit   Wikimedia What are portals? List of portals Featured portals