- published: 23 Nov 2009
- views: 189948261
Mammals are members of class Mammalia ( /məˈmeɪli.ə/), air-breathing vertebrate animals characterised by the possession of endothermy, hair, three middle ear bones, and mammary glands functional in mothers with young. Most mammals also possess sweat glands and specialised teeth. The largest group of mammals, the placentals, have a placenta which feeds the offspring during gestation. The mammalian brain, with its characteristic neocortex, regulates endothermic and circulatory systems, the latter featuring red blood cells lacking nuclei and a four-chambered heart. Mammals range in size from the 30–40 millimeter (1- to 1.5-inch) bumblebee bat to the 33-meter (108-foot) blue whale.
The word "mammal" is modern, from the scientific name Mammalia coined by Carl Linnaeus in 1758, derived from the Latin mamma ("teat, pap"). All female mammals nurse their young with milk, which is secreted from special glands, the mammary glands. According to Mammal Species of the World, which is updated through periodic editions, 5,676 species were known in 2005. These were distributed in 1,229 genera, 153 families and 29 orders. In 2008 the IUCN completed a five-year, 17,000-scientist Global Mammal Assessment for its IUCN Red List, which counted 5488 accepted species at the end of that period. In some classifications, the class is divided into two subclasses (not counting fossils): the Prototheria (order of Monotremata) and the Theria, the latter composed of the infraclasses Metatheria and Eutheria. The marsupials are the crown group of the Metatheria and therefore include all living metatherians as well as many extinct ones; the placentals are likewise the crown group of the Eutheria.
Oxi alla logia
na xareis den antexo
sopa ke mou ftanei
mou sto plai mou s' exo
Stin periptosi mas
de xoraei antio
adiko sou leo
na poname ki i dio
Mi mou les tipota allo
simasia den exei kamia
Mi mou les tipota allo
xorismos paei na pei maxeria
O,ti kai na poume
i kardia agapaei
pragmata apla
ki ap' tous dio mas zitaei
Stin periptosi mas
de xorane i lekseis
min to sizitas