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Mammalia
Mammals () are a group of vertebrate animals constituting the class Mammalia (), characterized by the presence of mammary glands which in females produce milk for feeding (nursing) their young, a neocortex (a region of the brain), fur or hair, and three middle ear bones. These characteristics distinguish them from reptiles (including birds) from which they diverged in the Carboniferous, over 300 million years ago. Around 6,400 extant species of mammals have been described divided into 29 orders. The largest orders, in terms of number of species, are the rodents, bats, and Eulipotyphla (hedgehogs, moles, shrews, and others). The next three are the Primates (including humans, apes, monkeys, and others), the Artiodactyla ( cetaceans and even-toed ungulates), and the Carnivora (cats, dogs, seals, and others). In terms of cladistics, which reflects evolutionary history, mammals are the only living members of the Synapsida (synapsids); this clade, together w ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Marsupialia
Marsupials are any members of the mammalian infraclass Marsupialia. All extant marsupials are endemic to Australasia, Wallacea and the Americas. A distinctive characteristic common to most of these species is that the young are carried in a pouch (marsupial), pouch. Marsupials include opossums, Tasmanian devils, kangaroos, koalas, wombats, Wallaby, wallabies, bandicoots, and the extinct thylacine. Marsupials represent the clade originating from the last common ancestor of extant metatherians, the group containing all mammals more closely related to marsupials than to Placentalia, placentals. They give birth to relatively undeveloped young that often reside in a pouch located on their mothers' abdomen for a certain amount of time. Close to 70% of the 334 extant taxon, extant species occur on the Australia (continent), Australian continent (the mainland, Tasmania, New Guinea and nearby islands). The remaining 30% are found in the Americas—primarily in South America, thirteen in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Platypus
The platypus (''Ornithorhynchus anatinus''), sometimes referred to as the duck-billed platypus, is a semiaquatic, egg-laying mammal Endemic (ecology), endemic to Eastern states of Australia, eastern Australia, including Tasmania. The platypus is the sole living representative or monotypic taxon of its Family (biology), family (Ornithorhynchidae) and genus (''Ornithorhynchus''), though a number of Fossil Monotremes, related species appear in the fossil record. Together with the four species of echidna, it is one of the five wikt:extant, extant species of monotremes, mammals that lay Egg (biology), eggs instead of giving birth to live young. Like other monotremes, it senses prey through electroreception, electrolocation. It is one of the few species of venomous mammals, as the male platypus has a spur (zoology), spur on the hind foot that delivers a Platypus venom, venom, capable of causing severe pain to humans. The unusual appearance of this egg-laying, duck-billed, beaver-t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Placentalia
Placental mammals (infraclass Placentalia ) are one of the three extant subdivisions of the class Mammalia, the other two being Monotremata and Marsupialia. Placentalia contains the vast majority of extant mammals, which are partly distinguished from monotremes and marsupials in that the fetus (biology), fetus is carried in the uterus of its mother to a relatively late stage of development. The name is something of a misnomer considering that marsupials also nourish their fetuses via a placenta, though for a relatively briefer period, giving birth to less developed young which are then nurtured for a period inside the mother's pouch (marsupial), pouch. Anatomical features Placental mammals are anatomically distinguished from other mammals by: * a sufficiently wide opening at the bottom of the pelvis to allow the birth of a large baby relative to the size of the mother. * the absence of epipubic bones extending forward from the pelvis, which are found in all other mammals. (Their ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Common Vampire Bat
The common vampire bat (''Desmodus rotundus'') is a small, leaf-nosed bat native to Latin America. It is one of three extant species of vampire bat, the other two being the hairy-legged and the white-winged vampire bats. The common vampire bat practices hematophagy, mainly feeding on the blood of livestock. The bat usually approaches its prey at night while they are sleeping. It then uses its razor-sharp teeth to cut open the skin of its hosts and lap up their blood with its long tongue. The species is highly polygynous, and dominant adult males defend groups of females. It is one of the most social of bat species with a number of cooperative behaviors such as social grooming and food sharing. Because it feeds on livestock and is a carrier of rabies, the common vampire bat is considered a pest. Its conservation status is categorized as Least Concern by the International Union for Conservation of Nature (IUCN) because of "its wide distribution, presumed large population toleran ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fox Squirrel
The fox squirrel (''Sciurus niger''), also known as the eastern fox squirrel or Bryant's fox squirrel, is the largest species of tree squirrel native to North America. Despite the differences in size and coloration, it is sometimes mistaken for American red squirrels or eastern gray squirrel The eastern gray squirrel (''Sciurus carolinensis''), also known, particularly outside of North America, as simply the grey squirrel, is a tree squirrel in the genus ''Sciurus''. It is native to eastern North America, where it is the most prodi ...s in areas where the species co-exist. Description The squirrel's total length measures , with a body length of and a similar tail length. They range in weight from . There is no sexual dimorphism in size or appearance. Individuals tend to be smaller in the west. There are three distinct geographical phases in coloration: In most areas the animal's upper body is brown-grey to brown-yellow with a typically brownish-orange underside, while in e ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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