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Wallabia Bicolor
The swamp wallaby (''Wallabia bicolor'') is a small macropod marsupial of eastern Australia. This wallaby is also commonly known as the black wallaby, with other names including black-tailed wallaby, fern wallaby, black pademelon, stinker (in Queensland), and black stinker (in New South Wales) on account of its characteristic swampy odour. The swamp wallaby is the only living member of the genus ''Wallabia''. Etymology Historic names for the swamp wallaby include Aroe kangaroo and ''Macropus ualabatus'', as well as ''banggarai'' in the Dharawal language. Habitat and distribution The swamp wallaby is found from the northernmost areas of Cape York Peninsula in Queensland, down the entire east coast and around to southwestern Victoria. It was formerly found throughout southeastern South Australia, but is now rare or absent from that region. It inhabits thick undergrowth in forests and woodlands, or shelters during the day in thick grass or ferns, emerging at night to feed. Brig ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Édouard Louis Trouessart
Édouard Louis Trouessart (25 August 1842 – 30 June 1927) was a French zoologist born in Angers. He studied military medicine in Strasbourg, but was forced to leave school due to serious health problems. In 1864 he started work as ''préparateur de physique'' at the Faculty of Poitiers, and in the process, dedicated his time and energies to natural history. He also resumed his studies in medicine, earning a medical doctorate in 1870. During the Franco-Prussian War, he served in the French army. Later, he was employed at the hospital in Villevêque. From 1882 to 1884, he was director at the Museum of Angers, and in the meantime taught classes in natural history at the high school in Angers. In 1885 he relocated to Paris, where he worked with Alphonse Milne-Edwards (1835-1900). After the death of Emile Oustalet (1844-1905), he attained the chair of zoology (mammals and birds), a position he maintained until 1926. Selected writings * '' Les microbes, les ferments et les moisiss ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Acacia Harpophylla
''Acacia harpophylla'', commonly known as brigalow, brigalow spearwood or orkor, is an endemic tree of Australia. The Aboriginal Australian group the Gamilaraay peoples know the tree as Barranbaa or Burrii. It is found in central and coastal Queensland to northern New South Wales. It can reach up to tall and forms extensive open-forest communities on clay soils. Description The tree is root-suckering and has hard, furrowed and almost black coloured bark. The glabrous or hairy branchlets are angular at extremities. Like most species of ''Acacia'' it has phyllodes rather than true leaves. The coriaceous, sericeous and evergreen phyllodes have a falcate shape with a length of and a width of and have many closely parallel nerves with three to seven of the nerves are more prominent than the others. When it blooms, between July and October, it produces condensed inflorescences in groups of two to eight on racemes, usually appearing as axillary clusters. The spherical flower-hea ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Placental Mammals
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 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. 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 function in non-placental mammals ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Marsupials
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. Marsupials include opossums, Tasmanian devils, kangaroos, koalas, wombats, 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 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 species occur on the Australian continent (the mainland, Tasmania, New Guinea and nearby islands). The remaining 30% are found in the Americas—primarily in South America, thirteen in Central America, and one species, the Virginia opossum, in North America, nor ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Therian Mammals
Theria (; Greek: , wild beast) is a subclass of mammals amongst the Theriiformes. Theria includes the eutherians (including the placental mammals) and the metatherians (including the marsupials) but excludes the egg-laying monotremes. Characteristics Therian mammals give birth (''see viviparity'') to live young without a shelled egg. This is possible thanks to key proteins called syncytins which allow exchanges between the mother and its offspring through a placenta, even rudimental ones such as in marsupials. Genetic studies have suggested a viral origin of syncytins through the endogenization process. The marsupials and the placental mammals evolved from a common therian ancestor that gave live birth by suppressing the mother's immune system. While the marsupials continued to give birth to an underdeveloped fetus after a short pregnancy, the ancestors of placental mammals gradually evolved a prolonged pregnancy. Therian mammals no longer have the coracoid bone, contr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Estrous Cycle
The estrous cycle (, originally ) is the set of recurring physiological changes that are induced by reproductive hormones in most mammalian therian females. Estrous cycles start after sexual maturity in females and are interrupted by anestrous phases, otherwise known as "rest" phases, or by pregnancies. Typically, estrous cycles repeat until death. These cycles are widely variable in duration and frequency depending on the species.Bronson, F. H., 1989. Mammalian Reproductive Biology. University of Chicago Press, Chicago, IL, USA. Some animals may display bloody vaginal discharge, often mistaken for menstruation. Many mammals used in commercial agriculture, such as cattle and sheep, may have their estrous cycles artificially controlled with hormonal medications for optimum productivity. The male equivalent, seen primarily in ruminants, is called rut. Differences from the menstrual cycle Mammals share the same reproductive system, including the regulatory hypothalamic system t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Embryonic Diapause
Embryonic diapause (from late 19th century English: dia- ‘through’ + pause- 'delay') (aka delayed implantation in mammals) is an evolutionary reproductive strategy used by several animal species across a number of kingdoms, including approximately 130 different mammals, which takes place in order to ensure the survival of offspring. The process occurs at the blastocyst stage of embryo development in most species, and is characterized by a dramatic reduction or complete cessation of mitotic activity, arresting most often in the G0 or G1 phase of division. In placental embryonic diapause, the embryonic blastocyst does not immediately implant in the uterus after sexual reproduction has created the zygote, but rather remains in this non-dividing state of dormancy until conditions allow for attachment to the uterine wall to proceed as normal. As a result, the normal gestation period is extended for a species-specific time. Organisms which undergo embryonic diapause are able to synchron ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Breastfeeding
Breastfeeding, or nursing, is the process by which human breast milk is fed to a child. Breast milk may be from the breast, or may be expressed by hand or pumped and fed to the infant. The World Health Organization (WHO) recommends that breastfeeding begin within the first hour of a baby's life and continue as often and as much as the baby wants. Health organizations, including the WHO, recommend breastfeeding exclusively for six months. This means that no other foods or drinks, other than vitamin D, are typically given. WHO recommends exclusive breastfeeding for the first 6 months of life, followed by continued breastfeeding with appropriate complementary foods for up to 2 years and beyond. Of the 135 million babies born every year, only 42% are breastfed within the first hour of life, only 38% of mothers practice exclusive breastfeeding during the first six months, and 58% of mothers continue breastfeeding up to the age of two years and beyond. Breastfeeding has a numb ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pouch (marsupial)
The pouch is a distinguishing feature of female marsupials, monotremes and possibly most extinct non-placental mammals including eutherians like ''Zalambdalestes'' (and rarely in the males as in the water opossumNogueira, José Carlos, et al.Morphology of the male genital system of Chironectes minimus and comparison to other didelphid marsupials. Journal of mammalogy 85.5 (2004): 834-841. and the extinct thylacine); the name marsupial is derived from the Latin ''marsupium'', meaning "pouch". Marsupials give birth to a live but relatively undeveloped fetus called a joey. When the joey is born it crawls from inside the mother to the pouch. The pouch is a fold of skin with a single opening that covers the teats. Inside the pouch, the blind offspring attaches itself to one of the mother’s teats and remains attached for as long as it takes to grow and develop to a juvenile stage. Variations Pouches are different amongst different marsupials, two kinds distinguishable (on the front ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gestation
Gestation is the period of development during the carrying of an embryo, and later fetus, inside viviparous animals (the embryo develops within the parent). It is typical for mammals, but also occurs for some non-mammals. Mammals during pregnancy can have one or more gestations at the same time, for example in a multiple birth. The time interval of a gestation is called the '' gestation period''. In obstetrics, ''gestational age'' refers to the time since the onset of the last menses, which on average is fertilization age plus two weeks. Mammals In mammals, pregnancy begins when a zygote (fertilized ovum) implants in the female's uterus and ends once the fetus leaves the uterus during labor or an abortion (whether induced or spontaneous). Humans In humans, pregnancy can be defined clinically or biochemically. Clinically, pregnancy starts from first day of the mother's last period. Biochemically, pregnancy starts when a woman's human chorionic gonadotropin (hCG) levels ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tail
The tail is the section at the rear end of certain kinds of animals’ bodies; in general, the term refers to a distinct, flexible appendage to the torso. It is the part of the body that corresponds roughly to the sacrum and coccyx in mammals, reptiles, and birds. While tails are primarily a feature of vertebrates, some invertebrates including scorpions and springtails, as well as snails and slugs, have tail-like appendages that are sometimes referred to as tails. Tailed objects are sometimes referred to as "caudate" and the part of the body associated with or proximal to the tail are given the adjective "caudal". Function Animal tails are used in a variety of ways. They provide a source of locomotion for fish and some other forms of marine life. Many land animals use their tails to brush away flies and other biting insects. Most canines use their tails to comunicate mood and intention . Some species, including cats and kangaroos, use their tails for balance; and some, such ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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