A wallaby is a small- or mid-sized macropod native to Australia and New Guinea, with introduced populations in New Zealand, UK and other countries. They belong to the same taxonomic family as kangaroos and sometimes the same genus, but kangaroos are categorised into the six largest species of the family; the term wallaby is an informal designation used for any macropod, smaller than a kangaroo or wallaroo that has not been designated otherwise. There are 11 species of brush wallabies, their head and body length is 45 to 105 cm and the tail is 33 to 75 cm long. The six named species of rock-wallabies live among rocks near water; the two species of hare-wallabies are small animals that have the movements and some of the habits of hares. Called "pademelons", the three species of scrub wallabies of New Guinea, the Bismarck Archipelago, Tasmania are small and stocky, with short hind limbs and pointed noses. Wallabies are hunted for fur. A similar species is quokka; the three named species of forest wallabies are native to the island of New Guinea.
The dwarf wallaby is the smallest member of the genus and the smallest known member of the kangaroo family. Its length is about 46 cm from nose to tail, it weighs about 1.6 kg. The name wallaby comes from Dharug walabi or waliba. Young wallabies are known like many other marsupials. Adult male wallabies are referred to as "bucks", "boomers", or "jacks". An adult female wallaby is known as a "doe", "flyer", or "jill". A group of wallabies is called a "court", "mob", or "troupe". Forest-dwelling wallabies are known as "pademelons" and "dorcopsises". Although members of most wallaby species are small, some can grow up to two metres in length, their powerful hind legs are not only used for bounding at high speeds and jumping great heights, but to administer vigorous kicks to fend off potential predators. The Tammar wallaby has elastic storage in the ankle extensor tendons, without which the animal's metabolic rate might be 30–50% greater, it has been found that the design of spring-like tendon energy savings and economical muscle force generation is key for the two distal muscle–tendon units of the Tammar wallaby.
Wallabies have a powerful tail, used for balance and support. Wallabies are herbivores whose diet consists of a wide range of grasses, vegetables and other foliage. Due to recent urbanization, many wallabies now feed in urban areas. Wallabies cover vast distances for food and water, scarce in their environment. Mobs of wallabies congregate around the same water hole during the dry season. Wallabies face several threats. Wild dogs and feral cats are among their predators. Humans pose a significant threat to wallabies due to increased interaction. Many wallabies have been involved in vehicular accidents as they feed near roads and urban areas. Wallabies are not a distinct genetic group, they fall into several broad categories. Typical wallabies of the genus Macropus, like the agile wallaby, the red-necked wallaby are most related to the kangaroos and wallaroos and, size aside, look similar; these are the ones most seen in the southern states. Rock-wallabies, rather like the goats of the northern hemisphere, specialise in rugged terrain and have modified feet adapted to grip rock with skin friction rather than dig into soil with large claws.
There are at least fifteen species and the relationship between several of them is poorly understood. Several are endangered. Captive rock wallaby breeding programs like the one at Healesville Sanctuary have had some success and a small number have been released into the wild; the banded hare-wallaby is thought to be the last remaining member of the once-numerous subfamily Sthenurinae, although once common across southern Australia, is now restricted to two islands off the Western Australian coast which are free of introduced predators. It is not as related to the other hare wallabies as the hare wallabies are to the other wallabies. New Guinea, until recent geological times part of mainland Australia, has at least five species of wallaby. Wallabies are distributed across Australia in more remote timbered, or rugged areas, less so on the great semi-arid plains that are better suited to the larger and more fleet-footed kangaroos, they can be found on the island of New Guinea. Wallabies of several species have been introduced to other parts of the world, there are a number of breeding introduced populations, including: Kawau Island in New Zealand is home to large numbers of tammar, Parma and brush-tailed rock-wallaby from introductions made around 1870.
They are considered a pest on the island, but a programme to re-introduce them to Australia has met with only limited success. The Lake Tarawera area of New Zealand has a large tammar population; the South Canterbury district of New Zealand has a large population of Bennett's wallaby. On the Isle of Man in the Ballaugh Curraghs area, there is a population of over 100 red-necked wallabies, descended from a pair that escaped from the nearby Curraghs Wildlife Park in 1970. Hawaii has a small non-native populatio
An adze is a cutting tool similar to an axe but with the cutting edge perpendicular to the handle rather than parallel. They have been used since the stone age. Adzes are used for carving wood in hand woodworking. Two basic forms of an adze are the hand adze—a short handled tool swung with one hand—and the foot adze—a long handled tool capable of powerful swings using both hands, the cutting edge striking at foot or shin level. A similar, but blunt, tool used for digging in hard ground is called a mattock; the adze is depicted in ancient Egyptian art from the Old Kingdom onward. The adze blades were made of stone, but in the Predynastic Period copper adzes had all but replaced those made of flint. While stone blades were fastened to the wooden handle by tying, metal blades had sockets into which the handle was fitted. Examples of Egyptian adzes can be found on the Petrie Museum website. A depiction of an adze was used as a hieroglyph, representing the consonants stp, "chosen", used as:... Pharaoh XX, chosen of God/Goddess YY...
The ahnetjer depicted as an adze-like instrument, was used in the Opening of the Mouth ceremony, intended to convey power over their senses to statues and mummies. It was the foreleg of a freshly sacrificed bull or cow with which the mouth was touched; as iron age technology moved south into Africa with migrating ancient Egyptians, they carried their technology with them, including adzes. To this day, iron adzes are used all over rural Africa for various purposes - from digging pit latrines, chopping firewood, to tilling crop fields - whether they are of maize, tea, beans, yams or a plethora of other cash and subsistence crops. Polynesian adzes were made of basalt, a type of stone, not uniformly available in the Pacific, it is not found on atolls, for example, its quality for tool-making varies according to the source island/quarry. This variation inspired a growing network of long-distance trade, in which sailing canoes carried this material over thousands of kilometres. With the advent of X-ray fluorescence, it is now possible to analyse an adze head and trace its geochemical source back to the originating quarry.
By applying this technique to archaeological finds of adze-heads, a vast web of long-distance prehistoric interaction has been revealed, providing hard evidence of intentional two-way navigation well before Europe's Age of Exploration began. Prehistoric Māori adzes from New Zealand, used for wood carving, were made from nephrite known as jadein the South Island. In the North Island they were made from greywacke or basalt. At the same time on Henderson Island, a small coral island in eastern Polynesia lacking any rock other than limestone, natives may have fashioned giant clamshells into adzes. American Northwest coast native peoples traditionally used adzes for both functional construction and art. Northwest coast adzes take two forms: D-handle; the hafted form is similar in form to a European adze with the haft constructed from a natural crooked branch which forms a 60% angle. The thin end is used as the handle and the thick end is flattened and notched such that an adze iron can be lashed to it.
Modern hafts are sometimes constructed from a sawed blank with a dowel added for strength at the crook. The second form is the D-handle adze, an adze iron with a directly attached handle; the D-handle, provides no mechanical leverage. Northwest coast adzes are classified by size and iron shape vs. role. As with European adzes, iron shapes include straight and lipped. Where larger Northwest adzes are similar in size to their European counterparts, the smaller sizes are much lighter such that they can be used for the detailed smoothing and surface texturing required for figure carving. Final surfacing is sometimes performed with a crooked knife. Ground stone adzes are still in use by a variety of people in Irian Jaya, Papua New Guinea and some of the smaller Islands of Melanesia and Micronesia; the hardstone is ground on a riverine rock with the help of water until it has got the desired shape. It is fixed to a natural grown angled wood with resin and plant fibers; the shape and manufacture of these adzes is similar to those found from the Neolithic stone age in Europe.
A variety of minerals are used. Their everyday use is on a steady decline, as it is much more convenient to cut firewood using imported steel axes or machetes. However, certain ceremonial crafts such as making canoes, ceremonial shields, drums, containers or communal houses etc. may require the use of traditional-made stone adzes. Modern adzes are made from steel with wooden handles, enjoy limited use: in semi-industrial areas, but by'revivalists' such as those at the Colonial Williamsburg cultural center in Virginia, USA. However, the traditional adze has been replaced by the sawmill and the powered-plane, at least in industrialised cultures, it remains in use for example by coopers. Adzes are in current use by artists such as Northwest Coast American and Canadian Indian sculptors doing pole work and bowls. "Adzes are used for removing heavy waste, shaping, or trimming the surfaces of timber..." and boards. The user stands astride a board or log and swings the adze downwards between his feet, chipping off pieces of wood, moving backwards as they go and leaving a smooth surface behind.
Foot adzes are most known as shipbuilder's or carpenter's adzes. They range in size from 00 to 5 being
In forestry and ecology, understory comprises plant life growing beneath the forest canopy without penetrating it to any great extent, but above the forest floor. Only a small percentage of light penetrates the canopy so understory vegetation is shade tolerant; the understory consists of trees stunted through lack of light, other small trees with low light requirements, shrubs and undergrowth. Small trees such as holly and dogwood are understory specialists. In temperate deciduous forests, many understory plants start into growth earlier than the canopy trees to make use of the greater availability of light at this time of year. A gap in the canopy caused by the death of a tree stimulates the potential emergent trees into competitive growth as they grow upwards to fill the gap; these trees tend to have straight trunks and few lower branches. At the same time, the bushes and plant life on the forest floor become more dense; the understory experiences greater humidity than the canopy, the shaded ground does not vary in temperature as much as open ground.
This causes a proliferation of ferns and fungi and encourages nutrient recycling, which provides favorable habitats for many animals and plants. The understory is the underlying layer of vegetation in a forest or wooded area the trees and shrubs growing between the forest canopy and the forest floor. Plants in the understory comprise an assortment of seedlings and saplings of canopy trees together with specialist understory shrubs and herbs. Young canopy trees persist in the understory for decades as suppressed juveniles until an opening in the forest overstory permits their growth into the canopy. In contrast understory shrubs complete their life cycles in the shade of the forest canopy; some smaller tree species, such as dogwood and holly grow tall and are understory trees. The canopy of a rainforest is about 10m thick, intercepts around 95% of the sunlight; the understory receive less intense light than plants in the canopy and such light as does penetrate is impoverished in wavelengths of light that are most effective for photosynthesis.
Understory plants therefore must be shade tolerant—they must be able to photosynthesize adequately using such light as does reach their leaves. They are able to use wavelengths that canopy plants cannot. In temperate deciduous forests towards the end of the leafless season, understory plants take advantage of the shelter of the still leafless canopy plants to "leaf out" before the canopy trees do; this is important because it provides the understory plants with a window in which to photosynthesize without the canopy shading them. This brief period is a crucial period in which the plant can maintain a net positive carbon balance over the course of the year; as a rule forest understories experience higher humidity than exposed areas. The forest canopy reduces solar radiation, so the ground does not heat up or cool down as as open ground; the understory dries out more than more exposed areas do. The greater humidity encourages epiphytes such as ferns and mosses, allows fungi and other decomposers to flourish.
This drives nutrient cycling, provides favorable microclimates for many animals and plants, such as the pygmy marmoset. Overgrazing Layers of rainforests https://www.eolss.net/sample-chapters/C10/E5-03-01-08.pdf
The kangaroo is a marsupial from the family Macropodidae. In common use the term is used to describe the largest species from this family those of the genus Macropus: the red kangaroo, antilopine kangaroo, eastern grey kangaroo, western grey kangaroo. Kangaroos are indigenous to Australia; the Australian government estimates that 34.3 million kangaroos lived within the commercial harvest areas of Australia in 2011, up from 25.1 million one year earlier. As with the terms "wallaroo" and "wallaby", "kangaroo" refers to a paraphyletic grouping of species. All three refer to members of the same taxonomic family and are distinguished according to size; the largest species in the family are called "kangaroos" and the smallest are called "wallabies". The term "wallaroos" refers to species of an intermediate size. There is the tree-kangaroo, another genus of macropod, which inhabits the tropical rainforests of New Guinea, far northeastern Queensland and some of the islands in the region. A general idea of the relative size of these informal terms could be: wallabies: head and body length of 45–105 cm and tail length of 33–75 cm.
Kangaroos have large, powerful hind legs, large feet adapted for leaping, a long muscular tail for balance, a small head. Like most marsupials, female kangaroos have a pouch called a marsupium in which joeys complete postnatal development; the large kangaroos have adapted much better than the smaller macropods to land clearing for pastoral agriculture and habitat changes brought to the Australian landscape by humans. Many of the smaller species are rare and endangered, while kangaroos are plentiful; the kangaroo is a symbol of Australia and appears on the Australian coat of arms and on some of its currency and is used by some of Australia's well known organisations, including Qantas and the Royal Australian Air Force. The kangaroo is important to both Australian culture and the national image, there are numerous popular culture references. Wild kangaroos are shot for meat, leather hides, to protect grazing land. Although controversial, kangaroo meat has perceived health benefits for human consumption compared with traditional meats due to the low level of fat on kangaroos.
The word "kangaroo" derives from the Guugu Yimithirr word gangurru. The name was first recorded as "kanguru" on 12 July 1770 in an entry in the diary of Sir Joseph Banks. Cook first referred to kangaroos in his diary entry of 4 August. Guugu Yimithirr is the language of the people of the area. A common myth about the kangaroo's English name is that "kangaroo" was a Guugu Yimithirr phrase for "I don't understand you." According to this legend and Banks were exploring the area when they happened upon the animal. They asked a nearby local; the local responded "Kangaroo", meaning "I don't understand you", which Cook took to be the name of the creature. This myth was debunked in the 1970s by linguist John B. Haviland in his research with the Guugu Yimithirr people. Kangaroos are colloquially referred to as "roos". Male kangaroos are called bucks, jacks, or old men; the collective noun for kangaroos is troop, or court. There are four extant species that are referred to as kangaroos: The red kangaroo is the largest surviving marsupial anywhere in the world.
It occupies the semi-arid centre of the country. The highest population densities of the red kangaroo occur in the rangelands of western New South Wales. Red kangaroos are mistaken as the most abundant species of kangaroo, but eastern greys have a larger population. A large male weighs 90 kg; the eastern grey kangaroo is less well-known than the red, but the most seen, as its range covers the fertile eastern part of the country. The range of the eastern grey kangaroo extends from the top of the Cape York Peninsula in north Queensland down to Victoria, as well as areas of south-eastern Australia and Tasmania. Population densities of eastern grey kangaroos peak near 100 per km2 in suitable habitats of open woodlands. Populations are more limited in areas of land clearance, such as farmland, where forest and woodland habitats are limited in size or abundance; the western grey kangaroo is smaller again at about 54 kg for a large male. It is found in the southern part of Western Australia, South Australia near the coast, the Darling River basin.
The highest population densities occur in the western Riverina district of New South Wales and in western areas of the Nullarbor Plain in Western Australia. Populations may have declined in agricultural areas; the species has a high tolerance to the plant toxin sodium fluoroacetate, which indicates a possible origin from the south-west region of Australia. The antilopine ka
Sclerophyll is a type of vegetation that has hard leaves, short internodes and leaf orientation parallel or oblique to direct sunlight. The word comes from the Greek sklēros and phyllon. Sclerophyllous plants occur in many parts of the world, but are most typical in the chaparral biomes, they are prominent throughout western and southern parts of Australia, in the Mediterranean forests and scrub biomes that cover the Mediterranean Basin, Californian chaparral and woodlands, Chilean Matorral, the Cape Province of South Africa. The sclerophyll leaves have three leaf stress traits used to cope with hot and dry summers: the leaves are hard due to lignin, which prevents wilting and allows plants to grow; the term was coined by A. F. W. Schimper in 1898 as a synonym of xeromorph, but was changed. Most areas of the Australian continent able to support woody plants are occupied by sclerophyll communities as forests, savannas or heathlands. Common plants include the Proteaceae, tea-trees, acacias and eucalypts.
The most common sclerophyll communities in Australia are savannas dominated by grasses with an overstorey of eucalypts and acacias. Acacia shrublands cover extensive areas. All the dominant overstorey acacia species and a majority of the understorey acacias have a scleromorphic adaptation in which the leaves have been reduced to phyllodes consisting of the petiole. Many plants of the sclerophyllous woodlands and shrublands produce leaves unpalatable to herbivores by the inclusion of toxic and indigestible compounds which assure survival of these long-lived leaves; this trait is noticeable in the eucalypt and Melaleuca species which possess oil glands within their leaves that produce a pungent volatile oil that makes them unpalatable to most browsers. These traits make the majority of woody plants in these woodlands unpalatable to domestic livestock, it is therefore important from a grazing perspective that these woodlands support a more or less continuous layer of herbaceous ground cover dominated by grasses.
Sclerophyll forests cover a much smaller area of the continent, being restricted to high rainfall locations. They have a eucalyptus overstory with the understory being hard-leaved. Dry sclerophyll forests are the most common forest type on the continent, although it may seem barren dry sclerophyll forest is diverse. For example, a study of sclerophyll vegetation in Seal Creek, found 138 species. Less extensive are wet sclerophyll forests, they have a taller eucalyptus overstory than dry sclerophyll forests, 30 metres or more, a soft-leaved dense understory. They require ample rainfall — at least 1000mm. Sclerophyllous plants are anything but newcomers. By the time of European settlement, sclerophyll forest accounted for the vast bulk of the forested areas. Most of the wooded parts of present-day Australia have become sclerophyll dominated as a result of the extreme age of the continent combined with Aboriginal fire use. Deep weathering of the crust over many millions of years leached chemicals out of the rock, leaving Australian soils deficient in nutrients phosphorus.
Such nutrient deficient soils support non-sclerophyllous plant communities elsewhere in the world and did so over most of Australia prior to European arrival. However such deficient soils cannot support the nutrient losses associated with frequent fires and are replaced with sclerophyllous species under traditional Aboriginal burning regimens. With the cessation of traditional burning non-sclerophyllous species have re-colonised sclerophyll habitat in many parts of Australia; the presence of toxic compounds combined with a high carbon: nitrogen ratio make the leaves and branches of scleromorphic species long-lived in the litter, can lead to a large build-up of litter in woodlands. The toxic compounds of many species, notably Eucalyptus species, are volatile and flammable and the presence of large amounts of flammable litter, coupled with an herbaceous understorey, encourages fire. All the Australian sclerophyllous communities are liable to be burnt with varying frequencies and many of the woody plants of these woodlands have developed adaptations to survive and minimise the effects of fire.
Sclerophyllous plants resist dry conditions well, making them successful in areas of seasonally variable rainfall. In Australia, they evolved in response to the low level of phosphorus in the soil — indeed, many native Australian plants cannot tolerate higher levels of phosphorus and will die if fertilised incorrectly; the leaves are hard due to lignin, which prevents wilting and allows plants to grow when there isn't enough phosphorus for substantial new cell growth. Mediterranean forests and scrub Chaparral California chaparral and woodlands Chilean Matorral Tropical and subtropical coniferous forest Fynbos Garrigue Kwongan Mallee Woodlands and Shrublands Maquis shrubland Matorral
Phalangeriformes is a suborder of any of about 70 small- to medium-sized arboreal marsupial species native to Australia, New Guinea, Sulawesi. The suborder includes animals known as possums and cuscus; the common name "possum" for various Phalangeriformes species derives from the creatures' resemblance to the opossums of the Americas. However, although opossums are marsupials, Australasian possums are more related to other Australasian marsupials such as kangaroos. Phalangeriformes are quadrupedal diprotodont marsupials with long tails; the smallest species, indeed the smallest diprotodont marsupial, is the Tasmanian pygmy possum, with an adult head-body length of 70 mm and a weight of 10 g. The largest are the two species of bear cuscus. Phalangeriformes species are nocturnal and at least arboreal, they inhabit most vegetated habitats, several species have adjusted well to urban settings. Diets range from generalist herbivores or omnivores to specialist browsers of eucalyptus and nectar-feeders.
About two-thirds of Australian marsupials belong to the order Diprotodontia, split into three suborders: the Vombatiformes. Note: this classification is based on Ruedas & Morales 2005. Suborder Phalangeriformes: possums and allies Superfamily Phalangeroidea Family †Ektopodontidae: Genus †Ektopodon †Ektopodon serratus †Ektopodon stirtoni †Ektopodon ulta Family Burramyidae: Genus Burramys Mountain pygmy possum, B. parvus Genus Cercartetus Long-tailed pygmy possum, C. caudatus Southwestern pygmy possum, C. concinnus Tasmanian pygmy possum, C. lepidus Eastern pygmy possum, C. nanus Family Phalangeridae: brushtail possums and cuscuses Subfamily Ailuropinae Genus Ailurops Talaud bear cuscus, A. melanotis Sulawesi bear cuscus, A. ursinus Genus Strigocuscus Sulawesi dwarf cuscus, S. celebensis Banggai cuscus, S. pelegensis Subfamily Phalangerinae Tribe Phalangerini Genus Phalanger Gebe cuscus, P. alexandrae Mountain cuscus, P. carmelitae Ground cuscus, P. gymnotis Eastern common cuscus, P. intercastellanus Woodlark cuscus, P. lullulae Blue-eyed cuscus, P. matabiru Telefomin cuscus, P. matanim Southern common cuscus, P. mimicus Northern common cuscus, P. orientalis Ornate cuscus, P. ornatus Rothschild's cuscus, P. rothschildi Silky cuscus, P. sericeus Stein's cuscus, P. vestitus Genus Spilocuscus Admiralty Island cuscus, S. kraemeri Common spotted cuscus, S. maculatus Waigeou cuscus, S. papuensis Black-spotted cuscus, S. rufoniger Blue-eyed spotted cuscus, S. wilsoni Tribe Trichosurini Genus Trichosurus Northern brushtail possum, T. arnhemensis Short-eared possum, T. caninus Mountain brushtail possum, T. cunninghami Coppery brushtail possum, T. johnstonii Common brushtail possum, T. vulpecula Genus Wyulda Scaly-tailed possum, W. squamicaudata Superfamily Petauroidea Family Pseudocheiridae: Subfamily Hemibelideinae Genus Hemibelideus Lemur-like ringtail possum, H. lemuroides Genus Petauroides Greater glider, P. volans Subfamily Pseudocheirinae Genus Petropseudes Rock-haunting ringtail possum, P. dahli Genus Pseudocheirus Common ringtail possum, P. peregrinus Genus Pseudochirulus Lowland ringtail possum, P. canescens Weyland ringtail possum, P. caroli Cinereus ringtail possum, P. cinereus Painted ringtail possum, P. forbesi Herbert River ringtail possum, P. herbertensis Masked ringtail possum, P. larvatus Pygmy ringtail possum, P. mayeri Vogelkop ringtail possum, P. schlegeli Subfamily Pseudochiropinae Genus Pseudochirops D'Albertis' ringtail possum, Pseudochirops albertisii Green ringtail possum, Pseudochirops archeri Plush-coated ringtail possum, Pseudochirops corinnae Reclusive ringtail possum, Pseudochirops coronatus Coppery ringtail possum, Pseudochirops cupreus Family Petauridae: Genus Dactylopsila Great-tailed triok, D. megalura Long-fingered triok, D. palpator Tate's triok, D. tatei Striped possum, D. trivirgata Genus Gymnobelideus Leadbeater's possum, G. leadbeateri Genus Petaurus Northern glider, P. abidi Yellow-bellied glider, P. australis Biak glider, P. biacensis Sugar glider, P. breviceps Mahogany glider, P. gracilis Squirrel glider, P. norfolcensis Family Tarsipedidae: Genus Tarsipes Honey possum or noolbenger, T. rostratus Family Acrobatidae: Genus Acrobates Feathertail glider, A. pygmaeus Genus Distoechurus Feather-tailed possum, D. pennatus The common brushtail possum was introduced to New Zealand by European settlers in an attempt to establish a fur industry.
There are no native predators of the possum in New Zealand, so its numbers in New Zealand have risen to the point where it is considered a serious pest. Numerous attempts to eradicate them have been made because of the damage they do to native trees and wildlife, as well as acting as a carrier of bovine tuberculosis. By 2009, these measures had reduced the possum numbers to less than half of the 1980s levels – from around 70 million to around 30 million animals. Fauna of Australia Opossum - distantly related marsupial of the Americas Possums and Gliders — Australia Zoo Urban Possums — ABC, Australian Broadcasting Corporation Ruedas, L. A.. C.. "Evolutionary relationships a
Marsupials are any members of the mammalian infraclass Marsupialia. All extant marsupials are endemic to Australasia and the Americas. A distinctive characteristic common to these species is that most of the young are carried in a pouch. Well-known marsupials include kangaroos, koalas, opossums and Tasmanian devils; some lesser-known marsupials are the dunnarts and cuscuses. Marsupials represent the clade originating from the last common ancestor of extant metatherians. Like other mammals in the Metatheria, they give birth to undeveloped young that 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 remaining 100 are found in the Americas — in South America, but thirteen in Central America, one in North America, north of Mexico. The word marsupial comes from the technical term for the abdominal pouch. It, in turn, is borrowed from Latin and from the ancient Greek μάρσιππος mársippos, meaning "pouch".
Marsupials are taxonomically identified as members of the mammalian infraclass Marsupialia, first described as a family under the order Pollicata by German zoologist Johann Karl Wilhelm Illiger in his 1811 work Prodromus Systematis Mammalium et Avium. However, James Rennie, author of The Natural History of Monkeys and Lemurs, pointed out that the placement of five different groups of mammals - monkeys, tarsiers, aye-ayes and marsupials - under a single order did not appear to have a strong justification. In 1816, French zoologist George Cuvier classified all marsupials under the order Marsupialia. In 1997, researcher J. A. W. Kirsch and others accorded infraclass rank to Marsupialia. There are two primary divisions: Australian marsupials. Marsupialia is further divided as follows:† - Extinct Superorder Ameridelphia Order Didelphimorphia Family Didelphidae: opossums Order Paucituberculata Family Caenolestidae: shrew opossums Superorder Australidelphia Order Microbiotheria Family Microbiotheriidae: monito del monte Order †Yalkaparidontia Order Dasyuromorphia Family †Thylacinidae: thylacine Family Dasyuridae: antechinuses, dunnarts, Tasmanian devil, relatives Family Myrmecobiidae: numbat Order Notoryctemorphia Family Notoryctidae: marsupial moles Order Peramelemorphia Family Thylacomyidae: bilbies Family †Chaeropodidae: pig-footed bandicoots Family Peramelidae: bandicoots and allies Order Diprotodontia Suborder Vombatiformes Family Vombatidae: wombats Family Phascolarctidae: koalas Family †Diprotodontidae: Giant wombats Family †Palorchestidae: Marsupial tapirs Family †Thylacoleonidae: marsupial lions Suborder Phalangeriformes Family Acrobatidae: feathertail glider and feather-tailed possum Family Burramyidae: pygmy possums Family †Ektopodontidae: sprite possums Family Petauridae: striped possum, Leadbeater's possum, yellow-bellied glider, sugar glider, mahogany glider, squirrel glider Family Phalangeridae: brushtail possums and cuscuses Family Pseudocheiridae: ringtailed possums and relatives Family Tarsipedidae: honey possum Suborder Macropodiformes Family Macropodidae: kangaroos and relatives Family Potoroidae: potoroos, rat kangaroos, bettongs Family Hypsiprymnodontidae: musky rat-kangaroo Comprising over 300 extant species, several attempts have been made to interpret the phylogenetic relationships among the different marsupial orders.
Studies differ on whether Didelphimorphia or Paucituberculata is the sister group to all other marsupials. Though the order Microbiotheria is found in South America, morphological similarities suggest it is related to Australian marsupials. Molecular analyses in 2010 and 2011 identified Microbiotheria as the sister group to all Australian marsupials. However, the relations among the four Australidelphid orders are not as well understood; the cladogram below, depicting the relationships among the various marsupial orders, is based on a 2015 phylogenetic study. DNA evidence supports a South American origin for marsupials, with Australian marsupials arising from a single Gondwanan migration of marsupials from South America to Australia. There are many small arboreal species in each group; the term "opossum" is used to refer to American species, while similar Australian species are properly called "possums". Marsupials have the typical characteristics of mammals—e.g. Mammary glands, three middle ear bones, true hair.
There are, striking differences as well as a number of anatomical features that separate them from Eutherians. In addition to the front pouch, which contains multiple nipples for the protection and sustenance of their young, marsupials have other common structural features. Ossified patellae are absent in most modern marsupials and epipubic bones are present. Marsupials lack a gross communication between the right and left brain hemispheres; the skull has peculiarities in comparison to placental mammals. In general, the skull is small and tight. Holes are located in the front of the orbit; the cheekbone extends further to the rear. The angular extension of the lower jaw is bent toward the center. Another feature is the hard palate which, in contrast to the placental mammals' foramina, always have more openings. The