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INTRODUCTION

Order Marsupials unites more than 250 species of animals. This order includes peaceful herbivores, such as kangaroos or koalas, and insectivores, such as marsupial moles or nambats, and predators, such as the Tasmanian devil, which can cope with medium-sized kangaroos.

In order to better understand all the specifics and features of the infraclass Marsupials, it is worth considering their classification.

Infraclass Marsupials:

Possum Squad

Squad Small tuberculate

Squad marsupial dormouse

Order Predatory marsupials

Bandicoot Squad

Squad Marsupial moles

Squad Two-Cutters

Infraclass Marsupials are of great interest in the study, which is due to the peculiarities of their reproduction, distribution area and life activity.

1. GENERAL CHARACTERISTICS OF THE ORDER Marsupials

Marsupials, with the exception of American possums, are common on the Australian mainland, New Guinea and nearby islands. About 200 species from 9 families belong to this order. Among the marsupials there are insectivorous, predatory and herbivorous forms. They also differ greatly in size. The length of their body, including the length of the tail, can range from 10 cm (Kimberley marsupial mouse) to 3 m (large gray kangaroo).

Marsupials are more complexly organized animals than monotremes. Their body temperature is higher (on average + 36 °). All marsupials give birth to live young and feed them with milk. However, compared with the higher mammals, they have many ancient, primitive structural features that sharply distinguish them from other animals.

The first characteristic feature of marsupials is the presence of so-called marsupial bones (special bones of the pelvis, which are developed in both females and males). Most marsupials have a pouch for carrying young, but not all have it to the same degree; there are species in which the bag is missing. Most primitive insectivorous marsupials do not have a "finished" bag - a pocket, but only a small fold that limits the milky field. This is the case, for example, with numerous marsupial mice, or mouse species. In the yellow-footed marsupial, one of the most archaic marsupials, there is only a slight uplift of the skin, like a border around the milky field; the fat-tailed marsupial mouse close to it has two lateral folds of skin, which grow somewhat after the birth of cubs; finally, the baby mouse has something that looks like a bag that opens back towards the tail. In kangaroos, the bag of which is more perfect, it opens forward, towards the head, like an apron pocket.

The second characteristic feature of marsupials is the special structure of the lower jaw, the lower (posterior) ends of which are bent inward. The coracoid bone in marsupials is fused with the scapula, as in higher mammals - this distinguishes them from monotremes.

The structure of the dental system is an important classification feature of the order of marsupials. On this basis, the entire detachment is divided into 2 suborders: multi-incisor and two-incisor. The number of incisors is especially large in primitive insectivorous and predatory forms, which have 5 incisors in each half of the jaw at the top and 4 incisors at the bottom. Herbivorous forms, in contrast, have no more than one incisor on each side of the lower jaw; their fangs are absent or underdeveloped, and their molars have blunt tubercles.

The structure of the mammary glands of marsupials is characteristic; they have nipples to which newly born cubs are attached. The mammary ducts open at the edge of the nipples, as in monkeys and humans, and not into an internal reservoir, as in most mammals.

However, the main difference between marsupials and all other mammals is the features of their reproduction. The process of reproduction of marsupials, the observation of which is very difficult, has only recently been fully elucidated.

The cubs in the mother's pouch are at first so small and underdeveloped that the first observers had a question: would they not be born directly in the pouch? F. Pelsart, a Dutch navigator, in 1629 first described a marsupial. He, like many later naturalists, thought that the young of marsupials are born right in the bag, "from the nipples"; according to these ideas, the cub grows on the nipple, like an apple on a tree branch. It seemed incredible that a half-formed embryo, hanging inertly on the nipple, could climb into the pouch on its own if it was born outside of it. However, already in 1806, the zoologist Barton, who studied the North American opossum, found that the newborn can move around the mother's body, get into the bag and attach to the nipple. For Australian animals this was confirmed in 1830 by the surgeon Colley. Despite these observations, the famous English anatomist R. Owen in 1833 returned to the already expressed idea that the mother carries the newborn into the bag. According to Owen, she takes the cub with her lips and, holding the opening of the bag with her paws, puts it inside. The authority of Owen for more than half a century fixed this incorrect point of view in science.

The embryo in marsupials begins to develop in the uterus. However, it is almost not connected with the walls of the uterus and to a large extent is only a “yolk sac”, the contents of which are quickly depleted. Long before the embryo is fully formed, it has nothing to eat, and its "premature" birth becomes a necessity. The duration of pregnancy is very short, especially in primitive forms (for example, in opossums or marsupial cats from 8 to 14 days, in koalas it reaches 35, and in kangaroos - 38-40 days).

The newborn is very small. Its dimensions do not exceed 25 mm in a large gray kangaroo - the largest representative of the detachment; in primitive insectivores and predators, it is even smaller - about 7 mm. The weight of the newborn is from 0.6 to 5.5 g.

The degree of development of the embryo at the time of birth is somewhat different, but usually the cub is almost devoid of hair. The hind limbs are poorly developed, bent and closed by the tail. On the contrary, the mouth is wide open, and the front legs are well developed, claws are clearly visible on them. The forelimbs and mouth are the first organs that a newborn marsupial will need.

No matter how underdeveloped the marsupial cub may be, it cannot be said that it is weak and lacks energy. If you separate him from his mother, he can live for about two days.

Kangaroo rats and some possums have only one baby; koalas and bandicoots sometimes have twins. Most insectivorous and predatory marsupials have much more babies: 6-8 and even up to 24. Usually the number of babies corresponds to the number of mother's nipples to which they must attach. But often there are more cubs, for example, in marsupial cats, in which there are only three pairs of nipples for 24 cubs. In this case, only the first 6 cubs attached can survive. There are also opposite cases: in some bandicoots, which have 4 pairs of nipples, the number of cubs does not exceed one or two.

To attach to the nipple, the newborn must enter the mother's pouch, where protection, warmth, and food await. How does this movement take place? Let's trace it on the example of a kangaroo.

A newborn kangaroo, blind and underdeveloped, very soon chooses the right direction and begins to crawl straight to the bag. It moves with the help of front paws with claws, wriggling like a worm, and turning its head around. The space in which he crawls is covered with wool; this, on the one hand, hinders him, but, on the other hand, helps: he clings tightly to the wool, and it is very difficult to shake him off. Sometimes the calf errs in direction: it crawls up to the mother's thigh or breast and turns back, searching until it finds a pouch, searching ceaselessly and indefatigably. Finding the bag, he immediately climbs inside, finds the nipple and attaches to it. Between the moment of birth and the time when the cub is attached to the nipple, in large kangaroos, it usually takes from 5 to 30 minutes. Attached to the nipple, the cub loses all its energy; he again for a long time becomes an inert, helpless fetus.

What does the mother do while her cub is looking for a bag? Does she help him in this difficult moment? Observations on this are still incomplete, and opinions are rather contradictory. During the time it takes for the newborn to reach the pouch, the mother takes a position and does not move. Kangaroos usually sit on the tail passing between the hind legs and pointing forward, or lying on their side. The mother holds her head as if she is watching the cub all the time. Often she licks it - immediately after birth or during the movement to the bag. Sometimes she licks her hair towards the bag, as if helping the cub to move in the right direction.

If the cub gets lost and cannot find the bag for a long time, the mother begins to worry, scratch and fidget, while she can injure and even kill the cub. In general, the mother is more of a witness to the energetic activity of the newborn than his assistant.

Initially, the nipple has an elongated shape. When a cub is attached to it, a thickening develops at its end, apparently associated with the release of milk; this helps the baby stay on the nipple, which he squeezes with his mouth all the time. It is very difficult to separate it from the nipple without tearing its mouth or damaging the glands.

The baby passively receives milk, the amount of which is regulated by the mother with the help of contractions of the muscles of the milky field. For example, in a koala, the mother supplies the cub with milk for 5 minutes every 2 hours. So that he does not choke on this stream of milk, there is a special arrangement of the respiratory tract: air passes directly from the nostrils to the lungs, since the palatine bones at this time have not yet been fully formed, and the epiglottic cartilage continues forward to the nasal cavity.

Protected and supplied with food, the cub grows rapidly. The hind legs develop, usually becoming longer than the front ones; the eyes open, and after a few weeks the immobility is replaced by conscious activity.

The baby begins to break away from the nipple and stick its head out of the bag. The first time he wants to get out, he is not allowed to go by his mother, who can control the size of the outlet of the bag. Different types of marsupials spend a different period in the bag - from several weeks to several months. The stay of the cub in the bag ends as soon as it becomes able to feed not on milk, but on other food.

The mother usually looks for a nest or a lair in advance, where the children live under her supervision for the first time.

2. BRIEF CHARACTERISTICS OF THE FAMILIES

marsupial herbivore insectivorous predator

Opossum (Didelphidae) is the largest family of marsupials. It includes the most ancient and least specialized marsupials, which appeared at the end of the Cretaceous and have not changed much since then. All living representatives of the possum family inhabit the New World. Most of the marsupials of South America became extinct after the emergence of a natural bridge between South and North America, through which new species began to penetrate from north to south. Only opossums were able to endure competition and even spread north.

The sizes of possums are small: body length 7-50 cm, tail 4-55 cm. The muzzle is elongated and pointed. The tail is entirely or only at the end naked, prehensile, sometimes thickened at the base with deposits of fat. The body is covered with short, dense fur, the color of which varies from gray and yellowish-brown to black. The structure of the dental system, limbs, bag testifies to the primitiveness of opossums. Their limbs are shortened, five-fingered; thumb the hind limb is opposed to the rest of the fingers and is devoid of a claw. The hind legs are usually more developed than the front ones. Opossums are inhabitants of forests, steppes and semi-deserts; found both on the plains and in the mountains up to 4000 m above sea level. Most lead a terrestrial or arboreal lifestyle, the water opossum is semi-aquatic. Active at dusk and at night. Omnivorous or insectivorous. Outside of the mating season, they lead a solitary lifestyle. Pregnancy lasts 12-13 days, in a litter up to 18-25 cubs.

Some opossums carry their young in a pouch, but most do not. Grown up cubs travel with their mother, holding on to the hair on her back. Sexual maturity occurs at 6-8 months of age; life expectancy 5-8 years.

Kangaroos (Macropodidae) are a family of marsupial mammals. This is the second largest family of marsupials (after the American opossums) and includes herbivores adapted to locomotion in leaps.

It includes animals of medium and large size - wallaby, wallaroo and kangaroo. Adult animals have a body length of 30 to 160 cm; weigh from 0.5 to 90 kg. The head is relatively small, the ears are large. In all genera, with the exception of tree wallabies (Dendrolagus) and philanderers (Thylogale), the hind legs are noticeably larger and stronger than the front ones. The front paws are small and have 5 fingers; rear - 4 each (the thumb is usually atrophied). Like other two-crested marsupials, the second and third toes on the hind legs of the kangaroo grow together. The limbs are plantigrade. Most species move by hopping on their hind legs. The length of the jump reaches 10-12 m; at the same time, kangaroos develop speeds of up to 40 - 50 km / h, however, for a short time. An important role in the kangaroo jump is played by the elastic Achilles tendons, which act like springs during the running jump. The tail of a kangaroo is usually long, thick at the base, not grasping. During the jump, it serves as a balancer, and in a calm state it is used as an additional support. Kangaroos usually keep themselves "standing", leaning on their hind legs and tail. It is curious that kangaroos do not know how to move backwards (which is why the kangaroo and emu, also unable to move backwards, got on the coat of arms of Australia: "Australia always goes only forward!").

The coat of kangaroos is usually short and soft, coloring from black, gray and brown to red and yellow. There may be stripes on the back and sacrum. The teeth are adapted to eating plant foods - wide incisors, small fangs and a diastema in front of large premolars; teeth 32-34. Wide molars erupt in pairs and change as the next pair wears out. Most kangaroos have 4 pairs of molars, and when the last pair wears off, the animal begins to starve. The stomach is complex, divided into compartments, where plant fiber is fermented under the influence of bacteria. Some species regurgitate food into the mouth for re-chewing. A well-developed brood pouch opens forward. Of the 4 nipples in females, only two usually function.

Kangaroos are found in Australia, Tasmania, New Guinea and the Bismarck Archipelago. Imported to New Zealand. Most species are terrestrial, living on plains overgrown with dense tall grass and shrubs. Tree kangaroos have adapted to climbing trees; mountain wallabies (Petrogale) live in rocky places. Kangaroos are predominantly nocturnal and twilight animals; the day is spent in grass nests or in shallow burrows. They usually keep in small groups, consisting of a male and several females with their growing cubs.

Kangaroos breed once a year; They do not have a specific breeding season. Pregnancy is short - 27-40 days. 1-2 cubs are born; in Macropus rufus - up to 3. In giant kangaroos, the body length of a newborn is about 25 mm - this is the smallest cub among mammals compared to an adult animal. The female bears offspring in a bag for 6-8 months. Many kangaroos experience a delay in embryo implantation. A new mating takes place 1-2 days after the birth of the cub (in the marsh wallaby, the day before the birth of the cub). After that, the embryo remains in a state of diapause until the previous cub grows or dies. From this moment, the embryo begins to develop. Under favorable conditions, a new cub is born as soon as the older one finally leaves the pouch. The life expectancy of large kangaroos exceeds 12 years.

The number of kangaroos varies depending on the species. Many species are intensively exterminated, some have become extinct; they are hunted for their fur as well as meat. With a large number of kangaroos, they can harm pastures; some species destroy agricultural crops. Kangaroos are caught for zoos, where they are easily tamed and breed well; some species are farmed.

Koalas are tree-moving, herbivorous marsupials native to Australia. The only representative of the Koal family is the koala.

In general, koalas are similar to wombats (their closest living relatives), but have thicker fur (soft and 2-3 cm thick), larger ears, and longer limbs. The koala has large sharp claws that help it with walking on tree trunks. The weight of a koala varies from about 14 kg of a large male from the south, to about 5 kg of a small female from the north.

The limbs of the koala are adapted for climbing. The hand of the front paw has 2 set aside "thumbs" fingers (in English: "thumbs"), having two phalanges that oppose the other three ordinary fingers (English: "fingers"), with three phalanges located along the brush. Calling the second finger of the koala index is not entirely correct, because it looks the same as the first, that is, the "thumb" finger. All fingers of the front paws end with strong claws. All this allows the animal to effectively grab the branches of trees, locking the hand into a secure lock, and the young koala to cling tenaciously to its mother's fur. At the same time, we recall that the koala sleeps in this position, and on occasion it can hang on one paw.

As for the hind limbs, there is only one "thumb" toe on the foot, and it is without a claw, and four ordinary ones, ending with claws. While the second, that is forefinger in the area of ​​the 1st and 2nd phalanges, it is fused with soft tissues with the middle toe of the foot.

Koalas are one of the few mammals, with the exception of primates, that have a papillary pattern on their fingertips. Koala fingerprints are similar to human fingerprints and are difficult to distinguish even with an electron microscope.

The teeth of the koala are adapted to the herbivorous diet of koalas and are similar to the teeth of other two-crested marsupials, such as the teeth of kangaroos and wombats. They have sharp incisors to cut leaves right at the front of their mouths.

Koalas inhabit eucalyptus forests, spending almost their entire lives in the crowns of these trees. During the day, the koala sleeps, sitting on a branch or in the forks of branches; climbs trees at night looking for food. Even if the koala does not sleep, he usually sits completely still for hours, clasping a branch or tree trunk with his front paws. Koala is immobile 16-18 hours a day. He descends to the ground only to go to a new tree, to which he cannot jump. Koalas jump from tree to tree with surprising deftness and confidence; when fleeing, these usually slow and phlegmatic animals break into a vigorous gallop and quickly climb the nearest tree. They know how to swim.

Female koalas lead a solitary life and stick to their territories, which they rarely leave. In fertile areas, the areas of individual individuals often overlap each other. Males are not territorial, but even less sociable - when they meet, especially during the breeding season, they often attack each other, causing injury.

Only during the breeding season, which lasts from October to February, koalas gather in groups consisting of an adult male and several females. At this time, males often rub their chest against the trees, leaving odorous marks, and emit loud calling cries, sometimes heard from a kilometer away. Since fewer males are born than females, harems of 2-5 females gather around male koalas during the mating season. Mating takes place on a tree (optionally a eucalyptus).

Pregnancy lasts 30-35 days. There is only one cub in the litter, which at birth has a length of only 15-18 mm and a weight of about 5.5 g; occasionally twins. The cub stays in the bag for 6 months, feeding on milk, and then for another six months it "travels" on the mother's back or stomach, clinging to her fur. At 30 weeks of age, he begins to eat semi-liquid mother's excrement, consisting of a kind of slurry of semi-digested eucalyptus leaves, - in this way, microorganisms necessary for the digestive process enter the digestive tract of young koalas. The mother excretes this slurry for about a month. At the age of one year, the cubs become independent - young females at the age of 12-18 months go in search of sites, but males often stay with their mothers until 2-3 years.

Koalas breed once every 1-2 years. Sexual maturity in females occurs at 2-3 years, in males at 3-4 years. On average, a koala lives 12-13 years, although there are cases when they lived to the age of 20.

Wommbats (Vombatidae) are a family of two-bladed marsupials native to Australia. Wombats are burrowing herbivores that look like small bears.

Wombats reach a length of 70 to 120 cm and a weight of 20 to 45 kg. Their body is compact, limbs are short and strong. Each of them has five fingers, of which the outer four are crowned with large claws adapted for digging the earth. The tail is short, the large head gives the impression of being slightly flattened laterally, the eyes are small.

Wombats live in southern and eastern Australia, in the states of South Australia, Victoria, New South Wales, Queensland and Tasmania. They are distributed in a variety of habitats, but require suitable soil for burrowing.

Wombats are the largest of modern mammals, engaged in digging and spending most of their lives underground. With their sharp claws, they tear out small habitable caves in the ground, which sometimes form complex tunnel systems. As a rule, most of them reach about 20 meters in length and 3.5 meters in depth. If the sites of individual individuals overlap, the caves may be used by different wombats at different times. Wombats are active at night when they come out in search of food. During the day they rest in their shelters.

Wombats eat young grass shoots. Sometimes plant roots, mosses, mushrooms and berries are also eaten.

Divided upper lip allows wombats to choose what they eat very precisely. Thanks to her, the front teeth can reach right to the ground and cut off even the smallest shoots. important role in food selection active at night wombats plays the sense of smell

Wombats breed throughout the year except in arid regions where their breeding is more seasonal. The bags of the females are turned back so that when digging, the earth does not get into them. Despite the fact that the female has two nipples, only one cub is born and raised at the same time. The offspring grows in the mother's pouch for six to eight months and stays nearby for the next year.

Wombats reach sexual maturity at the age of two years. Their life expectancy in nature reaches 15 years, in captivity they sometimes live up to 25.

CONCLUSIONS

After all of the above, certain conclusions can be drawn about the Marsupial Order. These animals are unique and have their pluses and minuses in the organization of the internal structure, in ensuring reproduction. Also, these animals are notable for their narrow habitat.

That is, we found out that the group of marsupial mammals includes animals such as kangaroos, koalas and opossums. They live only in Australia, New Guinea and North and South America. Females of most species have a special bag on their abdomen, in which they carry, protecting from adverse external conditions, their cubs until they are strong enough.

Baby marsupials are born tiny and underdeveloped. In some species, they are no larger than a grain of rice. However, they have strong forelimbs and tenacious claws, with which they crawl, clinging to the wool on the mother's abdomen, into a special bag. In the depths of it, they find the nipple and cling tightly to it. Cubs of marsupials develop very slowly.

They live mainly in Australia, New Guinea and South America. This is explained by the fact that South America and Australia have been island continents for the last 100 million years. When they separated from the rest of the continents, in Australia there were practically only marsupials, and in South America there were also several species of marsupial mammals. On both continents, marsupials have evolved to form a wide variety of species. When South America joined North America about 10 million years ago, most of the South American marsupials died out as they became the prey of more adaptable mammals that came from the north.

Kangaroos living in Australia and New Guinea, and their smaller relatives, wallabies and kangaroo rats, have strong hind legs. When animals are not in a hurry, they walk slowly on all fours. If it is necessary to move at a higher speed, they begin to jump on their hind legs. Large kangaroos can cover a distance of 10 m in one jump. These are herbivorous animals that are active mainly at twilight and at night.

Several small kangaroo species are threatened with extinction from the face of the Earth.

Koalas spend their lives among eucalyptus trees in the forests of eastern Australia. They feed exclusively on young leaves and shoots of eucalyptus trees. Usually animals sleep about 18 hours a day. In the past, they were hunted for their fur, but they are currently protected by law.

Australian wombats live on the surface of the earth and in burrows dug by them. Several animals can live in one hole at once, although each of them usually has several underground dwellings of its own. They are active at night - at this time of day they go out to feed on grass and plant roots.

Opossums are inhabitants of South and North America. The females of most species carry their young between two special folds of skin on their abdomens. Other species have pouches, while others do not have such special devices at all. Opossums live mainly in forests, and their characteristic feature is considered to be a bare, hairless tail, with which they cling to branches. The basis of their diet is small animals, mainly insects.

BIBLIOGRAPHY

1. Laboratory classes in zoology with the basics of ecology: Textbook for students of higher pedagogical educational institutions. Series: Higher education: Stepanyan E.N., Aleksakhina E.M. -- St. Petersburg, 2001 - 120 p.

2. Laboratory workshop on vertebrate zoology: - Moscow, Academy, 2004 - 272 p.

3. Naumov N.G. Vertebrate zoology: A textbook for students of ped. inst. according to biol. specialty.- 4th edition., revised.-M.: Education.1982.- 464 p., ill., 6 sheets. ill.

4. http://megaznanie.ru

5. http://www.floranimal.ru

6. http://www.zooeco.com

7. http://zooschool.ru

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Marsupials are a subclass of mammals, uniting, it would seem, animals that are completely different in appearance and habits. In this motley company there are predators and vegetarians, insectivorous and omnivorous animals, and even scavengers. Some are active during the day, others at night. Some live in trees, others live near water or underground.

Among them there are runners, jumpers, steeplejacks, diggers and even flyers. There are little ones no larger than a mouse, and there are giants the size of a man. About 280 species of marsupials living on the planet belong to various families, the most famous of which are kangaroos, bandicoots, American possums, carnivorous marsupials and possums.

Marsupials live mainly in Australia, New Guinea, Tasmania and New Zealand. In both Americas marsupial opossums are found. Marsupials are not related to placental mammals, but among them there are analogues of ordinary, marmots, wolves and foxes.

Marsupials - structural features

Before us is a vivid example of the convergence of forms, due to adaptation to similar conditions. There are quite a few primitive features in the structure of marsupials.

Their cerebral cortex is poorly developed, but their olfactory lobes are excellent. They are covered with thick hair, and numerous subcutaneous glands produce powdered substances and dyes. Low body temperature fluctuates depending on the temperature of the external environment.

Their teeth immediately grow permanent - up to 40 or more in number, and the virginian opossum hisses, splashing with saliva, fifty sharp teeth at the sight of danger. The emergence of similar forms in remote regions of the planet in the presence of similar external conditions. The Latin name for marsupials comes from "bag".

The brood pouch is formed by a special skin fold on the abdomen. Some species do not have a pouch, but all have abdominal support bones in their pelvic girdle that sharply distinguish marsupials from other mammals. In addition, female marsupials have a double vagina, and often a double uterus, and males of many species have a dilobed penis.

The placenta in marsupials is not formed - in rare cases, only its rudiment. After a short pregnancy, underdeveloped cubs ranging in size from 5 mm to 3 cm are born - tiny pink bodies covered with transparent skin with clawed front paws and a tail.

The newborn has a difficult and dangerous journey into the mother's pouch. Clinging to the mother's fur with claws, he crawls along the wet "path", which the female licks with her tongue. Having fallen down, the baby inevitably dies, so the female always has several reserve embryos in reserve.

In small species, several cubs are placed in one bag at once, which spend 6-8 months in it, hanging on their mother's nipples. A special subcutaneous muscle of the female compresses the mammary glands, and milk is injected directly into the baby's mouth.

marsupials - kunguru

Kangaroos living only in Australia belong to the “big-footed” family, which unites more than 50 species in a dozen and a half genera. Among them there are 30-centimeter dwarfs, and real giants. Recognized giants among marsupials are a large gray and a large red kangaroo. The growth of males of the latter species reaches 2 meters.

A long massive tail serves as a support for the kangaroo, supporting the body in an upright position, and on the run it acts as a counterweight - in a word, it acts like a third leg. Long muscular hind legs, like springs, allow the beast to jump 3 meters in height and up to 12 meters in length.

Kangaroo jumping is an extremely picturesque sight. Powerfully pushing off with its hind legs, the animal stretches into line and seems to hang in flight above the ground, and at the moment of landing it sharply flaps its tail up. Having accelerated well, the kangaroo speeds up to 40 km per hour.

Being staunch vegetarians, kangaroos are not averse to eating insects or larvae on occasion. They feed at night, keeping in small groups, consisting of one male father and several females with cubs. The male usually performs the functions of a watchman, vigilantly looking around the surroundings.

In this he is assisted by keen eyesight and sense of smell. Kangaroos willingly eat grass, alfalfa and clover, but most of all they like a plant with hard, sharp leaves that grows in the Australian semi-deserts. A full stomach makes up 15% of an animal's body weight. Its walls secrete a special secret in which bacteria that break down cellulose live.

Coarse pasture with a high content of silicon leads to rapid abrasion of molars, and during the life of a red kangaroo they are replaced 4 times.

During the day, kangaroos rest and comb out, breathing like a dog with their tongue hanging out. Fleeing from the heat, animals lick their front paws, chest and hind legs, and saliva, evaporating, cools the overheated body. As befits the inhabitants of semi-deserts, kangaroos can do without a watering place for several weeks, and thick fur serves as excellent thermal insulation in summer and winter.

Due to its dull color, it weakly absorbs solar energy, saving the animal from the heat. Peace-loving by nature, a kangaroo may well fend for itself. He fights off wild dingo dogs with deadly blows of his hind legs, leaning his back against a tree, and if there is a lake nearby, he runs headlong into the water and tries to drown the pressing enemies.

Males differ from females not only in size, but also in color, and during the rutting season, some put on a bright marriage outfit. So, the male red kangaroo becomes fiery red, the female retains a grayish-blue fur coat. Males have a strict hierarchy. Only the largest and strongest male gets the right to mate with females. Having started a mating match, the rivals box or kick as much as they can.

Kangaroo breeding is adapted to the annual alternation of dry and rainy seasons. After the birth of the cub, another fertilized egg descends into the uterus of the female, but its development begins only with the advent of the next rainy season. Meanwhile, a few months old kangaroo is safely sitting in the bag.

It happens that a grown-up cub is sitting in a mother’s bag, a newborn baby is hanging on the next nipple, and a fertilized egg in the uterus is just waiting for the older offspring to make room.

marsupials - koala

Only the smallest species of koala has survived to this day. In addition to appearance, this beast has nothing to do with bears. Belonging to the possum family, the koala lives on trees, eating eucalyptus leaves, and occasionally acacia. He can do without water for a long time, being content with the moisture contained in the leaves.

An adult koala weighing up to 10 kg eats 0.5 kg of greenery per night. Thanks to strong hind legs and an excellent sense of balance, he climbs trees well. The lack of a tail is compensated by wide grasping fingers and strong claws, and rough soles provide traction with smooth bark.

Koala is a nocturnal animal, so his eyesight is poor, but his sense of smell and hearing are well developed. He prefers to live in solitude, and the meeting of two males on the same tree inevitably ends in a fight - the opponents growl menacingly, bite and beat each other.

Females mark their territory with feces, and males leave claw marks and odorous marks secreted by the mammary gland on the bark. Mating takes place on a tree in an upright position. The female brings one cub a year, which weighs only 5 grams and must move into the mother's pouch on its own. By the way, it opens down, not up, like most marsupials. Thanks to this, the baby gets access to the semi-digested slurry of eucalyptus leaves, which is excreted with the mother's feces and serves as complementary foods for milk.

marsupials - possum

More than 40 species of tree marsupials belong to the possum family. In the tree bear kangaroo, unlike its terrestrial relatives, the fore and hind limbs are the same length, the feet are short and wide, and the claws look like long hooks. All these devices allow him to make 10-meter jumps from branch to branch.

The ring-tailed possum wraps its long tenacious tail around the branches for greater reliability, and the yellow-bellied flying squirrel gracefully glides from tree to tree, flying about 50 m. Skin folds between the wrists and knee joints serve as a glider. The largest representative of this family is a large flying possum, which can fly up to 100 meters.

Marsupials - flying squirrel

The only representative of the marsupial mole family lives in sandy deserts. His muzzle is protected by a strong keratinized shield, there are no auricles, and he is completely blind. His paws are very short, the front fingers are partially fused, and the 3rd and 4th fingers are armed with long digging claws. The animal makes its way with its nasal shield, and rakes the sand with its hind legs.

The marsupial anteater or nambat from the anteater family is similar to its South American counterpart with an elongated head with a narrow stigma and a thin long tongue with which it collects ants and termites. Unlike most marsupials, this animal is diurnal and does not have a pouch.

The cubs just hang on the nipples, and the mother drags them everywhere on her. In terms of the number of teeth, only some whales and armadillos can be compared with the nambat. Marsupial flying squirrel - aka feather-tailed acrobat - is the smallest animal of all marsupials. The length of her body with a tail does not exceed 14.5 cm. She looks like an ordinary mouse, with the only difference being that she can fly. The flying membrane of a sitting animal is folded in neat folds. The Tasmanian wombat is busy burrowing every day.

marsupials - the devil

Cubs master this science by digging side tunnels directly from the mother's dwelling. American opossums, with their pointed snouts and hairless tails, are very similar to rats. Bags in most species are absent.

The Tasmanian devil is a marsupial predator no larger than a fox terrier, wears a black fur coat and is very ferocious. He hunts for a variety of game - invertebrates, fish, mammals, reptiles and does not disdain carrion. But in captivity, the animal is very affectionate and flexible. Currently preserved only on the island of Tasmania.

Here is an essay about marsupials and their structure.

Australia is home to most of the world's marsupials. The geographical and climatic features, as well as the remote location from other continents, made this country an ideal place for the accumulation of 200 thousand species of animals. Moreover, most of these animals are completely unique, since they cannot be found on any other continent.

Of course, the most popular animals in Australia are marsupials such as kangaroo, koala, wombat and many others. To understand how interesting and unique these animals are, you should get to know them better and consider their features.

Remembering Australia, a rare person does not imagine kangaroo. It is here that they can be found in huge numbers, and various kinds. On this "marsupial" continent, there are about 55 species of famous jumping animals. Adult kangaroos can weigh up to 70 kilograms. Despite this fact, they can develop great speed when they move by jumping.

Characteristic features for kangaroos:

1. Elongated large ears and a rather small muzzle.
2. A very muscular tail that acts as a rudder when moving by jumping.
3. Short front legs with well-developed motor skills.
4. Strong and massive hind legs.

It is worth noting that kangaroos, despite their high growth and heavy weight, are born weighing only one gram and having a height of up to one centimeter. The female bears offspring for about a month, and carries a newborn kangaroo in a bag from 6 to 8 months. All this time, the baby feeds on mother's milk, gradually becoming more resilient and stronger. After some time, a small kangaroo may briefly crawl out of the mother's pouch, and then leave her forever.

In Australia, not only such interesting animals as Kangaroos live. Here you can meet a funny marsupial animal, which is also called a bear. This charming Wombat can reach a length of up to one meter and weigh about 45 kilograms. Tourists who come to Australia have great sympathy for this attractive animal, as it is very good-natured and clumsy.

Wombats eat only plant foods. In conditions wildlife the animal’s home is a hole dug by him up to 40 meters long. The body of the wombat is very compact, and its limbs are strong and short. He has very strong claws on his fingers so that he can dig a hole for himself. The wombat has a short tail and a large head with small eyes. This "bear" is good at contact with people. In Australia, this marsupial is a pet and is kept at home as well as cats and dogs in Russia.

In second place in popularity among marsupials in Australia is koala, following right behind the kangaroo. This animal strongly resembles a small bear. He has a very soft and thick coat. Despite their outward clumsiness, koalas move through trees with extraordinary ease thanks to their strong and sharp claws. The main diet of these marsupials is eucalyptus leaves, so they rarely move, preferring to rest on tree branches. Koalas can sleep 17-22 hours a day, and when they are awake, they are mostly in one place. Thus, they conserve their energy. It should be noted that the metabolism of koalas is very slow and its rate is almost two times lower than that of other mammals. Koalas live in the south and east of Australia, as these areas have a sufficient amount of moisture. By the way, eucalyptus leaves contain toxic substances, but the liver of this animal has long adapted to this.

A rather scary inhabitant of Australia is the marsupial tasmanian devil. This name was given to the animal thanks to the first inhabitants of this continent. The fact is that people were very frightened by his nightly cries, violent temper and sharp fangs, so they gave him such a name. The marsupial animal has a dark color and a squat dense body. It can be compared with a small bear or dog, as it is very similar to these animals. Now the Tasmanian devil lives mainly on the island of Tasmania. It is believed that they were driven out of Australia by the indigo dogs brought to the mainland. In general, this animal is an excellent cleaner of savannahs and local forests. It feeds on carrion, which in turn prevents the appearance of larvae in it that could infect other animals, as well as entire pastures of sheep and cows.

Another popular marsupial animal in Australia is, which lives mainly on the east coast. This mammal can reach a length of 30-60 centimeters. It lives in trees and feeds on berries and leaves of trees and plants. The main activity of this animal occurs at night. Fox kuzu has a rather funny appearance and attracts a lot of attention from tourists and locals. Its main enemies are monitor lizards and birds of prey.

One of Australia's rarest marsupial carnivores is the thylacine, which is otherwise called. His character and habits are practically unknown to man, since it is extremely difficult to study him. At the beginning of the 20th century, he lived only on the island of Tasmania, but in the 40s he was exterminated by man, as he stole pets. Some residents claim to have seen a marsupial at the present time. But this information has not yet been supported by facts.

The order of marsupials also includes opossums which are loved by both adults and children. These animals have a rather funny appearance, as their faces are sharp and light, and their tail is almost naked and very long. When opossums sense danger, they climb onto their mother's back, clinging to the fur with their claws. This animal prefers to eat mushrooms, mice, amphibians and cultivated plants such as cereals and corn. Such a love for cultivated plants greatly harms the gardens and fields of local residents.

Marsupials are a very large group of mammals. They differ from other animals in a special way of reproduction and anatomy. These animals are common not only in Australia, but also in New Guinea, North and South America. But still, in Australia there are a lot of completely unique species of marsupials that cannot be found on any continent of the earth. It was here that marsupials found their home, from peaceful to aggressive species. For this reason, thousands of tourists come to Australia every year to meet unusual and unique animals.

Marsupials ( Marsupialia) are a group (infraclass) of mammals. Like most other mammalian species, they give birth to live young, but only at an early stage of development. In some species, such as bandicoots ( Peramelemorphia), the gestation period is as short as 12 days. Newborn baby marsupials crawl over the mother's body into a bag located on her stomach. Once inside the pouch, the baby attaches itself to the mother's nipple and feeds on milk until it is large enough to live in the outside world.

While large marsupials tend to give birth to a single young, smaller species are more likely to produce large litters.

Marsupials were common in many areas during and outnumbered placental mammals. Today, the only living marsupial in North America is the opossum.

Marsupials first appear in the record from during the Late Paleocene. They later appear in the fossil record from during the Oligocene, where they diversified during the early Miocene. The first large marsupials appeared during the Pliocene.

Distribution map of modern marsupials/Wikipedia

Today, marsupials remain one of the dominant mammal groups in South America and Australia. In Australia, the lack of competition has led marsupials to be able to diversify and specialize. Today the continent is inhabited by insectivorous marsupials, carnivorous marsupials, and herbivorous marsupials. Most South American marsupial species are small and arboreal.

The reproductive tract of female marsupials differs from placental mammals. They have two vaginas and two uteri, while placental mammals have one uterus and one vagina. Distinctive features Male marsupials also have genital organs - they have a bifurcated penis. The brain of marsupials is also unique, it is smaller than that of placental mammals, there is no corpus callosum and nerve pathways that connect the two hemispheres of the brain.

Marsupials are very diverse in appearance. Many species have long hind legs and elongated snouts. The smallest species of marsupial is the northern marsupial, while the largest is the red kangaroo. To date, there are about 334 species of marsupial mammals, of which 70% of the species are found on the Australian continent (including Tasmania, New Guinea and nearby islands). The remaining 100 species are found in the Americas - mostly in South America, thirteen in Central America and one in North America, north of Mexico.

Classification

Marsupials are classified in the following taxonomic hierarchy:

⇒ ⇒ ⇒ ⇒ ⇒ ⇒ Marsupials

Marsupials are divided into two modern superorders and seven orders:

• Superorder American marsupials ( Ameridelphia) - there are about 100 species of marsupials living today. American marsupials are the older of the two contemporary bands, which means that the members of this group migrated to Australia and diversified. Superorder Ameridelphia subdivided into the following two divisions:
  • Possum Squad ( Didelphimorphia);
  • Caenoleste detachment ( Paucituberculata).

• Superorder Australian marsupials ( Australidelphia) - there are more than 200 species of Australian marsupials living today. Members of this group include Tasmanian devils, marsupial anteaters, bandicoots, wombats, marsupial moles, pygmy opossums, koalas, kangaroos, wallabies, and many other species. Australian marsupials are divided into five orders:
  • Detachment Microbiota ( Microbiotheria), found in South America;
  • Squad Marsupial moles ( Notoryctemorphia);
  • Order Predatory marsupials ( Dasyuromorphia);
  • Bandicoot Squad ( Peramelemorphia);
  • Detachment Dicissus marsupials ( Diprotodontia), includes most of the modern marsupial species.

marsupials animals are mammals that give birth to premature offspring. Cubs of marsupials are born at an early stage of development and further develop inside a special skin bag of the mother. Most marsupials, with the exception of opossums, are native to the Americas. For millions of years Australia has been isolated from the rest of the world. On other continents, marsupials have given way to placental animals (mammals whose young are fully developed in the womb) in the struggle for food and living space. Therefore, all of them, with the exception of, died out. But in Australia, marsupials had no rivals. A number of marsupials has more than 250 species.

Cubs of marsupials, being born, have tiny sizes; they are blind and hairless. Their limbs are underdeveloped, but the babies crawl along the mother's coat to her nipples. After a few months, the cubs leave the bag, but can return to it for the night until they reach the age of one. Marsupials eat plant and animal food.

Predatory marsupials‒ a range of small carnivorous marsupials, which include spotted marsupial martens, narrow-footed marsupial mice, nambat and Tasmanian devil.

Nambat

Nambat It is a marsupial with stripes on its back, dark stripes around the eyes, and a bushy tail (also known as the striped anteater). Termites form the basis of the nambat diet.

Spotted marsupial marten

Spotted marsupial marten also known as marsupial cat. They have a pink nose and white spots on their backs. In females, the bag is formed only during the mating season.

Tasmanian devil

- the most terrible predator of the whole family; lives on the Australian island of Tasmania. This is a squat animal with dark hair and white spots on the chest. It feeds mainly on carrion, but can also prey on small animals.

marsupial mole

marsupial mole- a marsupial animal, very similar to ordinary moles in appearance and habits. These creatures dig underground, preying on insects and worms. Females have pouches that open backwards and only have two nipples (meaning they can only give birth to two babies at a time).

Two-crested marsupials- a number of marsupials, which include kangaroos, wallabies, possums, koalas and wombats. They have two large front teeth in the lower jaw. The second and third toes of the hind paws of these animals are fused. They predominantly herbivores.

honey badger possum

honey badger possum- a small animal with a long tail and a very elongated muzzle, adapted to search for nectar and pollen in flowers. It is one of the few mammals that feed on nectar.

Koala

Lives in trees and feeds on leaves and shoots of eucalyptus; has a big nose and ears. With the help of tenacious paws, koalas deftly climb trees, while cubs hold on to their mother's back. Inhabits the eucalyptus forests of the southern and southeastern regions of Australia. A solitary animal, but the territorial ranges of males and females may overlap.

wallaby

wallaby- a small animal with thicker hair than its relative - a kangaroo; lives in rocky deserts, meadows and forests.

Wombat

It has a short tail and small paws. Wombats are wonderful diggers, they live in underground burrows. The females' pouches open backwards, protecting them from soil getting inside.

Kangaroo

Kangaroo live in Australia, Tasmania, New Guinea and the Bismarck archipelago. They live in groups (herds) on open grassy plains. Today there are about 50 different types. Kangaroo moves by jumping on long hind legs. All of them have fairly short forelimbs and strong hind limbs, and also - almost all species - a long powerful tail, which can reach a meter in length and serves as a balancer and additional support for the kangaroo. Females have a pouch on their abdomen in which the young develop. Kangaroo pregnancy lasts only 30-40 days. A baby is born the size of a human thumb. After that, it immediately moves into the mother's bag and firmly sticks to one of the nipples. The little kangaroo gets out for the first time only after a few months.

Some interesting facts about marsupials

The body sizes of marsupials range from a few centimeters to 1.5 meters. The smallest marsupial animal on Earth is the long-tailed marsupial mouse. The length of her body is from 80 to 100 mm, tail - from 180 to 210 mm. The largest marsupial animal is considered a large red kangaroo. Adult kangaroos can reach 2 m in height. A baby giant kangaroo stays in its mother's pouch for about 235 days.

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