What does monotreme mean? Characteristics of the order monotreme oviparous (Monotremata)

• Class: Mammalia Linnaeus, 1758 = Mammals
• Infraclass: Prototheria = Cloacal, primal beast, oviparous
• Order Monotremata Bo
• Family: Ornithorhynchidae Burnett, 1830 = Platypuses
• Family: Tachyglossidae Gill, 1872 = Echidnovidae

Order Monotremata Bo naparte, 1838 = Monotreme oviparous

A small group of the most primitive living mammals. Female monotremes lay 1 or 2, rarely 3, eggs of the telolecithal type (characteristically have a high content of yolk, the main mass of which is located at one of the poles of the egg). The hatching of young eggs occurs with the help of a special egg “tooth” formed on a small ovoid bone (os carunculae). Young animals hatched from eggs and are fed milk. During the breeding season, a brood pouch can form on the belly of the female, in which the deposits mature. The dimensions of monotremes are small: body length 30 - 80 cm. Monotremes (oviparous) have a heavy build, short plantigrade limbs, specialized for digging or swimming. The head is small, with an elongated “beak” covered with a cornea. The eyes are small, the external ears are barely noticeable or absent altogether. The body is covered with coarse hair and spines or soft, thick fur. Vibrissae are absent. In the heel region of the hind limbs there is a horny spur, especially strongly developed in males. The spur is pierced by a canal - a special duct connected to the so-called tibia gland, the function of which is not entirely clear. Apparently it has some significance in reproduction. There is also an assumption (unconvincing) that the secretion of the shin gland is poisonous and the spur serves as a weapon of defense. The mammary glands are tubular. There are no real nipples and the excretory ducts of the glands open separately from each other on the two glandular fields of the female’s abdomen.

The skull is flattened. The facial region is elongated. The cartilaginous skull and the relationship of bones in the roof of the skull are to a certain extent similar to those of reptiles. Roof of the skull with anterior and posterior frontal bones; the presence of these bones in the roof of the skull is a unique occurrence among mammals. The tympanic bone has the appearance of a flattened ring that does not fuse with the skull. The bony auditory canal is absent. The malleus and incus in the middle ear are fused together and have a long process (processus folii). The lacrimal bone is absent. The zygomatic bone is greatly reduced in size or absent. Only monotremes among all mammals have a prevomer. The premaxillary bone has a process similar to that of reptiles (processus ascendus); this is the only case among mammals. The articular fossa for the lower jaw is formed by the squamosal bone. The lower jaw has only two weakly defined processes - the coronoid and the angular.

Only young animals have teeth or are completely absent. The shape of the teeth to a certain extent resembles the shape of the teeth of the Mesozoic Microleptidae. The skeleton of the forelimb girdle is characterized by a coracoid (coracoideum) and a procoracoid (procoracoideum) that are unique among mammals. The presence of these bones reveals the similarity of the shoulder girdle of monotremes with the shoulder girdle of reptiles. Sternum with large episternum. The collarbone is very large. Blade without ridge. The humerus is short and powerful. The ulna is significantly longer than the radius. The wrist is short and wide. The fore and hind limbs are five-fingered. The fingers end in claws. In the pelvic girdle of males and females there are so-called marsupial bones (ossa marsupialia), articulated with the pubis. Their function is unclear. The symphysis of the pelvic bones is greatly elongated. Proximal fibula with a large flattened process (peronecranon). The spinal column consists of 7 cervical, 15-17 thoracic, 2-3 lumbar, 2 sacral, 0-2 coccygeal and 11-20 caudal vertebrae. The entire body is covered with a highly developed layer of subcutaneous muscles (rap-niculus carnosus). Only in the area of ​​the head, tail, limbs, cloaca and mammary glands, the subcutaneous muscles are not developed. The lower jaw has a musculus detrahens attached to its inner side; this is the only case in mammals. The larynx is primitive and does not have vocal cords.

The brain is generally large, has the structural features of a mammal, but retains a number of reptilian characteristics. Large hemispheres with numerous, sometimes few, grooves. The structure of the cerebral cortex is primitive. The olfactory lobes are very large. The cerebellum is only partially covered cerebral hemispheres. The corpus callosum is absent; it is presented only in the form of commissura dorsalis. The sense of smell is highly developed. The Jacobson organ is well developed. The structure of the hearing organs is primitive. Eyes with or without nictitating membrane. The sclera has cartilage. The choroid is thin. Musculus dilatatorius and Musculus ciliaris are absent. The retina has no blood vessels.

Salivary glands small or large. The stomach is simple, without digestive glands, which is the only case in mammals. Its function appears to be to store food, similar to that of the crop of birds. The digestive tract is divided into small and large intestines, and there is a cecum. The intestines open into the cloaca, which is present in both sexes. The liver is multilobular, with gallbladder. The heart of monotremes has a structure characteristic of mammals, but it also retains some reptile-like features, such as, for example, the fact that the right atrioventricular foramen is equipped with only one valve.

The average body temperature is lower than that of other mammals (the platypus averages 32.2 ° C, the echidna - 31.1 ° C). Body temperature can vary between 25° and 36° C. The bladder, into which the ureters empty, opens into the cloaca. The oviducts empty into the cloaca separately (there is neither a vagina nor a uterus). The testes are located in the abdominal cavity. The penis is attached to the ventral wall of the cloaca and serves only to remove sperm.

Monotremes live in forests different types, in the steppes overgrown with bushes, on the plains and in the mountains, rising to 2.5 thousand m above sea level. They lead a semi-aquatic (platypus) or terrestrial (echidnas) lifestyle; twilight and nocturnal activity; feed on insects and aquatic invertebrates. Life expectancy is up to 30 years. Distributed in Australia, Tasmania, New Guinea. There are 2 families in the order: echidnas - Tachyglossidae Gill, 1872 platypuses - Ornithorhynchidae Burnett, 1830. Modern monotremes are most similar in characteristics to reptiles in comparison with all other modern mammals. They, however, are not the ancestors of marsupials or placental mammals, but represent a separate specialized branch in the evolution of mammals.

Fossil remains of representatives of the order Monotremes are known only from Australia. The most ancient finds date back to the Pleistocene and do not differ significantly from modern forms. There are two possible theories to explain the origin of monotremes. According to one of them, monotremes developed independently and in complete isolation from other mammals, starting from the early period of the emergence of mammals, possibly from their reptile-like ancestors. According to another theory, the group of monotremes separated from the ancient marsupials and acquired their features through specialization, retaining a number of characteristics characteristic of marsupials, and underwent degeneration and, perhaps, to a certain extent, a return to the forms of their ancestors (reversion). The first theory seems more plausible. Significant differences in morphology between echidnas and platypus arose over a relatively short period of time - starting in the Upper Eocene. Echidnas are secondary land mammals, separated from ancient aquatic platypuses (Gregory, 1947).

It is a secretive, nocturnal, semi-aquatic animal that inhabits the banks of small rivers and standing ponds in eastern Australia over a wide range from the cold plateaus of Tasmania and the Australian Alps to the tropical rainforests of coastal Queensland. In the north, its range reaches the Cape York Peninsula (Cooktown).

The body length of the platypus is 30-40 cm, the tail is 10-15 cm, and it weighs up to 2 kg. Males are about a third larger than females. The body of the platypus is squat, short-legged; the tail is flattened, similar to the tail of a beaver, but covered with hair, which noticeably thins with age. Fat reserves are deposited in the tail of the platypus. Its fur is thick, soft, usually dark brown on the back and reddish or gray on the belly. The head is round. In front, the facial section is extended into a flat beak about 65 mm long and 50 mm wide. The beak is not hard like that of birds, but soft, covered with elastic bare skin, which is stretched over two thin, long, arched bones. The oral cavity is expanded into cheek pouches, in which food is stored during feeding. Down at the base of the beak, males have a specific gland that produces a secretion with a musky odor. Young platypuses have 8 teeth, but they are fragile and quickly wear out, giving way to keratinized plates.

The platypus has five-fingered feet, adapted for both swimming and digging. The swimming membrane on the front paws protrudes in front of the toes, but can bend in such a way that the claws are exposed, turning the swimming limb into a digging limb. The membranes on the hind legs are much less developed; For swimming, the platypus does not use its hind legs, like other semi-aquatic animals, but its front legs. The hind legs act as a rudder in the water, and the tail serves as a stabilizer. The gait of the platypus on land is more reminiscent of the gait of a reptile - it places its legs on the sides of the body.

Its nasal openings open on the upper side of its beak. There are no auricles. The eyes and ear openings are located in grooves on the sides of the head. When an animal dives, the edges of these grooves, like the valves of the nostrils, close, so that under water its vision, hearing, and smell are ineffective. However, the skin of the beak is rich in nerve endings, and this provides the platypus not only with a highly developed sense of touch, but also with the ability to electrolocate. Electroreceptors in the beak can detect weak electrical fields, which arise, for example, when the muscles of crustaceans contract, which helps the platypus in searching for prey. Looking for it, the platypus continuously moves its head from side to side during underwater hunting.

Young platypuses of both sexes have the rudiments of horny spurs on their hind legs. In females, by the age of one year they fall off, but in males they continue to grow, reaching 1.2-1.5 cm in length by the time of puberty. Each spur is connected by a duct to the femoral gland, which produces a complex “cocktail” of poisons during the mating season. Males use spurs during mating fights. Platypus venom can kill dingoes or other small animals. For humans, it is generally not fatal, but it causes very severe pain, and swelling develops at the injection site, which gradually spreads to the entire limb.

The platypus lives along the banks of reservoirs. Its shelter is a short straight hole (up to 10 m long), with two entrances and an internal chamber. One entrance is underwater, the other is located 1.2-3.6 m above the water level, under tree roots or in thickets.

The platypus is an excellent swimmer and diver, remaining underwater for up to 5 minutes. He spends up to 10 hours a day in water, since he needs to eat up to a quarter of his food per day. own weight. The platypus is active at night and at dusk. It feeds on small aquatic animals, stirring up the silt at the bottom of the reservoir with its beak and catching living creatures that have risen. They observed how the platypus, while feeding, turns over stones with its claws or with the help of its beak. It eats crustaceans, worms, insect larvae; less often tadpoles, mollusks and aquatic vegetation. Having collected food in its cheek pouches, the platypus rises to the surface and, lying on the water, grinds it with its horny jaws.

Every year, platypuses enter a 5-10-day winter hibernation, after which they enter the breeding season. It lasts from August to November. Mating occurs in water. The male bites the female’s tail, and the animals swim in a circle for some time, after which mating occurs (in addition, 4 more variants of the courtship ritual have been recorded). The male covers several females; Platypuses do not form permanent pairs.

After mating, the female digs a brood hole. Unlike a regular burrow, it is longer and ends with a nesting chamber. A nest of stems and leaves is built inside; The female wears the material with her tail pressed to her stomach. Then she seals the corridor with one or more earthen plugs 15-20 cm thick to protect the hole from predators and floods. The female makes plugs with the help of her tail, which she uses like a mason uses a trowel. The inside of the nest is always moist, which prevents the eggs from drying out. The male does not take part in building the burrow and raising the young.

2 weeks after mating, the female lays 1-3 (usually 2) eggs. Platypus eggs are similar to reptile eggs - they are round, small (11 mm in diameter) and covered with an off-white leathery shell. After laying, the eggs stick together with an adhesive substance that covers them on the outside. Incubation lasts up to 10 days; During incubation, the female rarely leaves the burrow and usually lies curled up around the eggs.

Platypus babies are born naked and blind, approximately 2.5 cm long. When hatching from the egg, they pierce the shell with an egg tooth, which falls off immediately after leaving the egg. The female, lying on her back, moves them to her belly. She does not have a brood pouch. The mother feeds the cubs with milk, which comes out through the enlarged pores on her stomach. Milk flows down the mother's fur, accumulating in special grooves, and the cubs lick it off. The mother leaves the offspring only for short time to feed and dry the skin; leaving, she clogs the entrance with soil. The cubs' eyes open at 11 weeks. Breastfeeding continues up to 4 months; at 17 weeks, the cubs begin to leave the hole to hunt. Young platypuses reach sexual maturity at the age of 1 year. The lifespan of platypuses in the wild is unknown; in captivity they live an average of 10 years.

Bruina's echidna
Western Long-beaked Echidna
(Zaglossus bruijni)

The habitat of the echidna is the highlands of the northwestern part of New Guinea and the islands of Salawati and Waigeo (Indonesia). Its natural habitat is moist montane forests, although it is sometimes found on alpine meadows at an altitude of up to 4000 m above sea level.

Body length up to 77 cm and weight 5-10 kg. The most well-fed individuals weigh more than 16 kg. The tail is rudimentary, 5-7 cm in length. The limbs are higher than those of echidnas, with developed muscles and powerful claws. Males have horny spurs on the inner surface of their hind legs, similar to those of the platypus, but not poisonous. The hind limbs of the echidna are five-fingered, the front three-fingered. The beak (rostrum) of the prochidna occupies 2/3 of the length of the head and is strongly curved downwards; at its end there are nostrils and a small mouth. Small ears are visible on the head. The tongue of the echidna is very long (up to 30 cm) and covered with sharp spines that compensate for the lack of teeth. The body of the echidna is covered with coarse fur of a dark brown or black color; Short spines grow on the back and sides, almost hidden by fur. The color of the needles varies from almost white to black, length 3-5 cm.

The echidna's diet consists almost entirely of earthworms, which it searches for by digging its beak in the ground. Having caught a large worm, the echidna steps on it with its front paw, captures the tip of the worm in its mouth and, actively helping itself with its tongue, pulls it inside. In this case, the worm is impaled on the sharp spines of the tongue. Less commonly, echidnas eat termites, insect larvae, and possibly ants.

The echidna needs its beak not only to search for food. It turned out that this is an additional tenacious limb, allowing the animal to overcome obstacles or turn over stones as a lever. She moves rather slowly, with her head lowered to the ground. If a stone or log gets in the way of an echidna, it prefers to climb over it rather than go around it; a lake or puddle - swim across. If the echidna is frightened, it hides or crouches, tucking its beak under itself and exposing its spines.

Prochidnas are heterothermic animals; their temperature, depending on the ambient temperature, can vary from 36 to 25 °C. At the same time, echidnas continue to remain active and only at the most unfavorable conditions hibernate.

The breeding season for echidnas begins in July. After mating, the female lays one egg, which she places in her pouch. After about ten days, the egg hatches into a baby, which the female feeds with milk for up to 6 months.

The longest life expectancy recorded for an individual living at the London Zoo was 30 years and 8 months.

Barton's echidna
Eastern Long-beaked Echidna
(Zaglossus bartoni)

Distributed in the mountains of central and eastern New Guinea. Lives in tropical forests at an altitude of about 4100 m above sea level.

Body weight is 5-10 kg, body length is from 60 to 100 cm. Unlike other representatives of the genus, it has 5 claws on the forelimbs.

The genus (Zaglossus) also includes Attenborough's echidna (Zaglossus attenboroughi). This species is only known from a single specimen, which was found during the Dutch colonial period in 1961. Since then, no other copies have been found.

Australian echidna
Short-beaked Echidna
(Tachyglossus aculeatus)

It lives in Australia, Tasmania, New Guinea and the islands in Bass Strait.

The Australian echidna is smaller than the echidna: its usual length is 30-45 cm, weight from 2.5 to 5 kg. The Tasmanian subspecies is somewhat larger - up to 53 cm. The echidna's head is covered with coarse hair; The neck is short, almost invisible from the outside. The ears are not visible. The echidna's muzzle is elongated into a narrow “beak” 75 mm long, straight or slightly curved. It is an adaptation to searching for prey in narrow crevices and burrows, from where the echidna reaches it with its long sticky tongue. The mouth opening at the end of the beak is toothless and very small; it does not open wider than 5 mm. Like the platypus, the echidna’s “beak” is richly innervated. Its skin contains both mechanoreceptors and special electroreceptor cells; with their help, the echidna detects weak fluctuations in the electric field that occur during the movement of small animals. No such electrolocation organ has been found in any mammal, other than the echidna and the platypus.

This is a terrestrial animal, although if necessary it is capable of swimming and crossing fairly large bodies of water. The echidna is found in any landscape that provides it with enough food - from rain forests to dry bush and even deserts. It is found in mountainous areas, where there is snow part of the year, on agricultural lands, and even in the suburbs of the capital. The echidna is active mainly during the day, however hot weather makes her switch to night look life. The echidna is poorly adapted to heat, since it does not have sweat glands, and its body temperature is very low - 30-32 °C. When it's hot or cold weather she becomes lethargic; when it gets very cold, it goes into hibernation for up to 4 months. Reserves subcutaneous fat allow her to fast for a month or more if necessary.

It feeds on ants, termites, and less commonly other insects, small mollusks and worms. She digs up anthills and termite mounds, digs with her nose into the forest floor, strips the bark from fallen rotten trees, moves and turns over stones. Having discovered insects, the echidna throws out its long sticky tongue, to which the prey sticks. The echidna has no teeth, but at the root of the tongue there are keratin teeth that rub against the comb palate and thus grind food. In addition, the echidna, like birds, swallows earth, sand and small pebbles, which complete the grinding of food in the stomach.

The echidna leads a solitary lifestyle (except for the mating season). This is not a territorial animal - echidnas that meet simply ignore each other; it does not make permanent burrows and nests. The echidna rests in any convenient place - under roots, stones, in the hollows of fallen trees. The echidna runs poorly. Its main defense is thorns; the disturbed echidna curls up into a ball, like a hedgehog, and if it has time, it partially buries itself in the ground, exposing its back to the enemy with its needles raised.

Echidnas live so secretly that the peculiarities of their mating behavior and reproduction were published only in 2003, after 12 years of field observations. It turned out that during the courtship period, which lasts from May to September (in different parts range, the time of its onset varies), these animals keep in groups consisting of a female and several males. Both females and males at this time emit a strong musky odor, allowing them to find each other. The group feeds and rests together; When crossing, echidnas follow in single file, forming a “train” or caravan. The female walks ahead, followed by males, of which there may be 7-10. Courtship lasts up to 4 weeks. When the female is ready to mate, she lies down, and the males begin to circle around her, throwing lumps of earth aside. After some time, a real trench with a depth of 18-25 cm is formed around the female. The males violently push each other, pushing them out of the trench, until only one winning male remains inside the ring. If there was only one male, the trench is straight. Mating (on the side) lasts about an hour.

Pregnancy lasts 21-28 days. The female builds a brood burrow, a warm, dry chamber often dug under an empty anthill, termite mound, or even a pile of garden debris near human habitation. Typically, a clutch contains one leathery egg with a diameter of 13-17 mm and weighing only 1.5 g. For a long time It remained a mystery how the echidna moves the egg from the cloaca to the brood pouch - its mouth is too small for this, and its paws are clumsy. Presumably, when putting it aside, the echidna deftly curls up into a ball; in this case, the skin on the abdomen forms a fold that secretes sticky liquid. Freezing, she glues the egg that has rolled out onto her stomach and at the same time gives the bag its shape.

After 10 days, a tiny baby hatches - it is 15 mm long and weighs only 0.4-0.5 g. When hatching, the puggle breaks the shell of the egg with the help of a horny bump on the nose, an analogue of the egg tooth of birds and reptiles. The eyes of a newborn echidna are hidden under the skin, and the hind legs are practically undeveloped. But the front paws already have well-defined toes. With their help, in about 4 hours a newborn moves from the back of the pouch to the front, where there is a special area of ​​skin called the milk field, or areola. In this area, 100-150 pores of the mammary glands open; each pore is equipped with a modified hair. When the baby squeezes these hairs with its mouth, milk enters its stomach. The high iron content gives echidna milk its pink color.

Young echidnas grow very quickly, increasing their weight by 800-1000 times in just two months, that is, up to 400 g. The cub remains in the mother's pouch for 50-55 days - until the age when it develops spines. After this, the mother leaves him in the shelter and until the age of 5-6 months comes to feed him once every 5-10 days. In total, milk feeding lasts 200 days. Between 180 and 240 days of life, the young echidna leaves the burrow and begins to lead an independent life. Puberty occurs at 2-3 years. The echidna reproduces only once every two years or less; according to some data - once every 3-7 years. But its low reproduction rate is compensated by its long life expectancy. In nature, the echidna lives up to 16 years; The recorded longevity record at the zoo is 45 years.

Oviparous - belong to the class mammals, subclass cloacal. Among all known vertebrates, monotremes are the most primitive mammals. The detachment received its name due to the presence of a special characteristic among its representatives. Oviparous animals have not yet adapted to viviparity and lay eggs to reproduce offspring, and after the babies are born, they feed them with milk.

Biologists believe that monotremes emerged from reptiles, as an offshoot from a group of mammals, even before the birth of marsupials and placentals.

The platypus is a representative oviparous species

Structure of the skeleton of the limbs, head, organs circulatory system, the breath of primal beasts and reptiles is similar. In the fossils Mesozoic era remains of oviparous animals have been identified. Monotremes then inhabited the territory of Australia, and later occupied the South American expanses and Antarctica.

Today, the first beast can be found only in Australia and the islands located nearby.

Origin and diversity of mammals. Oviparous and true animals.

The ancestors of mammals are the reptiles of the Paleozoic. This fact confirms the similarity in the structure of reptiles and mammals, especially at the stages of embryogenesis.

In the Permian period, a group of theriodonts formed - the ancestors of modern mammals. Their teeth were placed in the recesses of the jaw. Most animals had a bony palate.

However, the environmental conditions that formed during the Mesozoic era contributed to the development of reptiles and they became the dominant group of animals. But the Mesozoic climate soon changed dramatically and reptiles were unable to adapt to new conditions, and mammals occupied the main niche of the animal world.

The class of mammals is divided into 2 subclasses:

• Subclass Primordial or Monotreme;
• subclass Real animals.

Real animals and monotremes share a number of characteristics: a hairy or spiny outer covering, mammary glands, and a hard palate. Also, primal beasts have common characteristics with reptiles and birds: the presence of a cloaca, laying eggs, and a similar skeletal structure.

Order Monotremes - general characteristics

Echidna is a representative of monotremes

Oviparous animals are not large sizes with a body flattened from top to bottom, short limbs with large claws and a leathery beak. They have small eyes and a short tail. Oviparous animals do not have a developed external auricle.

Only representatives of the duckbill family have teeth and they look like flat plates equipped with protrusions along the edges. The stomach is intended only for storing food; the intestines are responsible for digesting food. The salivary glands are very developed, large in size, the stomach passes into the cecum, which, together with the urogenital sinus, flows into the cloaca.

First beasts do not have a real uterus and placenta. Reproduction by laying eggs, they contain little yolk, and the shell contains keratin. The mammary glands have many ducts that open on the ventral side in special glandular fields, since monotremes do not have nipples.

Body temperature can vary: it does not rise above 36°C, but with significant cold weather it can drop to 25°C. Echidnas and platypuses do not make sounds because they lack vocal cords. The lifespan of echidnas is about 30 years, platypuses - about 10. They inhabit forests, steppes with shrubs and are even found in mountainous areas (at an altitude of up to 2500m).

Representatives of oviparous species have poisonous glands. On the hind limbs there is a bone spur through which a poisonous secretion flows. The poison is potent, in many animals it provokes disruption of the functioning of vital organs, and it is also dangerous for humans - it causes severe pain and extensive swelling at the site of the lesion.

Catching and hunting for representatives of the detachment is prohibited, as they are listed in the Red Book due to the threat of extinction.

Platypus and Echidna

The platypus and echidna are oviparous mammals, the only representatives of the order.

A small animal about 30-40cm long (body), tail part up to 15cm, weighing 2kg. Males are always larger than females. It lives near bodies of water.

Five-fingered limbs are well adapted for digging the ground; on the coast, platypuses dig holes for themselves about 10 meters in length, arranging them for later life(one entrance is underwater, the other is a couple of meters above the water level). The head is equipped with a beak, like a duck’s (hence the name of the animal).

Platypuses stay in the water for 10 hours, where they obtain food: aquatic vegetation, worms, crustaceans and mollusks. Swimming membranes between the toes on the front paws (almost undeveloped on the hind limbs) allow the platypus to swim well and quickly. When the animal dives underwater, the eyes and ear openings close, but the platypus can navigate the water thanks to sensitive nerve endings on its beak. It even has electroreception.

Platypuses carry their young for a month and produce from one to three eggs. First, the female incubates them for 10 days, and then feeds them with milk for about 4 months, and at the age of 5 months, the platypuses, already capable of independent life, leave the hole.

TO oviparous mammals also applies echidna, found in forests appearance looks like a hedgehog. To obtain food, the echidna digs the ground with powerful claws and, with the help of a long and sticky tongue, obtains the necessary food (termites, ants).

The body is covered with spines, which protect it from predators; when danger approaches, the echidna curls up into a ball and becomes inaccessible to enemies. The female weighs approximately 5 kg, and lays an egg weighing 2 g. The echidna hides the egg in a pouch formed by a leathery fold in the abdominal area and carries it, warming it with its warmth, for two weeks. A newborn calf is born with a weight of 0.5 g and continues to live in the mother’s pouch, where it is fed with milk.

After 1.5 months, the echidna leaves the pouch, but continues to live in the hole under the protection of its mother. After 7-8 months, the baby is able to find food on his own and differs from an adult only in size.

Lesson type - combined

Methods: partially search, problem presentation, reproductive, explanatory and illustrative.

Target: mastering the ability to apply biological knowledge in practical activities, use information about modern achievements in the field of biology; work with biological devices, instruments, reference books; conduct observations of biological objects;

Tasks:

Educational: the formation of cognitive culture, mastered in the process of educational activities, and aesthetic culture as the ability to have an emotional and value-based attitude towards objects of living nature.

Educational: development of cognitive motives aimed at obtaining new knowledge about living nature; cognitive qualities personalities associated with mastering the fundamentals scientific knowledge, mastering methods of studying nature, developing intellectual skills;

Educational: orientation in the system of moral norms and values: recognition of the high value of life in all its manifestations, the health of one’s own and other people; environmental awareness; nurturing love for nature;

Personal: understanding of responsibility for the quality of acquired knowledge; understanding the value of adequately assessing one’s own achievements and capabilities;

Cognitive: ability to analyze and evaluate the impact of environmental factors, risk factors on health, the consequences of human activities in ecosystems, the impact of one’s own actions on living organisms and ecosystems; focus on continuous development and self-development; the ability to work with various sources of information, transform it from one form to another, compare and analyze information, draw conclusions, prepare messages and presentations.

Regulatory: the ability to organize independent completion of tasks, evaluate the correctness of work, and reflect on one’s activities.

Communicative: formation of communicative competence in communication and cooperation with peers, understanding of the characteristics of gender socialization in adolescence, socially useful, educational and research, creative and other types of activities.

Technologies : Health conservation, problem-based, developmental education, group activities

Types of activities (content elements, control)

Formation of students’ activity abilities and abilities to structure and systematize the subject content being studied: teamwork- study of the text and illustrative material, compilation of the table “Systematic groups of multicellular organisms” with the advisory assistance of student experts, followed by self-test; pair or group performance laboratory work with the advisory assistance of a teacher followed by mutual verification; independent work on the studied material.

Planned results

Subject

understand the meaning of biological terms;

describe the structural features and basic life processes of animals of different systematic groups; compare the structural features of protozoa and multicellular animals;

recognize organs and organ systems of animals of different systematic groups; compare and explain reasons for similarities and differences;

establish the relationship between the structural features of organs and the functions they perform;

give examples of animals of different systematic groups;

distinguish the main systematic groups of protozoa and multicellular animals in drawings, tables and natural objects;

characterize the directions of evolution of the animal world; provide evidence of the evolution of the animal world;

Metasubject UUD

Cognitive:

to Work with different sources information, analyze and evaluate information, transform it from one form to another;

write theses, different kinds plans (simple, complex, etc.), structure educational material, give definitions of concepts;

carry out observations, perform elementary experiments and explain the results obtained;

compare and classify, independently choosing criteria for the specified logical operations;

build logical reasoning, including establishing cause-and-effect relationships;

create schematic models highlighting the essential characteristics of objects;

identify possible sources necessary information, search for information, analyze and evaluate its reliability;

Regulatory:

organize and plan your educational activities - determine the purpose of the work, the sequence of actions, set tasks, predict the results of the work;

independently put forward options for solving assigned tasks, anticipate the final results of the work, choose the means to achieve the goal;

work according to plan, compare your actions with the goal and, if necessary, correct mistakes yourself;

master the basics of self-control and self-assessment for making decisions and making informed choices in educational, cognitive and educational and practical activities;

Communicative:

listen and engage in dialogue, participate in collective discussion of problems;

integrate and build productive interactions with peers and adults;

adequately use verbal means for discussion and argumentation of one’s position, compare different points of view, argue one’s point of view, defend one’s position.

Personal UUD

Formation and development of cognitive interest in the study of biology and the history of the development of knowledge about nature

Techniques: analysis, synthesis, inference, translation of information from one type to another, generalization.

Basic Concepts

Diversity of mammals, division into orders; general characteristics of units, the relationship between lifestyle and external structure. The importance of mammals in nature and human life, the protection of mammals.

During the classes

Updating knowledge ( concentration when learning new material)

Choose the correct answer option in your opinion.

1. Which one common feature in all vertebrates?

presence of a spine

habitat in the air-terrestrial environment

multicellularity

2. How is the vertebrate brain protected?

sink

shell

skull

3. How many types of vertebrates are there?

4. What is the special respiratory organ in fish?

leather

5. What are the respiratory organs of amphibians?

lungs and skin

6. Which vertebrates first appeared on earth?

Reptiles

Amphibians

7. How do reptiles reproduce?

give birth to babies

lay eggs

lay eggs

8. Which one distinctive feature birds?

live in the air-terrestrial environment

body covered with feathers

only they lay eggs

9. Which group of vertebrates is the most organized on earth?

mammals

10. How do mammals differ from other vertebrates?

feed the young with milk

breathe with their lungs

warm-blooded

Learning new material(teacher's story with elements of conversation)

Monotreme mammals: general characteristics, features and origin .

Amazing organisms that lay eggs and feed their young with milk are monotreme mammals. In our article we will look at the systematics and features of the life activity of this class of animals. general characteristics class Mammals.

The class Mammals, or Animals, includes the most highly organized representatives of the Chordata type. Their characteristic feature is the presence of mammary glands in females, the secretion of which they feed their young. TO external features their structure includes the location of the limbs under the body, the presence of hair and various derivatives of the skin: nails, claws, horns, hooves

Most mammals are also characterized by the presence of seven cervical vertebrae, a diaphragm, exclusively atmospheric breathing, a four-chambered heart, and the presence of a cortex in the brain

Subclass of the Prime Beast. This subclass of Mammals includes a single order called Monotremes. They received this name due to the presence of a cloaca. This is one hole into which the ducts of the reproductive, digestive and urinary systems open. All these animals reproduce by laying eggs. How can animals with such features be members of the class Mammals? The answer is simple. They have mammary glands that open directly onto the surface of the body, since monotremes do not have nipples. Newborns lick it directly from the skin. Primitive structural features inherited from reptiles are the absence of cortex and convolutions in the brain, as well as teeth, the function of which is performed by horny plates. In addition, their body temperature fluctuates within certain limits depending on its changes in the environment from +25 to +36 degrees. Such warm-bloodedness can be considered quite relative. Oviposition of monotremes cannot be called real. It is often called an incomplete viviparity. The fact is that the eggs do not immediately come out of the animal’s genital ducts, but linger there for a certain time. During this period, the embryo develops by half. After emerging from the cloaca, monotremes incubate their eggs or carry them in a special leathery pouch.

Monotreme mammals: fossil species Paleontological finds of monotremes are quite few in number. They belong to the Miocene, Upper and Middle Pleistocene eras. The oldest fossil of these animals is 123 million years old. Scientists have concluded that the fossil remains are practically no different from modern species. Monotreme mammals, whose representatives are endemic, live only in Australia and the adjacent islands: New Zealand, Guinea, Tasmania.

Echidna Prime Beasts- represented by only a few species. The echidna is a monotreme mammal. Due to the fact that its body is covered with long, hard spines, this animal looks like a hedgehog. In case of danger, the echidna curls up into a ball, thus protecting itself from enemies. The body of the animal is about 80 cm long, its front part is elongated and forms a small proboscis. Echidnas are nocturnal predators. During the day they rest, and at dusk they go hunting. Therefore, their vision is poorly developed, which is compensated by an excellent sense of smell. Echidnas have burrowing limbs. Using them and their sticky tongue, they hunt for invertebrates in the soil. Females usually lay one egg, which is incubated in a fold of skin.

Prochidna These are also representatives of the class Mammals, order Monotremes. They differ from their closest relatives, echidnas, by a more elongated proboscis, as well as the presence of three fingers instead of five. Their needles are shorter, most of them are hidden in the fur. But the limbs, on the contrary, are longer. Prochidnas are endemic to the island of New Guinea. The basis of the diet of these monotremes is earthworms and beetles. Like echidnas, they catch them with sticky long tongue, on which numerous small hooks are located.

Platypus. This animal seems to have borrowed its body parts from other representatives of this kingdom. The platypus is adapted to semi-aquatic image life. Its body is covered with dense thick hair. It is very tough and practically waterproof. This animal has the beak of a duck and the tail of a beaver. The fingers have swimming membranes and sharp claws. In males, horny spurs develop on the hind limbs, into which the ducts of the poisonous glands open. For humans, their secretion is not fatal, but can cause severe swelling, first of a certain area, and then of the entire limb.

It’s not for nothing that the platypus is sometimes called “God’s joke.” According to legend, at the end of the creation of the world, the Creator had unused parts from various animals. From these he created the platypus. It's not just Australian endemic. This is one of the symbols of the continent, the image of which is found even on the coins of this state. This mammal hunts well in water. But it builds nests and burrows exclusively on land. It swims at considerable speed, and grabs prey almost at lightning speed - within 30 seconds. Therefore, aquatic animals have very little chance of escaping from a predator. Thanks to its valuable fur, the number of platypus has decreased significantly. At the moment, hunting them is prohibited.

V.V. Latyushin, E. A. Lamekhova. Biology. 7th grade. Workbook to the textbook V.V. Latyushina, V.A. Shapkina “Biology. Animals. 7th grade". - M.: Bustard.

Zakharova N. Yu. Control and testing work in biology: to the textbook by V.V. Latyushin and V.A. Shapkin “Biology. Animals. 7th grade” / N. Yu. Zakharova. 2nd ed. - M.: Publishing house "Exam"

Presentation hosting

Marsupials: Range: Australia, Tasmania, New Guinea, other adjacent islands including the Greater Sunda Islands, North and South America. Acclimatized in New Zealand. Food: herbivores, insectivores, carnivores and omnivores. Body length: from 4-10 to 75-160 cm.

The marsupial order includes more than 250 species of animals. They are often not similar to each other in appearance, size, or body structure and lead different lifestyles. This order includes peaceful herbivores, such as kangaroos or koalas, and insectivores, such as marsupial moles or numbats, and predators such as Tasmanian devil, capable of handling medium-sized kangaroos. What these animals have in common is that they give birth to underdeveloped young, which the mother carries for a long time in the brood pouch. The order MONTREME OR EGG-PLAYING (Monotremata) is the most primitive among modern mammals, retaining a number of archaic structural features inherited from reptiles (laying eggs, the presence of a well-developed coracoid bone not connected to the scapula, some details of the articulation of the skull bones, etc.). The development of so-called marsupial bones (small pelvic bones) in monotremes is also considered as a heritage of reptiles. The presence of distinct coracoid bones distinguishes monotremes from marsupials and other mammals, in which this bone has become a simple outgrowth of the scapula. At the same time, hair and mammary glands are two interrelated characteristics characteristic of mammals. However, the mammary glands of monotremes are primitive and similar in structure to the sweat glands, while the mammary glands of marsupials and higher mammals They are grape-shaped and look like sebaceous glands.

Quite a few similarities between monotremes and birds are adaptive rather than genetic. The laying of eggs by these animals brings monotremes closer to reptiles than to birds. However, in the egg, the yolk of monotremes is much less developed than that of birds. The keratinized egg shell is composed of keratin and also resembles the shell of reptile eggs. Monotremes resemble birds and such structural features as some reduction of the right ovary, the presence of pockets in the digestive tract resembling a bird's crop, and the absence of an external ear. However, these similarities are rather adaptive in nature and do not give the right to talk about any direct relationship between monotremes and birds. Adult oviparous animals do not have teeth. The body temperature of the echidna fluctuates around 30°, and that of the platypus - about 25°. But these are only average numbers: they change depending on the external temperature. ECHIDNA family. Echidnas are animals covered with quills, like porcupines, but their feeding type is reminiscent of anteaters. The size of these animals usually does not exceed 40 cm. The body is covered with needles, the length of which can reach 6 cm. The color of the needles varies from white to black.. The strong limbs of the echidna bear 5 spatulate-shaped extensions