Order Monotremes or Oviparous. Characteristics and origin

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The platypus is recognized as one of the most amazing animals on Earth.
It combines the characteristics of birds, reptiles and mammals. The platypus was chosen as the animal that symbolizes Australia. They even mint money with his image in this country. When this animal was discovered, scientists, researchers and zoologists were very puzzled. They were not immediately able to determine what kind of animal was in front of them. A nose incredibly similar to a duck's beak, a beaver's tail, spurs on the legs like a rooster and many other features have baffled scientists.

Origin of the species and description

Photo: Platypus

The animal belongs to the waterfowl mammals. Together with the echidnovas, it belongs to the order Monotremes. Today, only these animals are representatives of the duckbill family. Scientists note a number of characteristic features that unite them with reptiles.

The animal's skin was first discovered in Australia in 1797. At that time, researchers could not find an explanation of who this skin actually belonged to. Scientists even decided at first that it was some kind of joke, or perhaps it was created by Chinese scarecrow craftsmen. At that time, skilled craftsmen of this genre were able to fasten body parts of completely different animals.

Video: Platypus

As a result, amazing non-existent animals appeared. After the existence of this amazing animal was proven, researcher George Shaw described it as a flatfooted duck. However, a little later, another scientist Friedrich Blumenbach described him as a paradoxical bearer of a bird's beak. After much debate and striving to come to a consensus, the animal was given the name “duck-shaped bird-beak.”

With the advent of the platypus, all ideas about evolution were completely shattered. Scientists and researchers for almost three decades could not determine which class of animals to classify it into. In 1825 they assigned it to mammals. And only almost 60 years later it was found out that platypuses tend to lay eggs.

It has been scientifically proven that these animals are among the oldest on Earth. The oldest representative of this genus, discovered in Australia, dates back more than 100 million years. It was a small animal. It was nocturnal and could not lay eggs.

Table "Orders of Mammals"

Many zoologists also include the family of humans in the order of primates, with the only modern species being Homo sapiens.

In addition to these main units, the following units are also distinguished:

• aardvarks;
• woolwings;
• sirens;
• lizards;
• proboscis;
• calluses;
• hyraxes.

The order Aardvarks includes one species.

Rice. 1. African aardvark.

Woolly wings are represented by two species.

Sirens are marine herbivorous animals, similar to cetaceans, but with a pronounced neck. These include manatees and dugongs.

Lizards or pangolins look like a large fir cone. Their body is covered with scales. They feed on termites and ants.

Rice. 2. Pangolin.

The order Proboscis consists of 2 species - African and Indian elephants.

Calloused animals include camels, vicunas and guanacos. Their limbs are two-fingered.

Hyraxes are similar to marmots.

Rice. 3. Hyrax.

The glands on the soles of hyraxes secrete a rubber-like substance, thanks to which hyraxes are able to run along vertical surfaces of rocks and trees.

Appearance and features

Photo: Platypus animal

The platypus has a dense, elongated body and short limbs. The body is covered with a rather thick coat of dark, almost black color. In the belly area, the fur has a lighter, reddish tint. The head of the animal is small in comparison with the body, round in shape. On the head there is a large, flat beak, reminiscent of a duck's in shape. The eyeballs, nasal and ear passages are located in special recesses.

When diving, these holes in the recesses close tightly, preventing water from entering. At the same time, in the water the platypus is completely deprived of the ability to see and hear. The main guide in this situation is the nose. It contains a large number of nerve endings, which help not only to perfectly navigate the water space, but also to detect the slightest movements, as well as electrical signals.

Platypus dimensions:

• body length is 35-45 cm. Representatives of the duckbill family have clearly expressed sexual dimorphism. Females are one and a half to 2 times smaller than males;
• tail length 15-20 cm;
• body weight 1.5-2 kg.

The limbs are short, located on both sides, on the lateral surface of the body. That is why animals, when moving on land, walk, waddling from side to side. The limbs have an amazing structure. They have five fingers, which are connected by membranes. Thanks to this structure, animals swim and dive well. In addition, the membranes can bend, revealing long, sharp claws that help dig the ground.

The membranes on their hind limbs are less pronounced, so they use their forelimbs to swim quickly. The hind legs are used as a direction corrector. The tail serves as a balance. It is flat, long, and covered with hair. Thanks to the thickness of the hair on the tail, the age of the animal can be determined. The more fur it has, the younger the platypus. It is noteworthy that fat reserves accumulate mainly in the tail, and not on the body.

This animal is characterized by a number of features:

• The body temperature of a mammal does not exceed 32 degrees. It has the ability to regulate its body temperature, thanks to which it perfectly adapts to various environmental conditions.
• Male platypuses are poisonous.
• The beak of animals is soft.
• Platypuses are distinguished by the slowest course of all metabolic processes in the body among all mammals existing today.
• Females tend to lay eggs, like birds, from which offspring are subsequently hatched.
• Platypuses are able to stay underwater for five minutes or more.

An excerpt characterizing Monotremes

X Returning to the guardhouse, Petya found Denisov in the entryway. Denisov, in excitement, anxiety and annoyance at himself for letting Petya go, was waiting for him. - God bless! - he shouted. - Well, thank God! - he repeated, listening to Petya’s enthusiastic story. - Why don’t you, I didn’t sleep because of you! - Denisov said. - Well, thank God, go to bed now. Let's wait until we finally get to the point. “Yes... No,” said Petya. – I don’t want to sleep yet. Yes, I know myself, if I fall asleep, it’s over. And then I got used to not sleeping before the battle. Petya sat for some time in the hut, joyfully recalling the details of his trip and vividly imagining what would happen tomorrow. Then, noticing that Denisov had fallen asleep, he got up and went into the yard. It was still completely dark outside. The rain had passed, but drops were still falling from the trees. Close to the guardhouse one could see black figures of Cossack huts and horses tied together. Behind the hut were two black wagons with horses standing, and in the ravine the dying fire was red. The Cossacks and hussars were not all asleep: in some places, along with the sound of falling drops and the nearby sound of horses chewing, soft, as if whispering voices were heard. Petya came out of the entryway, looked around in the darkness and approached the wagons. Someone was snoring under the wagons, and saddled horses stood around them, chewing oats. In the darkness, Petya recognized his horse, which he called Karabakh, although it was a Little Russian horse, and approached it. “Well, Karabakh, we’ll serve tomorrow,” he said, smelling her nostrils and kissing her. - What, master, aren’t you sleeping? - said the Cossack sitting under the truck. - No; and... Likhachev, I think your name is? After all, I just arrived. We went to the French. - And Petya told the Cossack in detail not only his trip, but also why he went and why he believes that it is better to risk his life than to make Lazar at random. “Well, they should have slept,” said the Cossack. “No, I’m used to it,” answered Petya. - What, you don’t have flints in your pistols? I brought it with me. Isn't it necessary? You take it. The Cossack leaned out from under the truck to take a closer look at Petya. “Because I’m used to doing everything carefully,” said Petya. “Some people just don’t get ready, and then they regret it.” I don't like it that way. “That’s for sure,” said the Cossack.

Monotremes ( Monotremata

), or oviparous, or cloacal, is a unique species that lays eggs rather than giving birth to live young, like placentals or mammals. The order includes only a few species of echidnas and platypus.

Where does the platypus live?

Photo: Platypuses echidna

Until the 20s of this century, animals lived exclusively in Australia. Today, animal populations are concentrated from the Tasmanian possessions through the Australian Alps, right up to the outskirts of Queensland. The bulk of representatives of the platypus family is concentrated in Australia and Tasmania.

The mammal leads a hidden lifestyle. They tend to inhabit the coastal areas of water bodies. It is typical that they choose only fresh water bodies for living. Platypuses prefer a certain water temperature – from 24 to 30 degrees. Animals build burrows for living. They are not long, straight moves. The length of one hole does not exceed ten meters.

Each of them has two entrances and a furnished room. One entrance is accessible from land, the second from a reservoir. Those who want to see the platypus in person can visit the zoo or national reserve in Melbourne, Australia.

Echidnas

The family is divided into two genera - echidnas proper and proechidnas, which include five species. They all live in Australia, on the islands of Tasmania and New Guinea. Echidnas are medium-sized terrestrial animals (body length up to 80 cm, weight up to 10 kg). They have a squat body, a short neck, a head with a strongly elongated front part (beak) and a very small mouth opening. The tail is greatly shortened. The front legs have five (in the echidna) or three (in the echidna) fingers, armed with powerful curved claws, which are used as a tool for opening anthills or termite nests. The thick skin is covered with hair and spines - modified hair. There are no needles only on the belly. When in danger, echidnas quickly bury themselves, leaving only their back with sharp spines on the surface. Externally, echidnas resemble a giant hedgehog or porcupine. They can roll up into a ball or hide in rock crevices or hollows.

Externally, echidnas resemble a giant hedgehog

Reproduction of echidnas

The breeding season for echidnas occurs in the Australian spring. Two weeks after mating, the female lays a single egg. She places it in a special pouch that forms on her belly. After about ten days, the cub breaks through the shell of the egg, but remains in the pouch for two to three months, feeding on the fatty milk secreted there.

What does the platypus eat?

Photo: Platypus in the water

Platypuses are excellent swimmers and divers. To do this they need a large amount of energy. The daily volume of food must be at least 30% of the animal’s body weight in order to cover energy costs.

What is included in the platypus diet:

• shellfish;
• seaweed;
• crustaceans;
• tadpoles;
• small fish;
• insect larvae;
• worms.

While in the water, platypuses collect food in the cheek space. Having got out, they grind the food they have obtained with the help of horny jaws. Platypuses tend to instantly grab the victim and send it to the cheek area.

Aquatic vegetation can serve as a source of nutrition only if difficulties arise with other food sources. But this happens extremely rarely. Platypuses are considered excellent hunters. They are able to turn over stones with their nose, and also feel confident in muddy, silt-filled water.

Features of character and lifestyle

Photo: Australian platypus

Animals tend to spend a third of their lives in water. These animals tend to hibernate. It can last 6-14 days. Most often, this phenomenon is observed before the onset of the mating season. Thus, the animals gain strength and rest.

The platypus is most active at night. At night he hunts and gets his food. These representatives of the duckbill family prefer an isolated lifestyle. It is unusual for them to form groups or create families. By nature, platypuses are endowed with excessive caution.

Platypuses inhabit mainly coastal areas of water bodies. Due to their unique ability to regulate body temperature and perfectly adapt to environmental conditions, they settle near not only warm rivers and lakes, but also near cold high-mountain streams.

For permanent residence, adult individuals create tunnels and burrows. They dig them with strong paws and large claws. The burrow has a special structure. It has two entrances, a small tunnel and a spacious, cozy inner chamber. Animals build a hole in such a way that the entrance corridor is narrow. While moving along it into the inner chamber, all the liquid on the platypus’s body is squeezed out.

Placental Mammals

And marsupials are dioecious animals with internal fertilization. The placental representatives of this class have the most progressive structural features. They are most widespread in nature. During embryonic development, a baby's place or placenta is formed. This is the organ that provides communication between the embryo and the mother’s body. The gestation period of placentals ranges from 11 days in mouse-like rodents to 24 months.

This group of mammals is represented by a large number of orders. Thus, representatives of insectivores are hedgehogs, moles, muskrats, shrews, and shrews. Their common feature is not only the nature of the food, but also the appearance. The anterior section of the head of insectivores is elongated and forms a short proboscis, on which there are sensitive hairs.

Placentals have mastered all habitats except the organismic one. Chiropterans are capable of flight due to the presence of a fold of skin between the fingers, which serves as their wing. Pinnipeds spend most of their lives in water, and Cetaceans live there constantly. Terrestrial placentals include Rodents, Lagomorphs, Pairs and Odd-toeds, Carnivores and Primates. The man represents the last squad.

Mammals - monotremes, marsupials and placentals feed their young with milk. Each of the listed superclasses has its own characteristic features. In monotremes, the cloaca is preserved; in marsupials, a skin fold is formed, in which the newborn develops for a certain period. All of them are endemic to Australia. Marsupials and monotremes do not have a placenta. Thanks to the presence of an organ that connects the body of mother and child during intrauterine development, completely viable individuals are born. Therefore, placentals are the most highly organized representatives of the class.

Social structure and reproduction

Photo: Baby platypus

The mating season for platypuses begins in August and lasts until the end of October and mid-November. Females attract individuals of the opposite sex by wagging their tail. During this period, males come to the territory of females. For some time they smoothly follow each other in a kind of dance. Then the male begins to pull the female by the tail. This is a kind of courtship that lasts a very short period of time.

After mating and fertilization, females build a home for themselves, in which they subsequently give birth to offspring. Such a hole differs from the standard home of animals. It is somewhat longer, and at the very end is the female's nest. The female lines the bottom with leaves, to collect which she uses her tail, with which she rakes it into a pile. After construction and arrangement is completed, the female blocks all the corridors with earth. This is a way to protect against flooding and attacks from dangerous predators.

After this, she lays one to three eggs. Outwardly, they look like reptile eggs. They have a grayish tint and a leathery shell. After laying eggs, the expectant mother constantly nourishes them with her warmth until the moment when the cubs are born. The offspring hatch ten days after the female laid her eggs. The cubs are born tiny, blind and without hair. Their size does not exceed 3 cm. Babies are typically born through an egg tooth, designed to pierce the shell. Then it falls out as unnecessary.

After birth, the mother places the babies on her stomach and feeds them with her milk. Females have no nipples. They have pores in the abdomen through which milk is secreted. The cubs simply lick it off. The female is with her babies almost all the time. It comes out of the hole only to get food for itself.

After 10 weeks from birth, the baby’s body becomes covered with hair and their eyes open. The first hunt and experience of independent food production appears at 3.5-4 months. After a year, young individuals lead an independent lifestyle. The average life expectancy in natural conditions is not precisely determined. Zoologists suggest that it is 10-15 years.

An excerpt characterizing Monotremes

X Returning to the guardhouse, Petya found Denisov in the entryway. Denisov, in excitement, anxiety and annoyance at himself for letting Petya go, was waiting for him. - God bless! - he shouted. - Well, thank God! - he repeated, listening to Petya’s enthusiastic story. - Why don’t you, I didn’t sleep because of you! - Denisov said. - Well, thank God, go to bed now. Let's wait until we finally get to the point. “Yes... No,” said Petya. – I don’t want to sleep yet. Yes, I know myself, if I fall asleep, it’s over. And then I got used to not sleeping before the battle. Petya sat for some time in the hut, joyfully recalling the details of his trip and vividly imagining what would happen tomorrow. Then, noticing that Denisov had fallen asleep, he got up and went into the yard. It was still completely dark outside. The rain had passed, but drops were still falling from the trees. Close to the guardhouse one could see black figures of Cossack huts and horses tied together. Behind the hut were two black wagons with horses standing, and in the ravine the dying fire was red. The Cossacks and hussars were not all asleep: in some places, along with the sound of falling drops and the nearby sound of horses chewing, soft, as if whispering voices were heard. Petya came out of the entryway, looked around in the darkness and approached the wagons. Someone was snoring under the wagons, and saddled horses stood around them, chewing oats. In the darkness, Petya recognized his horse, which he called Karabakh, although it was a Little Russian horse, and approached it. “Well, Karabakh, we’ll serve tomorrow,” he said, smelling her nostrils and kissing her. - What, master, aren’t you sleeping? - said the Cossack sitting under the truck. - No; and... Likhachev, I think your name is? After all, I just arrived. We went to the French. - And Petya told the Cossack in detail not only his trip, but also why he went and why he believes that it is better to risk his life than to make Lazar at random. “Well, they should have slept,” said the Cossack. “No, I’m used to it,” answered Petya. - What, you don’t have flints in your pistols? I brought it with me. Isn't it necessary? You take it. The Cossack leaned out from under the truck to take a closer look at Petya. “Because I’m used to doing everything carefully,” said Petya. “Some people just don’t get ready, and then they regret it.” I don't like it that way. “That’s for sure,” said the Cossack.

Natural enemies of platypuses

Photo: Platypus in Australia

In their natural habitat, platypuses have few enemies in the animal world, these are:

• python;
• monitor lizard;
• sea ​​leopard.

The worst enemy of a mammal is considered to be man and his activities. At the very beginning of the 20th century, poachers and hunters mercilessly exterminated animals in order to get their fur. At that time, it was especially valued among fur manufacturers. The animal was on the verge of complete extinction. To make just one fur coat, it was necessary to destroy more than five dozen animals.

Population and species status

Photo: Platypus animal

Due to poachers and hunters who exterminated platypuses in large numbers in pursuit of wool, the platypus family was almost completely destroyed at the beginning of the 20th century. In this regard, hunting these animals was completely prohibited.

Today, the animal is not in danger of complete extinction, but its habitat has shrunk significantly. This is due to the pollution of water bodies and the development of large territories by humans. Rabbits brought by colonists are also reducing their habitats. They dig holes in the places where the animals live and force them to look for other habitats.