Everyone knows from the school curriculum aboutmammals. And do you know that the egg-laying mammal is a separate species of animals that lives only on the territory of one continent - Australia? Let's look at this particular kind of animal in more detail.
Discovery of egg-laying
For a long time about the existence of unique in itsthe kind of animals that breed, hatching eggs, was not known. The first message about these creatures came to Europe in the XVII century. At this time a skin of a marvelous creature with a beak covered with wool was brought from Australia. It was a platypus. The copied specimen was brought only 100 years later. The fact is that the duck-billed platypus practically does not tolerate bondage. It is very difficult for them to create conditions during transportation. Therefore, observations were conducted only in the natural environment.
Following the discovery of the platypus was the news ofone more creature with a beak, only now it is covered with needles. This is a viper. For a long time, scientists argued about which class to classify these two creatures. And they came to the conclusion that the platypus and echidna, the egg-laying mammals, must be taken out into a separate order. So a detachment monotransit, or cloaca.
Amazing Platypus
Unique in its kind being, leading nightLifestyle. The platypus is common only in Australia and Tasmania. The animal lives half in water, that is, it builds holes with access to water and land, it also feeds in water. The creature is small in size - up to 40 centimeters. It has, as already mentioned, duck nose, but it is soft and covered with skin. Only in appearance is very similar to duck. There is also a 15 centimeter tail, similar to a beaver's tail. The paws have membranes, but they do not interfere with the platypus walking the ground and dig holes well.
Since the urogenital system and intestines come outanimal in one hole, or cloaca, it is attributed to a separate species - Cloaca. It is interesting that the platypus swims, unlike ordinary mammals, with the help of front paws, and the rear ones serve as a rudder. Among other things, let's pay attention to how it multiplies.
Breeding platypus
Interesting fact:before breeding, the animals hibernate for 10 days, and only after that the mating season begins. It lasts almost all autumn, from August to November. The platypus mate in water, and after a two-week period, the female lays an average of 2 eggs. Males do not participate in the further life of the offspring.
The female builds a special hole (up to 15meters) with a nest at the end of the tunnel. It is lined with raw leaves and stems to maintain a certain moisture level so that the eggs do not dry out. Interestingly, to protect it, it also builds a barrier wall 15 centimeters thick.
Only after the preparatory work shelays eggs in the nest. Hatching the platypus eggs curled up around them. After 10 days, babies are born, naked and blind, like all mammals. The female feeds the babies with milk, which flows from the pores right through the fur to the grooves and accumulates in them. Kids lick milk and thus feed. Feeding lasts about 4 months, and then the kids learn to independently produce food. It is the breeding method that gave this species the name "egg-laying mammal".
Extraordinary echidna
Echidna is also an egg-laying mammal.This is a land creature of small size, reaching up to 40 centimeters. It also lives in Australia, Tasmania and the islands of New Guinea. This animal looks like a hedgehog, but with a long narrow beak, not exceeding 7.5 centimeters. Interestingly, the echidna has no teeth, and it catches prey with the help of a long sticky tongue.
The body of the echidna is covered on the back and sides with prickles,which formed from coarse wool. The coat covers the belly, head and paws of the animal. Echidna is fully adapted for a certain type of food. It feeds on termites, ants and small insects. She leads a daytime life, although it is not easy to find. The fact is that it has a low body temperature, up to 32 degrees, and this does not allow it to tolerate a decrease or increase in ambient temperature. In this case, the echidna becomes lethargic and rests under the trees or hibernates.
Breeding method vipers
Ехидна - яйцекладущее млекопитающее, но доказать this was only possible at the beginning of the 21st century. Interesting marriage games echidn. Up to 10 males per one female. When she decides that she is ready to mate, she lies on her back. The males at the same time pull up a trench around it and begin to fight for the championship. Coping with the female one who was stronger.
Pregnancy lasts up to 28 days and endsthe appearance of one egg, which the female moves to the brood fold. It is still not clear how the female moves the egg into the bag, but after 10 days the baby appears. Cub comes into the world is not fully formed.
Young
The birth of such a baby is very similar to the appearanceto light young marsupial animals. They also take final development in the mother’s bag and leave it as adults, ready for independent living. Interesting fact: marsupial mammals are also common only in Australia.
What is the baby echidna?He is blind and naked, his hind limbs are not developed, his eyes are closed with a leathery film, and only his forelegs have fingers. It takes 4 hours for the baby to reach the milk. It is interesting that in the bag the mother has 100-150 pores, which release milk through special hairs. The baby only needs to get to them.
The baby is in the mother's bag for about 2 months.He very quickly gains weight due to nutritious milk. Echidna milk is the only one that has a pink color due to the large amount of iron in it. Feeding lasts up to 6.5 months. After the youngsters learn to get food on their own.
Prohidna
Prochidna is another egg-layingmammal. This creature is much larger than its fellows. Habitat is the north of New Guinea and the island of Indonesia. The dimensions of the project are impressive, up to 80 centimeters, while its weight is up to 10 kilograms. It looks like a snake, but the beak is much longer and the needles are much shorter. She lives in a mountainous area and feeds mostly on worms. The structure of the oral cavity is interesting: the tongue has teeth in it, and with the help of it it is capable of not only chewing food, but, as was noted, even turning stones.
This species is the least studied since it lives inthe mountains. But it was noted that the animal does not lose mobility in any weather, does not hibernate and is able to regulate the temperature of its own body. The reproduction of egg-laying mammals, to which the prochid belongs, occurs in the same way as in the other two species. She breeds only one egg, which is placed in a bag on her stomach, and feeds her cub with milk.
Comparative characteristics
And now let's look at the types of mammalsliving on the Australian continent. So, what is the difference between egg-laying, marsupial and placental mammals? First you need to say that all mammals feed their offspring with milk. But the birth of babies has huge differences.
Oviparous animals have one commonfeature. They lay eggs like birds and hatch them for a specific time. After the appearance of offspring, the mother's body produces milk, which the babies eat. It should be noted that the young do not suck milk, and lick it from the grooves in the female on the stomach. The absence of nipples distinguishes egg-laying from other mammals.
The marsupial mammals have a brood bag,hence their name. The bag is located on the belly of females. The newborn baby, reaching it, finds the nipple and hangs on it, as it were. The fact is that babies are born unformed and spend a few months in the mother’s bag until they are fully developed. It must be said that egg-laying and marsupial mammals in this respect have similarities. Babies of echidna and prochid are also born underdeveloped and placed in a kind of brood fold.
And what about the placental mammals?Their babies are born fully formed due to the placenta in the uterus. Due to it, the process of feeding and development of the cub occurs. The bulk of the animals belongs to the placental.
Here is a variety of species exists on the same continent.
