Everyone knows from the school program on mammals. But do you know that an oviparous mammal is a separate animal species that lives only on the territory of one continent - Australia? Let's look at this particular kind of animal in more detail.
Opening oviparous
For a long time, the existence of unique animals that breed, hatching eggs, was not known. The first report of these creatures came to Europe in the 17th century. At this time, a skin of a marvelous creature with a beak covered with wool was brought from Australia. It was a platypus. Alcoholic copy was brought only after 100 years. The fact is that platypuses practically do not tolerate captivity. It is very difficult for them to create conditions during transportation. Therefore, they were observed only in the natural environment.
Following the discovery of the platypus, news came of another creature with a beak, only now it is covered with needles. This is echidna. 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, egg-laying mammals, should be placed in a separate squad. So there was a single-pass squad, or cloacal.
Amazing platypus
A unique creature leading a nocturnal lifestyle. Platypus is common only in Australia and Tasmania. The animal lives half in the water, that is, it builds burrows with access to water and on land, also feeds in water. The creature is small - up to 40 centimeters. It has, as already mentioned, a duck nose, but at the same time it is soft and covered with skin. Only in appearance is very similar to duck. There is also a 15-centimeter tail, similar to the tail of a beaver. The paws have membranes, but they do not interfere with the platypus walking on the ground and digging holes perfectly.
Since the genitourinary system and intestines of the animal go into one hole, or cloaca, it was attributed to a separate species - Cloacaceous. Interestingly, the platypus swims, unlike ordinary mammals, with the front paws, and the hind legs serve as a helm. Among other things, let's pay attention to how it multiplies.
Breeding platypus
An interesting fact: before breeding, the animals fall into a 10-day hibernation, and only after that the mating season begins. It lasts almost all autumn, from August to November. Platypuses mate in water, and after a two-week period, the female lays an average of 2 eggs. Males do not participate in the future life of offspring.
The female builds a special hole (up to 15 meters long) with a nest at the end of the tunnel. Lines it with raw leaves and stems to maintain a certain humidity so that the eggs do not dry out. Interestingly, for protection, she also builds a barrier wall 15 centimeters thick.
Only after preparatory work does she lay eggs in the nest. The platypus hatches 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 directly from the pores into the furrows and accumulates in them. Toddlers lick milk and thus feed. Feeding lasts about 4 months, and then the kids learn to get their own food. It was 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. In appearance, this animal looks like a hedgehog, but with a long narrow beak, not exceeding 7.5 centimeters. Interestingly, the echidna has no teeth, and she catches prey with a long sticky tongue.
The body of the echidna is covered on the back and sides with thorns that are formed from coarse wool. The hair covers the stomach, head and paws of the animal. Echidna is fully adapted for a certain type of food. She feasts on termites, ants and small insects. She leads a daily lifestyle, although finding it is not easy. The fact is that it has a low body temperature, up to 32 degrees, and this does not allow it to suffer a decrease or increase in ambient temperature. In this case, the echidna becomes lethargic and rests under the trees or hibernates.
The method of reproduction of echidna
Echidna is an egg-laying mammal, but it was only possible to prove this at the beginning of the XXI century. Interesting mating games echidnas. There are up to 10 males per female. When she decides she is ready to mate, she lies on her back. At the same time, the males dig a trench around her and begin the struggle for primacy. The one who is stronger copulates with the female.
Pregnancy lasts up to 28 days and ends with the 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. A baby comes into the world not fully formed.
Young
The birth of such a baby is very similar to the birth of young marsupial animals. They also undergo final development in the mother’s bag and leave it as adults, ready for independent life. Interesting fact: marsupials are also common only in Australia.
How does the baby echidna appear? He is blind and naked, his hind limbs are not developed, his eyes are covered with a leathery film, and fingers are formed only on the front paws. To get to the milk, the baby needs 4 hours. It is interesting that in the bag the mother has 100-150 pores that secrete milk through special hairs. The kid only needs to get to them.
The baby is in the mother’s bag for about 2 months. He gains weight very quickly through 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 young growth learns to get food on their own.
Passageway
Passage is another ovipositing mammal. This creature is much larger than its counterparts. The habitat is the north of New Guinea and the islands of Indonesia. The projidina’s dimensions are impressive, up to 80 centimeters, while its weight is up to 10 kilograms. In appearance, it looks like a echidna, but the beak is much longer, and the needles are much shorter. She lives in mountainous areas and feeds mainly on worms. The structure of the oral cavity is interesting: the tongue has teeth, and with it it is able to not only chew food, but, as has been noticed, even turn stones over.
This species is the most poorly studied, as it lives in the mountains. But at the same time it was noticed that the animal does not lose mobility in any weather, does not hibernate and is able to regulate the temperature of its own body. Reproduction of oviparous mammals, which include prochidna, occurs in the same way as in the other two species. She displays only one egg, which is placed in a bag on her stomach, and feeds the cub with milk.
Comparative characteristics
Now let's look at the species of mammals that live 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 thing in common. They lay eggs like birds, and hatch them for a certain time. After the appearance of the offspring, the mother's body produces milk, which the babies eat. It should be noted that the cubs do not suck milk, but lick it from the grooves on the female’s stomach. The absence of nipples distinguishes the egg-laying from other mammals.
Marsupial mammals have a brood pouch, hence their name. The bag is located on the stomach of females. Having reached her, a newborn baby finds a nipple and, as it were, hangs on it. The fact is that babies are born unformed and spend a few months in their mother’s bag until they are fully developed. It must be said that ovipositing and marsupial mammals in this respect have similarities. Toddlers are echidna and prokhidny also born underdeveloped and placed in a kind of brood fold.
And what about placental mammals? They have babies born fully formed due to the presence of the placenta in the uterus. Due to it, the process of nutrition and development of the cub occurs. The bulk of the animals belongs to the placental.
This kind of species exists on one continent.