The ancestors of the platypus appeared as early as 180 million years ago in the Jurassic Period, when they were widely distributed. But by 70 million years ago, many more advanced mammals multiplied in large numbers, and these ancient animals gradually became extinct. But animals living on the Australian continent are lucky. Australia was separated from other continents due to crustal movement. Therefore, mammals that appeared later could not reach this place. The ancestors of the platypus were able to live and multiply here, and have always preserved their original egg-laying state. It plays an important role in studying the origin of mammals.
The rhinoceros is a strange animal, because most mammals are viviparous, but this Australian animal is oviparous. Among all mammals, only they and the echidna, another rare animal also native to Australia, lay eggs.
Although the mother also secretes milk to feed her young, they are not viviparous but oviparous. That is, the eggs are laid by the mother and hatched by the temperature of the mother's body like birds. The mother has no breasts and nipples, and secretes milk on both sides of the abdomen. The cubs lie on the mother's abdomen to lick food. The larvae have teeth, but the adult gums have no teeth and are replaced by horny plates that can continue to grow. The front biting surface of the plates forms many raised transverse ridges, which are used to crush or chop shells of molluscs such as shellfish and snails. To crush other food, the rear horny plate is flat, and the flat uvula opposite to the plate has an auxiliary "chewing" effect. It is a poisonous egg-laying mammal.
Spring is the season when platypuses give birth to their young. Usually the female finds a stable place on the bottom of the water and then digs a cave about 20 meters long. The tiny platypus actually dug such a large cave and built a mansion for himself and his future children. The female usually lays two eggs in a mansion, and after two weeks of hard work, her baby is finally born. At this time, the platypus mother can hold her babies in her arms and feed them milk. It takes three to four months for the cubs to grow up.
During the breeding season, the adult platypus digs a special hole on the river bank with the wide nails on its front feet. The hole is about 30 meters long and contains one or more small nests.
The female platypus will lay 2 or 3 soft-shell eggs, and the young will hatch after 10 days. From then on, they behaved more and more like mammals: young platypuses feed on their mother's milk until they are old enough to leave their burrows.
The platypus is a carnivore - preying on insects and other small animals that live in flowing streams and river bottoms. Under water, the platypus closes its eyes and uses its soft and sensitive bill to dig through the mud in search of food.
The platypus chases and mates in the water, and its eggs are shaped like turtle eggs. After the baby platypus hatches, it needs to be breastfed for 4 months before it can go out to find food on its own.
The female digs a 16-meter-long ravine and lays her eggs in a nest made of wet aquatic plants. She lays three eggs per lay, sometimes three. The eggs are smaller than sparrow eggs and stick to each other. During the incubation period, the hole is blocked, and the hatched cubs are very incompletely developed. The platypus has neither a brood pouch nor nipples, and the bundled mammary glands open directly to the abdominal mammary gland area. The cubs use their retractable tongue to take in the milk from the milk area, and the lactation period lasts for about five months. More than two hundred years ago, when the first British explorers brought back a platypus specimen from Australia, all the scientists could not believe their eyes: the body was like an otter, covered with thick fur, and the mouth was as wide as a duck's bill. Flat, with four webbed feet and a tail as broad as a coypu. Scientists believe that this strange mixture must be a fake made by someone as a prank. The most incomprehensible thing is that this animal can lay eggs like a reptile or bird. After the eggs hatch, they can feed their young with milk like mammals. This goes against scientists' established distinctions between mammals and non-mammals. After much controversy and research, scientists finally concluded that this strange animal belongs to the "monotremes" family, that is, "egg-laying mammals", and was named "duckbilled platypus" (platypus). This animal represents a step in the evolution from reptiles to mammals.