In 1798, a man named John Hunter sent a special specimen to the British Museum, when this specimen appeared in front of scientists, almost no one believed that it was a real animal, because it was too many strange places on its body, so much so that in the next 85 years scientists are still debating.
This strange specimen came from Australia and was close to the size of a rabbit, with a mole-like body, and a beaver-like tail, webbed limbs, and a duck-like beak that was too magical for Europeans at the time.
All the museum scientists feel that this is a prank, someone has made this "fake specimen", but they can not find any fault. When the specimen was exhibited in the London Museum, there was a steady stream of visitors, each hoping to find the "hidden thread", but none could succeed, because it was a real creature - the platypus.
Have three types of biological characteristics
After scientists confirmed the existence of the platypus, a new question arose about the classification of the platypus. Although the platypus had a long, tight, smooth coat that was very much in line with the characteristics of a mammal, no nipples were found on its body. Even the platypus' mammary glands were only found by scientists in the 1830s.
After further digging, scientists found that the platypus had a cloaca that only birds and reptiles have, which means they excrete and reproduce by this one organ.
According to the Australian Aborigines, there was a runaway duck that was taken captive by a giant water rat, and when the duck escaped back, it laid two eggs that hatched into the platypus. Although this is just a story, it also points out a characteristic of the platypus: it is oviparous.
But if it is a bird, it does not have the presence of the stomach organ in the body, the esophagus and intestine directly connected, which does not meet the characteristics of birds, but in some lower mammals and fish.
All kinds of contradictory manifestations made scientists scratch their heads, and finally, scientists had to set up a whole new category under the Mammalia: Monotremes. Of course, another monotremata was later discovered, the echidna, which also lives in the magical Australia.
The peculiar duckbill
The most prominent feature of the platypus' appearance is its duck beak, which is also the origin of its Chinese name. However, its mouth and the duck is only similar in appearance, but in fact, it is very different. The platypus beak is not hard, but similar to the rubber-like soft and flexible, but also has a very magical function.
When the platypus dives underwater to feed, its eyes, ears and nostrils are all closed, which means that the platypus is deaf and blind. But they can still accurately find small fish and shrimp, a variety of insects, worms and shellfish, they do not use intuition, but electromagnetic induction.
The platypus' mouth is densely covered with sensitive nerve endings, as well as a sensor that picks up a weak bio-current. Although we usually do not feel, but in fact, any living organism, as long as it is still alive will produce bio-current. The platypus relies on the induction of bio-current to find prey.
And when they hunt, they do not eat the food directly, but first stored in a "small sac" at the cheek, so they are hunting when the action is smooth, basically no time to stop. After completing the hunt, they will begin to slowly handle the prey.
Because of a long duck beak, unable to chew action, so another characteristic of mammals: teeth, also abandoned by the platypus. Only young platypus have teeth, and when they reach adulthood, they will all lose their teeth. In their place, the teeth are replaced by keratinous plates that continue to grow on the dental bed. The platypus then relies on the horny plates to grind up food and then finish eating.
They eat a lot, a platypus a day to eat 20% of their own body weight of food, if it is in the lactating female platypus, even eat and their own weight of food.
Retractable webbing
Platypus is also a master builder, their nests are usually built on the edge of rivers and lakes, they rely on strong forelimbs to dig burrows, and do not have to worry about the webbing on their feet will therefore be injured, because their webbing is different from other animals, can be like a tiger's claws contracted up, when they are on the shore, they will be webbed into the palm of the foot, revealing sharp claws.
The entrance to the platypus nest is generally 20 centimeters above the water surface, but the depth of the hole is able to reach more than 15 to 20 meters, which is equivalent to about seven or eight floors underground if calculated according to the height standard of 2.2 meters on our underground floors, and the platypus will also dig three escape exits.
In the entrance and exit, the platypus also set up a variety of partitions, able to regulate the temperature and humidity inside the cave, but also to prevent the invasion of predators, can be said to be both comfortable and safe.
The platypus that is "as good as it looks"
In 2008, the United States, Australia, the United Kingdom and other countries on a female platypus genetic sequencing, found that they are really "the same", not only the appearance of reptiles, birds and mammals have three types of animal characteristics, from the genetic point of view, the platypus also contains a number of genes unique to the three types of animals.
For example, the three yolk-producing genes are capable of forming all the nutrients needed for the development of oviparous animals. These three genes are simply useless to fetal mammals because they do not produce eggs, but compared to normal birds and reptiles, the platypus has genes that can only sustain egg formation. Therefore, the platypus also has the mammalian gene for milk secretion, and relies on milk to provide nutrition for the growth of baby platypus.
However, platypus do not have nipples, and their duck beaks do not support the action of "sucking". So their way of breastfeeding is also completely different from other mammals. Its milk is like sweating, from the pores on the skin of the abdomen, seeping out through the fur converge to a depression on the platypus stomach, the baby platypus on the mother's stomach to lick the milk.
Because the milk is in direct contact with the outside world, inevitably exposed to a variety of bacteria, in order to prevent the baby platypus from being infected by bacteria, the milk secreted by the platypus also contains a platypus unique antibacterial protein. Such as
In addition to this, the platypus also possesses a gene for toxin production, which is extremely rare in mammals, but is more commonly found in reptiles such as snakes and lizards. The platypus does not have venom glands, but the male platypus has a venomous stinger on his hind feet that stores venom made from a mixture of toxic proteins, three of which are unique to the platypus and can not only sting, but also squirt venom out like a viper.
Their toxicity is capable of killing an animal the size of a dog, and while not fatal to humans, it is enough to incapacitate them. After being stabbed by a platypus' venomous stinger, the entire wound will quickly swell and produce severe pain. This severe pain may also last for dozens of days, or even months.
The venomous spines of the platypus, however, are not used for hunting but for competition for mating rights, so only male platypus possess venom, and only in spring and winter, their mating season.
Scientists' research has also found that the proteins in their venom can also alleviate cancer patients, and perhaps through the study of these proteins, mankind will one day in the future defeat the demon of cancer.
The genetic peculiarities of the platypus do not stop there, their sex chromosomes are also very strange. People and most other mammals usually have two sex chromosomes, X and Y, to determine gender, but the platypus has a full 10 sex chromosomes, and the genes on the sex chromosomes are more similar to those of birds after comparison.
After tens of millions of years of evolution, the platypus has never gone extinct, but also became the oldest existing mammal, with three types of animal characteristics, as if stopped at the junction of evolution, every time we know more about it, it will generate new questions and controversies, no wonder some people say, if there is no information on the record, I'm afraid that millions of years later, humans can not imagine that the world has existed such a magical creature it.
References
The Way of the Platypus with Poison
The Intriguing Platypus" by Nianhua Li
The Living Fossil, the Platypus" by Hu Guanglin
The Platypus from the Ancient World" Lily Du
The Platypus of the Four Unlikes" Fang Yueqing