Prehistoric civilization has always been a favorite topic, especially in the United States, where conspiracy theories and mysticism were prevalent. Even without evidence, these enthusiasts can produce one research report after another, let alone dig up the real hammer.
Since the beginning of the twentieth century, a strange spiral-like thing, like a huge drill, has often been found in the desert of Nebraska, usa.
Everyone is puzzled by this, these "drill bits" are well-shaped and hard, much like auger pipes for exploration.
Everyone was immediately excited, was this a tool for ancient civilizations to repair the earth?
But as the full picture of the spiral was discovered, everyone felt that this should not be a drill bit, because these spiral-like things still have a long slash underneath, and this "drill bit" is generally found in soft sandstone, and these drill bits are exposed after the sandstone is weathered.
After careful observation, it was found that the surface of these spirals basically had strange parallel grooves, like scratches of some kind of animal.
So a zoologist Larry. Martin made the bold assumption that these drills were not home to some kind of animal.
Sure enough, he opened the huge drill and found a fossil of a rodent, which was the ancient beaver.
They have strong teeth and powerful claws, and those grooves on the surface of the spiral are actually their tooth marks.
Ancient beavers lived in the Mesozoic Era, 20 million years ago, when they weren't very good at swimming, but engineers' genes are estimated to have been passed down since then.
Spiral-shaped nests are warm in winter and cool in summer, which is also conducive to confusing enemies. The ancient beaver also laid a lot of plant fibers on the cave wall, making the storage room and nursery below dry and comfortable.
As the ancient beaver gradually disappeared, the silica particles in the surrounding formation gradually seeped into the plant fibers of the cave wall, and finally formed a hard inverted fossil. This is where those strange "drill bits" come from.
The current beaver has inherited the fine traditions of its ancestors and has made new breakthroughs in the construction of water conservancy projects. They are not satisfied with living underground, but have built a lot of lake-view villas by themselves.
Today's beavers are much larger than their ancestors, reaching up to a meter and a third in length and weighing up to 27 kilograms. It is almost four times the size of an ancient beaver and is the second largest rodent in existence.
The main species of beavers are the American beaver and the Eurasian beaver, and living in China is a subspecies of the Eurasian beaver, called the Mengxin beaver. They are mainly distributed in the Ulungu River Basin in Xinjiang, and the number is less than 1,000.
Beavers don't move fast on land, running slower than sheep. But they are not afraid of wolves or snow leopards, because beavers can swim in addition to running.
Even the entrance to the nest is placed in the water, and if you do not understand their habits, you will not be able to find where they live.
Beavers are master builders among animals, cutting down many branches to build their nests and reinforcing the walls of their nests with mud. Their home is like a fortress, with a height of 1.5 meters to 3 meters, and a diameter of about 2.5 meters at the bottom, which is very spacious. The thickness of the façade is about 30 cm, which is very strong.
On the periphery of the beaver house, there is always a circle of water surface like a moat, and they must keep the water depth above 1.2 meters in order to effectively flood the entrance and ensure safety.
To this end, they have spared no effort to build large-scale construction, build embankments and maintain water levels. If they live farther away from the tree, they will even dig a canal to transport the wood over.
There are also risks in the logging process, and from August to November every year, the beaver dam construction period is relatively tight, and work injuries are inevitable at this time.
In the case of a surplus of wood, the beaver will build four or five houses, this one is tired of living that, and the other is tired of living in this. Writing this, the author shed tears of envy.
But in the winter, they mainly stay in a nest. They will store a large number of juicy branches as a reserve grain, and then the cat will be in the nest, rubbing its stomach, eating snacks, and happily staying in the house for a winter.
Beavers generally live together as husband and wife, crossing the river of love in January and February every year, and ushering in the crystallization of love in April and May every year. Babies may be only children or sextuplets.
Babies can swim the day after they are born, but they can't live independently until they're three years old, and beavers can live up to 20 years.
Beavers are the dominant species in the local area, and its presence can improve the local ecological environment, increase the area of river irrigation, and indirectly expand the forest coverage.
The world's longest beaver dam is in Canada, with a total length of 850 meters, and this dam has been built since 1975, and countless beavers have worked hard for it. The dam is the length of two and a half Hoover dams, 1/3 three Gorges Dam, and now there are about 4-5 beaver families living here, and the size of this dam continues to expand. The red line in the picture is the dam.
Due to their architectural nature, beavers are not suitable for captivity.
In 2017, a baby beaver moved into a ranger's house after losing its parents. The little ones are cute and quiet. But gradually the owner found that everything in the family had been moved by this guy to build a dam on the floor. As for why the dam is built in the house, it can only be said that this is an engineer's instinct.
Beavers have beautiful furs, and eggs secrete an aroma similar to vanilla ice cream. So beavers are also a traditional source of fur animals and spices. The picture below is a beaver skin, and in the lower right corner is its dried eggs.
However, we can wear no leather clothes and do not use this type of perfume.
Let them go, let the beaver happily go to the logging to move the bricks, and be happy to be an engineer.
Thank you for watching.
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