Author: Jiang Hong (Yantai Museum)
Source: Knowledge is Power magazine
The world we live in is full of mysteries of all kinds, and as science progresses, many mysteries are finally solved. There is a mystery that comes from the underground of the Interior of the United States, which is a number of strange rocks in the form of spirals, known as the "Devil's Spiral". What kind of secrets are hidden behind the "devil's spiral"? Let's explore how the mystery that has plagued scientists for nearly a century has been solved.
Spiral rocks beneath the plains
Nebraska is located in the Midwest of the United States, where the terrain is flat and the open plains are not visible. Located in northwestern Nebraska, bordering South Dakota and Wyoming, Sioux County is a symbol of the Sioux Indians who once lived on the land. When the whites drove out the Indians and occupied the land, they began to carry out modern agriculture and animal husbandry. In 1891, a rancher dug up a strange stone while reclaiming his ranch, and when he continued to dig down the shape of the stone, he actually dug out a spiral-shaped strange stone with a height of 3 meters, which no one had ever seen. The rancher reported his discovery to the county government, which brought in Elvin Sinclair Barber, a geologist and paleontologist at Nebraska State University.
The spiral rocks dug by the excavators have tunnels at the bottom that extend to both sides.
As soon as Barber got the news, he rushed to Su County, and after seeing the strange rocks, he immediately began to dig up the surrounding area, and many of the same strange stones were excavated. As a paleontologist, Barber's first reaction was whether the strange stone could be the remains of some prehistoric creature. After consulting the extensive literature, Barber did not find any similar findings, so he said in the report: "This structure is so magnificent and perfectly symmetrical that I cannot understand." Barber named the strange stone "Daimonelix," which means "devil's spiral, or "devil's corkscrew."
Paleontologist Elvin Sinclair Barber
Thanks to the eye-catching name of "Devil's Spiral", the news of the discovery of spiral-shaped strange stones in the Nebraska wilderness immediately spread throughout the United States, and the strange stones attracted the attention of many scientists. In 1892, Barber published an explanation for the origin of the "Devil's Spiral", arguing that the strange rocks were actually the remnants of a prehistoric giant freshwater sponge, which today's arid and desolate Nebraska was once covered by a huge inland lake 20 million years ago. Later, Barber added that the "devil's spiral" may also be formed by the coiling entanglement of some kind of plant root system, which is filled with minerals after the root system decays to form fossils. Barber's explanation was quickly accepted, after all, he was the first researcher of the "devil's spiral" and he had a large amount of first-hand information, but some people did not agree with his views.
In 1893, Edward Drick Kopp, one of America's most legendary and famous paleontologists, put forward a different view, arguing that the "devil's spiral" was a cave casting mold excavated by some kind of large rodent. Soon after, Theodore Fox, an Austro-Hungarian paleontologist and authority on fossil and monumental science, expressed support for popular science and believed that the animals digging burrows should be related to today's sac rats. Fox also pointed out that the rock formation where the Devil's Spiral is located is not a lacustrine deposit, and that the plant fibers found in the filler can be interpreted as the food stored by rodents. Another paleontologist, Olaf Peterson, purchased a batch of "Devil's Spirals" to enrich the Carnegie Museum's collection, many of which had tunnel-like extensions at the bottom. Peterson cleaned and studied the tunnel structure, and when he cleaned up to the end of the tunnel structure, he found a fossil of rodents, which was identified as belonging to the extinct ancient beaver, an animal that lived in an arid area and had the habit of digging cave dwellers.
Fossil skulls of ancient beavers have huge upper and lower front teeth
Regarding the cause of the "devil's spiral", the "plant school" represented by Barber and the "animal school" represented by science popularization were eventually formed, and the two factions did not give in to each other, and they tried their best to find evidence that could support their own views. In this way, the exploration of the causes of the "devil's spiral" has reached an impasse, which has lasted for more than 70 years, and the "devil's spiral" remains a mystery.
Abandoned underground mansion
In the 1970s, Larry Martin, a well-known paleontologist at Kansas State University, restarted research on the "devil's spiral", and he led the team to carry out research from multiple perspectives. At the same time, geologists have also re-studied the strata around the Devil's Spiral, showing that the fine-grained sediments in the formation were formed by the action of wind piles under seasonal drought conditions, which is roughly similar to the environment in Nebraska today. It is this particularly dry environment that preserves the "Devil's Spiral", in addition to the abundant fossils of small mammal caves, insects and plant roots.
Paleontologist Larry Martin
Martin's team published a research paper that determined that the "devil's spiral" was excavated by the ancient beaver, and also gave a detailed explanation and explanation of the excavation methods and processes. An important reason why Barber previously opposed the ancient beaver as a "devil's spiral" excavator was that no traces of claw excavation were found on the inner wall of the spiral structure, and today's mammals that can dig holes are excavated with claws on the forelimbs. The explanation given by Martin's team is that the ancient beaver used not claws but front teeth, because the front teeth of the ancient beaver are wide and strong, shaped like a hoe for planing the ground, and the marks left on the inner wall of the "Devil's Spiral" also match the front teeth of the ancient beaver.
Since the "devil's spiral" was really excavated by ancient beavers, how did they dig out such a symmetrical spiral structure? When the ancient beaver digs down the cave, it will support the bottom or side of the cave with its hind limbs, and then dig down with its front teeth in the direction of the cave spiral, so that its hind limbs become the axis, and the previous half of the body is radius, and it is spiraling downward to dig out a cave with a nearly perfect spiral structure.
Martin also explains why the cave is full of plant fibers, arguing that the plants were not stored as food by ancient beavers, because the spiral structure is a passageway, not a storage room. When the ancient beaver became extinct, the cave was abandoned, but the warm and humid environment in the cave was very suitable for the growth of plants, so it became a small paradise for plants. Martin's team explained the cause of the "devil's spiral" with a comprehensive investigation and meticulous analysis, and their research convinced everyone that a mystery that had long plagued the scientific community was finally solved.
Ancient beavers: the "living home" full of wisdom
Although we have already cracked the secret behind the "Devil's Spiral", its very unique structural shape is still fascinating, and the builder is the ancient beaver mentioned earlier.
Paleo beavers lived in North America from the end of the Oligocene to the early Miocene, 25 million to 20 million years ago, and belonged to the beaver family in taxonomy. The existing beavers should not be unfamiliar to everyone, this large rodent widely distributed in the temperate regions of the northern hemisphere prefers to live in pond wetlands, and a large flat tail on the back proves that they are all good swimmers. Beavers have a convincing ability to search for and process branches to build, which ensure that the pond water level does not drop, and their home is located in the center of the pond, away from danger.
In terms of appearance, there is a clear difference between ancient beavers and beavers, they are not only smaller, but also do not have a flat tail for swimming. Ancient beavers and beavers are not similar, but somewhat similar to marmots and gophers, which is to adapt to land life, and the ancient beaver is the representative of the beaver family marching into the inland environment.
The beaver is one of the world's ancient animals, known as the "architect" of the animal world and the "living fossil" of the ancient vertebrates.
Restoration of the ancient beaver
Despite their distance from water sources, ancient beavers still possess the greatest building abilities in the beaver family, except that they do not build dikes, but build top mansions underground. The "devil's spiral" is actually just the passage of the ancient beaver's underground mansion, and the spiral-like passage has three advantages: the first is to regulate temperature and humidity, the spiral-like passage lengthens the distance of the air into the bottom of the cave, which is convenient for cooling the air and increasing humidity; the second is to prevent invasion, when the carnivores drill into the spiral-shaped channel, it is easy to be surrounded and lose the sense of direction; the third is easy to clean, compared to the cave straight up and down, the spiral-shaped channel slope is more gentle, and it is easy to push the excavated soil or domestic garbage outside the hole.
The spiral passage is actually only the first half of the ancient beaver cave, and at the bottom of the passage there will be a straight extension tunnel at a 30-degree angle upwards, and different spaces will be separated in the extension tunnel, such as living rooms, baby rooms, storage rooms, etc. Paleontologists have even found small but deep spaces, most likely "sinks" used by ancient beavers to go to the toilet. In order to increase the comfort of living, the ancient beaver will spread dry plants in the living room and the baby room, which is very comfortable to think about. It has to be said that the ancient beaver is an animal full of "wisdom" and has a pursuit of life.
At the bottom of the spiral channel, there will be a straight extension tunnel at an angle of 30 degrees, separating different spaces in the extended tunnel. (Drawing/Luo Mei)
Ancient beavers with underground mansions have also changed their breeding strategies, and unlike rodents, which breed by quantity, ancient beavers prefer to win by quality, giving birth to only a few offspring per litter, and then raising their cubs in the cave until they can live independently and dig their own burrows. It is precisely because of the ability to excavate unique and complex caves that the ancient beaver was able to survive in the harsh inland environment.
The ancient beaver, which had the art of building underground mansions, became extinct about 20 million years ago, because its living environment changed from relative humidity to seasonal drought or even complete drought desertification. After the ancient beavers disappeared, the caves they dug were occupied by plants, and the roots of the plants absorbed the silica in the surrounding soil, causing the hollow walls to gradually silicate and harden, forming the silicified structure of the white fibers we see today. In this way, the cave of the ancient beaver became a relic fossil, becoming the famous "devil's spiral".
Today, we have full insight into how the "devil's spiral" is formed, and the insistence of scientists in searching for answers for nearly a century is the epitome of human beings never giving up in search of truth!
(Editor-in-Charge / Huang Yingying Art Editor / Zhou You)