At that time, there were two theories about this fossil. One tooth comes from a shark's tooth, and the other comes from a fin on the back of some marine creature. At that time, people used their imaginations about the position of teeth. 1952, an archaeologist suggested that if the spiral teeth are located in the lower jaw of a living thing, it will hinder its eating, so it should grow in the upper jaw to play a protective role. However, human beings have not exactly analyzed the position of rotating teeth, and can only simulate the position of such teeth according to speculation. Later, a scientist discovered another spiral tooth fossil connected with the jaw, and people finally determined the position of the spiral tooth. Spiral tooth is the lower jaw of spiral tooth shark, which is located on the left and right sides of the joint between lower jaw and upper jaw. This shark is also called spiral tooth shark.
Spiral tooth shark
At present, Megalodon is extinct. It mainly lived in the Permian period and was about 7- 15 meters long. Because Megalodon is a cartilaginous fish, it is difficult to leave fossils. So far, scientists have unearthed a complete skeleton fossil, so people don't know much about it, but we can see a corner of it from its teeth. From the point of view of teeth, spiral tooth shark is a carnivorous species, because the tooth structure of carnivores and herbivores is different. We know that herbivores need to grind the stems and leaves of plants, so herbivores' teeth are flat. On the other hand, carnivores have sharp teeth because they tear food and attack prey with their teeth. The bite force of spiral tooth shark is similar to that of crocodile now. Once the spiral tooth bites the prey, it can hold the prey and then bite it down. The angle of spiral tooth shark's mouth is 90 degrees after opening, while the angle of cannibal shark is only 60 degrees after opening, so it is easy for it to push food deeply into its mouth.
Scientists have carefully studied the tooth fossils of more than 50 spiral-toothed sharks in/kloc-0, and found that these tooth fossils are rarely worn, so they guess that the food of spiral-toothed sharks is mainly fish mollusks, similar to octopus. It has many teeth, but most of them are rolled together. Only about 10 teeth are exposed. These exposed teeth are all new teeth, and most of them are involuted. Old teeth? Therefore, scientists also speculate that the number of teeth of spiral-toothed sharks will increase with age, new teeth will grow out of the lower jaw, and old teeth will gradually curl.
So far, scientists have not studied the natural enemies of spiral toothed sharks, and they are probably the top hunters in the ocean. Megalodon lived 290 million to 250 million years ago and survived for nearly 4,000 years. It is a globally distributed fish, and its fossils have been found in many parts of the world. Because the spiral toothed shark is a cartilaginous fish, its bones are difficult to form fossils, and only hard teeth have been preserved so far, so people's research on spiral toothed shark mainly focuses on teeth. However, according to the available data, the spiral toothed shark may not be a shark, but a vertebrate, but there is no evidence to prove it, or with the help of archaeological excavation, we can further understand the secret of the spiral toothed shark.