【雑学】子供の疑問 || なぜユニコーンは存在しないのか？

I wonder why kids overseas love unicorns so much. They're now so beloved that they're considered dreamy cute, and I started making videos thinking I should show them some reality. I wonder how many Japanese children are enthralled by unicorns. If anything, I'm more impressed by older kids yelling "UNICOOOOOOOOO!" That's why I aimed to make a unicorn video for adults. Yuunicooooooooooo!! Beep beep beep beep~ Useless knowledge you won't be able to use tomorrow, This is a compressed trivia channel. This channel aims to create videos that pack in a lot of useless knowledge, into a short amount of time. Due to the creator's circumstances, updates will be irregular. Instead, I'll make videos that will make you chuckle, so please support me if you enjoy. Horn Structure and Types The horns of modern mammals are often organs formed from modified bones. The horn of the rhinoceros shown in the video is composed primarily of keratin, like a stiff, solid tuft of hair. Because it is a tuft of hair, it naturally does not affect the skeleton, and the horn's shape is unlikely to remain as a fossil. The horns known as "solid horns" were prized as traditional Chinese medicine, leading to overhunting and a sharp decline in their numbers. Rhinoceroses are currently protected by the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES), and hunting for their horns is generally prohibited. However, poaching and shooting continues unabated. As a result, conservation agencies sometimes resort to the desperate measure of removing rhinoceros horns beforehand. Horns of other ungulates can be classified as "branched antlers," "sinus antlers," and "ossicones." Branched antlers refer to the branched horns of animals such as sika deer and reindeer. Horns grow from a part called the antler bone at the tip of the skull. Once the antlers have fully grown, their base is destroyed by osteoclasts and they fall off. So where do these shed antlers go? In fact, small animals gnaw on them as part of their diet. Because antlers are rich in calcium, phosphorus, and minerals, this tendency is particularly pronounced in areas with mineral deficiencies. The remaining remains decompose in the soil, helping to replenish the soil with phosphorus, an essential nutrient for plants. The antler shedding practice in deer families is therefore a very logical evolutionary process, as it maintains the surrounding ecosystem and indirectly allows them to grow their own food. Dormitory antlers are a form of antler found primarily in the Bovidae and Prognatidae families. A horn protrusion that serves as the core of the antler is located on a part of the skull, and the horn skin grows over this bone. It's like the relationship between a Japanese sword and its sheath, and the part we see is the sheath. For this reason, the horns are also called horn sheaths. The horn sheath is made of protein and keratin, and in proghorns these sheaths are replaced. In contrast, the horns of bovids continue to grow throughout their lives. The ossicone is a horn of the giraffe family, and forms directly on the skull. Giraffes have five horns: one between the eyebrows, two on the caput, and two on the upper part. These horns are covered on the outside by skin and hair, and are not exposed like other species. Incidentally, giraffes engage in a behavior called necking, in which they use centrifugal force to swing their necks around and hit each other. This behavior, which is mainly seen during the breeding season, involves the horns increasing the weight of the head and helping to maximize centrifugal force. However, compared to other organisms, their horns aren't as well-used, and the purpose of the horns between their eyebrows and on the back of their heads remains unknown. During mating season, males have the strange habit of rubbing their heads against the female's crotch to encourage urination and then shower her. If they use the bones on the back of their heads exclusively for this purpose, they must have had quite the fetish. Bonus: Pronotheridae A species thought to have branched off from the earliest Equidae, appearing in the early Eocene. Fossil remains show horn-like bones formed on the skull, like those of cows, making them similar to the now-defunct Perissodactyla, which possessed bony horns. Classification-wise, they are generally considered distinct from modern Perissodactyla and are considered a separate family, the Pronotherioidea. However, some researchers have included them in the Equiformes, while others have included them in the Horned Order, such as rhinoceroses, so their relationships and classification are not entirely stable. The Pronotheriidae family continued to expand their reach by increasing in size until the Oligocene epoch. But climate change made it difficult to obtain food, and they went extinct. If they had survived after that, they might have evolved into something we could call a unicorn. How romantic....