(5) Ancient rhinoceros ‘Elasmotherium’
Preparing for the Elasmotherium exhibition at the Utsi Museum in the Czech Republic. You can tell the size of the horn. Source | Czech Utsi Museum
It has cute funnel-shaped ears that move freely back and forth and left and right, and its eyes are located on both sides of its face. If I explain it up to this point, it may seem like a cute and pitiful mammal whose daily life is in danger, but in reality, it is an animal that has no natural enemies in the wild. The rhinoceros has horns, thick and hard skin, and is the second largest mammal after the elephant.
There are 4 genera and 5 species in the Rhinoceros family, which belongs to the order Horse. They are the Indian rhino, Javan rhino, black rhino, white rhino, and Sumatran rhino. The one-horned Indian rhinoceros and Javan rhinoceros belong to the genus Rhinoceros, while the other two-horned rhinos belong to the same genus as their species names. Rhinoceros generally have poor eyesight, but have very sensitive hearing and a developed sense of smell.
Among the five species, only the white rhino has different characteristics. While other rhinos eat leaves, fruits, and grass as they can, white rhinos eat only grass. Additionally, except for white rhinos, all rhinos stay with their mothers only when they are young, and then live alone. Since there are no animals that dare attack them, there is no need to live in a group. There is plenty of food and no predators.
But it’s strange. Although they have no natural enemies in the wild, Javan rhinos, black rhinos, and Sumatran rhinos are critically endangered species, and the remaining Indian rhinos and white rhinos are also vulnerable to extinction. Even in the northern white rhino, one of the two subspecies of white rhino, there are only two female, mother and daughter, left. There is only hope that the semen of the last male, who died in 2018 at the age of 45, may be able to prevent extinction.
Elastotherium skeleton fossil. A huge dome structure at the base with a height of 15 cm and a circumference of 30 cm, which would have been equipped with horns, is visible.
Why are rhinos on the brink of extinction? We already know. This is because people covet rhino horn as an aphrodisiac. People who protect rhinos catch rhinos, cut off their horns, and then release them. It’s not just people who do this. Rhinoceros are also reducing their horns. It is getting smaller. By analyzing photos of wild rhinos taken around the world between 1886 and 2018, we were able to confirm that rhino horns became shorter over time.
This isn’t just about rhinos. Elephant tusks, sheep horns, and rhinoceros horns have been disappearing or decreasing in size over the past 100 years. 33% of female African elephants are born without tusks. 95% of male Asian elephants in Sri Lanka have no tusks. The size of the horns of bighorn sheep in Alberta, Canada has decreased by 20% over the past 20 years.
Elephants use their tusks to dig, lift objects, find food, and defend themselves. Horned sheep use their horns not only for confrontation and defense, but also to impress females. Rhinoceros use their horns for various purposes, such as finding food or fending off enemies. Ivory and horn exist for a reason, but they are decreasing due to human greed. This is the result of the standard distribution curve moving toward smaller or no horns and tusks, as animals with large, attractive horns and tusks have difficulty leaving behind descendants while being hunted.
Divided from modern rhinos 2.5 million years ago
The body is much larger, measuring 6 m in length and weighing 4 to 5 tons.
Large herbivores are hunted and become extinct.
Surviving modern rhinos also face the risk of extinction
Because humans covet horns as an aphrodisiac.
Do you know that you yourself will die because of your horns?
Over the past 100 years, horn size has become smaller and smaller.
Schematic diagram of the skeleton of Elasmotherium. We can guess that it had enough muscles on its back to support its huge horns. Source | Wikipedia
So what did ancient rhinos look like? In 1807, Princess Ekaterina Dashkova, former president of the Russian Academy of Sciences, donated the ‘Cabinet of Natural History and Rare Specimens’ to Moscow University, and began studying the premolars (small teeth) of certain animals included in it, leading to the discovery of Elasmotherium. ) was introduced to the world. The name comes from elasmos, meaning tooth enamel, and therium, meaning mammal.
Elasmotherium’s head has a structure that allows it to reach very low places. There are no incisors or canines, but the premolars and molars (large molars) have a much higher crown (the part visible to the eye, not hidden in the gums, and surrounded by enamel) than other animals in the horse’s neck. From this, we can see that Elsasmotherium lived by eating grass.
Elasmotherium diverged from a common ancestor with modern rhinos 47 to 35 million years ago and became independent as the genus Elasmotherium 2.6 million years ago. Elasmotherium can also be divided into several species due to subtle differences in teeth, jaw, and skull.
Elasmotherium arrived in Eastern Europe 2.5 million years ago. It is a time when the Earth’s temperature was 2 to 3 degrees higher than it is now, and it has become cold again. At this time, Antarctica was deforested, covered with glaciers, and the Arctic seas froze. Tropical rainforests were formed only in a narrow area near the equator, and most of the northern hemisphere was occupied by coniferous forests and tundra. Dry savannas or deserts appeared in Asia and Africa, and grasslands expanded throughout the world except Antarctica. This was the heyday of Elasmotherium.
The ancient rhinoceros ‘Elasmotherium’ appears in the cave paintings of Rufinac, France. Source | Paper collection Cranium 22, 1 (2005)
Elasmotherium was much larger than modern rhinos. It is estimated to have reached up to 6 m in length, approximately 2.5 m at the shoulder, and weighed up to 4 to 5 tons (modern rhinos were 2.5 to 4 m, 1.6 to 1.8 m, and 0.8 to 2.3 tons, respectively). You could say it was the size of an elephant these days.
Unlike modern rhinos, which are relatively short and stubby, Elasmotherium had long legs suited for running. It would have been a much more active animal, with a horse-like gait (of course, due to its large body, it would not have been able to run as fast and for long periods of time; it could be considered to have moved roughly at the same level as an elephant). Unlike modern rhinos, which have almost no hair on their bodies, Elasmotherium had thick fur covering their bodies, showing that they were well adapted to the colder Earth environment at the time.
These days, wild rhinos have their horns cut off and incinerated for protection, so you can’t see rhinos with normal horns, but if left alone, they can grow up to 55cm in length. So how big was Elasmotherium’s horn? Opinions are divided. This is because not a single horn of Elasmotherium has been found. The size of the horns can only be inferred from the size and shape of the base of the skull where the horns would have been attached.
The base of the forehead protrudes into a dome shape 15cm high and 30cm in diameter. So some scholars have suggested calling Elasmotherium dome-fronted rhinoceros or dome-fronted rhinoceros. However, relatively many scholars thought it had horns. A horn growing from a base with a diameter of 30 cm would have a base circumference of over 90 cm. Based on the size of the base and the size of blood vessels remaining on the surface around the dome, it was estimated that the horn could have grown up to 2 meters long. The vertebral structure, which suggested a large muscle mass on the back, supported the estimate of size.
There are no fossils, so on what basis would one make such an assumption? Elasmotherium lived at the same time as humans. Recently, fossils from 29,000 years ago were discovered. Wouldn’t an animal with such a huge and unique appearance have been recorded in human history? Scientists who believed that Elasmotherium had a horn used to call it a unicorn. Wouldn’t it have seemed special to ancient humans? It actually did. The picture remains.
In the Rufinac Cave in France, there are many works of art depicting nature by Paleolithic people, including two types of ancient rhinos. The authors of the paper ‘On the Fossil Rhinoceros Elasmotherium’ published in the paleontology journal ‘Cranium’ in 2005 interpreted the two-horned one as a woolly rhinoceros. Woolly rhinos are found in several cave paintings and also lived on the Korean Peninsula. The authors of the paper interpreted the other as Elasmotherium. This is because one of them had horns of exactly the shape imagined based on the size of the base remaining on the forehead of the skull.
The Rupignac cave paintings have sparked controversy. Until then, the geographical limits of Elasmotherium were limited to the Soviet Union and China, where fossils were discovered. The scientific name of Elasmotherium, which has been studied the most, is Elasmotherium sibiricum. In other words, it means Siberian Elasmotherium. Even considering that the border of Siberia in the early 19th century included the left Volga and Ural regions, it was almost a guess to conclude that the French cave paintings were Elasmotherium. Meanwhile, the fact that unicorn legends remain in various places is also indirect evidence of the wide distribution of Elasmotherium.
But it’s strange. Dinosaurs that lived tens to hundreds of millions of years ago also showed their characteristics through fossils. Like the colorful neck decoration of the Triceratops and the back plate of the Stegosaurus. But why can’t we see the horns of Elasmotherium from just tens of thousands of years ago as fossils? This is because the ingredients are different. The frills, which are decorations for Triceratops and Stegosaurus, are made of bone and are left behind when other skeletons are turned into fossils, but the rhinoceros horns are not bones and are not left behind.
Like other rhinoceroses, Elasmotherium’s horn may also be made of keratin. Keratin is a protein. Like hair or nails, skin tissue is hard and keratinized. Proteins do not remain as fossils. Skin also does not remain as a fossil. Therefore, Elasmotherium horns from just a few tens of thousands of years ago also did not remain as fossils.
Elasmotherium mostly disappeared about 200,000 years ago, but existed in the western Siberian plains until 30,000 years ago. It’s very recent. So, the story goes that Elasmotherium lived together with Homo sapiens and Neanderthals. It is reasonable to point out two human species as the culprits of the extinction event. In fact, the remains of Elasmotherium that were captured and transported 50,000 years ago remain in a Siberian cave.
So why did Homo sapiens and Neanderthals hunt Elasmotherium? It is highly unlikely that they targeted the horn as an aphrodisiac. They probably hunted to make a living. Instead of hunting Elasmotherium, they left them as art. Thanks to this, we now know exactly what Elasmotherium looks like.
Elasmotherium lived on grass in the vast grasslands during the Ice Age. He plucked the grass with his soft lips and crushed it with his thick, hard molars. The crowns of the teeth were high enough that the sand brought in when eating grass could wear down the teeth. But as the climate changed and the grasslands became smaller, the grass was replaced by moss. Other rhinos left south. They changed their diet from eating only grass to eating leaves and fruits as well. However, Elasmotherium insisted on only grass.
At that moment, humans invaded the Elasmotherium residence. They wiped out mammals weighing more than 45 kg. Elasmotherium could not escape humanity either.
Author Lee Jeong-mo
I believe that humanity, which is facing its sixth mass extinction, must learn from past extinction events in order to be even a little more sustainable. Although he studied biochemistry at graduate schools such as Yonsei University and researched organic chemistry at the University of Bonn in Germany, he is not a Ph.D. He has worked at the Seodaemun Museum of Natural History, the Seoul Science Museum, and the Gwacheon National Science Museum, and is currently writing, lecturing, and broadcasting to promote science to the public. <과학이 가르쳐준 것들> <과학관으로 온 엉뚱한 질문들> <살아 보니, 진화> <달력과 권력> <공생 멸종 진화> etc. was written.
