One of the last three remaining white rhinos on Earth
Prehistoric Behemoths: The Evolutionary History of Rhinos
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Rhinos are just a dying species in our time:
There are only 5 species of rhinos left on Earth, except for the white rhino, which is in better condition, the other 4 species are in danger.
Rhinos are a species destined to perish, and even if no one appears, their life trajectory is difficult to change, the only thing that can be changed is the speed and slowness of extinction. There may be some truth to this claim, after all, the rise of even-ungulates has greatly reduced the territory of the order Odd-hoofed (horses, rhinos, tapirs, etc.). However, the evidence of human slaughter of rhinos is conclusive, far from the indiscriminate killing of woolly rhinos by primitive people, and the plundering of rhino horns by civilized people in the near future. Without humans, rhinos would be in a much better position than they are now.
The rhinos we see now all look very different: long horns, bulky, thick skin, and hairless are the common features.
But historically, rhinos have been a very prosperous group, and there have been dozens of differently shaped rhinos on Earth: the largest behemoth on land since the age of the dinosaurs; the dexterity of running fast; the furry of rhinos that grow in the coldest regions; the rhinoceros that are amphibious in the tropics like hippos; the rhinoceros with a large horn; and the many hornless rhinos. Their origin and evolution constitute a bright chapter in the evolutionary history of mammals.
The decay of the rhinoceros is a living example of the rapid decline of vertebrates after the emergence of humans. In this sense, the rhinoceros's journey is the most typical mammalian journey.
Whether a rhinoceros is extinct is no longer a decision that the rhinoceros can decide, but by humans
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Rhinos belong to the order Perissodactyla
Extant ungulates consist of three families: horses, rhinos, and tapirs, and their common feature is that the number of toes on their hooves is odd, which is the opposite of even-ungulates. Odd-hoofed order appeared around the Eocene, probably evolved from naked programs like protogulates, and is not too closely related to other mammalian subjects that exist today.
After the appearance of the strange hoofed order, it quickly divided into several branches of development. The first is horses and donkeys, the second is tapirs and rhinos, they have a relatively close relationship, there have been more similar species in evolutionary history, and the other two are long-extinct animals, the Thunderbeast family and the Clawed Beast family.
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Tapirs and rhinos first appeared in North America, and according to current belief, tapirs appeared first, while rhinos differentiated from tapirs.
An early representative of this animal was the rhino tapir
The status of the rhino tapir has long been a matter of debate in the scientific community. When it was discovered in 1873, it was classified as a tapir; later some people thought it was a rhinoceros; and then some people classified it as a type of tapir; although more and more people recently regarded it as the most primitive rhinoceros, because its teeth are very similar to rhinos, but in a more conservative and rigorous view, the rhino tapir belongs to the subfamily of marsh tapirs, which is not close to today's rhinos and tapirs, and is still a class of ancient tapirs.
The size of the rhino tapir was similar to that of the tapirs and horses at that time, far lighter than the rhinoceros of today, and far from being comparable to the behemoths of the time, such as the thunder beasts. Judging from its skeleton, it also has many primitive characteristics, such as it also has 4 toes, of which 3 are used for walking, and the other one has no effect. In later evolution, this toe gradually disappeared, and the rhinoceros completely became a "strange hoof"
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After that, the rhinos were rapidly differentiated, mainly divided into 3 branches.
The first developed in a light direction and became a running rhinoceros (Hyracodontidae),
The second branch developed in the direction of amphibians, forming the amphibian rhinoceros (Amynodontidae),
The last branch developed in the direction of the modern rhinoceros, forming rhinocerotidae .-
Hyracodon appeared in the North American continent of the Eocene and then spread to Eurasia.
It is about 1.5 meters in size and about 75 centimeters in height. Compared with its ancestors, the running rhinoceros has lighter bones, more slender legs, and is more adept at running, so whether in terms of form or life habits, the running rhinoceros is more like its distant relative, the horse. Like horses, the development of the rhinoceros has witnessed the development of the earth's natural ecology from the Eocene to oligocene. In the Eocene, the land was dominated by forests, but as the weather dried up, the savanna gradually became the mainstream ecological environment, and the rhinoceros gradually changed. The earliest rhinoceros, molars are relatively simple and suitable, the lips are more developed, based on young leaves for a living, in the Oligocene, some rhinoceros molars became complex, suitable for a grass-based diet. Rhinos have evolved leaf-fed brownsers and grass-fed grazers on almost every branch. The change of environment caused by climate change has always been throughout the evolution of vertebrates, including rhinos. The extinction of the running rhinoceros may have stemmed from competition from the even-hoofed animals that appeared later
Running rhinoceros restoration diagram
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There are as many as 12 genera of rhinoceros, the vast majority of which are medium-sized running animals like running rhinos. However, one of them evolved into a miracle of the mammalian kingdom in the middle of the Oligocene, the largest land mammal in history, the paraceratherium or Indricotherium or Baluchirium.
Giant rhinos cruise from the Caucasus in Asia to Central Asia up to Mongolia, and four species have been identified. There are three main species: the giant rhinoceros, the secondary giant rhinoceros, and the Dzungar giant rhinoceros. The Tianshan Deputy Giant Rhinoceros and the Tianshan Junggar Giant Rhino are both famous large species. It is up to 5 and a half meters high at the shoulder and 8 meters long (not counting the tail). The height of the head is 7 and a half meters, and the skull alone is 1 meter 3. It is estimated to weigh between 15 and 20 tons and up to 30 tons. The tallest animal, the giraffe, is now about 6 meters tall, and the heaviest land animal, the African elephant, can reach about 7 tons.
Giant rhinos reach the pinnacle of terrestrial mammals in both height and weight. This body size of the giant rhino is very unusual. Breaking through the 20-ton mark that other terrestrial animals are difficult to overcome, the Mesozoic sauropods broke through this limit and created a physiological miracle (spinosaurus 20 tons is absolute nonsense, the fossil network of 14 tons is almost the same, otherwise it is also exceeded) 30 million years later, the giant rhinoceros once again broke through this limit, it is the only animal other than the large metamorphosed sauropod dinosaurs to do this.
Of course, such a large animal can only live by eating plants, and just from its height, it is almost certain that it eats tree branches and leaves. Its front teeth are highly specialized, leaving only a pair of upper and lower teeth, protruding, awl-shaped, and looking like small tusks. It has a flexible upper lip that can be used to grab branches. These are all suitable for its life habits.
The cause of the extinction of the giant rhino is unknown, it may be related to the change of climate and vegetation In the history of mammalian history, a variety of famous large animals, including the thunder beasts we mentioned above, have inexplicably and naturally disappeared, and then replaced by other large animals. The giant rhinoceros could not escape this fate.
Giant Rhino restoration
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Another branch of the rhinoceros developed in a different direction, developing a rather alternative branch, the amphibian rhinoceros, which first appeared in the North American continent during the Eocene and then spread to Eurasia. Amphibian rhinos resemble modern hippos, with short limbs, huge bodies, and large hippo-like fangs. Living by the river. These are believed to be similar to modern hippos, and they are semi-aquatic creatures.
Early representatives of amphibian rhinoceros were Amphibian rhinoceros Amynodon in the Eocene, and Mid- to late-Stage representatives were Metamynodon and Cadurcodon in the Oligocene.
Metamynodon is 4 meters long and weighs about 3 to 4 tons. It has two pairs of well-developed fangs, most likely for digging or self-defense, and it is believed that its food is dominated by hard plants.
Cadurcodon is a very different kind of amphibian rhinoceros, it should be said that it is very different in the entire rhino family, it has a flexible nose. This is very similar to modern tapirs.
Amphibian rhinos reached their peak in the Oligocene, particularly in North America, and eventually became extinct at the end of the Oligocene.
Amphibian rhinoceros restoration map
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Running rhinos and amphibian rhinos reached their peak in the Eocene and Oligocene, forming the first generation of rhinoceros dynasties. However, at the end of the Oligocene, both declined, and the last few representatives of the Gou extended to the Miocene and became extinct. The original inconspicuous one of the running rhinoceros began to appear in the Oligocene, and in the Miocene began to develop rapidly, creating a second dynasty of rhinos, which is the rhinoceros.
Rhinos are the most prosperous of the three rhinos, and all extant rhinos fall into this category, so we are more familiar with these rhinos. They also originated in the North American continent and spread across the vast North American continent, and later they marched into Eurasia and finally successfully entered Africa and Southeast Asia. They developed more than 50 genera.
The earliest rhinoceros is represented by the paracynch rhinoceros, which lived in Oligocene north America. Its ancestors believed to be one of the running rhinoceros, which also had no horns, but it developed different characteristics. The biggest difference between rhinoceros and running rhinoceros is its front teeth. Their first pair of front teeth are shovel-shaped, and the second pair of front teeth are pointed cone-shaped, which becomes a distinguishing rhinoceros. The new-legged rhinoceros is about the size of a cow, 3.5 meters long, weighs about 2 tons, is larger than the average running rhinoceros, and is also a typical stout animal. This heralds the direction of rhinoceros development.
Secondary rhinoceros restoration diagram
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Beginning with the para-rhinoceros, hornless rhinos have been greatly developed in North America, occupying the ecological niche of north American large plant-eating animals. The Miocene hornless rhinoceros (Aceratherium) was the pinnacle of this prosperous family. Compared with the paratrogen, the lower front teeth of the hornless rhinoceros are more prominent and are the most important weapon against predators. Hornless rhinos are probably one of the more adept rhinos, and their speed is roughly similar to that of the North American bison.
At the same time as hornless rhinos developed, other rhinos also began to develop the most important, which is the most recognizable feature - rhino horns.
Rhino horn is unique among all horned mammals in that it is not part of a bone, but a hair-like derivative of skin. Can hair be so hard? Yes, because it is particularly tightly bonded. But if you scrape the horns of a rhinoceros by hand, you'll scrape off a single strand of hair-like fiber. It's not strictly horned, so the horned animals such as the odd-horned deer, the thunder beast, the heavy-legged beast, and the North American miramar are completely gone, and the rhinoceros is not a real nose horned animal.
Since rhino horns are not part of the bone, they cannot be seen directly in fossilized rhino skulls. But this is difficult for paleontologists, because horned rhinos leave a wrinkled mark on the skull, which is very easy to identify. The shape of rhino horn is speculated to be based mainly on the size of the horn cavity. Unless some frozen woolly rhinoceros carcass left horns.
Rhinos develop four different horn types. The earliest to appear was the one-horned rhinoceros. The earliest representatives of the monocorne rhinoceros were teleoceras in Europe, which originated in the Oligocene, migrated to North America during the Miocene and reached its peak in North America. This is a very specialized rhinoceros, its limbs are extremely short, but its body is very large, similar to today's hippopotamus. It has an extremely short horn and is not estimated to be primarily used for defense. The ecology of the far-horned rhinoceros is similar to that of hippopotamus and its cousin amphibian rhinoceros, which live a semi-aquatic life along the river.
The far-horned rhinoceros is abundant in North America. They left so many fossils that even The Indians of North America made extensive use of their rib fossils as raw materials for building houses.
Another rhino horn type is the side-by-side double horn. This rhino is represented by the North American origin of the Diceratherium, a rhinoceros that is only the size of a pig, and has two horns on the tip of its nose, which are side-by-side, not one after the other, somewhat similar to a heavy-legged beast, which is rare among rhinos. The horned rhinoceros is extremely widespread in North America, becoming the dominant animal in the North American savannah for 10 million years.
Teleoceras and Diceratherium
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The Miocene was the peak of rhinos, and they were an important member of the ecosystem, both in North America and In Eurasia. But at the junction of the Miocene and Pliocene (about 5 million years ago), rhinos in Eurasia and North America became extinct in large numbers, and the North American rhinoceros was completely extinct, and even the woolly rhinoceros that flourished in the north did not enter the Americas since then.
The cause of the extinction is estimated to be a change in climate, with the climate cooling and drying at the junction of the Miocene and Pliocene, and the North American prairies were gradually replaced by semi-dry steppes (Steppe). A large number of other mammals have not been able to cross this hurdle.
In the Late Miocene, the hornless rhinoceros showed its last glory, and the Asian and European large-lipped rhinoceros became the dominant plant-eating animal in China and other places at that time, but soon the large-lipped rhinoceros inexplicably perished, and the hornless rhinoceros also became a historical term.
Large-lipped rhinoceros restoration
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At this time, the rhinos of the Old World did not stop their development. About 15 million years ago, in the middle miocene, another branch of the hornless rhinoceros in Eurasia also developed horns alone, and this branch of the rhinoceros formed the double-horned rhinoceros.
The horns of the two-horned rhinoceros are one before and one after, which is different from the side-by-side horn of the parallel horned rhinoceros. The two-horned rhinoceros is the most widespread of the Old World rhinoceros, and can be found in Asia, Europe and Africa.
The two-horned rhinoceros is divided into two branches, one is the Asian double-horned rhinoceros and the other is the African double-horned rhinoceros.
The oldest branch of the Asian dipterocarp remains to this day. In order to cope with the severe cold, they moved south, and finally reached India, Indochina, Sumatra and Sulimantan, forming today's Sumatra rhinoceros.
The Sumatran rhinoceros is the oldest extant rhinoceros, having appeared 15 million years ago. He lives in the dense forests of Sumatra and is constantly dwarfed. It is the smallest rhino in existence, standing just 1.2 meters tall and weighing just over 600 kilograms. The northern subspecies of the Sumatran rhinoceros (which once lived in China) may be extinct, and the other two subspecies of the Sumatran rhinoceros are also in jeopardy.
The other Asian two-horned rhinoceros has been holding out its homeland, and they have developed a long body of hair to cope with the cold. The most famous of these is the Woolly Rhino , woolly rhino ) , which was active during the Pleistocene ( 1.8 million to 10,000 years ago ) during the ice age. It's a creature that's perfect for cold climates, covered with long fur rarely seen in rhinos. Its horns are very flat, like two sabers. This big guy is 3.7 meters tall and has a horn length of up to 1 meter, and together with the mammoth, becomes a large animal in the cold Siberian wilderness of the ice age
The woolly rhinoceros and the mammoth are both famous prehistoric behemoths of humanity's contemporaries, and they all walked with the ancients during the long ice age. In the caves of Europe, Neanderthals painted a lifelike portrait of the woolly rhinoceros with charcoal brushes on the stone walls, which became the earliest work of human art, reflecting the status of the woolly rhinoceros in the life of the ancients at that time.
Like mammoths, woolly rhinos eventually did not survive the last ice age. The cause of their extinction is widely debated, with one opinion believing that the indiscriminate killing of humans is the main cause, and the other believing that they cannot adapt to climate change. I think it should be a combination of two factors.
Phi Chiros, Mammoth and Ancient Humans are animals that coexist and evolve
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The second type of rhinoceros that evolved from hornless rhinos grew even more bizarrely, the Elasmotheres.
Siberian plate-toothed rhinos and Caucasian plate-toothed rhinos weigh 5 tons, and can be 7 tons larger, almost no smaller than Asian elephants and long-haired mammoths. Such a large rhino has only one horn, but extends from the forehead to the tip of the nose. Its large horns are up to two meters long, almost equal to their own height.
The original plate-toothed rhinoceros members such as the Mongolian Gobi rhinoceros, the Madrid Spanish rhinoceros did not have large horns, and the early members of the plate-toothed rhinoceros family such as the Iranian rhinoceros, which lived from the Miocene to the Pliocene. There are also some members of the plate-toothed rhinoceros family that are not true plate-toothed rhinoceros, such as the Chinese rhinoceros (the Chinese plate-toothed rhinoceros) in the Chinese rhinoceros (the fossil of this species appears to be missing the upper jaw, so its horn shape can only be restored according to the size of the body and compared to other plate-toothed rhinoceros families) can grow to the size of the real plate-toothed rhinoceros.
The most famous representative of the plate-toothed rhinoceros is the plate-toothed rhinoceros (Elasmotherium), which originated in the Caucasus. Its appearance in the Pliocene was distributed over vast lands from Siberia to Europe. The true plate-toothed rhinoceros refers to the Siberian plate-toothed rhinoceros and the Caucasian plate-toothed rhinoceros, which may have evolved from primitive taxa such as the paleo-toothed rhinoceros and the Pere's plate-toothed rhinoceros. Its front teeth have been completely degenerated, while the molars are very suitable for grazing. Presumably, its lips are well developed and can be pulled apart by the grass in a lump. This is the most specialized of the rhinos that graze. It is also covered with long hair, suitable for the harsh climate of the north. Like the woolly rhinoceros, it did not survive the last ice age.
Plate tooth rhinoceros restoration diagram
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The third type of rhino developed a single horn independently among hornless rhinos. This is the Asian one-horned rhinoceros. This rhinoceros emerged probably 25 million years ago and continues to this day, becoming today's Indian rhino and Javan rhinoceros.
The Indian rhinoceros appeared about 4 million years ago, and the Javan rhino appeared about 2 million years ago, both of which are the most "new" members of the rhino family. The Indian rhino is probably the largest of the extant rhinos. The Javan rhino is only slightly larger than the Sumatran rhinoceros, and like the Sumatran rhinoceros, it lives in the dense forests of South and Southeast Asia.
From the earliest group of rhino tapirs, rhinos have undergone three ups and downs, the first in the Oligocene, which was dominated by running rhinos (including giant rhinos) and amphibian rhinos, and they went extinct at the end of the Oligocene.
The second time was in the Miocene, when rhinoceros, which developed from a branch of the running rhinoceros, replaced the status of the above two big brothers, and was greatly developed in North America and Eurasia, and also developed a variety of different forms of rhino horns. At the turn of the Miocene and the Miocene, rhinos, like many other animals, were unable to adapt to the harsh climate and became mass extinct, and the North American rhinoceros became completely extinct.
The third boom emerged in the Old World, with the two-horned rhinoceros becoming the most widely distributed rhinoceros. At the end of the Pleistocene, the extinction of its asian main representatives, the woolly rhinoceros and the plate-horned rhinoceros, heralded the end of the rhinoceros' last boom
After entering the Holocene (which began 10,000 years ago), under the hunting of humans, the remaining rhinos continued to decrease significantly, and now the rhinos in Asia exist only in India and a few islands, and the African black rhino is also very dangerous, and the black rhino is more dangerous than the giant panda due to the rampant black market in Central Africa due to the chaos in Africa.
African white rhinos are slightly better, but they are also mainly distributed in various national parks. The current situation of this once glorious family can be described as surviving. The death knell has sounded for them, their fate has entered the countdown, and whether they can escape this fate is not up to them, but to see if the rulers of this earth are willing to do something for them.
The era of human life is the era of the extinction of the giant beasts, is this the sadness or glory of the human beings at the top of the food chain?