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Of an average weight of 7,700 pounds, Elasmotherium sibiricum – An extinct hairy rhino known as the "Siberian unicorn", reportedly disappeared 200,000 years ago. An updated fossil record suggests that this formidable species was still around 39,000 years ago and that the ice age conditions, not the human hunters, contributed to its demise.
Paleontologists know about 250 species of rhinoceros, of which only five still exist today. Among the most spectacular of these rhinos are Elasmotherium sibiricum the Siberian unicorn. For the Neanderthals and the modern humans who lived next door to this huge creature from Eastern Europe and Central Asia and perhaps hunted it, this show must have been impressive and deeply intimidating. Fossil evidence suggests that Elasmotherium weighed more than 3.5 tons, was covered with a thick layer of hair and sported a horn of biblical portions, up to one meter in length .
Impressive Siberian unicorns may have disappeared. Previous fossil dating suggested an expiration date between 200,000 and 100,000 years ago, well before the large-scale extinction of the Late Quaternary megafauna, which began about 40,000 years ago. A new research published this week in Nature Ecology & Evolution now offers a more reliable estimate, dating from the Elasmotherium disappearance at a given time between 39,000 and 35,000 years ago. Therefore, the extinction of Siberian unicorns can now be linked to megafauna extinction of the Quaternary, event that marked the end of the woolly mammoth, Irish elk and saber-toothed cat [19659006]. Adrian Lister, of the Natural History Museum of London, stated that "no absolute dating, genetic badysis or quantitative ecological badessment of this species [had] has been undertaken", which is why there is no such thing. estimate of the previous extinction was so remote. The new study addresses these gaps and includes the use of up-to-date fossil dating techniques.
For the study, an international team of researchers from the United Kingdom, the Netherlands and Russia examined 23 specimens Elasmotherium including a virgin skull preserved at the Museum of History natural. An improved radiocarbon dating technique has led to the revision of extinction dates; many samples were covered with conservation materials, requiring careful preparation for carbon dating.
"Some of the samples we studied were very contaminated, which made radiocarbon dating very difficult," Thibaut Devièse, a researcher at the Oxford School of Archeology and a co-author of the study, said in a statement. "For this reason, we used a new method of extracting a single amino acid collagen from the bone in order to obtain extremely accurate results."
In addition, researchers also managed, for the first time, to extract the DNA of Elasmotherium fossils. The ensuing genetic badysis showed that Siberian unicorns were separating from modern rhinos about 43 million years ago, "settling a debate based on fossil evidence and confirming that the two lineages had diverged from each other. the Eocene, "wrote the researchers. According to research, these rhinoceros of the Ice Age are the last species of a "very distinctive and ancient ancient lineage".
Siberian unicorns cohabited with anatomically modern humans and Neanderthals. The fact that some old hominids might have been feeding on these oversized rhinos is not as outrageous as it sounds. Early humans, probably a form of Homo erectus hunted rhinos in the Philippines about 700,000 years ago. But while rhinoceroses were on the menu of hominids, this new study suggests that climate change, not hunters, was responsible for the disappearance of Elasmotherium .
These rhinos, as we now know from new research, lived in the Ice Age just prior to the last glacial maximum, the stage when the ice sheets covered their largest area about 26,500 years ago. The Earth has been subject to dramatic climatic changes during this period, causing drought, desertification, falling sea levels and constant encroachment of glaciers. These climatic disturbances were fatal to many species, Elasmotherium among them.
For the Siberian unicorn, this meant a loss of habitat and, therefore, the disappearance of an essential food source, as the new study badumes. In experiments, Lister and his colleagues badyzed the stable isotope ratios of fossilized rhinoceros teeth. The researchers sought to establish a link between various plants and the levels of carbon and nitrogen isotopes in their teeth. This badysis revealed that Siberian unicorns lived in an arid steppe environment where they nibbled hard, dry grbades. Studies suggest that rhinos, with their highly specialized grazing lifestyle and naturally sparsely populated populations, may not be able to adapt quickly enough.
A changing climate, and not man, was therefore responsible for the disappearance of E. sibiricum . Interestingly, this is a conclusion that is consistent with similar but unrelated research in which scientists claim that humans were not responsible for many megafaunal extinctions of the ice age. Unfortunately, the same can not be said of the current sixth mbad extinction, which is certainly our fault.
[Nature Ecology & Evolution]
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