With a weight of up to 7,700 pounds, Elasmotherium sibiricum– an extinct rhino, known as the "Siberian unicorn" – was thought to have disappeared as long as 200,000 years ago. An updated analysis of the fossil suggests that this formidable species was still about 39,000 years ago, and that ice conditions, not human hunts, contributed to its disappearance.
Paleontologists know about 250 species of rhino, of which only five still exist today. Among the most spectacular of these rhinos was Elasmotherium sibiricum– The Siberian Unicorn. For the Neanderthals and modern humans who lived alongside and probably hunted this massive creature in Eastern Europe and Central Asia, it must have been an impressive and deeply intimidating view. Fossil evidence suggests Elasmotherium has weighed over 3.5 tons, was covered with a thick layer of hair and raised a horn of biblical portions of at least three meters in length.
Impressive, though it may have been, unicorns in Siberia eventually disappeared. The former fossil dating suggested an expiration date at any one time between 200,000 and 100,000 years ago long before the quaternary megafaunal disappearance that was defeated some 40,000 years ago. New research published this week in Nature Ecology & Evolution now offers a more reliable, deadly estimate Elasmotherium at some point between 39,000 and 35,000 years ago. Therefore, the disappearance of Siberian unicorns can be linked to the late quaternary megafaunal disappearance, an event that witnessed the end of the lean mammoth, the Irishman and the cat with the sabot.
Writing in their new study led by Adrian Lister of the Museum of Natural History in London, researchers said there was no absolute dating, genetic analysis or a quantitative ecological assessment of this species [had] have been undertaken, "which explains why the previous estimate of the disappearance was so far. The new study overcomes these shortcomings and includes the use of updated data on fossil data.
For this study, an international team of researchers from the UK, the Netherlands and Russia took a closer look at 23 years Elasmotherium specimens, including a clean skull kept at the Museum of Natural History. An improved radiocarbon dating technique resulted in revised extinction data; many of the samples have been treated in conservation materials, requiring careful preparation for carbon sequestration.
"Some of the samples we studied were highly contaminated, which made the encounter with carbon emissions very challenging," said Thibaut Devièse, a researcher at the Oxford Archeology School and co-author of the study. For this reason, we used a new method of extracting a single amino acid from bone collagen to provide very accurate results.
In addition, researchers have, for the first time, been able to extract DNA from Elasmotherium fossils. The subsequent genetic analysis showed that Siberian unicorns parted from modern rhinoes 43 million years ago, "resolving a debate based on fossil evidence and confirming that the two lines broke apart from Eocen," they wrote researchers. These vintage rhinoes are the last species of a "distinctive and ancient line", according to research.
Unicorns in Siberia lived alongside modern and non-Anatomical people. That ancient hominids might be prey to these oversized rhinoceroses is not such a scandalous proposition as it would seem. Early people, probably a form of Homo erectus, hunted rhinos in the Philippines 700,000 years ago. But while rhinos were on the hominid menu, this new research suggests that climate change, not hunters, were responsible for Elasmotherium– resignation.
These rhinos, as we now know from the new research, lived during the Ice Age just before the last Glacial Maximum – the stage where ice covers the largest surface, about 26,500 years ago. The earth has been prone to dramatic climate change during this period, causing drought, desertification, declining sea levels and constant glacier intervention. These climatic disturbances have been found to be fatal to many species, Elasmotherium among them.
For the Siberian unicorn, this meant a loss of habitat and therefore the disappearance of a critical food source, as assumed in the new study. In experiments, Lister and colleagues analyzed stable isotopes reports of fossil fossil teeth. Researchers have sought to link different plants to levels of carbon isotopes and nitrogen in their teeth. The Siberian unicorns, as this analysis showed, lived in a dry steppe environment, where they sat on rugged and dry grass. Rhinoceros, with their highly specialized lifestyle and a very small population, could not adapt quickly enough to changing conditions, study shows.
A changing climate, not a man, was responsible for the resignation E. sibiricum. Interestingly, it is a conclusion that is due to similar but unrelated research in which scientists claim that humans were not responsible for many megafaunal extinctions in the ice age. Unfortunately, the same can not be said for the sixth mass disappearance, which is certainly our fault.[Nature Ecology & Evolution]