The story of unicorn and its extinction

Restoration of E. sibiricum in a steppe environment
Image: Wiki

The image of a unicorn was long thought to be stuff of fairly tales. However, it is now believed that the image was spurned by the animal whose rendering you can see above. And yes, early humans who got to inhabit the steppes of southern Siberia and Kazakhstan some 40 thousand years ago. So while real world unicorn, also known as Siberian rhinoceros looked a bit different than a slender unicorn you get to see in children's sketchbooks it was a lot more real - and a lot better adapted to its real world environment.

These beasts weighing in at up to 5 tonnes and stood up to 5 meters tall. They roamed endless plains grazing on grasses that were plentiful in the steppes of the time. Their large size made them a suitable target for human hunters who were believed to capture hem by way of trapping them in holes they would dig in the ground along the migration paths used by the Siberian rhinoceros. I would imagine that could well be true - at the very least, whenever the rhinos had to traverse a patch of woods, due to their sheer size they would have had very limited options when it came to paths they could take. Simply put, when you weigh up to 5 tones are are a couple of meters across you can't just randomly limp over bushes, and even deer who are much slender are still often confined to their paths, especially in thick brush.

Siberian rhino skeleton at the Stavropol Museum of Natural History, Stavropol, Russia

The skeleton pictured above is one of the few near complete skeletons of the species that have been recovered and assembled. On a personal note, yours truly got to see it some 40 years ago as a child, and this was one of the few things I got to see as a kid that impressed me enough for me to still hold a memory of it. Note the absence of the horn - that was one of the few pieces seemingly missing from this skeleton.

The prevailing hypothesis of the extinction of this species for a time was human predation. A 2018 article in Nature Ecology & Evolution summarizes findings of a team of researchers which found that it was most likely not human activity but rather the climate change that killed the animal that gave us the image of unicorn. The climate turning colder and grasses turning sparser killed the species whose size, might and a horrifying horn must have worked just fine to scare away most other threats.

We obviously don't have a data set that would allow us to fill all the gaps in our knowledge about this fascinating species. It is possible that there were other factors involved in the unicorn's extinction - novel infections, etc. It is possible that both the changing climates and emerging and spreading prehistoric humans had a role to play. But a thought I get is that changes bring forth success of some and demise of others - and that, most likely, changing climate and other environmental changes has been causing extinction of some species and emergence of others throughout the whole history of life on Earth.