Do unicor ns exist ?

When most of us are small we have always been shown a picture of a unicorn and told that it is this magical, special, beautiful things. However where did the thought of this creature arise from? Did some one decide that they did not like the way the regular horses looked so they created their own horse, which was extremely beautiful, white and had a spectacular horn on it and decided to call it a unicorn? Was that how the story of a unicorns started? Or was there a time when they did actually exist but due to the various problems of destruction, global warming etc , they were driven to extinction. I recently read an article that said that scientists had found fossil remains that showed that unicorns did exist, however it wasn't how we pictured them , they weren't mystical but resembled a rhino more. I feel this evidence proves how the s tory of unicorns originated. Therefore I feel that yes, unicorns did exist at one point.