Note: After this was originally posted, T.J. commented (See Below) that there is a single horned Rhinoceros, the Rhinoseros Unicornis, but no skeletal remains have ever been found in the Middle East.
One additional thing, the often atheists quoted heroes of Aristotle and Pliny, the Elder, mentioned the unicorn, in their writings, a point totally glossed over, by the atheists. But what were the Bible authors, Aristotle and Pliny talking about, when they mentioned the unicorn.
Amazingly, if you ask the local indigenous people of the Middle East, you'll quickly find the answer. They will show you the unruly Arabian Oryx. Even though the Oryx has two horns, some do lose their horns in battle or rough play. Once lost, their horns do not grow back, making them a unicorn. Even with their horns intact, they appear to be a single horned animal.
Well, once again, the Bible has been proven correct. However, I wonder if the atheists will continue to exploit the ignorance of others, and ridicule the Bible and its believers.
...and that's what you'll find, When You Search For The Truth.