Unicorns Once Existed

Now lets me provide some scientific examples of why the existence of Unicorns in the past is highly unlikely. My opponents position in this debate is that Unicorns once existed, as such I should present some scientific (i. e fossil, genetic) evidence to show that it is highly unlikely that Unicorns once existed. My opponent defined Unicorns in the comments section as "a legendary animal that has been described since antiquity as a beast with a large, pointed, spiraling horn projecting from its forehead. " If we consider the etymology of the word, then it must hold true that "uni" means one. (1) So we need to consider evidence for a one horned animal, where this horn projects from its forehead in a spiraling manner. At this point, I am not trying to bore you to death, I just really need to get the definition understood for the facts presented below to make sense. So what animals could have existed (or do exist) that could be considered a unicorn? The Narwhal is one animal, whose horn was used in times past as proof for Unicorns. (2) However, we can be certain that this is not the elusive Unicorn, as it still exists today and this is a debate about the past existence of Unicorns. What does make the Narwhal most probably contribute most to the myth of the Unicorn is its spiral shaped horn. The Rhinoceros similar to the Narwhal cannot be used as an example of the unicorn as they still exist today. Additionally, this horn is not spiraled. The second animal that comes to mind would be the now extinct Tsintaosaurus spinorhinus. (3) While this may seem like a likely candidate for the now extinct animal which could classify as a unicorn, it is highly unlikely. This horn was in no way spiraled if anything it looked like an appendage from a bad alien movie, see picture below. In fact, there is no consensus among scientists, that I am aware of, as to what the exact shape of this "horn" was. For this reason it is obvious that the now extinct dinosaur is not our elusive unicorn. . http://www.dinosaur-world.com...; width="485" height="513" /> The last and probably the most widely used example for the existence of unicorns is the genetic deformity or physical deformity unicorns, see example below. This group is two horned animals that have undergone some genetic deformity to produce only one horn, or have had one horn broken off. In all these cases the animal is not a unicorn as it genetically has two horns in the species but is in fact a genetic mutation which would have to breed with the exact same mutation to produce and offspring with that mutation. As far as I am aware there is no example of this kind of unicorn species and as such we can say this is not the fabled unicorn. It is my belief that this opening argument shows that the existence of the non existent unicorn is highly unlikely. The only way it is possible is if we change the definition and accept past animals like Tsintaosaurus spinorhinus to be the elusive unicorn. However, if we do this then we really are moving outside the scope of a scientific debate. I now hand the debate over to my opponent for rebuttals. (1) . http://www.etymonline.com...- (1) . http://animals.nationalgeographic.com...(2) . http://www.dinosaur-world.com...