The picture looks like the medevial imagination of a unicorn and what we normally think of today. This Answers in Genesis article discusses possibilities for the animal refered to in its Biblical references. :)
A worldwide Flood would create large amounts of sediment. This in turn would have trapped many creatures, killing them quickly, and enabling them to become fossilized. It is our contention, therefore, that the majority of the world’s fossils were formed during the Flood.