This is my theory of why the Polar was found in Tunisia.
The island is behind millions of years. Thus, in the real world, the island has moved due to continental drift, and is today located in Tunisia. It is much like how there is evidence that Antarctica was located on the equator millions of years ago. This theory would also explain why there is no native life on the island. Human life is not on the earth yet.
Just another theory to chew on.