Gene, i'm sorry to be such a stick in the mud here, but i'm afraid that your confusion will probably continue and the exact origin will probably not ever be discovered unless you get lucky enough to find a very similar example that has certain provenance. Just about ALL cultures use animal imagery and turtles and pigs (as well as dozens of other animals) are pretty pervasive across the entire world. Artisans are also a fanciful bunch and will use animals in their imagery that are not even local to their culture. Just look at the British Lion that became so common in their heraldry in the Middle Ages, but the lion had been extinct in England for about 13,000 years.
I'm afraid that all we can do about this for now is guess...
