Way back in AS, I posed the question, "How did the Sumerians invent a counting system using 'base 12' when they had ten fingers, just like us?" Somebody replied that a lot of primitive societies started using base 12 to count their stock animals, because they used the thumb of one hand to count the knuckles of the same hand. If you used the other hand to count the dozens counted by the first hand, you could keep track of 144 animals that way. Of course, there's no way of being sure the people of the Black Sea area counted that way, but if that's where the original Sumerians came from, it's a definite possibility.