As mentioned earlier, the Minoans traded widely and their writing systems were perhaps influenced by those of the Mesopotamians and Egyptians. There is also evidence that the Egyptians were impressed by Minoan ceramics, as many examples have been found in Egyptian archeological sites. We know, too, that the Minoans imported papyrus from Egypt and that their palaces and paintings were influenced by the art and architectural styles of Egypt. The Mesopotamian connection would seem to be based more on mythic or religious ideas. Both the ancient Sumerians and the prehistoric cultures that preceded them in Mesopotamia and Anatolia placed an emphasis on bull-human combinations, on the double axe, and on powerful goddesses. All these elements are evident in what we know of Minoan mythology.