Possibly the most mysterious objects of stonework are the enormous heads. 17 have been found yet. Only few archaeologists are willing to admit that. In recent years, some even seriously investigate this question. Maybe, some day, a satisfying answer will emerge.
Many theories exist about the possible African origin of the Olmecs.
This theory looked to me not more interesting than others, until I found a particular picture in a book about Ancient Egypt. I'm very sorry, that I can't place this picture here, because I don't have this book myself. I have never before seen something like this made in the Old World, but it is a common theme in Mesoamerican cultures, especially the Aztec. In these cultures, the animal typically would be an eagle, a coyote or a snake. I found this picture here somewhere on the net.