This is a stone disk of the mystical Chamula people of central Mexico. After weeks of study I have finally been able to translate the hieroglyphics on this ancient stone disk. It seems it is some sort of archaic calendar. According to my translation the writings read as follows:
"Our calendar, ancient and mysterious, lasts 278 days every three years, and 71 days the other two in a sequence that varies depending on whether the number of chicken sacrifices we make in the previous two years is an odd or even number. It is all very complicated..."Fascinating! I find it astonishing that thousands of years ago these supposedly primitive people had such advanced knowledge of the workings of the cosmos.