GEOGRAPHICAL DIFFUSION AND CALENDRICS IN PRE-COLUMBIAN MESOAMERICA

Of paramount importance to the cultural and religious life of the pre-Columbian civilizations of Mesoamerica was a complex calendrical system of both a 260-day sacred almanac and a 365-day secular count. This article examines the development of a level of astronomical sophistication by the Olmecs and Mayas in the core of Mesoamerica that allowed them to predict eclipses. Concurrently, on the northern periphery of the region, because of spatial-temporal lag in diffusion, the Toltecs and Aztecs were only beginning to evolve their much cruder versions of the same fundamental time-count.