Abstract
Four-part figures equal cyclic completion in ancient Mesoamerica, but they do not necessarily correspond to the cardinal directions; they refer, rather, to four-place cycles within the apparent annual path of the sun. The earliest excavated Maya example of such a quadripartite diagram in architectural form is Structure E-VII Sub at Uaxactun, which was part of a solar observatory. Later this E Group at Uaxactun was used for katun celebration. It is suggested that in Early Classic times Mexicans introduced to central Peten a type of celebration of solar cycles observed at Teotihuacan. This new ritual was rapidly Mayanized and institutionalized as the celebration of katuns or 20-year periods. The iconography of katun celebration emphasizes quadripartition and the rainy, stormy sky symbolism of the agricultural year as expressed in Tlaloc ritual at Teotihuacan. Katun celebration probably also served to undermine the original dynastic significance of the ancient Maya Long Count and thus enhanced the public ritual role of the new Mexican elite.