From simple row of dots to the rain god calendar: Interpretation of the pecked cross petroglyph from the Late Postclassic Tetzcotzinco

Abstract This article presents and analyzes a newly discovered petroglyph from Tetzcotzinco (mun. Texcoco, Mexico) in the form of arranged pecked dots. Based on what is known about Mesoamerican divinatory systems, calendars, and the perception of space, the interpretation takes into account both the encoded numerical values and the layout of the dots. The main argument is that this and similar representations’ function was not limited to simple counting of days or serving as a kind of astronomical marker, in which the arms of the cross indicated, for example, equinoxes, which is by far their most common interpretation in academic literature. Instead, it represented calendrical cycles through the numbers, as suggested by some scholars. Based on this hypothesis, the article explores the possible connection between numbers registered in Tetzcotzinco's “pecked cross” and specific diagrams from indigenous divinatory books. Therefore, the plausible interpretation of the symbolism of this petroglyph is that it either expressed a series of meanings related to the agrarian period(s) and rain god(s) or less-known Mesoamerican calendrical cycles, such as half trecenas or seven- and nine-day periods.