The ceramic urns from Atzompa belong to the pottery tradition that developed in the Valley of Oaxaca, around the city of Monte Albán. These objects, commonly known as effigy vessels, are characterized by the integration of a container with modeled representations of human or animal figures, as well as glyphic elements and features characteristic of Zapotec aesthetics. Although they are frequently referred to as funerary urns, their function was not restricted to the mortuary sphere. Based on their iconography, archaeologists have proposed that these effigies may represent elite individuals, ancestors, and deities associated with the Zapotec calendrical system.
One of the distinctive features of Zapotec effigy urns is the use of masks, whether in the form of a mouth mask, an eye mask, or facial markings that may suggest the same function. This distinction can become more complex when the mask incorporates or is integrated with other elements, for example, when it forms part of a headdress, covers the face partially or completely, or displays a jaw. Within the iconography of masks, certain calendrical glyphs and zoomorphic motifs stand out as representations of social identities or sacred entities.
In the case of Monte Albán, the element identified as the “serpent mouth mask” is composed of an open jaw with fangs; in some instances, a bifurcated tongue hangs down; in early representations, a tooth appears at the center of the upper jaw; in later effigies, this tooth is replaced by a nose. Early iconographic studies attempted to link these features to the mouth mask of Ehécatl-Quetzalcóatl, a god from Central Mexico; however, this correspondence has recently been debated, since the attributes bear little resemblance to one another. Although the serpent mask appears on effigies wearing “lampshade” headdresses, and some examples also wear conical caps, its presence extends to other groups and types of vessels.