Our interdisciplinary study provides new information and interpretations of Ossuary I, a large assemblage of human bones associated with the ceremonial center dedicated to a life-size clay figure of a splendidly attired human skeleton (often identified as Mictlantecuhtli in the archaeological literature) at the site of El Zapotal in south-central Veracruz-Recovered in 1971, this assemblage has been interpreted as a ritual deposit of women who died during childbirth, whose bodies were dedicated in later Aztec lore to the Tlazolteotl goddess. The present paper provides new insights into the depositional sequence, the type and number of individuals within the assemblage, the sex and age profile of the mostly female cohort, the distribution of artificial head shapes as an ethnic marker, and evidence of perimortem violence and postmortem processing in the form of flaying. Our evidence indicates that Ossuary I represents the slow accumulation of loose bones and limb segments of partially skinned individuals in a circular shaft. Postdating the functioning of the Death God adoratorio and showing fluctuations in the patterns of pre-depositional body treatment, the assemblage expresses the Late Classic period ritual practice of flaying both males and females in Veracruz. In later stages, the ossuary was used again for a female cult, consistent with the original interpretation of women who died during childbirth.