Terrestrial Gastropod Traces on Medieval Human Remains: Taphonomic Evidence from Nysa in Western Anatolia

This study investigates mollusc-induced taphonomic modifications on human skeletal remains unearthed from 11th–12th century burials at the ancient city of Nysa (Aydın, western Turkey). Taphonomic alterations—such as pitting, linear grooves, and superficial abrasions—were identified on cranial, tibial, rib, and scapular bones. These modifications were evaluated in connection with three terrestrial gastropod species found in situ: Cornu aspersum (=  Helix aspersa ), Oxychilus camelinus , and Caracollina lenticula . Macroscopic and stereomicroscopic observations revealed distinct morphological patterns consistent with biological activity, particularly the gnawing and burrowing behavior typical of Cornu aspersum . Endocranial and ectocranial surfaces of cranial bones exhibited small perforations (1–2 mm), while the tibiae showed linear, sequential cavities (2–3 mm), indicating prolonged and directed contact. The spatial association of gastropod shells and modified bones, especially the scapula, strengthens the hypothesis of direct biological interaction. Furthermore, ecological traits and seasonal activity cycles of the gastropods support the inference that the burials may have occurred during spring or autumn, when gastropod activity peaks. This study documents a rarely addressed taphonomic phenomenon and emphasizes the interpretive potential of gastropod-bone interactions for reconstructing burial conditions, microenvironmental dynamics, and seasonality. By integrating malacological, archaeological, and taphonomic evidence, the research contributes to a more nuanced understanding of inhumation processes and highlights the need to consider invertebrate activity as a significant factor in post-mortem bone alteration.