Assessing the Suitability of Native Mollusk Shells for Sclerochronochemistry Studies: An Analysis of Eight Persian Gulf Species

Abstract

This study aimed to identify suitable mollusk shells for use in sclerochemistry and sclerochronochemistry studies which, applied on shells in archaeological record, can help researchers reconstruct past climatic conditions. The shell features of eight commonly occurring native mollusk species in the Persian Gulf were examined. Four sea snails (Bufonaria echinata (Link, 1807), Tibia fusus (Linnaeus, 1758), Architectonica perspectiva (Linnaeus, 1758), Cypraea turdus winckworthi (F. A. Schilder & M. Schilder, 1938)) and four bivalves (Vepricardium asiaticum (Bruguière, 1789), Callista umbonella (Lamarck, 1818), Saccostrea cucullata (Born, 1778), Anodonta cygnea (Linnaeus, 1758)) were collected from their natural habitat in 2020, for analysis. The study used micro Raman spectroscopy to identify shells with an aragonite outer layer, a requirement for sclerochemistry research. Additionally, the study utilized sclerochronological methods to determine whether the shell samples could be appropriately studied for sclerochronochemistry research. Raman spectroscopy results indicated the presence of aragonite in all species, excluding Saccostrea cucullata. Pigments were also present on the surface of all shells except those of Callista umbonella. Cross-sectional analysis indicated that the shells of Callista umbonella exhibit clear daily, monthly, and annual growth lines with a thickness of 1650 µm in the outer layer, making them excellent candidates for sclerochemistry and sclerochronochemistry studies.