Unlocking the potential of the terrestrial gastropod species Zootecus insularis as a climate archive for arid regions

Local-scale climate reconstruction in arid regions is challenging due to the scarcity of suitably preserved archives. While several well-studied climate proxy datasets exist for southeastern Arabia, including those preserved in speleothems, sedimentary deposits and paleosoils, and occasionally sediment cores collected for pollen analysis, snails have not yet been explored as a potential archive. This study investigates the potential of the terrestrial gastropod Zootecus insularis collected from geoarchaeological sections as new climate archive for arid environments. Isotope analysis was conducted on specimens from Holocene contexts in Oman to reconstruct long-term climate trends. Previously published water temperatures calculated from oxygen isotope data of Melanoides tuberculata, a freshwater gastropod species found in the same geoarchaeological sections as the terrestrial Zootecus shells, were interpolated to the age of the terrestrial snails, allowing for the recalculation of an oxygen isotope signal used to identify wet or dry periods. The resulting dataset showed a strong correlation with existing paleoclimate datasets from speleothems and paleolakes. Additionally, the δ13C values of Z. insularis indicated a significant shift towards more negative values over time, which probably suggests a transition from C4 grass-dominated vegetation to mixed C4/C3 xerophilic vegetation. This integrated approach suggests that snails could provide a valuable new archive for paleoclimate studies in arid regions.