*Corresponding Author
Abstract word count: 213
Main text word count: 2891
Number of references: 60
Keywords : Bivalvia, dataset bias, diversity gradient, intertidal diversity, mollusca
Author Contributions : MRK, MAK and JA conceived the study and planned the fieldwork; MRK carried out fieldwork, curated the data, ran analyses and wrote the initial draft. MRK and NC processed and identified field material. All authors contributed to the final manuscript.
Data Accessibility : Upon acceptance of the manuscript, data used will be stored in an appropriate data repository such as Dryad. Any associated data DOI will be included in the article. Supporting data has been attached to this submission for review purposes.