AbstractUsing techniques applied by Eagar and by Broadhurst to investigate sedimentary environments of Westphalian non‐marine shell beds, an attempt is made to assess the palaeoecology of the earliest recorded Carboniferous non‐marine lamellibranchs. The latter pose a special problem of ecology by virtue of their antiquity and presumed closeness in time to a marine ancestry. Since the species under discussion occur with few other fossils the usual recourse to a study of faunal relationships provides only limited evidence of ecol