microgastropod fauna from the upper devonian cephalopod bed and overlying lower tournaisian strata of the original reference section of the shishtu formation have been examined. twenty genera and one unknown genus have been identified. the original aragonite shells have been replaced either by pyrite or fluorapatite

The early Tournaisian (Carboniferous) stage represents a key episode in the evolution of vertebrates. It follows end-Devonian Hangenberg extinction event, which led to major perturbation both terrestrial and aquatic vertebrate ecosystems, resulted significant restructuring assemblages. However, few faunal associations this age have been described, our understanding turnover across Devonian-Carb...