Coprolite diversity reveals a cryptic ecosystem in an early Tournaisian lake in East Greenland: Implications for ecosystem recovery after the end-Devonian extinction

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-Carboniferous boundary remains poor. In paper, we present an analysis coprolite material from lacustrine facies at Celsius Bjerg on Ymer Ø East Greenland, overlies world-famous latest Devonian tetrapod-bearing localities. Fifty-five specimens (defined as single or piece shale containing coprolites) were analysed using propagation phase-contrast synchrotron microtomography (PPC-SR?CT). Through study external morphology, shape size combined with information about internal structures, categorise morphotypes, interpret their origin. Notably, identify greater number morphotypes compared taxa known skeletal material, indicating existence cryptic ecosystem that has not yet recovered body fossils. Vertebrate diversity immediate aftermath is inferred higher than expected, might included transient elements within open system, perhaps involving marine basin connections. Our results show coprolites offer alternative fossil data source, revealing otherwise always captured by record.