Decoding the drivers of deep‐time wetland biodiversity: insights from an early Permian tropical lake ecosystem

Wetlands are important to continental evolution, providing both arenas and refugia for emerging declining biotas. This significance the high preservation potential make resulting fossiliferous deposits essential our understanding of past future biodiversity. We reconstruct trophic structure age early Permian Manebach Lake ecosystem, Germany, a thriving wetland at time when tropical biosphere faced profound upheaval in peaking Late Palaeozoic Icehouse. Nine excavations, high-resolution spatiotemporal documentation fossils strata, U–Pb radioisotopic dating tuffs allow us distinguish autogenic allogenic factors shaping limnic biocoenosis. The was an exorheic, oxygen-stratified, perennial water body on 101–102 km2 scale, integrated into catchment draining much European Variscides. formation paralleled Asselian regional wet climatic interval benefited from rising base level due post-Variscan half-graben tectonics. Stromatolite-forming cyanobacteria, bivalves, several crustaceans, amblypterids xenacanthid sharks formed differentiated biocoenosis lake. Fossil stomach remains teeth prove rare presence acanthodians, branchiosaurs large amphibians. results indicate woody-debris-bearing lake littorals devoid semi-aquatic aquatic plants as places suitable stromatolites grow, underpin model freshwater-shark diversity most Variscan basins, demonstrate fish/amphibian ratios assemblages measure perenniality reveal taphonomic biases taphocoenoses. Our outcomes call more knowledge about diversity, ecology fossilization pathways biotas, particularly microorganisms actinopterygian fishes, deep-time ecosystems.