Palaeoecological Implications of Lower-Middle Triassic Stromatolites and Microbe-Metazoan Build-Ups in the Germanic Basin: Insights into the Aftermath of the Permian–Triassic Crisis

Following the end-Permian crisis, microbialites were ubiquitous worldwide. For instance, Triassic deposits in Germanic Basin provide a rich record of stromatolites as well microbe-metazoan build-ups with nonspicular demosponges. Despite their palaeoecological significance, however, all these have only rarely been studied. This study aims to fill this gap by examining and comparing from Upper Buntsandstein (Olenekian, Lower Triassic) lower Middle Muschelkalk (Anisian, Germany. By combining analytical petrography (optical microscopy, micro X-ray fluorescence, Raman spectroscopy) geochemistry (?13Ccarb, ?18Ocarb), we show that studied formed slightly evaporitic environments. Olenekian Jena area Anisian strata at Werbach contain stromatolites. successions Hardheim, contrast, host build-ups. Thus, key difference is absence or presence demosponges microbialites. It plausible microbes had mutualistic relationship, it tempting speculate investigated microbial-metazoan reflect an ancient evolutionary ecological association. The widespread occurrence (e.g., stromatolites/microbe-metazoan build-ups) after catastrophe may resulted suppressed competition vacant niches. distribution and/or might controlled subtle differences salinity water depth, latter influencing hydrodynamic processes nutrient supply down microscale. To obtain more complete picture such earth’s history, fossil records need be (re)investigated. time being, environmental taphonomic studies modern are urgently required.