Marine paleoecology during the aftermath of the end-Permian mass extinction

During the latest Paleozoic and earliest Mesozoic the Earth experienced the most devastating biotic crisis in the Phanerozoic history of life, the end-Permian mass extinction. Several lines of evidence indicate that physiological and chemical stresses likely linked to the cause(s) of the end-Permian mass extinction pulsed throughout its aftermath during the Early Triassic (Scythian) for 5-6 million years. However, the majority of studies on the Permian-Triassic biotic crisis are boundary-centric and focus on determining taxonomic patterns; very few studies have focused on determining the prolonged effects of these lingering environmental perturbations on the Earth's biota.; The purpose of this research was to evaluate marine paleoecology during the aftermath of the end-Permian mass extinction to test the hypothesis that, in addition to the mass extinctions, temporary and permanent ecological changes in Earth's marine biota resulted from the prolonged latest Paleozoic-earliest Mesozoic environmental perturbations. Presented in this dissertation are: (1) a taphonomic evaluation of Early Triassic fossils; (2) a case study of ecologic/numerical dominance during the Early Triassic; (3) a study of the proliferation of microbial mats in benthic level-bottom marine subtidal environments; (4) a synthesis of temporary and permanent structural changes in benthic level-bottom marine paleocommunities; and (5) a new mechanism that is hypothesized to have been one of the causes of the Permian-Triassic marine biotic crisis.; The focus on marine paleoecology during the aftermath of the end-Permian mass extinction represents a novel approach to understanding mass extinctions and the effects of global environmental changes and perturbations on Earth's biota. This research reveals that: (1) the aftermath of the end-Permian mass extinction was as crucial as the mass extinction in shaping the evolutionary history of life on Earth; and (2) an understanding of paleoecology during the aftermaths of mass extinctions can help to constrain causal mechanisms for biotic crises. An understanding of how the Earth's biota react to environmentally stressed intervals in Earth's history, such as mass extinctions, will enable the present biodiversity crisis to be better managed.