Early and middle Cambrian metazoan biodiversity and fine-scale stratigraphy: aspects of the Cambrian Radiation Event and environmental controls on Cambrian continents

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The project aims at a precise documentation of changes in the biota and depositional environments during the Cambrian Series 2 and 3 on various Cambrian continents. Such changes are believed to portray (i) changes and diversification in the biodiversity that indicates the character of phylogeny of major animal groups, and (ii) shifts or conversions in regional, and eventually global environments. Better constraints on these changes will not only permit significant refinements in stratigraphic correlation to be achieved but they will also provide clues for the so far poorly studied conversions from skeletal faunas with a high degree of endemism in the early Cambrian (Cambrian Series 2) to distinctly more uniform faunas in the early middle Cambrian (Cambrian Series 3) that features the terminal phase of the so-called Cambrian Radiation Event, the most dramatic period of evolution in the organic world during the entire earth history. It will also contribute to a better understanding of changes from generally well oxygenated and relatively high energy environments of the traditional fossil-bearing early Cambrian strata via dysoxic, often stagnant condition to the surprisingly uniform environments of the middle Cambrian observed on most continents. The planned research activities will focus on taxonomic investigations of imperfectly studied skeletal fossils together with studies on faunal composition and the correlation of the biotic changes with sea-level fluctuations and its characters in various regions of the Cambrian continents. Previously undescribed skeletal metazoan fossils (primarily trilobites) from various regions will be systematically studied and described. The ultimate objective of the three-year project is a global synthesis of faunal and sea-level changes on tropical and temperate palaeocontinents (i.e., West Gondwana, Avalonia, Baltica, Laurentia, and the Yangtze Platform) for one of the most dramatic intervals in earth history. The synthesis will allow a resolution of highly divergent views for intercontinental correlation of this interval and the poorly investigated reasons for the changes and is a major contribution to the global subdivision project of the ISCS.