Erik Sperling

Abstract INTRODUCTION RESULTS DISCUSSION MATERIALS AND METHODS Acknowledgments Supplementary Materials REFERENCES Information & Authors Metrics & Citations View Options References Figures Tables Media Share Abstract The dawn of animal life is preserved by fossils of the Ediacara Biota, which have been separated into three biotic assemblages: the Avalon, White Sea, and Nama. Geographic and temporal isolation of these faunas leads to uncertainties regarding patterns of change.

Abstract Knowing the past temperature of the Earth is crucial for understanding the mechanisms driving climate change and biosphere evolution, but there is significant debate about the range of past temperature variation. Previous interpretations, largely based on oxygen isotope records, suggest that global temperature has generally declined over the past 539 million years, but substantial uncertainties persist.