Jonathan R. Hendricks, 2013. "Global distributional dynamics of Cambrian clades as revealed by Burgess Shale-type deposits", Early Palaeozoic Biogeography and Palaeogeography, D. A. T. Harper, T. Servais
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The Cambrian geographical and temporal distributions of many clades remain poorly understood, despite their importance for elucidating the palaeobiogeographical context of the Cambrian radiation. New species and genus level occurrence databases were developed to analyse temporal and geographical distributional patterns in taxa belonging to 14 clades from over 60 globally distributed early and Middle Cambrian Burgess Shale-type lagerstätten. Analyses demonstrate that clades with confirmed Precambrian origins were, on average, more widespread and temporally persistent than clades with first fossil occurrences in the Cambrian. Despite their dominance in diversity, arthropods were less widely distributed and temporally persistent than many other groups. Finally, a significant correlation between geographical range and temporal persistence is demonstrated, supporting the hypothesis that Cambrian taxa with wider geographical ranges were less likely to go extinct than those with narrower ranges.
Species and genus data tables are available at: http://www.geolsoc.org.uk/SUP18665
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The Early Palaeozoic was a critical interval in the evolution of marine life on our planet. Through a window of some 120 million years, the Cambrian Explosion, Great Ordovician Biodiversification Event, End Ordovician Extinction and the subsequent Silurian Recovery established a steep trajectory of increasing marine biodiversity that started in the Late Proterozoic and continued into the Devonian. Biogeography is a key property of virtually all organisms; their distributional ranges, mapped out on a mosaic of changing palaeogeography, have played important roles in modulating the diversity and evolution of marine life. This Memoir first introduces the content, some of the concepts involved in describing and interpreting palaeobiogeography, and the changing Early Palaeozoic geography is illustrated through a series of time slices. The subsequent 26 chapters, compiled by some 130 authors from over 20 countries, describe and analyse distributional and in many cases diversity data for all the major biotic groups plotted on current palaeogeographic maps. Nearly a quarter of a century after the publication of the ‘Green Book’ (Geological Society, London, Memoir 12, edited by McKerrow and Scotese), improved stratigraphic and taxonomic data together with more accurate, digitized palaeogeographic maps, have confirmed the central role of palaeobiogeography in understanding the evolution of Early Palaeozoic ecosystems and their biotas.