Author : Karma Nanglu
Publisher :
ISBN 13 :
Total Pages : 0 pages
Book Rating : 4.:/5 (133 download)
Book Synopsis Revisiting the Cambrian Burgess Shale Palaeocommunity in Light of New Field Discoveries from Marble Canyon, Kootenay National Park, British Columbia by : Karma Nanglu
Download or read book Revisiting the Cambrian Burgess Shale Palaeocommunity in Light of New Field Discoveries from Marble Canyon, Kootenay National Park, British Columbia written by Karma Nanglu and published by . This book was released on 2019 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: The 508-million-year-old Burgess Shale (British Columbia) is among the most important fossil localities in the world as it provides a direct window into the Cambrian Explosion, the phenomenon whereby most metazoan groups appeared rapidly in the fossil record for the first time. For over 100 years, Burgess Shale fossils have provided unique insights into the early evolutionary history of animal life, but a holistic description of the community ecology of the Burgess Shale has remained elusive. This dissertation aims to reinvestigate the Burgess Shale paleocommunity in light of the recently discovered Marble Canyon fossil site in Kootenay National Park, integrating this new dataset with those from the type areas in Yoho National Park, 40km to the northwest (Walcott Quarry, Raymond Quarry, and Tulip Beds). The first three chapters of this dissertation focus on the organismal level. An experimental decay study (Chapter 1) provides a framework for the interpretation of taphonomic bias in community reconstructions. The redescription of three enigmatic Cambrian taxa (Chapters 2 and 3) provide novel phylogenetic and ecological information for understanding the patterns of diversity and niche structure at Marble Canyon. The community analysis (Chapter 4) represents the largest quantitative study of the Burgess Shale to date. Patterns of faunal stasis between most adjacent bedding assemblages followed by periodic variations in abundance and species identity are found at both Marble Canyon and Walcott Quarry, the two best-studied sites with the finest level of stratigraphic/temporal data. Across the entire Burgess Shale paleocommunity, major shifts in representative taxonomic groups and ecological modes occur between major localities. The results of this work suggest that the Burgess Shale as a paleocommunity was highly heterogeneous in both its taxonomic and ecological composition. Shifting abiotic and environmental variables are determined to be more significant in the long-term structuring of Burgess Shale communities than species interactions such as predation, which was previously considered paramount.
