Understanding the role of sediment-gravity flows in the formation of the Cambrian Burgess Shale Lagerstätte.
[sciencythoughts.blogspot.com]
The fossil record has been used to reconstruct a history of the evolution of life on Earth, but itself preserves a rather incomplete record. Almost all fossils are of biomineralised or other hard tissues, with only rare sites, known as Konservat Lagerstätten, preserving soft tissues or the bodies of organisms which lack hard tissues. Estimates of the preservation potential of modern organisms suggest that 30% of marine megafuana, and 80% of megafauna overall, would leave no fossil record in normal deposits. Much of our understanding of the emergence of modern Animals comes from Cambrian Konservat Lagerstätten, such as the Burgess Shale, where it is estimated that 86% of the preserved fauna would not be preserved under normal conditions. This makes understanding the processes which led to the creation of these deposits particularlt important. It is often assumed that the Burgess Shale represents the near-faithful preservation of an intact biological community, and these fossils have been used to reconstruct food webs and community structures, but it is unclear whether the conditions which led to the preservation of these fossils did indeed preserve a high fidelity impression of a living community, or created biases which we have not detected and have worked into our understanding of how these ancient communities worked, and thus how modern communities developed from those early, Cambrian examples.