Deconstructing Biases in the Fossil Record of the Oldest Animals: Experimental and Geochemical Studies in Soft-Tissue Preservation

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The fossil record is fickle and biased. Sites that preserve soft-bodied organisms, as opposed to typical fossil assemblages of bones, teeth, and shells, are exceedingly rare and truly exceptional (Konservat-Lagerstätten of Seilacher, 1970). Lagerstätten represent the richest source of anatomical information for extinct species, offer more complete views of diversity patterns in deep time, and ultimately open a window into the workings of ancient ecosystems typically afforded only to biologists studying modern systems. However, there is a growing recognition that Lagerstätten are fraught with preservational biases, which are in urgent need of systematic characterization. For instance, Lagerstätten are unevenly distributed through geological time, are typically restricted to specific environmental settings, and preferentially preserve certain tissue types over others (Allison and Briggs, 1993; Schiffbauer and Laflamme, 2012). Interdisciplinary studies that examine the physical, chemical, and biological factors controlling the tempos and modes of fossil preservation (taphonomy) are offering critical new perspectives on the content and accuracy of the fossil record, and are a necessary first step in correctly identifying trends in the evolution of life. My long-term research objective is to elucidate the taphonomic pathways responsible for fossilization, and to identify physical, chemical, and biological controls biasing the fossil record.****The proposed experimental and taphonomic studies of soft-tissue preservation have profound implications on evaluating the fidelity of the fossil record, specifically at the dawn of animal life. My work proposes to undertake the first comprehensive investigation of Ediacaran taphonomic scenarios, combining experimental taphonomy, and geochemical analyses in order to finally understand their distribution in time and space. Ultimately, taphonomic ground-truthing is necessary to validate all paleontological trends at any scale extrapolated from the fossil record.