QUANTIFYING TRACE FOSSILS ON EDIACARAN-CAMBRIAN SAMPLES FROM DEATH VALLEY

The Ediacaran-Cambrian boundary is a crucial interval in Earth History, marking the rise of metazoans in benthic ecosystems and the disappearance of the enigmatic Ediacara biota. Trace fossils from this interval are crucial, as they record both rates and patterns of metazoan evolution, as well as increasing intensity in animal ecosystem engineering and modification of the substrate. Here, I describe and quantify a new collection of trace fossils from an Ediacaran-Cambrian boundary section in Death Valley, along with a description of the paleoenvironment. I quantify trace fossils and intensity of metazoan activity using both Bedding-Plane Bioturbation Indices (BPBI) and Ecosystem Engineering Impact (EEI) values. Comparing these patterns with other localities and facies worldwide helps to provide a more complete picture of evolving metazoan benthic ecology prior to the Cambrian explosion of animals and may also help with biostratigraphic correlation between sites in this critical interval.