RETRODEFORMATION OF EDIACARAN FOSSILS AT THE MISTAKEN POINT ECOLOGICAL RESERVE, NEWFOUNDLAND, CANADA

Ediacaran fossils represent the first case of large, biologically complex organisms in Earth’s History. The Ediacaran fossils analyzed in this study are located at Mistaken Point, Newfoundland, Canada. First appearing around 585 million years ago, these fauna were fossilized as impressions in sedimentary turbidite sequences and have since been deformed by tectonic processes. This begets the questions of what the original bodyforms of the fauna were prior to deformation, and the range of diversity in bodyforms for various species. However, most research regarding Ediacaran fossils has been conducted under the assumption that we know their original morphology, prior to being deformed. Examples include assuming holdfasts or disc shaped species were perfectly circular. However, with no modern analog to provide any sort of validation for the assumption of body forms circular reasoning is introduced into the retrodeformation process. The assumed body shape is used to force the same shapes in all individuals of a species, thereby ignoring the actual, natural diversity in their forms. In this study, we utilize strain quantified at macro scales to provide estimates of Layer Parallel Shortening (LPS) to be compared to micro scale strain quantified using grain-scale analysis to extract Rf and ɸ values. If on a single bed the micro strain estimates are all similar in Rf and ɸ values, we can than see if there are relationships between LPS at larger scales and those micro scale strain estimates to infer retrodeformation parameters at further locations. However, as prior researchers have suggested, the variability of strain accommodated by each individual fossil may be heterogenous across a single small surface, meaning that micro scale strain analysis needs to be considered at all sites. Additionally, geostatistical methods will need to be used to determine Rf and ɸ values at each fossil location between rock sample locations. As this project is ongoing, we present the most recent findings of our research on the Ediacaran fossils at Mistaken Point, Newfoundland, Canada.