MORPHOLOGICAL COMPARISONS BETWEEN PRECAMBRIAN AND PHANEROZOIC MARINE TRACE FOSSILS

Trace fossils from Precambrian rocks are rare and unvaried, reflecting the comparative sparsity of biodiversity at the time. Only several categories of traces are represented in these early rocks, almost all being epifaunal and almost none being infaunal. In this study, we looked at four Ediacaran-aged rocks that were noted to contain traces. These specimens were housed in the personal collection of the late Dr. Rex H. Powell and were provided to the authors for study by Dr. Marie-Alice L’Heureux. The Precambrian materials in this study were collected in the 1970s and 1980s from the White Sea region of Russia and Fortune Head, Newfoundland and Labrador, Canada. Here we compare the mechanics and morphology of these traces to those of Upper Devonian traces collected by the authors in shale-dominated stream beds in Erie, Pennsylvania. Precambrian and Phanerozoic traces of similar ichno-classification share similar morphology and habitus but show differences in terms of biotic sediment interactions and preservation. Based on these differences, we tentatively suggest expanding the current system of ichnological classification to provide for more accurate descriptions of Precambrian trace fossils, perhaps introducing new ichnotaxa that reflect the uniqueness of these early traces.