TAXONOMY OF THE TERMINAL EDIACARAN VERMIFORM BIOTA, WOOD CANYON AND DEEP SPRING FORMATIONS, NEVADA

Owing to their temporal position between the complex multicellular oddities of the classic Ediacara biota and the more recognizable, true Metazoa of the Cambrian, the tubular, vermiform fossils of the terminal Ediacaran Period (~550–541 Ma) can contribute to our understanding of both extinction and biotic turnover preceding the Cambrian explosion. New fossil reports from Nevada and Namibia, including putative Conotubus and Gaojiashania, are comparable to the well documented assemblage from the Gaojiashan Lagerstätte, South China, and are preserved in a similar taphonomic window (via pyritization in mixed carbonate-clastic siltstone units). However, understanding the phylogeny and biostratigraphic significance of these organisms requires careful taxonomic study. Here we present results from our on-going effort to classify and detail the vermiform fossils from the broadly correlative Wood Canyon and Deep Spring formations of Nevada. A total of 93 slabs were assessed for standard body size and morphological characterization, including maximum and minimum lengths and widths for both smallest and largest repeating units for articulated fossils, and inner and outer cross-sectional widths for disarticulated specimens. The large number of analyzed specimens allows for a more rigorous application of statistical methods for morphological comparison with Gaojiashan Lagerstätte collections.