Spygoria zappania new genus and species, a Cloudina-like biohermal metazoan from the Lower Cambrian of central Nevada

A new enigmatic Lower Cambrian fossil, Spygoria zappania, is described from the Nevadella zone (Botoman) of Lander County, central Nevada. In gross mo rphology, Spygoria fossils consist of stacks of small (5-10 mm in diameter) irregular calcified cups that are preserved in vertical, concave-up life o rientation. Stacks are linked laterally into large monospecific bioherms wh ich flourished in a shallow turbulent marine environment. The Spygoria organism is interpreted as a metazoan which presumably inhabit ed the uppermost cup in each stack and periodically secreted new cups as it grew upward. Absence of holdfast structures suggest that the organism was held in place by sticky mud until opportunistically cementing to adjacent i ndividuals. The affinity of Spygoria remains problematical, though we sugge st that irs stacked structure somewhat resembles the cone-in-cone structure of Cloudina, which formed similar dense thickets in shallow turbulent carb onate environments during the terminal Proterozoic.