Rare Hyolithid Fossil from Emu Bay

Description: The Emu Bay Shale is Australia’s only Burgess Shale type deposit. It has fauna in common with both the younger Burgess Shale and the slightly older Chengjiang Biota. Unlike the Burgess Shale and Chengjiang Biota, however, the Emu Bay Shale deposits were a shallow water depositional environment. This is a member of the Hyolitha, a phylum with problematic affinities, thought to be related to the mollusks. They are thought to have lived on the substrate, resting on the flatter side of the shell for stability. The two stabilizing structures are termed the Helens. While Hyolthiods are a common fossil of the Chengjiang Biota, many have not been described. This one is a quite a rare example, and the only I have seen.