Landing, E., Westrop, S., 2004. Environmental Patterns in the Origin and Evolution and Diversification Loci of Early Cambrian Skeletalized Metazoa: Evidence from the Avalon Microcontinent, in: Lipps, J., Wagoner, B. (Eds.), Neoproterozoic-Cambrian Biological RevolutionsPaleontological Society. pp. 93-105.