Evidence for Decoupling of Relative Abundance and Biodiversity of Marine Organisms in Initial Stage of GOBE: A Preliminary Study on Lower Ordovician Shellbeds of South China

摘要

INTRODUCTION Shellbeds are defined as any relatively dense accumulation of bioclasts with various amounts of sedimentary matrix (Kidwell et al., 1986). Shellbeds have various taxonomic compositions, state of preservation, and degree of post-mortem modification (Kidwell et al., 1986), controlled primarily by the evolutionary changes in ecology, diversity, and environmental distribution of bioclast-producing and bioclast-destroying organisms (Kidwell and Brenchley,1994).