Diverse pelagic predators from the Chengjiang Lagerstätte and the establishment of modern-style pelagic ecosystems in the early Cambrian

New information obtained from exceptionally preserved nonmineralized fossils in the Chengjiang Lagerstätte indicates the presence of diverse pelagic predators in the early Cambrian, including ctenophores ( Maotianoascus octonarius Chen and Zhou, Trigoides aclis Luo and Hu, Botafasciculus ramificans Hou et al., and a new species, Yunnanoascus haikouensis gen. et sp. nov.), chaetognaths ( Protosagitta spinosa Hu = Eognathacantha ercainella Chen and Huang), eldoniids ( Stellostomites eumorphus Sun and Hou, and Rotadiscus grandis Sun and Hou), and epipelagic nektonic arthropod predators (e.g., Isoxys), as well as some meroplankton (e.g., Anomalocaris and Amplectobelua). Trophic analysis of the early Cambrian pelagic community of the Chengjiang Biota reveals a phytoplankton-based food web with a complex trophic structure containing at least three (probably four) trophic levels. A complex, modern-style pelagic ecosystem may have been developed by the time of early Cambrian.