ANOMALOCARIS AND OTHER LARGE ANIMALS IN THE LOWER CAMBRIAN CHENGJIANG FAUNA OF SOUTHWEST CHINA

Five anomalocaridids are described from the Lower Cambrian Chengjiang fauna of China: Anomalocaris saron sp.n., Anomalocaris sp., Amplectobelua symbrachiata gen. et sp.n., Cucumericrus decoratus gen, et sp.n., and Parapeytoia yunnanensis gen. et sp.n. Ventral trunk appendages are reported for the first time. In C. decoratus and P. yunnanensis, each appendage has a distal segmented walking leg, and a wide lateral extension of a long proximal portion forms the structure previously described as a lateral fin. Furthermore, the structure of the dorsum is elucidated. The supposed ventrolateral gills are flat scales covering the back in transverse rows. The mouth was directed backwards, as in the Middle Cambrian Opabinia regalis, and not directed ventrally as in previous reconstructions. The radial arrangement of the circum-oral sclerites suggests that anomalocaridids were related to aschelminth worms rather than to arthropods.