Shishania is a chancelloriid and not a Cambrian mollusk

The Cambrian evolutionary radiation is noted for its profusion of bizarre and unfamiliar body forms, many of which illuminate the early ancestry of major animal groups. The spine-covered fossil Shishania aculeata (Cambrian Stage 4, Yunnan, China) has been interpreted as intermediate between mollusks and their lophotrochozoan ancestors. Our new material challenges this interpretation. We propose taphonomic explanations for apparent molluscan features and instead identify prominent anatomical similarities to coeval chancelloriids from nearby strata. Our reinterpretation of Shishania as an early-diverging chancelloriid helps to consolidate a model for the early evolution of this enduringly problematic group of sponge-like metazoans.