 Hence they classify "Odontogriphus" and "Wiwaxia" as close to the ancestors of the first true molluscs.One scientist has presented a different analysis, arguing since 1990 that "Wiwaxia" is not closely related to molluscs but is much more like a polychaete worm.He argues that the supposed "radula" is nothing of the sort; he classifies "Odontogriphus" as a basal lophotrochozoan, in other words close to the last common ancestor of molluscs, annelid worms and brachiopods.