This brought "Odontogriphus" into the center of a debate that had been going on since 1990, when Butterfield denied that "Wiwaxia" was a forerunner of molluscs and argued that it was an evolutionary "aunt" of annelids. In particular he had argued that: "Wiwaxia"’s sclerites were internally much more like the bristles of polychaete annelids such as "Canadia" than like any forerunner of molluscan shell plates; and in his opinion "Wiwaxia"’s feeding apparatus was more similar to that of some polychaetes than to a molluscan radula. Caron, Scheltema, et al. (2006) thought Wiwaxia bore little resemblance to polychaetes as it showed no signs of segmentation, appendages in front of the mouth, or "legs" – all of which are typical polychaete features.