Supporters of a close relationship with molluscs maintained that a pair of bars, running across the mouth and armed with backward-pointing teeth, were a rudimentary form of the radula, the toothed tongue that molluscs use to scrape up food and convey it back to the throat.[27][52][53] Nicholas Butterfield, the one academic who has so far published articles placing Wiwaxia closer to polychaetes, stated that Wiwaxia′s two-row feeding apparatus could not have performed the sophisticated functions of the multi-row, conveyor-belt radula,[54] suggesting instead that Wiwaxia′s apparatus was like the side-by-side pair of toothed bars found in some polychaetes.[55] Later he found some fragmentary fossils, 5 to 10 million years before the Burgess Shale, that he regarded as a much more convincing early radula.[56] Butterfield has also described Wiwaxia′s armor plates and spines as similar in internal structure to the chetae ("hairs") of polychaetes.[55] Supporters of the link with molluscs have stated that Wiwaxia shows no signs of segmentation, appendages in front of the mouth, or "legs—–all of which are typical polychaete features.[27] One writer adopted a neutral position, saying he saw no strong grounds for classifying Wiwaxia as a proto-annelid or a proto-mollusc, although he thought the objections against classification as a proto-annelid were the stronger.[57]