Radulichnus is an ichnogenus of trace fossil

Trace fossil

Trace fossils, also called ichnofossils , are geological records of biological activity. Trace fossils may be impressions made on the substrate by an organism: for example, burrows, borings , urolites , footprints and feeding marks, and root cavities...

 which resembles the marks produced by the action of a mollusc's radula

Radula

The radula is an anatomical structure that is used by molluscs for feeding, sometimes compared rather inaccurately to a tongue. It is a minutely toothed, chitinous ribbon, which is typically used for scraping or cutting food before the food enters the esophagus...

 on sediment. As an ichnogenus, its classification is based solely on appearance, and does not necessarily imply anything of the affinity of the organism which produced the trace.
However, fossils of Kimberella

Kimberella

Kimberella is a monospecific genus of bilaterian known only from rocks of the Ediacaran period. The slug-like organism fed by scratching the microbial surface on which it dwelt in a manner similar to the molluscs, although its affinity with this group is contentious.Specimens were first found in...

have been found at or near the ends of Radulichnus traces, leading to the suspicion (accepted nearly as fact by some) that the traces were made by Kimberella.