Vinther and Nielsen (2005) proposed instead that "Halkieria" was a crown group mollusc, in other words more similar to modern molluscs that to annelids, brachiopods or any intermediate groups. They argued that: "Halkieria"’s sclerites resembled those of the modern solenogaster aplacophoran shell-less molluscs (see ), of some modern polyplacophoran molluscs, which have several shell plates, and of the Ordovician polyplacophoran "Echinochiton"; "Halkieria"’s shells are more similar to the shells of conchiferan molluscs, since shells of both of these groups show no trace of the canals and pores seen in polyplacophoran shell plates; the bristles of brachiopods and annelids are similar to each other but not to "Halkieria"’s sclerites.