Hadoprion cervicornis (Hinde, 1879) from the Upper Ordovician and Lower Silurian (Cincinnatian to Medinian) replaces four generic and eight specific names: Arabellites cervicornis, A. aciculatus, Oenonites acinaces, Ildraites horridus, I. laeohorridus, I. cervicornis, Nereidavus hamus, and N. alatus. This example illustrates the advantages of a nomenclature in accordance with the ICZN. The authors reject the use of parataxonomy for fossil jawed polychaetes.