Eutrephoceras subplicatum (Steinmann, 1895) is a junior synonym of Eutrephoceras dorbignyanum (Forbes in Darwin, 1846) (Cephalopoda, Nautiloidea) from the Maastrichtian Quiriquina Formation of Chile

► Two senior synonyms of Eutrephoceras suplicatum were discovered. ► Available type material is figured. ► A neotype for E. subplicatum is selected. ► Only a single nautiloid species from the Quiriquina Formation is recognized.