The holotype of Psephodus minutus, Wellburn, 1901 (chondrichthyes, cochliodontiformes) is a gastropod steinkern

Abstract

The holotype of Psephodus minutus Wellburn, from the Millstone Grit Group (Carboniferous, Lower Pennsylvanian Series, Marsdenian Substage) of Lancashire (now Greater Manchester), England, was originally interpreted as a set of three articulated tooth plates of a chondrichthyan fish. No figure was published with the description, though a drawing was published 32 years later. Examination of the specimen shows it to be a steinkern of an indeterminate high-spired gastropod. Psephodus minutus is thus rendered as a nomen nudum.