Taxonomic notes on "Phoebodus heslerorum" and Symmorium reniforme (Chondrichthyes, Elasmobranchii)

The revision of shark teeth from the Pennsylvanian black shales of central USA, ascribed to “Phoebodus heslerorum” Williams, 1985 and Symmorium reniforme Cope, 1893, shows that “Ph. heslerorum” is a junior synonym of “Cladodus” divergens Trautschold, 1879. This species belongs neither to Phoebodusn or to Cladodus, so a new genus Heslerodus is proposed. Very common, robust cladodont teeth with a deep labio−basald epression and two buttons, often referred to as S. reniforme, do not belong to the latter species, but to "Cladodus” occidentalis Leidy, 1859. The generic affinity of “C.” occidentalisis yet undetermined, but it is possible that it represents ctenacanthoids.