The Trochidae and Turbinidae of the Kermadec Ridge (Mollusca: Gastropoda)

Molecular phylogeny suggests polyphyly of both the turban shells (family Turbinidae) and the superfamily Trochoidea (Mollusca: Vetigastropoda)

Bayesian and parsimony phylogenetic analyses of sequence from two nuclear and two mitochondrial genes suggest that neither the molluscan superfamily Trochoidea, nor the family Turbinidae are monophyletic. The family Turbinidae s.l. divides into two main groups. The first group includes taxa previously referred to the five subfamilies Angariinae, Colloniinae, Phasianellinae, Tricoliinae, Gabrieloninae, and the liotiine genus Cinysca; these subfamilies are here recognized as Angariidae, Colloniidae, and Phasianellidae (with subfamilies Phasianellinae, Tricoliinae, and Gabrieloninae). The second group, which corresponds to Turbinidae sensu stricto, includes Prisogasterinae, Turbininae, and the liotiine genus Liotina, all of which are more closely related to trochids than they are to the first group. Several morphological studies have suggested previously that the family Phasianellidae is distinct from Turbinidae. However, this is the first study to suggest that Phasianellidae forms a group with some taxa previously thought of as turbinids, but excluding the nominotypical genus Turbo and its allies. The family Turbinidae has traditionally been described as the only family in the Vetigastropoda group that has a calcified operculum. The non-monophyly of Turbinidae suggests that calcareous opercula may have arisen independently more than once within the Vetigastropoda.