The phylogeny of the family Tritoniidae has recently been studied with significant advances, but the relationships between genera are still controversial. In our study, we investigated the phylogeny of Tritoniidae using the most diverse taxon sampling possible. We applied an integrative approach based on new sequences of two mitochondrial genes (COI and 16S), a nuclear gene (H3) and morpho-anatomical characters. The monophyly of the family Tritoniidae was not recovered in our phylogenetic analyses. In view of our results, we propose a new rearrangement at the subfamily and genus levels. The plate-bearing genera are raised to the subfamily level as the monophyletic Marioniinae subfam. nov., formed by
Marionia and the reinstated
Marioniopsis. The remaining plate-less genera are raised to the subfamily level as the monophyletic Tritoniinae subfam. nov.. The genus
Myrella is reinstated to assign the Antarctic and sub-Antarctic tritoniids. The taxonomic status of the monotypic
Tritonidoxa is confirmed. Species delimitation analyses reveal a new large
Marionia species from the Gulf of Cádiz (south-west Spain, Atlantic Ocean) and evidence for the pseudocryptic speciation of numerous Atlantic–Mediterranean and Indo-Pacific tritoniids. Finally, taxonomic notes are provided for several species according to the proposed rearrangement.