Vertiginid land snails are tiny and constitute a tiny (but yet ill-studied) group of the Neotropical fauna. Apart from a monograph by Pilsbry in his Manual of Conchology, hardly any recent studies are known on this faunal element. For the Nearctic vertiginids Jeff Nekola has done much work and he has just published a note on the supraspecific taxonomy of the family (Nekola & Coles, 2016).
A detailed phylogenetic study revealed that there are two clades, the Vertiginidae and Nesopupinae. The latter comprising tropical species. The paper discusses the use of genetical markers, and the interpretation of the results in the light of the number of taxa included in a family. The authors plead for a reconsideration of supraspecific concepts within the Orthurethra.
Nekola, J.C. & Coles, B.F. Supraspecific taxonomy in the Vertiginidae (Gastropoda: Stylommatophora). – Journal of Molluscan Studies 82: 208–212.