A recent paper by Harasewych et al. (2015) explores the phylogenetic relationships within the Cerionidae and its relations to other families. This makes this group one of the more well-studied Neotropical land snails since the work of Uit de Weerd and other recent publications by Harasewych and co-workers.
The new paper is summarized as follows: “Phylogenetic analyses of partial DNA sequences of the mitochondrial COI and 16S rDNA genes derived from Mexistrophia reticulata Thompson, 2011, the type species of the genus Mexistrophia, indicate that this genus is sister taxon to all remaining living Cerionidae, and that the family Cerionidae is most closely related to Urocoptidae. Relationships among representative cerionid taxa are consistent with the zoogeographic hypothesis that Mexistrophia has been isolated from the remaining living Cerionidae since the Cretaceous, and suggest that the near-shore, halophilic habitat that has commonly been associated with this family is likely a Cenozoic adaptation that coincided with the transition from continental to island habitats. The genus Protocerion is described to include the Late Cretaceous species Cerion acherontis Roth and Hartman, 1998, as its retention in Cerion would render this genus paraphyletic”.
Harasewych, .G., Windsor, A.M., Lopez-Vera, E. & Thompson, F.G., 2015. On the phylogenetic relationships of the genus Mexistrophia and of the family Cerionidae (Gastropoda: Eupulmonata). – The Nautilus 129: 156–162.