Recently a study by Jonathan Miller came to my attention about Cuban Cerion species. Morphometric studies are becoming more popular, but the methodology may not be familiar to the readers and can be challenging to perform.
The abstract reads: “Cerion mumia is a complex of eight subspecies distributed along the north coast of Cuba from Pinar del Rio to Camaguey provinces. The geometric morphometric analysis presented here was aimed at identifying patterns of shell shape variation to test the hypothesis of colonisation through land bridges during the Eocene-Oligocene. C. mumia cuspidatum, the easternmost population, was similar in shape to the subspecies from the north coast of Havana, but showed morphometric differences suggesting allopatric speciation followed by dispersal. The shells from the west were more globose than those from Havana or the east, which tended to be more cylindrical, as shown by the thin-plate spline analysis. As a result of the morphometric analysis I propose to elevate C. noriae comb. nov. and C. wrighti comb. nov. to species rank and to include C. noriae hondanum comb. nov. as a subspecies of C. noriae comb. nov. I report a second locality of C. noriae comb. nov. at Playa Santa Fe formation from the late upper Pleistocene. Geometric morphometric techniques are useful in species identification through comparing new samples with type material”.
The author collected his shells in the field, photographed them in situ and released them afterwards. Therefore, as far as I understand, no vouchers are available in a museum collection of the material studied. This might be a challenging procedure and may hamper the repeatability of this study. Otherwise this seems a nice study with as outcome that this species group may be split into three species with disjunct distribution along the Cuban north coast.
Miller, J.P., 2016. Geometric morphometric analysis of the shell of Cerion mumia (Pulmonata: Cerionidae) and related species. – Folia Malacologica, 24: 239-250.