Fossil shells in the Neotropics are scarce, but very interesting as they can give us a clue about distributions (and possibly habitats) in the past. A study of fossils from the Itaborai basin in eastern Brazil (Salvador et al., 2011), now has lead to the conclusion that Brasilennea species have been wrongly assigned to the Streptaxidae. Instead, they should be placed within the Cerionidae. This family is now occurring in the Caribbean region, and this re-classification sheds a new light on the past distribution of this group. The type species of this genus, B. arethusae Maury, has several characteristics that are more in accordance with cerionids than streptaxids.
Salvador, R.B., Rawson, B. & Simone, L.R.L., 2011. Rewriting the fossil history of Cerionidae (Gastropoda, Pulmonata): new family assignment of the Brazilian Palaeocene genus Brasilleannea Maury, 1935. – Journal of Molluscan Studies: 1-3 [published under advance access, doi:10.1093/mollus/eyr021]