Radiation of giant snails across sub-Saharan Africa: the molecular phylogenetic evidence

Abstract The radiation of giant African snails in sub-Saharan Africa is examined critically for the first time. New molecular evidence reveals phylogenetic groups that display distinct geographical ranges. The type genus of the Achatininae, Achatina is not, as currently recognized, a trans-African monophyletic group but one confined to West Africa, with neither Tropical Central African Achatina (Achatina) nor East African Achatina (Lissachatina) being sister to it. We consider that the monophyletic subgroup of Achatina with a tropical Central African distribution should be attributed to Serpaea Bourguignat, 1890. The East African Achatina group previously placed in Achatina (Lissachatina) Bequaert, 1950, with type species Achatina fulica Bowdich, 1822, is confirmed as a distinct genus-level taxon, Lissachatina. The proposed West African origin of the Achatininae during the Pleistocene is revisited, and an alternative hypothesis of a possible Eocene origin is suggested.