It was previously the only family in the superfamily
Achatinelloidea (according to the
taxonomy of the Gastropoda by Bouchet & Rocroi, 2005). It is now classified under the superfamily
Pupilloidea. The family Achatinellidae represents a diverse
adaptive radiation. All species of tree-snail in Hawaii are believed to have come from a single ancestral snail. How that ancestral snail made the trip across the ocean is unknown. A longstanding theory is that a bird carried a notably smaller ancestor across the ocean and dropped it on the islands, as bird mediated dispersal has been documented in other snail species. Alternative theories include that it floating across the ocean on a mat of debris, or that it island hopped across the Pacific in a combination of the theories. Subfamilies in the family Achatinellidae include: • Achatinellinae Gulick, 1873 - synonym: Helicterinae Pease, 1870 (inv.) •
Auriculellinae Odhner, 1921 •
Elasmatininae Iredale, 1937 • tribe Elasmatinini Iredale, 1937 - synonyms: Strobilidae Zilch, 1959 (n.a.); Pitysinae Cooke & Kondo, 1961 • tribe Antonellini Cooke & Kondo, 1961 • tribe Tubuaiini Cooke & Kondo, 1961 •
Pacificellinae Steenberg, 1925 • tribe Pacificellini Steenberg, 1925 - synonym: Tornatellinoptini Cooke & Kondo, 1961 • tribe Lamellideini Cooke & Kondo, 1961 •
Tekoulininae Solem, 1972 •
Tornatellidinae Cooke & Kondo, 1961 • tribe Tornatellidini Cooke & Kondo, 1961 • tribe Tornatellariini Cooke & Kondo, 1961 •
Tornatellininae Sykes, 1900 • tribe Tornatellinini Sykes, 1900 • tribe Elasmiatini Kuroda & Habe, 1949 == Anatomy ==