Nonmarine mollusks recovered during archaeological excavations on the island of Mo‘orea, Society Islands, French Polynesia, were analyzed as part of a multidisciplinary study of anthropogenic environmental change. Records of now-extinct taxa in dated archaeological contexts were combined with historic collection data from the 1830s to the present to determine the chronology of extinction of the 10 species of land snails of the family Endodontidae that formerly inhabited the island. One species known only from a stratum antedating human settlement on the island and three known only archaeologically but from imprecisely dated strata were certainly extinct by the late nineteenth century but may have disappeared earlier. One species collected in 1838 was extinct by the late nineteenth century, and all of the described endodontid species present in the mid- to late nineteenth century are undoubtedly now extinct because none was collected by the 1934 Mangarevan Expedition or by subsequent collectors. Only a single unidentified living endodontid has been observed on Mo‘orea since the nineteenth century. Additional extinctions or extirpations have occurred among the Helicarionidae, terrestrial Assimineidae, and probably also in the Helicinidae. Four new species of Endodontidae are described: Libera kondoi, Minidonta opunohua, Nesodiscus nummus, and N. cookei. Libera jacquinoti, described in 1850 from poorly localized material and until now not collected subsequently, is shown to have inhabited Mo‘orea.