The spectacular partulid tree snail fauna of the Society Islands has been almost completely extirpated in recent decades following the deliberate introduction of the alien carnivorous snail Euglandina rosea. The greatest loss has occurred on the island of Raiatea, French Polynesia, home to an estimated 34 species (including 33 single-island endemics), all of which have been deemed extirpated in the wild. However, we report here the February 2006 discovery of two surviving Raiatean partulid lineages on the upper slopes of Mount Tefatua, the highest peak on the island. They have been identified using morphological and molecular phylogenetic analyses, the latter approach employing available museum and captive reference samples. One population, at 750 m elevation, consisted of Samoana attenuata. It has a multi-island distribution within the archipelago and surviving populations persist also on Tahiti and Moorea. A second population, present just below the summit at 950 m, consisted of a previously unstudied morphospecies and it has been formally described as Partula meyeri. It is unclear if a stable altitudinal refuge from E. rosea predation exists on Mount Tefatua but the unexpected discovery of these two surviving montane populations raises the possibility of preserving some fraction of Raiatea's endemic tree snail diversity in the wild.

Following the well documented extinctions of many species of endemic tree snail (family Partulidae) throughout French Polynesia, field surveys were undertaken on four islands in the Society archipelago to provide up to date information for the international conservation programme for this group of invertebrates. These surveys have confirmed the loss of all species of Partula in the wild on the Society Islands other than Tahiti. Thirty-three species have been lost from Raiatea, thereby eliminating one of the most outstanding examples of island evolutionary radiation. On Huahine the disappearance of P. varia and P. rosea, used for making lei (shell jewellery), had an economic and social effect on the local community: many of the women of the villages lost their livelihoods, and the artisan's association folded. The seven species of Partula on Moorea were extinct in the wild by the mid 1980s, terminating almost 100 years of biological research. It now seems that the remnant populations of Samoana attenuata discovered only 5 years ago are the only species of partulid still surviving beyond Tahiti on the Society Island group. The mixed species populations in the Te Pari area of Tahiti-Iti are still extant, but the predatory snail Euglandina rosea has now spread to the last valley on the Peninsula that did not have previous evidence of predator activity. On Tahiti-Nui populations of partulid, without the predator, were found near the crest of Mount Tahiti above Orofero Valley. Partulidae are clearly a highly threatened family of invertebrates, and in need of the most intense conservation focus.