Tiny tropical snails with beautiful, jewel-like shells are going extinct almost as fast as scientists can discover them. The minute mollusks, which average just 1 to 3 millimeters long, are members of the genus Plectostoma. Their shells are elaborate and irregularly coiled, unlike the snail shells we're used to seeing.
Plectostoma make their homes on the lichens and moss that cover limestone hills of peninsular Malaysia and other parts of southeast Asia; they don't get around that much, so it's not uncommon for different hills to host separate species that are found only on that one hill, say the scientists who published a report documenting 31 species of spectacular snails, including 10 previously undescribed, today in Zookeys. The team used old collections, new observations, and CT scans of shell shapes to determine which snails belonged to which species.
Unfortunately, those limestone hills are easy targets for miners, and they're disappearing as limestone is taken to make cement. As a result, the hills' tiny snail inhabitants are disappearing, too. Extinctions are happening quickly, the team says. They predict that one of their new finds, a snail called Plectostoma tenggekensis, will probably be gone by the end of year.
