One lineage of the Ellobioidea, the Carychiidae has successfully accomplished a
complete transition onto land. Extant carychiid snails inhabit
aphotic and permanently wet
epigean (
Carychium) or subterranean (
Zospeum) environments throughout their
Holarctic distribution. This dramatic shift from a marine to a terrestrial habitat has occurred independently of the
stylommatophoran land-snails of the Eupulmonata. ==References==