The gastropods described herein where sampled
from a 6 m-thick section, comprising less than 1% of
the sedimentary infill of the Nanning Basin (Deng &
Wu 1992). Judging from the huge, largely undisturbed succession of more than 600 m of lake sediments,
which encompass a time span from the Palaeocene
to at least the mid Oligocene, and thus more than 25
Ma (Deng & Wu 1992), the Palaeogene Nanning Lake
may be suspected to be an extremely long-lived lake. If
this is true, the high rate of endemism in the Nanning
Lake fauna and the discovery of further new mollusc
species would be no surprise.