- GeoRef, Copyright 2004, American Geological Institute. Reference includes data supplied by Institute of Geological and Nuclear Sciences (SIRIS), Lower Hutt, New Zealand
Nonionellina flemingi (Vella) reaches reproductive maturity at earlier stages in lower latitudes. Adults from the continental shelf off northern New Zealand are small and trochospiral, while those from off the subantarctic islands are commonly twice the size and planispiral. The mean length and number of chambers in the final whorl of a local population is an inverse function of the temperature at which the animals are living. The relationship is used in a palaeotemperature study of the New Zealand Upper Miocene to Recent.