Abstract

The new subfamily Nodoconchiinae of the Cytheridae Baird is erected to accommodate three genera: Austrocythere Hartmann, 1989a, Nodoconcha Hartmann, 1989a and Ectonodoconcha gen. nov.. Austrocythere seems to be known only from the type species A. reticulotuberculata Hartmann, from its type locality in the Recent Antarctic and from the Antarctic Oligocene. Nodoconcha, however, apart from its original record by Hartmann from the Antarctic as Nodoconcha minuta, has also been encountered in the Oligocene of the Antarctic. In the present study, we have identified seven species of Nodoconcha from the Maastrichtian and Danian of the Neuquén Basin, together with a new genus from the Danian, Ectonodoconcha lepidotus gen. et sp. nov.. The new species of Nodoconcha are N. polytorosa sp. nov., N. sanniosis sp. nov. and N. upsilon sp. nov., and Nodoconcha? sp. that is the possible ancestor of the entire group. Previously described species now placed in the genus are: N. paleocenica (Bertels, 1973), N. jaguelensis (Bertels, 1974) and Nodoconcha sp. (Bertels, 1974). The Nodoconcha species are divided into the Minuta and Upsilon groups.