Alterbidinium?: novozealandicum, a new dinoflagellate from the Herring Formation (Upper Cretaceous), southern Marlborough, New Zealand

The new dinoflagellate Alterbidinium? novozealandicum n.sp. from the uppermost lower Haumurian (middle to upper Campanian) Isabelidinium korojo-nense Interval Zone in New Zealand, is a large, fusiform, dorso-ventrally compressed, peridinioid cyst without endocyst. The apical part of the cyst has two folds on the dorsal side. The cyst bears a long apical horn and a long left antapical horn. The right antapical horn is very reduced. The paratabulation is expressed by the intercalary 2a periarcheopyle only. Alterbidinium? novozealandicum was encountered in a narrow stratigraphic interval in the Herring Formation, and may be a potential stratigraphic marker.