The dinoflagellate speciesIsabelia druggii(Stover) andI. seelandica(Lange): their association in the Teurian of Woodside Creek, Marlborough, New Zealand

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Abstract
Palynofloras from immediately above the Cretaceous-Tertiary (Haumurian-Teurian) boundary at Woodside Creek are dominated by Isabelia druggii (Stover) Lentin & Williams and I. seelandica (Lange) Lentin & Williams. A similar situation occurs at the base of the type Danian at Stevns Klint, Denmark, where palynofloras from the basal Danian Fish Clay contain fairly abundant I. druggii and relatively rare I. seelandica. A detailed study of a large number of specimens of the two species, both from Woodside Creek and from Stevns Klint, indicates that I. seelandica differs from I. druggii only in the possession of an apical horn; intermediate forms, with relatively small apical protuberances, are included in I. seelandica. Both species are apparently restricted to the Late Maastrichtian-Early Danian interval.