Nannotax

Description: Elliptical placolith with narrow rim and wide central-area spanned by disjunct transverse bridge.

Remarks: This species is very rare but highly distinctive. Its range in the Indian Ocean (Young 1987) is similar to that recorded by Theodoridis (1984) in the Mediterranean. In the absence of electron micrographs it is difficult to be confident of the structure but in cross-polars the rim strongly resembles that of Coccolithus pelagicus, hence inclusion in the Coccolithaceae seems reasonable. The bridge is strongly birefringent, with inclined extinction.

Range: NN3 to 9