Calcidiscus macintyrei (Bukry and Bramlette, 1969) Loeblich and Tappan, 1978 [Cyclococcolithus]
Description: Large circular species of Calcidiscus with central opening.
Remarks: Usually confined to specimens >10μm to allow unambguous biostratigraphic use. Essentially this is a large variant of C. tropicus.
Range: NN17 to 19 (use of the name C. macintyrei is normally confined to the large specimens occurring in this time interval although similar morphotypes do occur in the Miocene).