Helicosphaera carteri

Coccosphaera carteri Wallich 1877

A helicolith with a Type III (Helicosphaera carteri type) blanket, an expanded flange termination, and a proximal plate featuring two large semi-circular pores aligned along the long axis of the helicolith.

Helicosphaera carteri exhibits inclined extinction angles of about 55° on the blanket on the distal side and shows length-fast (−) elongation.

Helicosphaera carteri differs from Helicosphaera burkei by possessing two large pores in the proximal plate, whereas Helicosphaera burkei has a non-porous proximal plate. Helicosphaera carteri is distinguished from Helicosphaera paleocarteri by the placement of its two large pores along the axial suture. In contrast, Helicosphaera paleocarteri has two small round pores positioned off the axial suture. Excellent SEM photo compatible with the holotype of Helicosphaera carteri was published by Konno & Jordan, 2006 (Pl. 4, Fig. 10)

Konno, S., Jordan, R. W., 2006. Lagoon coccolithophorids from the Republic of Palau, NW Equatorial Pacific. Journal of Nannoplankton Research 28(2), 95-110.

Wallich, G. C. 1877. Observations on the coccosphere. Annals and Magazine of Natural History 19: 342-350.

Theodoridis, S. 1984. Calcareous nannofossil biostratigraphy of the Miocene and revision of the helicoliths and discoasters. Utrecht Micropaleontological Bulletin. 32: 1-271.

Kamptner, E., 1954. Untersuchungen über den Feinbau der Coccolithen. Archiv für Protistenkunde 100, 1-90.

Hay, W. W., Mohler, H. P., Roth, P. H., Schmidt, R. R. & Boudreaux, J. E. 1967. Calcareous nannoplankton zonation of the Cenozoic of the Gulf Coast and Caribbean-Antillean area, and transoceanic correlation. - Transactions of the Gulf-Coast Association of Geological Societies 17: 428-480.

Black, M. 1971c. The systematics of coccoliths in relation to the paleontological record. In: Funnell, B. M. & Riedel, W. R. (Eds), The Micropaleontology of the Oceans. Cambridge University Press, Cambridge. 611-624.