Type Species

Heliorthus tenuis Stradner, 1961


Cruciolithus Stradner, 1968

Catostaura Aubry & Bord, 2009

Cruciplectus Aubry in Aubry & Bord, 2009

Stauronertha Aubry & Bord 2009


Elliptical to circular placolith having a birefringent tube cycle and a proximal shield and often birefringent axial cross.


Cruciplacolithus differs from Coccolithus Schwarz (1894), Chiasmolithus Hay, Mohler & Wade, (1966) and Sullivania Varol (1992) by having an axial cross. Coccolithus lack of central structure but both Sullivania and Chiasmolithus have a diagonal cross in the central area.


Aubry, M. -P. & Bord, D., (2009): Reshuffling the cards in the photic zone at the Eocene/Oligocene boundary. In, Koeberl, C. & Montanari, A. (eds) The Late Eocene Earth—Hothouse, Icehouse, and Impacts. - Geological Society of America, Special Papers. 452: 279-301.

Hay, W. W., Mohler, H. P. & Wade, M. E., (1966): Calcareous nannofossils from Nal'chik (northwest Caucasus). - Eclogae Geologicae Helvetiae. 59: 379-399.

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

Schwarz, E. H. L., (1894): Coccoliths. - Annals and Magazine of Natural History. 14: 341-346.

Stradner, H. & Edwards, A. R., (1968): Electron microscopic studies on Upper Eocene coccoliths from the Oamaru Diatomite, New Zealand. - Jahrbuch der Geologischen Bundesanstalt. 13(66): 1-48.

Varol, O., (1992): Sullivania a new genus of Palaeogene coccoliths. - Journal of Micropalaeontology. 11: 141-150.