Helicosphaera intermedia

Helicosphaera intermedia Martini, 1965

Helicosphaera limasera de Kaenel & Villa 1996

Helicopontosphaera rhomba Bukry, 1971

Helicosphaera rhomba (Bukry, 1971) Jafar and Martini, 1975

Helicosphaera zeta de Kaenel & Bergen in Beoseiget et al. 2017

Helicolith having a Type III (Helicosphaera carteri type) blanket, an expanded flange termination and a central area with a diagonal disjunct bar leaving open space in the central area in various width.

Helicosphaera intermedia differs from Helicosphaera euphratis Haq (1966) by having a diagonal disjunct bar leaving some open space in the central area. In Helicosphaera euphratis, the central area is entirely covered by a disjunct multi-segmented plate.

Helicosphaera intermedia is distinguished from Helicosphaera leesiae da Gama & Varol (2013) by having a diagonal disjunct bar whilst the latter has a traverse disjunct bar.

Boesiger, T. M., de Kaenel, E., Bergen, J. A., Browning, E. & Blair, S. A. , (2017): Oligocene to Pleistocene taxonomy and stratigraphy of the genus Helicosphaera and other placolith taxa in the circum North Atlantic Basin. - Journal of Nannoplankton Research. 37(2-3): 145-175.

Bramlette, M. N. & Wilcoxon, J. A., (1967b): Middle Tertiary calcareous nannoplankton of the Cipero section, Trinidad, W.I. - Tulane Studies in Geology and Paleontology. 5: 93-131.

Bukry, D., (1971b): Cenozoic calcareous nannofossils from the Pacific Ocean. - San Diego Society of Natural History Transactions. 16: 303-327.

da Gama, R. O. B. P. & Varol, O., (2013): New Late Oligocene to Miocene Species. - Journal of Nannoplankton Research. 33(1): 1-12.

de Kaenel, E. & Villa, G., (1996): Oligocene-Miocene calcareous nannofossil biostratigraphy and paleoeecology from the Iberian Abyssal Plain. - Proceedings of the Ocean Drilling Program, Scientific Results. 149: 79-145.

Haq, B. U., (1966): Electron microscope studies on some upper Eocene calcareous nannoplankton from Syria. - Stockholm Contributions in Geology. 15: 23-37.

Jafar, S. A. & Martini, E., (1975): On the validity of the calcareous nannoplankton genus Helicosphaera. - Senckenbergiana Lethaea. 56: 381-397.

Martini, E., (1965): Mid-Tertiary calcareous nannoplankton from Pacific deep-sea cores. - Colston Papers. 17: 393-411.