Helicosphaera euphratis Haq, 1966
Helicosphaera parallela Bramlette & Wilcoxon, 1967
Large helicolith having a Type III (Helicosphaera carteri type), an expanded flange termination and the central area with multi-segmented disjunct plate filling the entire central opening.
Helicosphaera euphratis differs from Helicosphaera intermedia Martini (1965) and Helicosphaera leesiae da Gama & Varol (2013) by having a multi-segmented disjunct plate instead of a disjunct bar in the central area.
Bramlette, M. N. & Wilcoxon, J. A., (1967): Middle Tertiary calcareous nannoplankton of the Cipero section, Trinidad, W.I. - Tulane Studies in Geology and Paleontology. 5: 93-131.
da Gama, R. O. B. P. & Varol, O., (2013): New Late Oligocene to Miocene Species. - Journal of Nannoplankton Research. 33(1): 1-12.
Haq, B. U., (1966): Electron microscope studies on some upper Eocene calcareous nannoplankton from Syria. - Stockholm Contributions in Geology. 15: 23-37.
Martini, E., (1965): Mid-Tertiary calcareous nannoplankton from Pacific deep-sea cores. - Colston Papers. 17: 393-411.
Helicosphaera euphratis
Haq, 1966
Late Eocene
Tabqua, Raqqa, NW Syria [borehole]