Helicosphaeroides scissurus

Helicosphaera scissura Miller, 1981

Coccolithus pelagicus diademata Gardet, 1955

Helicolith has a Type I (Helicosphaeroides ampliaperta type) blanket, expanded wing termination and a central area with a narrow slit-like opening

Helicosphaeroides scissurus differs from Helicosphaeroides ampliaperta Bramlette & Wilcoxon (1967) Varol, n. comb. by having a narrow slit-like central opening instead of a wide elliptical or subcircular central opening.

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.

Gardet, M., 1955. Contribution à l'étude des coccolithes des terrains néogènes de l'Algérie. Publications du Service de la Carte Géologique de l'Algérie (Nouvelle Série) 5, 477-550.

Miller, P. L., 1981. Tertiary calcareous nannoplankton and benthic foraminifera biostratigraphy of the Point Arena area, California. Micropaleontology 27(4), 419-443.