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.