Helicosphaera walbersdorfensis


Ancestry: Coccolithophores -> Zygodiscales -> Helicosphaeraceae -> Helicosphaera -> H. walbersdorfensis group -> Helicosphaera walbersdorfensis
Sister taxa: H. magnifica, H. stalis, H. vedderi, H. walbersdorfensis, H. waltrans, H. watkinsii,

Short diagnosis: Small to medium sized. Flange ends in broad wing. Central-area with two normally oblique pores separated by narrow conjunct bar.


Taxonomy:

Citation: Helicosphaera walbersdorfensis Muller, 1974
Rank: Species
Variants: H. californiana Bukry, 1981 - bar absent, cf. Theodoridis (1984) this is usually a result of dissolution.
H. minuta Muller, 1981 - without prominent wing, or possibly a senior synonym of H. stalis.
Synonyms:
H. muellerae Varol, 1989 - alternative name for H. walbersdorfensis based on interpretation that the type specimen is atypical.

Farinacci & Howe catalog pages: Helicosphaera californiana * Helicosphaera minuta * Helicosphaera muellerae * Helicosphaera walbersdorfensis + *

Short diagnosis: Small to medium sized. Flange ends in broad wing. Central-area with two normally oblique pores separated by narrow conjunct bar.

Geological Range:
Last occurrence (top): within NN7 zone (10.89-11.90Ma, top in Tortonian stage). Data source: Young 1998
First occurrence (base): within NN5 zone (13.53-14.91Ma, base in Langhian stage). Data source: Young 1998

Plot of occurrence data:

References:

Bukry, D., (1981). Pacific coast coccolith stratigraphy between Point Conception and Cabo Orientes, Deep Sea Drilling Project Leg 63. Initial Reports of the Deep Sea Drilling Project, 63: 445-471.

Müller, C., (1974). Nannoplankton aus dem Mittel-Miozän von Walbersdorf (Burgenland). Senckenbergiana lethaea, 55: 389-405.

Müller, C., (1981). Beschreibung neuer Helicosphaera-Arten aus dem Miozän und Revision biostratigraphischer Reichweiten einiger neogener Nannoplankton-Arten. Senckenbergiana lethaea, 61: 427-435.

Theodoridis, S., (1984). Calcareous nannofossil biostratigraphy of the Miocene and revision of the helicoliths and discoasters. Utrecht Micropaleontological Bulletin, 32: 1-271.

Varol, O., (1989). Calcareous nannofossil study of the central and western Solomon Islands., Circum-Pacific Council for Energy and Mineral Resources Earth Sciences. Geology and offshore resources of Pacific island arcs, pp. 239-268.

Young, J.R., (1998). Neogene. In: Bown, P.R. (Editor), Calcareous Nannofossil Biostratigraphy. British Micropalaeontological Society Publications Series. Chapman & Hall, London, pp. 225-265.


Nannotax3 - Coccolithophores - Helicosphaera walbersdorfensis by: Jeremy R. Young, Paul R. Bown, Jacqueline A. Lees viewed: 28-4-2017

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Ines Galovic (Croatia)
First occurrence is observed in Paratethian NN4b subzone of Badenian (Andreyeva-Grigorovich et al., 2001), which belongs to Mediterranean MNN4b respectinely (Fornaciari et al, 1996).
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