Nannotax3 - ntax_cenozoic - Helicosphaera stalis Nannotax3 - ntax_cenozoic - Helicosphaera stalis

Helicosphaera stalis


Classification: ntax_cenozoic -> Zygodiscales -> Helicosphaeraceae -> Helicosphaera -> H. walbersdorfensis group -> Helicosphaera stalis
Sister taxa: H. stalis, H. vedderi, H. walbersdorfensis, H. waltrans, H. watkinsii

Taxonomy:

Citation: Helicosphaera stalis Theodoridis, 1984
taxonomic rank: Species
Synonyms: N.B. H. walbersdorfensis sensu Varol (1989) = H. stalis of other authors.
Variants:

Distinguishing features:
Parent taxon (H. walbersdorfensis group): Miocene small to medium sized Helicosphaera species with wing ending flush with flange rather than terminating abruptly. Openings usually strongly oblique. Blanket confiend to central area, in xpl flange dark around whole coccolith.
This taxon: Small, lenticular or rhomboid outline. No distinct flange ending. Two normally inclined pores in central-area.

Farinacci & Howe catalog pages: H. stalis * , H. stalis stalis * , H. stalis ovata * , H. girgisii *

Search data:
LITHS: placolith, asymmetric, CA: ca_conjunct, bar,
CSPH: elongated, monomorphic, CROSS-POLARS: rim-bicyclic, V-prominent, R-prominent,
Lith size: 4->6µm;
Data source notes: lith size from illustrated specimens
The morphological data given here can be used on the advanced search page. See also these notes

Geological Range:
Last occurrence (top): within NN11 zone (5.59-8.29Ma, top in Messinian stage). Data source: Young 1998; Boesiger et al 2017
First occurrence (base): within NN6 zone (11.90-13.53Ma, base in Serravallian stage). Data source: Young 1998; Boesiger et al 2017

Plot of occurrence data:

References:

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. gs O

Salomon, R. (1999). The Calcite Palace. Website - https://ina.tmsoc.org/galleries/CalcitePalace/index.htm. -. gs

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

Varol, O. (1989a). Calcareous nannofossil study of the central and western Solomon Islands. Circum-Pacific Council for Energy and Mineral Resources Earth Sciences. 239-268. gs

Young, J. R. (1998). Neogene. In, Bown, P. R. (ed.) Calcareous Nannofossil Biostratigraphy. British Micropalaeontological Society Publication Series . 225-265. gs


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Helicosphaera stalis compiled by Jeremy R. Young, Paul R. Bown, Jacqueline A. Lees viewed: 21-6-2024

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Short stable page link: https://mikrotax.org/Nannotax3/index.php?id=688 Go to Archive.is to create a permanent copy of this page - citation notes
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