Nannotax3 - ntax_cenozoic - Helicosphaera waltrans Nannotax3 - ntax_cenozoic - Helicosphaera waltrans

Helicosphaera waltrans


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

Taxonomy:

Citation: Helicosphaera waltrans Theodoridis, 1984
taxonomic rank: Species

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: Similar to H. walbersdorfensis but larger and with larger openings.

Farinacci & Howe catalog pages: H. waltrans *

Search data:
LITHS: placolith, asymmetric, CA: ca_conjunct, bar,
CSPH: elongated, monomorphic, CROSS-POLARS: rim-bicyclic, V-prominent, R-prominent,
Lith size: 8->12µm;
The morphological data given here can be used on the advanced search page. See also these notes

Geological Range:
Notes: This seems to be a predominantly Mediterranean taxon and the restricted range there reported by Theodiridis 1984. This was supported by detailed work of Fornaciari et al. 1996 and Turco et al. 2011,  however they reported it as sporadic and rare in occurrence.
Last occurrence (top): within NN5 zone (13.53-14.91Ma, top in Serravallian stage). Data source: Young 1998
First occurrence (base): within NN4 zone (14.91-17.95Ma, base in Burdigalian stage). Data source: 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

Fornaciari, E., di Stefano, A., Rio, D. & Negri, A. (1996). Middle Miocene quantitative calcareous nannofossil biostratigraphy in the Mediterranean region. Micropaleontology. 42(1): 38-64. 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

Turco, E., Cascella, A., Gennari, R., Hilgen, F. J., Iaccarino, S. M. & Sagnotti, L. (2011). Integrated stratigraphy of the La Vedova section (Conero Riviera, Italy) and implications for the Burdigalian/Langhian boundary. Micropaleontology. 8(2-3): 89-110. 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 waltrans compiled by Jeremy R. Young, Paul R. Bown, Jacqueline A. Lees viewed: 18-7-2024

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Short stable page link: https://mikrotax.org/Nannotax3/index.php?id=693 Go to Archive.is to create a permanent copy of this page - citation notes
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