Poricalyptra magnaghii


Classification: ntax_cenozoic -> Holococcoliths -> flat-topped -> Poricalyptra -> Poricalyptra magnaghii
Sister taxa: P. aurisinae, P. isselii, P. magnaghii, S. gaarderae HOL, P. sp.

Taxonomy:

Citation: Poricalyptra magnaghii (Borsetti & Cati 1976) Kleijne, 1991
Rank: Species
Basionym: Helladosphaera magnaghii Borsetti & Cati 1976
Synonyms: Helladosphaera fastigata Okada & McIntyre 1977

Distinguishing features: Distal surface has hexagonal mesh fabric, but no large openings.
3 concentric rings of crystallites around margin

Farinacci & Howe catalog pages: H. magnaghii * , H. fastigata *


Morphology: NB With the hexagonal mesh one third of the crystallite positions are empty leaving a regular array of perforations each surrouned by 6 crystallites. This is a distinctive fabric but occurs in holococcoliths which are unlikely to be directly related. The presence of 3 concentric rings of crystalites around edge of the dital surface seems to be a consistent features of the species. In addition the openings in the tube are smaller than inother species, being mostly cofined to the lower part of the tube. 

Search data:
TagsLITHS: holococcolith, elliptical, hollow, CA: pores, closed,
CSPH: elongated, CFC, CROSS-POLARS: V-prominent, R-prominent,
MetricsLith size: 2.1->2.4µm; Coccosphere size: 7->12µm; Liths per sphere: 40->80
Data source notes: lith size from Kleijne 1991; csph size from illustraed specimens; lith numbers from Yang & Wei 2003, range of estimates
The morphological data given here can be used on the advanced search page. See also these notes

Geological Range:
Last occurrence (top): Extant Data source: present in the plankton (Young et al. 2003)
First occurrence (base): within No known fossil record modern (0.00-0.00Ma, base in "Holocene" stage). Data source: [JRY rough estimate]

Plot of occurrence data:

References:

Borsetti, A. M. & Cati, F. (1976). Il Nannoplancton calcareo vivente nel Tirreno Centro-meridionale. Parte II. Giornale di Geologia. 40(1): 209-240. gs V O

Okada, H. & McIntyre, A. (1977). Modern coccolithophores of the Pacific and North Atlantic Oceans. Micropaleontology. 23(1): 1-55. gs

Yang, T-N., Wei, K-Y. & Gong G-C. (2001). Distribution of coccolithophorids and coccoliths in surface ocean off northeastern Taiwan. Botanical Bulletin of the Academia Sinica. 42: 287-302. gs

Young, J. R., Geisen, M., Cros, L., Kleijne, A., Probert, I. & Ostergaard, J. B. (2003). A guide to extant coccolithophore taxonomy. Journal of Nannoplankton Research, Special Issue. 1: 1-132. gs V O


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Poricalyptra magnaghii compiled by Jeremy R. Young, Paul R. Bown, Jacqueline A. Lees viewed: 16-4-2021

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Short stable page link: https://mikrotax.org/Nannotax3/index.php?id=1110 Go to Archive.is to create a permanent copy of this page - citation notes



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