Nannotax3 - ntax_cenozoic - Helicosphaeraceae

Nannotax3 - ntax_cenozoic - Helicosphaeraceae Nannotax3 - ntax_cenozoic - Helicosphaeraceae

Helicosphaeraceae

Classification: ntax_cenozoic -> Zygodiscales -> Helicosphaeraceae
Sister taxa: Helicosphaeraceae, Pontosphaeraceae, Zygodiscaceae

Daughter taxa (time control age-window is: 0-800Ma)					Granddaughter taxa
				Helicosphaera Coccoliths with helical flange; arranged spirally on the coccosphere	H. carteri group H. walbersdorfensis group H. ampliaperta group H. recta group H. lophota group Helicosphaera sp.

Taxonomy:

Citation: Helicosphaeraceae Black, 1971

Rank: Family

Taxonomic discussion: Taxa included: family contains only one genus, Helicosphaera

Distinguishing features:
Parent taxon (Zygodiscales): 2N: Heterococcoliths with V-units forming upper/outer cycle of imbricated elements and R-units forming basal plate and central mass of irregular elements. Usually motile
N: Form holococcoliths formed of single block
This taxon: Varimorphic; liths placolith-like but with helical shield structure; arranged in spiral on coccosphere

Farinacci & Howe catalog pages: Helicosphaeraceae [no catalog entry yet]

Morphology:

Coccospheres ellipsoidal with a prominent flagellar opening. Coccoliths arranged spirally round the coccosphere and may vary slightly in size and shape from the antapex to the flagellar pole.
Coccolith structure - Outer rim (V-units) of the coccoliths are modified into a helical flange, ending in a wing or spike. R-units form the baseplate and extend to form blanket of small elements (Young et al. 2004). Central-area bars may be conjunct, disjunct or absent. Theodoridis (1984) discusses the structure.

Search data:

Lith size: 4->22µm;

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: Total of range of species in this database
First occurrence (base): in lower part of Ypresian Stage (28% up, 53.7Ma, in Ypresian stage). Data source: Total of range of species in this database

Plot of occurrence data:

Range-bar - range as quoted above, pink interval top occurs in, green interval base occurs in.
Triangles indicate an event for which a precise placement has been suggested
Neptune data: this is a higher taxon page so Neptune data is not plotted. For the customisable plot option go to a genus page Parent: Zygodiscales

References:

Black, M. (1971c). The systematics of coccoliths in relation to the paleontological record. In, Funnell, B. M. & Riedel, W. R. (eds) The Micropaleontology of the Oceans. Cambridge University Press, Cambridge 611-624. gs O

Perch-Nielsen, K. (1985). Cenozoic calcareous nannofossils. In, Bolli, H. M., Saunders, J. B. & Perch-Nielsen, K. (eds) Plankton Stratigraphy. Cambridge University Press, Cambridge 427-555. 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

Young, J. R., Henriksen, K. & Probert, I. (2004). Structure and morphogenesis of the coccoliths of the CODENET species. In, Thierstein, H. R. & Young, J. R. (eds) Coccolithophores - From molecular processes to global impact. Springer, Berlin 191-216. gs O

Helicosphaeraceae compiled by Jeremy R. Young, Paul R. Bown, Jacqueline A. Lees viewed: 10-6-2023

Taxon Search:

Advanced Search

AphiaID: 235836 Nomenclatural data on WoRMS
Short stables page link: https://mikrotax.org/Nannotax3/index.php?id=696 Go to Archive.is to create a permanent copy of this page - citation notes

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