Nannotax3 - ntax_cenozoic - fossil holococcoliths Nannotax3 - ntax_cenozoic - fossil holococcoliths

fossil holococcoliths


Classification: ntax_cenozoic -> Holococcoliths -> fossil holococcoliths
Sister taxa: tubeless, convex, bridged, flat-topped, septate, open-tube, fossil holococcoliths, U. extant holococcolith

Daughter taxa (time control age-window is: 0-800Ma)Granddaughter taxa
Holococcoliths formed from multiple blocks
Daktylethra
Domed cavate holococcoliths with surficial shallow pits.
Daktylethra punctulata
Daktylethra probertii
Daktylethra unitatis
Daktylethra basilica
Daktylethra sp.

Holodiscolithus
Elliptical holococcoliths with perforations.

Lanternithus
Cavate holoccoliths with distinct crystallographic blocks.
Lanternithus arcanus
Lanternithus duocavus
Lanternithus jawzii
Lanternithus minutus
Lanternithus procerus
Lanternithus simplex
Lanternithus unicavus
Munarinus emrei
Lanternithus sp.

Multipartis
Holococcoliths with multiple elements in the central area
Multipartis ponticus

Octolithus
Holoccoliths with distinct rim and cover blocks, typically eight.
Octolithus multiplus
Octolithus sp.

Quadrilateris
Rectangular holococcoliths formed from four thin blocks that are birefringent in XPL.
Quadrilateris imparidividuus
Quadrilateris sp.

Semihololithus
Paleogene holococcoliths usually seen in side view and comprising a thick proximal plate and spine or process, typically with a cavity or axial canal.
Semihololithus biskayae
Semihololithus dimidius
Semihololithus kanungoi
Semihololithus pseudobiskayae
Semihololithus sp. cf. S. biskayae
Semihololithus tentorium
Naninfula figularia
Naninfula hexaporus
Semihololithus sp.

Varolia
Cavate, thin walled, box-like holococcoliths usually seen in side view.
Varolia boomeri
Varolia cistula
Varolia gracilimura
Varolia macleodii
Varolia sicca
Varolia sp.

Youngilithus
Geometrically shaped non-birefringent holococcoliths typically possessing lateral rim spines and central area bars.
Youngilithus arcaeformis
Youngilithus bipons
Youngilithus oblongatus
Youngilithus pyxis
Youngilithus quadraeformis
Youngilithus transversipons
Youngilithus sp.

Zygrhablithus
Spinose holococcoliths, which are birefringent in side view. In plan view the coccoliths are non-birefringent with a distinct figure-of-eight shaped central structure.
Zygrhablithus bijugatus
Zygrhablithus sileensis
Zygrhablithus sp.

Holococcoliths formed from a single block
Aubrysphaera

Aubrysphaera deconinckii

Corannulus
Discoidal holococcoliths with large central openings and marginal perforations or indentations; non-birefringent in plan view.
Corannulus germanicus
Corannulus horridulus
Corannulus tauricus
Corannulus sp.

Orthozygus
Single-block holococcoliths that typically have a spine or process and transverse bridge or bars.
Orthozygus arcus
Orthozygus aureus
Orthozygus brytika
Orthozygus occultus
Orthozygus sudis
Orthozygus suggrandis
Orthozygus sp.

Peritrachelina
Unusual holococcoliths with non-coccolith morphology typically comprising an elliptical, concavo-convex, domed, perforate framework.
Peritrachelina arenaria
Peritrachelina joidesa
Peritrachelina minuta
Peritrachelina ornata
Peritrachelina sp.

Unidentified fossil holococcoliths


Taxonomy:

Citation: fossil holococcoliths
taxonomic rank: informal group of genera
Synonyms: Calyptrosphaeraceae Boudreaux & Hay, in Hay et al 1967
Taxonomic discussion: As indicated there is a significant group of fossil holococcoliths which behave as a single crystal unit, or block, in cross-polars, and typically show very low birefingence in plan view. This spearation is not perfectly refelcted in the taxonomy though as some species which show this crystallography occur in Youngilithus and Holococcolithus

Distinguishing features:
Parent taxon (Holococcoliths): Haploid life-cycle stages, with liths formed of numerous rhombohedral microcrystals
This taxon: Holococcolith genera only known from the fossil record

Original description: Diagnosis: Coccolithophores bearing bolococcoliths.

Farinacci & Howe catalog pages: Calyptrosphaeraceae


Morphology:

Whilst this is a very disparate group of genera they are mostly larger than extant holococcoliths and tend to have distinctive shapes, rather than being simple discs.

Search data:
Lith size: 0->0µm;
The morphological data given here can be used on the advanced search page. See also these notes

Geological Range:
Last occurrence (top): at top of NN20 zone (100% up, 0.3Ma, in Ionian stage). Data source: Total of ranges of the species in this database
First occurrence (base): within Campanian Stage (72.17-83.65Ma, base in Campanian stage). Data source: Total of ranges of species in this database

Plot of occurrence data:

References:

Hay, W. W., Mohler, H. P., Roth, P. H., Schmidt, R. R. & Boudreaux, J. E. (1967). Calcareous nannoplankton zonation of the Cenozoic of the Gulf Coast and Caribbean-Antillean area, and transoceanic correlation. Transactions of the Gulf-Coast Association of Geological Societies. 17: 428-480. gs O


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fossil holococcoliths compiled by Jeremy R. Young, Paul R. Bown, Jacqueline A. Lees viewed: 10-12-2024

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Short stable page link: https://mikrotax.org/Nannotax3/index.php?id=595 Go to Archive.is to create a permanent copy of this page - citation notes
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