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.
D. punctulata
D. probertii
D. unitatis
D. basilica
D. sp.

Holodiscolithus
Elliptical holococcoliths with perforations.

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

Multipartis
Holococcoliths with multiple elements in the central area
M. ponticus

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

Quadrilateris
Rectangular holococcoliths formed from four thin blocks that are birefringent in XPL.
Q. imparidividuus
Q. 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.
S. biskayae
S. dimidius
S. kanungoi
S. pseudobiskayae
S. sp. cf. S. biskayae
S. tentorium
N. figularia
N. hexaporus
S. sp.

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

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

Holococcoliths formed from a single block
Aubrysphaera

A. deconinckii

Clathrolithus
Unusual holococcoliths with non-coccolith morphology typically comprising an elliptical, concavo-convex, domed, perforate framework.
C. arenarius
C. ellipticus
C. joidesa
C. minutus
C. sp.

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

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

Unidentified fossil holococcoliths


Taxonomy:

Citation: fossil holococcoliths
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

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


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:
TagsLITHS:
MetricsLith 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): in upper part of Ionian Stage (75% up, 0.3Ma, in Ionian stage). Data source: Total of range of species in this database
First occurrence (base): at base of Campanian Stage (0% up, 83.6Ma, in Campanian stage). Data source: Total of range 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 V O


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fossil holococcoliths compiled by Jeremy R. Young, Paul R. Bown, Jacqueline A. Lees viewed: 6-12-2021

Taxon Search:
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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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