Holococcoliths


Ancestry: Coccolithophores -> Holococcoliths
Sister taxa: advancedsearch.php, Isochrysidales, Coccolithales, Zygodiscales, Syracosphaerales, Coccolith families inc sed, Mesozoic Survivors, Holococcoliths, Braarudosphaerales, Discoasterales, Nannolith families inc sed, hidden,

Short diagnosis: Haploid life-cycle stages, with liths formed of numerous rhombohedral microcrystals


Daughter taxa (blue => in age window 0-300Ma) Granddaughter taxa
Holococcoliths without a tube, flat or cap-shaped

Holococcoliths with tube, covered distally by a convex cover

Holococcoliths with tube, spanned distally by a bridge

Holococcoliths with tube, covered distally by a flat cover

Holococcoliths with tube, open distally and subdivided internally by vertical septae

Holococcoliths with tube, open distally (or cover recessed)

Holococcolith genera only known from the fossil record

Taxonomy:

Citation: Holococcoliths sensu Young et al., 2003
Rank: informal grouping
Synonyms: Family Calyptrosphaeraceae Boudreaux & Hay, 1969.
Notes & discussion: It used to be conventional to place all holococcoliths in the Famly Calyptrosphaeraceae, however this is manifestly artificial, since it is now known that holococcoliths are formed during the haploid life-cycle stage of species belonging to numerous different families. Moreover, the type species of the Family Calyptrosphaeraceae, Calyptrosphaera oblonga , is now known to be a life-cycle phase of Syracosphaera pulchra, hence the name Calyptrosphaeraceae is a junior synonym of Syracosphaeraceae.
It is still convenient to group the holococcoliths together for identification purposes, but giving this artificial grouping a formal taxonomic name (e.g. Calyptrosphaeraceae) is no longer defensible.
Similarly the generic classification is increasingly anachronistic as more life cycle comobinations are discovered. We do still use tradtional names but groupings usedhere are based on morphology.  

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

Short diagnosis: Haploid life-cycle stages, with liths formed of numerous rhombohedral microcrystals


Morphology remarks: Holococcoliths are formed of numerous, minute rhombohedral calcite crystallites (Young & Henriksen 2003). They are produced during the haploid phase of the life-cycle of a wide range of coccolithophores that bear heterococcoliths in their diploid life-cycle phase.

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

Geological Range:
Notes: Although diverse holococcolith assemblages have been described from Cretaceous and Palaeogene assemblages, they are virtually absent from Neogene nannofloras. This is rather surprising, given that modern nannofloras include >60 holococcolithophores (see, e.g., Kleijne, 1991; Jordan & Kleijne, 1994; Young et al. 2003), but most species produce very small holococcoliths (often <2µm) with low preservation potential.
Last occurrence (top): Extant Data source: Total of range of species in this database
First occurrence (base): within Campanian Stage (72.05-83.64Ma, base in Campanian stage). Data source: Total of range of species in this database

Plot of occurrence data:

References:

Boudreaux, J.E. & Hay, W.W., (1969). Calcareous nannoplankton and biostratigraphy of the late Pliocene-Pleistocene-Recent sediments in the Submarex cores. Revista Española de Micropaleontología, 1(3): 249-292.

Jordan, R.W. & Kleijne, A., (1994). A classification system for living coccolithophores. In: Winter, A. and Siesser, W.G. (Editors), Coccolithophores. Cambridge University Press, Cambridge, pp. 83-105.

Kleijne, A., (1991). Holococcolithophorids from the Indian Ocean, Red Sea, Mediterranean Sea and North Atlantic Ocean. Marine Micropaleontology, 17: 1-76.

Young, J.R. & Henriksen, K., (2003). Biomineralization within vesicles: the calcite of coccoliths. Reviews in Mineralogy and Geochemistry, 54: 189-215.

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.


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Holococcoliths compiled by Jeremy R. Young, Paul R. Bown, Jacqueline A. Lees viewed: 23-10-2017

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