Citation: Holococcoliths sensu Young et al., 2003Taxonomic rank: informal group of familiesSynonyms: Family Calyptrosphaeraceae Boudreaux & Hay, 1969.Taxonomic 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 traditional names but the groupings used here are based on morphology.
Distinguishing features: Parent taxon (ntax_main): This taxon: Haploid life-cycle stages, with liths formed of numerous rhombohedral microcrystals
Morphology: Holococcoliths are formed of numerous, minute (ca 0.1 µm) 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.
Intracellular calcification Holococcolith formation has long been suggested to occur outside the cell (e.g Rowson et al. 1986). However Langer et al. (2021) illustrated intracellular holococcolith formation in Coccolithus and this was confirmed by work of Ben Joseph et al. (2023) and by Meyer & Taylor (2025). NotablyMeyer & Taylor (2025) showed well-formed holococcoliths inside C. leptoporus haploid cells.
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: 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 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:
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: ntax_main
References:
Ben-Joseph, O., et al. (2023). Crystallization of coccolith calcite at different life-cycle phases exhibits distinct degrees of cellular confinement. Small Structures. 4: 1-9. gs
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. gsO
Jordan, R. W. & Kleijne, A. (1994). A classification system for living coccolithophores. In, Winter, A. & Siesser, W. G. (eds) Coccolithophores. Cambridge University Press, Cambridge 83-105. gs
Kleijne, A. (1991). Holococcolithophorids from the Indian Ocean, Red Sea, Mediterranean Sea and North Atlantic Ocean. Marine Micropaleontology. 17: 1-76. gs
Langer, G., et al. (2021). Role of silicon in the development of complex crystal shapes in coccolithophores. New Phytologist. New Phytologist. 1-13. gs
Meyer, E. M. & Taylor, A. R. (2025). A comparison of calcification mechanisms in haploid and diploid cells of the coccolithophore Calcidiscus leptoporus (Murray & Blackman 1898). Journal of Phycology. 1-19. gs
Rowson, J. D., Leadbeater, B. S. C. & Green, J. C. (1986). Calcium carbonate deposition in the motile (Crystallolithus) phase of Coccolithus pelagicus (Prymnesiophyceae). British Phycological Journal. 21: 359-370. gs
Young, J. R. & Henriksen, K. (2003). Biomineralization within vesicles: the calcite of coccoliths. Reviews in Mineralogy and Geochemistry. 54(1): 189-215. 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. S1: 1-132. gs
Holococcoliths compiled by Jeremy R. Young, Paul R. Bown, Jacqueline A. Lees viewed: 15-7-2025
These terms and conditions contain rules about posting comments. By submitting a comment, you are declaring that you agree with these rules:
Although the administrator will attempt to moderate comments, it is impossible for every comment to have been moderated at any given time.
You acknowledge that all comments express the views and opinions of the original author and not those of the administrator.
You agree not to post any material which is knowingly false, obscene, hateful, threatening, harassing or invasive of a person's privacy.
The administrator has the right to edit, move or remove any comment for any reason and without notice.
Failure to comply with these rules may result in being banned from submitting further comments.
These terms and conditions are subject to change at any time and without notice.
{"commentics_url":"\/\/www.mikrotax.org\/comments\/","page_id":826536,"enabled_country":true,"country_id":0,"enabled_state":false,"state_id":0,"enabled_upload":false,"maximum_upload_amount":3,"maximum_upload_size":5,"maximum_upload_total":5,"captcha":true,"captcha_url":"https:\/\/www.mikrotax.org\/comments\/frontend\/index.php?route=main\/form\/captcha&page_id=826536","cmtx_wait_for_comment":"cmtx_wait_for_comment","lang_error_file_num":"A maximum of %d files are allowed to be uploaded","lang_error_file_size":"Please upload files no bigger than %.1f MB in size","lang_error_file_total":"The total size of all files must be less than %.1f MB","lang_error_file_type":"Only image file types are allowed to be uploaded","lang_text_loading":"Loading ..","lang_placeholder_country":"Country","lang_placeholder_state":"State","lang_text_country_first":"Please select a country first","lang_button_submit":"Add Comment","lang_button_preview":"Preview","lang_button_remove":"Remove","lang_button_processing":"Please Wait.."}
/Calcidiscus leptoporus subsp. leptoporus HOL/Young_etal_2003_bl08-rigidus.JPG)
/Syracosphaera periperforata HOL/Syracosphaera periperforata var. periperforata HOL/Young_etal_2003_145-22b.JPG)
-83.JPG)
Comments