Taxonomy:
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_cenozoic): Extant coccolithophores and Cenozoic calcareous nannofossils - Mesozoic nannofossils are in a separate module
This taxon: Haploid life-cycle stages, with liths formed of numerous rhombohedral microcrystals
Farinacci & Howe catalog pages: Holococcoliths [no catalog entry yet], Calyptrosphaeraceae
Morphology:
Lith size: 0->0µm; |
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:
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. gs O 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 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 References:
Holococcoliths compiled by Jeremy R. Young, Paul R. Bown, Jacqueline A. Lees viewed: 12-11-2024
Short stable page link: https://mikrotax.org/Nannotax3/index.php?id=714 Go to Archive.is to create a permanent copy of this page - citation notes |
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