Nannotax3 - ntax_cenozoic - Nannolith families inc sed Nannotax3 - ntax_cenozoic - Nannolith families inc sed

Nannolith families inc sed

Classification: ntax_cenozoic -> Nannolith families inc sed
Sister taxa: Isochrysidales, Coccolithales, Zygodiscales, Syracosphaerales, Coccolith families inc sed, Mesozoic Survivors ⟩⟨ Holococcoliths, Braarudosphaerales, Discoasterales, Nannolith families inc sed, hidden

Daughter taxa (time control age-window is: 0-800Ma)Granddaughter taxa
Horseshoe-shaped rod-shaped nannoliths and simple hoop-coccoliths formed in one phase of life cycle, planolith heterococcoliths in the other.

Hemispherical to cylindrical nannoliths, with walls constructed from one to several cycles of thin elements, enclosing a hollow central space; the nannolith tapers distally, and may have long apical spines or processes.

Large (10-20µm) triangular to stellate nannoliths with porous structure formed from small crystallites. In xpl behave as single crystal unit with low birefringence

Nannolith genera inc sed
Three apparently unique genera, not-included in described families
Unidentified nannoliths

Nannoliths with rhombic and tri-radiate morphologies, and non-birefringent images in XPL. Incorporating the genera Rhomboaster and Tribrachiatus.


Citation: Nannolith familes incertae sedis - informal
Rank: informal group of families

Distinguishing features:
Parent taxon (ntax_cenozoic): Extant coccolithophores and Cenozoic calcareous nannofossils - Mesozoic nannofossils are in a separate module
This taxon: Haptophytes forming calcareous structures not obviously homologous with heterococcoliths, holococcoliths, or discoasteralids

Farinacci & Howe catalog pages: Nannolith families inc sed [no catalog entry yet]


These groups of nannofossils are thought to be related to coccolithophores, but produce structures which are neither heterococcoliths nor holococcoliths.
The term nannolith has been used, especially by palaeontologists, as a convenient term for structures about the same size as coccoliths and occurring with coccoliths, but lacking definite coccolith affinities. In the modern nannoflora, there are fewer groups of cryptic origins, and the term has been less widely used. However, it is useful for calcareous structures that are thought to be formed by haptophytes, but probably by a different biomineralisation process to either heterococcoliths or holococcoliths (Young et al. 1999).
NB The first use of the term in this sense appears to have been by Haq (1978, in Introduction to Marine Micropaleontology), and this was followed by Perch-Nielsen (1985, in Plankton Stratigraphy). By contrast, Aubry (1988 et seq., Handbook of Calcareous Nannofossils) places most of these groups in the Ortholithae.

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

Geological Range:
Last occurrence (top): Extant. Data source: Total of range of species in this database
First occurrence (base): at base of Aptian Stage (0% up, 126.3Ma, in Aptian stage). Data source: Total of range of species in this database

Plot of occurrence data:


Aubry, M. -P. (1988a). Handbook of Cenozoic calcareous nannoplankton. Book 2: Ortholithae (Catinasters, Ceratholiths, Rhabdoliths). Micropaleontology Press, American Museum of Natural History, New York. 1-279. gs

Haq, B. U. (1978). Calcareous nannoplankton. In, Haq, B. U. & Boersma, A. (eds) Introduction to marine micropaleontology. Elsevier, Amsterdam 79-108. gs

Perch-Nielsen, K. (1985). Mesozoic calcareous nannofossils. In, Bolli, H. M., Saunders, J. B. & Perch-Nielsen, K. (eds) Plankton Stratigraphy. Cambridge University Press, Cambridge 329-426. gs

Perch-Nielsen, K. (1985). Cenozoic calcareous nannofossils. In, Bolli, H. M., Saunders, J. B. & Perch-Nielsen, K. (eds) Plankton Stratigraphy. Cambridge University Press, Cambridge 427-555. gs

Young, J. R., Davis, S. A., Bown, P. R. & Mann, S. (1999). Coccolith ultrastructure and biomineralisation. Journal of Structural Biology. 126: 195-215. gs


Nannolith families inc sed compiled by Jeremy R. Young, Paul R. Bown, Jacqueline A. Lees viewed: 9-6-2023

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