Classification: ntax_cenozoic -> Syracosphaerales -> Rhabdosphaeraceae
Sister taxa: Calciosoleniaceae, Rhabdosphaeraceae, Syracosphaeraceae

Daughter taxa (time control age-window is: 0-800Ma)Granddaughter taxa
Body coccoliths with well-developed radial lath cycle, low mound in centre; coccospheres polymorphic, usually some coccoliths with well-developed spines

Body coccoliths with well-developed radial lath cycle; domal or double-lipped protrusion; coccosphere dimorphic, CFCs larger and taller

Coccoliths process-bearing with complex base including outer rim, radial lath and lamellar cycles

Body coccoliths with well-developed radial lath cycle, protrusion in centre; coccospheres varimorphic higher protrusions on circum-flagellar coccoliths

Body coccoliths with well-developed radial lath cycle; trumpet-like process; coccospheres monomorphic

Coccoliths without radial lath cycle; coccospheres monomorphic, all spine-bearing

Coccoliths without radial lath cycle; coccospheres dimorphic, only some spine-bearing

Coccoliths without radial lath cycle; coccosphere dome-shaped, polymorphic


Citation: Rhabdosphaeraceae Haeckel, 1894
Rank: Family

Distinguishing features: BCs planoliths with radial lath cycle and highly-variable axial structures. Often polymorphic and/or varimorphic

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

Morphology: Coccospheres: Motile or non-motile, typically with spine-bearing and non-spine-bearing coccoliths with similar shields, but polymorphic, varimorphic and monomorphic genera also occur. The spine-bearing coccoliths may be confined to the poles or distributed around the coccosphere, greatly increasing its outer diameter.
Coccoliths: Typically disc-shaped (planoliths) and formed of three components.
  1. Rim: narrow; slightly elevated; formed of two cycles of elements. A. Upper/outer rim cycle of simple non-imbricate elements (Kleijne 1992), these are V-units (our LM obs.). B. Lower/inner rim cycle showing strong obliquity. Crystallographic orientation uncertain.
  2. Radial cycle - joins rim to central lamellar cycle; radial laths, of equal number to rim units; slits often present between the laths (absent in Rhabdosphaera and Saturnulus).
  3. Lamellar cycle(s) - lamellar elements showing clockwise imbrication, often multiple cycles with inner cycles more elongate, inclined and in helical arrangement forming spine or protrusion. May end in a "cuneate cycle" of a few well-formed elements.

Biology & life-cycles: A couple of species are known to form HOL-HET combinations, only Algirosphaera robusta has been maintained in culture.

Search data:
MetricsLith size: 1->30µm;
The morphological data given here can be used on the advanced search page. See also these notes

Geological Range:
Notes: Most extant Rhabdosphaeraceae are very small and, apart from R. clavigera, are rarely recorded in the fossil record. There is, however, a diverse and abundant group of larger Rhabdosphaeraceae in the Eocene (see also Perch-Nielsen 1985b; Varol 1989; Shafik 1989; Aubry 1999, Bown 2005).
Last occurrence (top): Extant Data source: Total of range of species in this database
First occurrence (base): at base of Selandian Stage (4% up, 61.5Ma, in Selandian stage). Data source: Total of range of species in this database

Plot of occurrence data:


Aubry, M. -P. (1999). Handbook of Cenozoic calcareous nannoplankton. Book 5: Heliolithae (Zygoliths and Rhabdoliths). Micropaleontology Press, American Museum of Natural History, New York. 1-368. gs

Bown, P. R. (2005d). Palaeogene calcareous nannofossils from the Kilwa and Lindi areas of coastal Tanzania (Tanzania Drilling Project 2003-4). Journal of Nannoplankton Research. 27(1): 21-95. gs V O

Bown, P. R. (2010). Calcareous nannofossils from the Paleocene/Eocene Thermal Maximum interval of southern Tanzania (TDP Site 14). Journal of Nannoplankton Research. 31(1): 11-38. gs V O

Haeckel, E. (1894). Systematische Phylogenie der Protisten und Pflanzen. Reimer, Berlin. -. gs

Kleijne, A. (1992). Extant Rhabdosphaeraceae (coccolithophorids, class Prymnesiophyceae) from the Indian Ocean, Red Sea, Mediterranean Sea and North Atlantic Ocean. Scripta Geologica. 100: 1-63. gs

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

Probert, I., Fresnel, J., Billard, C., Geisen, M. & Young, J. R. (2007). Light and electron microscope observations of Algirosphaera robusta (Pymnesiophyceae). Journal of Phycology. 43: 319-332. gs

Shafik, S. (1989). Some new calcareous nannofossils from Upper Eocene and Lower Oligocene sediments in the Otway Basin, southeastern Australia. Alcheringa. 13: 69-83. gs

Varol, O. (1989b). Eocene calcareous nannofossils from Sile (northwest Turkey). Revista Española de Micropaleontología. 21: 273-320. gs V O


Rhabdosphaeraceae compiled by Jeremy R. Young, Paul R. Bown, Jacqueline A. Lees viewed: 13-6-2021

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Short stable page link: https://mikrotax.org/Nannotax3/index.php?id=1201 Go to Archive.is to create a permanent copy of this page - citation notes

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