This set of pages is developed from a terminology guide produced by an INA working group and published in the journal Palaeontology (Young et al. 1997). N.B. The terminology here is essentially confined to terms for the coccoliths, for cytological and other terms related to the organisms see Jordan et al. (1995).
NB  In places these pages have been lightly edited to reflect changes in knowledge since the original publication.

Prime reference (full list at base of page)
Young, J.R., Bergen, J.A., Bown, P.R., Burnett, J.A., Fiorentino, A., Jordan, R.W., Kleijne, A., Niel, B.E. van, Romein, A.J.T. and Salis, K. von, 1997. Guidelines for coccolith and Calcareous nannofossil terminology. Palaeontology, 40/4, 875-912.


The descriptive terminology of coccoliths evolved on an ad hoc basis until the 1950s. Then the development of electron microscopy stimulated a major revision and introduction of new terms, in a co-operative effort (Braarud et al. 1955a, 1955b; Halldal and Markali 1955, Hay et al. 1966). This concentrated on standardisation of names for the distinctive types of coccoliths found on coccospheres, e.g. placolith, caneolith. Subsequent work on diverse fossil coccoliths lead to a different approach concentrating on element-level structure. The appropriate terminology was synthesised during a Round Table Session at the Rome 1970 Plankton Conference (Farinacci 1971).
There had been intensive research on coccoliths since 1970 and so the existing guides had become increasingly obsolescent. In response to this a terminology workshop was held during the International Nannoplankton Association (INA) conference in Prague 1991. Following this a working group was set up and a two day workshop was held in London in 1992. Various publications have resulted from these discussions. Young (1992a), discusses new recommendations on controversial topics. Burnett and Bown (1992) provide a checklist for systematic descriptions. van Niel (1994) reviews in depth the descriptive terminology of nannoconids. Jordan et al. (1995) provide a glossary for living Haptophyta, including cytological terms and an overview of taxonomic concepts. The present paper represents the main proceedings of the working group and is a synthesis of the descriptive terminology applied to coccoliths and other nannoliths based on its discussions.
In addition to the workshop discussions this paper is based on a wide range of published sources including: Braarud et al. (1955a, 1955b), Halldal and Markali (1955), Farinacci et al. (1971), Black (1972), Hay (1977), Okada and McIntyre (1977), Romein (1979), Theodoridis (1984), Aubry (1984 et seq., 1989), Perch-Nielsen (1985a, 1985b), Bown (1987), van Heck and Prins (1987), Varol (1989, 1992), Young (1989), Young and Bown (1991), Kleijne (1991, 1992, 1993), Young and Westbroek (1991), van Niel (1992), Heimdal (1993), Winter and Siesser (1994). General works consulted include Brown (1954), Gower (1954), Fowler (1965), and Stearn (1983).


The main text is organised into thematic categories covering different aspects of coccolith morphology. This is followed by a section on special terms needed for particular taxonomic groups. The paper is confined to the calcareous structures and does not consider organic components, terminology for these is reviewed in Jordan et al. (1995). Synonyms which we have not included in the main text are discussed in an appendix.
The terms recommended are underlined and given short explanations - the primary purpose of these is to explain the use of the term to coccolith workers, not to give a rigorous dictionary definition, still less an encyclopaedic explanation. The figures are meant to clarify the logic, but for various reasons not all terms are illustrated. For many terms genera or species that show the feature particularly well are cited; good sources for illustrations of these taxa are Perch-Nielsen (1985a, 1985b) and Winter and Siesser (1994).
For terms which have been specially invented for coccoliths (e.g. placolith) the original author is given in curly brackets {}, this information is mostly from Hay et al. (1966).

Choice of terms

The general objective of the work is to summarise existing terminology rather than to create a new system. Nonetheless in order to enhance precision it has been necessary in several cases to select between synonyms, or to assess the utility of obscure terms and, in a few cases, to coin new terms. The following principles have been used as guides. Where we have selected from possible alternatives the alternative is discussed in the appendix with a reference to it in the text - e.g. "alternative spelling nanoplankton, see appendix".

Origin of terms

Throughout these pages curly brackets {} are used to indicate first use/coining of the term - e.g. {Lohmann 1902}. But note that the modern use may be rather different to the original author's concept.

Site Map

There are two versions of the pages - large text only versions, (good for slow connections and quick searching) and then the same text but broken up into numerous pages, with diagrams (prettier and more educational but slower).

Navigation - the placolith icon returns you to this index page
Copyright - This site is primarily based on Young et al. (1997) and copyright belongs to the Palaeontological Association. The content here is reproduced with their permission. Material from these pages can further be used in non-profit educational and research purposes provided that acknowledgement to the Palaeontological Association is given and that the source of the reproduced material is given in full.


Aubry, M.-P., (1984). Handbook of Cenozoic calcareous nannoplankton. Book 1: Ortholithae (Discoasters). Micropaleontology Press, American Museum of Natural History, New York, 266 pp.

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

Aubry, M.-P., (1988). Phylogeny of the Cenozoic calcareous nannoplankton genus Helicosphaera. Paleobiology, 14: 64-80.

Aubry, M.-P., (1989). Handbook of Cenozoic calcareous nannoplankton. Book 3: Ortholithae (Pentaliths, and others), Heliotithae (Fasciculiths, Sphenoliths and others). Micropaleontology Press, American Museum of Natural History, New York, 279 pp.

Aubry, M.-P., (1989). Phylogenetically based calcareous nannofossil taxonomy: implications for the interpretation of geological events. In: Crux, J.A. and Heck, S.E.v. (Editors), Nannofossils and their aplications: Proceedings INA Conference.London 1987. Ellis Horwood, Chichester, pp. 21-40.

Aubry, M.-P., (1990). Handbook of Cenozoic calcareous nannoplankton. Book 4: Heliolithae (Helicoliths, Cribriliths, Lopadoliths and others). Micropaleontology Press, American Museum of Natural History, New York, 381 pp.

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

Black, M., (1972). British Lower Cretaceous Coccoliths. I-Gault Clay (Part 1). Palaeontographical Society Monograph, 126: 1-48.

Bown, P.R., (1987). Taxonomy, evolution, and biostratigraphy of Late Triassic-Early Jurassic calcareous nannofossils. Special Papers in Palaeontology, 38: 118 p.

Braarud, T.; Deflandre, G.; Halldal, P. & Kamptner, E., (1955). Terminology, nomenclature, and systematics of the Coccolithophoridae. Micropaleontology, 1(2): 157-159.

Braarud, T.; Deflandre, G.; Halldal, P. & Kamptner, E., (1955). Terminologie, nomenclature et systematique chez les Coccolithophorides. Compte Rendu 8th International Botanical Congress, (Paris, 1954), 17: 69-70.

Brönnimann, P., (1955). Microfossils incertae sedis from the Upper Jurassic and Lower Cretaceous of Cuba. Micropaleontology, 1(28-51).

Brown, R.W., (1954). Composition of scientific words: a manual of methods and a lexicon of materials for the practice of logo technics., Baltimore.

Burnett, J.A. & Bown, P.R., (1992). An hierarchical descriptive checklist for calcareous nannofossils. Journal of Nannoplankton Research, 14(3): 103-106.

Chrétiennot-Dinet, M.-J., (1990). Atlas du Phytoplancton Marin, III. Editions du Centre National de la Recherche Scientifique, Paris.

Covington, J.M., (1985). New morphologic information on Cretaceous nannofossils from the Niobrara Formation (Upper Cretaceous) of Kansas. Geology, 13(10): 683-686.

Deflandre, G., (1950). Observations sur les Coccolithophoridés, à propos d'un nouveau type de Braarudosphaeridé, Micrantholithus, à éléments clastiques. Comptes Rendus (Hebdomadaires des Séances) de l'Académie des Sciences Paris, 231: 1156-1158.

Deflandre, G., (1952). Classe des Coccolithophoridés. (Coccolithophoridae. Lohmann, 1902). In: Grassé, P.P. (Editor), Traite de Zoologie. Masson, Paris, pp. 439-470.

Deflandre, G. & Deflandre-Rigaud, M., (1962). Remarques sur l'évolution des Nannoconidés à propos de quelques nouveaux types du Crétacé inferieur de Haute-Provence. Comptes Rendus de l'Academie des Sciences, Paris, 255: 2948-2951.

Deflandre, G. & Fert, C., (1954). Observations sur les coccolithophoridés actuels et fossiles en microscopie ordinaire et électronique. Annales de Paléontologie, 40: 115-176.

Evitt, W.R., (1985). Sporopollenin dinojlagellate cysts: their morphology and interpretation. American Association of Stratigraphic Palynologists Foundation.

Farinacci, A., (1971). Round Table on calcareous Nannoplankton.Roma, September 23-28, 1970. In: Farinacci, A. (Editor), Procedings of the II Planktonic Conference. Roma 1.970. Ed. Tecnoscienza, Roma, pp. 1343-1369.

Fowler, H.W., (1965). A dictionary of modern English usage. 2nd edn. Oxford University Press, Oxford, 725 pp.

Gower, E., (1954). The Complete Plain Words, 2nd edn. HMSO, London, 209 pp.

Gran, H.H. & Braarud, T., (1935). A quantitative study of the phytoplankton in the Bay of Fundy and the Gulf of Maine (including observations on hydrography, chemistry and turbidity). Journal of the Biological Board of Canada, 1: 279-467.

Green, J.C. & Jordan, R.W., (1994). Systematic history and taxonomy. In: Green, J.C. and Leadbeater, B.S.C. (Editors), The Haptophyte Algae. Systematics Association Special Volumes. Clarendon Press, Oxford, pp. 1-21.

Halldal, P., (1954). Comparative observations on coccolithophorids in light and electron microscopes and their taxonomic significance. . Reports and Communications of the 8th International Botanical Congress, Section 17: 122-123.

Halldal, P. & Markali, J., (1955). Electron microscope studies on coccolithophorids from the Norwegian Sea, the Gulf Stream and the Mediterranean. Avhandlinger utgitt av det Norske Videnskapsakademi i Oslo. Mat.- Naturvid. Klasse, 1: 1-30.

Haq, B.U., (1978). Calcareous nannoplankton. In: Haq, B.U. and Boersma, A. (Editors), Introduction to marine micropaleontology. Elsevier, Amsterdam, pp. 79-108.

Hay, W.W., (1977). Calcareous nannofossils. In: Ramsay, A.T.S. (Editor), Oceanic Micropalaentology. Academic Press, London, pp. 1055-1200.

Hay, W.W.; Mohler, H.P. & Wade, M.E., (1966). Calcareous nannofossils from Nal'chik (northwest Caucasus). Eclogae Geologicae Helvetiae, 59: 379-399.

van Heck, S.E. & Prins, B., (1987). A refined nannoplankton zonation for the Danian of the Central North Sea. Abhandlungen der Geologischen Bundesanstalt, 39: 285-303.

Heimdal, B.R., (1993). Modern Coccolithophorids. A Guide to Naked Flagellates and Coccolithophorids. In: Tomas, C.R. (Editor), Marine Phytoplankton. Academic Press, London, pp. 147-243.

Heimdal, B.R. & Gaarder, K.R., (1980). Coccolithophorids from the northern part of the eastern central Atlantic I. Holococcolithophorids. "Meteor" Forschungsergebnisse. Reihe D, Biologie, 32: 1-14.

Huxley, T., (1858). Appendix A. In: Dayman, J. (Editor), Deep sea soundings in the North Atlantic Ocean between Ireland and Newfoundland made in H.M.S. Cyclops. The Admiralty Commissioners, London, pp. 63-68.

Janofske, D., (1996). Ultrastructure types in recent "calcispheres". Bulletin de l'Institut Oceanographique Monaco Numero Special, 14/4: 295-204.

Janofske, D. & Keupp, H., (1992). Mesozoic and Cenozoic 'calcispheres'- update in systematics. Newsletter of the International Nannoplankton Association, 14(1): 14-16.

Jordan, R.W.; Kleijne, A.; Heimdal, B.R. & Green, J.C., (1995). A glossary of the extant Haptophyta of the world. Journal of the Marine Biological Association of the United Kingdom, 75: 769-814.

Kamptner, E., (1931). Nannoconus steinmanni novo gen., novo spec., ein merkwurdiges gesteinbildendes Mikrofossil aus dem jungeren Mesozoikum der Alpen. Paläontologische Zeitschrift, 13: 288-298.

Kamptner, E., (1948). Coccolithen aus dem Torton des Inneralpinen Wiener Beckens. Anzeiger. Österreichische Akademie der Wissenschaften. Mathematische-Naturwissenschafliche Klasse. Wien, 157: 1-16.

Keupp, H., (1991). Fossil calcareous dinoflagellate cysts. In: Riding, R. (Editor), Calcareous Algae and Stromatolites. Springer, Berlin, pp. 267-286.

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

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.

Kleijne, A., (1993). Morphology, Taxonomy and distribution of extant coccolithophorids (Calcareous nannoplankton). Drukkerij FEBO B.V., Katwijk, 321 pp.

Lohmann, H., (1902). Die Coccolithophoridae, eine Monographie der Coccolithen bildenden Flagellaten, zugleich ein Beitrag zur Kenntnis des Mittelmeerauftriebs. Archiv für Protistenkunde, 1: 89-165.

Lohmann, H., (1909). Die Gehause und Gallertblasen der Appendicularien und ihre Bedeutung fur die Erforschung des Lebens im Meer. Verhandlungen Deutsche Zoologische Geselleschaft, 19: 200-239.

Lohmann, H., (1913). Über Coccolithophoriden. Verhandlungen der Deutschen Zoologischen Gesellschaft, 23: 143-164.

van Niel, B.E., (1993). New observations on the morphology of Nannoconus. In: Hamrsmid, B. and Young, J.R. (Editors), Nannoplankton Research. ZPN, Knihovnicha, pp. 73-85.

van Niel, B.E., (1994). A review of the terminology used to describe the genus Nannoconus (calcareous nannofossil, incertae sedis. Cahiers de Micropaleontologie, 9(27-47).

van Niel, B.E., (1995). Unusual twin specimens of Nannoconus abundans (calcareous nannofossil, incertae sedis). Journal of Micropalaeontology, 14: 159-164.

Noël, D., (1959). Étude de coccolithes du Jurassique et du Crétacé inférieur. Publications du Service de la Carte Géologique de l'Algérie (Nouvelle Série) Bulletin, 20: 155-196.

Norris, R.E., (1965). Living cells of Ceratolithus cristatus (Coccolithophorineae). Archiv für Protistenkunde, 108: 19-21.

Norris, R.E., (1983). The family position of Papposphaera Tangen and Pappomonas Manton & Oates (Prymnesiophyceae) with records from the Indian Ocean. Phycologia, 22(2): 161-169.

Norris, R.E., (1985). Indian Ocean nanoplankton. II. Holococcolithophorids (Calyptrosphaeraceae, Prymnesiophyceae) with a review of extant genera. Journal of Phycology, 21: 619-641.

Okada, H. & McIntyre, A., (1977). Modern coccolithophores of the Pacific and North Atlantic Oceans. Micropaleontology, 23(1): 1-55.

Outka, D.E. & Williams, D.C., (1971). Sequential coccolith morphogenesis in Hymenomonas carterae. Journal of Protozoology, 18: 285-297.

Perch-Nielsen, K., (1985). Cenozoic calcareous nannofossils. In: Bolli, H.M., Saunders, J.B. and Perch-Nielsen, K. (Editors), Plankton Stratigraphy. Cambridge University Press, Cambridge, pp. 427-555.

Perch-Nielsen, K., (1985). Mesozoic calcareous nannofossils. In: Bolli, H.M., Saunders, J.B. and Perch-Nielsen, K. (Editors), Plankton Stratigraphy. Cambridge University Press, Cambridge, pp. 329-426.

Perch-Nielsen, K., (1988). New Lower Cretaceous calcareous nannofossil species from England. Newsletter of the International Nannoplankton Association, 10(1): 30-37.

Perch-Nielsen, K. & Franz, H.E., (1977). Lapideacassis and Scampanella, calcareous nannofossils from the Paleocene at sites 354 and 356, DSDP Leg 39, Southern Atlantic. Initial Reports of the Deep Sea Drilling Project, 39: 849-862.

Prins, B., (1971). Speculations on relations, evolution and stratigraphic distribution of discoasters. In: Farinacci, A. (Editor), Proceedings of the Second Planktonic Conference Roma 1971. Edizioni Tecnoscienza, Rome, pp. 1017-1037.

Romein, A.J.T., (1979). Lineages in Early Paleogene calcareous nannoplankton. Utrecht Micropaleontological Bulletins, 22: 231.

Roth, P.H., (1983). Jurassic and Lower Cretaceous calcareous nannofossils in the western North Atlantic (Site 534): biostratigraphy, preservation, and some observations on biogeography and palaeoceanography. Initial Reports of the Deep Sea Drilling Project, 76: 587-621.

Roth, P.H. & Thierstein, H.R., (1972). Calcareous nannoplankton: Leg 14 of the Deep Sea Drilling Project. In: Hayes, D.E. and Pimm, A.C. (Editors), Initial Reports of the Deep Sea Drilling Project. U.S. Government Printing Office, Washington, pp. 546-559.

Schmidt, O., (1870). Uber Coocolithen und Rhabdolithen. Akademie der Wissenschaften in Wien, Mathematische Naturwissenschaftliche Klasse, Abteilung I(62): 669-682.

Self-Trail, J.M. & Bybell, L.M., (1995). Cretaceous and Paleogene calcareous nannofossil biostratigraphy of New Jersey, in Contributions to the Paleontology of New Jersey, (ed. E.B. Baker). Geological Association of New Jersey, XII, pp. 102-139.

Sergeant, W.A.S., (1982). Dinoflagellate cyst terminology, a discussion and proposals. Canadian Journal of Botany, 60: 922-945.

Siesser, W.G. & Winter, A., (1994). Composition and morphology of coccolithophore skeletons. In: Winter, A. and Siesser, W.G. (Editors), Coccolithophores. Cambridge University Press, Cambridge, pp. 51-62.

Stearn, W.T., (1983). Botanical Latin. David & Charles, Newton Abbot, 566 pp.

Stradner, H., (1961). Vorkommen von Nannofossilien im Mesozoikum und Alttertiär. Erdöl-Zeitschrift, 77(3): 77-88.

Stradner, H. & Grün, W., (1973). On Nannoconus abundans nov. spec. and on laminated calcite growth in Lower Cretaceous nannofossils. Verhandlungen der Geologischen Bundesanstalt (Wien), 2: 267-283.

Stradner, H. & Papp, A., (1961). Tertiäre Discoasteriden aus Österreich und deren stratigraphische Bedeutung mit Hinweisen auf Mexico, Rumanien und Italien. Jahrbuch der Geologischen Bundesanstalt (Wien); Special Volume, 7: 1-159.

Sujkowski, Z., (1931). Étude pétrographique de Crétacé de Pologne. Sprawozdanie Polski Inst Geol, 6: 485-628.

Tappan, H., (1980). Haptophyta, coccolithophores, and other calcareous nannoplankton. In: Tappan, H. (Editor), The Paleobiology of plant protists. W. H. Freeman and Company, San Francisco, pp. 678-803.

Theodoridis, S., (1984). Calcareous nannofossil biostratigraphy of the Miocene and revision of the helicoliths and discoasters. Utrecht Micropaleontological Bulletin, 32: 1-271.

Thomsen, H.A.; Ostergaard, J.B. & Hansen, L.E., (1991). Heteromorphic life histories in Arctic coccolithophorids (Prymnesiophyceae). Journal of Phycology, 27: 634-642.

Trejo, M.H., (1960). La famillia Nannoconidae y su alcance estratigraphico en America (Protozoa, incertae sedis). . Bolletin de la Associacion Mexicana de Geologos Petroleros, 12: 259-314.

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

Varol, O., (1992). Taxonomic revision of the Polycyclolithaceae and its contribution to Cretaceous biostratigraphy. Newsletters on Stratigraphy, 27(93-127).

Wallich, G.C., (1860). Results of soundings in the North Atlantic. Annals and Magazine of Natural History, Series 3, 6: 457-458.

Williams, G.L.; Sergeant, W.A.S. & Kidson, E.J., (1978). A glossary of the terminology applied to dinoflagellate amphiesmae and their cysts and acritarchs. American Association of Stratigraphic Palynologists, Contributions Series, 2a: 1-121.

Winter, A.; Reiss, Z. & Luz, B., (1979). Distribution of living coccolithophore assemblages in the Gulf of Elat ('Aqaba). Marine Micropaleontology, 4: 197-223.

Winter, A. & Siesser, W.G., (1994). Coccolithophores. Cambridge University Press, Cambridge.

Young, J.R., (1989). Observations on heterococcolith rim structure and its relationship to developmental processes. In: Crux, J.A. and Heck, S.E.v. (Editors), Nannofossils and their applications. Ellis Horwood, Chichester, pp. 1-20.

Young, J.R., (1992). Report - Terminology working Group meeting, London April 1992. International Nannoplankton Association Newsletter, 14(1): 6-8.

Young, J.R., (1994). Variation in Emiliania huxleyi coccolith morphology in samples from the Norwegian EHUX experiment, 1992. Sarsia, 79: 417-425.

Young, J.R. & Bown, P.R., (1991). An ontogenetic sequence of coccoliths from the Late Jurassic Kimmeridge Clay of England. Palaeontology, 34: 843-850.

Young, J.R.; Bown, P.R. & Burnett, J.A., (1994). Palaeontological perspectives. In: Green, J.C. and Leadbeater, B.S.C. (Editors), The Haptophyte Algae. Systematics Association Special Volume. Clarendon Press, Oxford, pp. 379-392.

Young, J.R.; Didymus, J.M.; Bown, P.R.; Prins, B. & Mann, S., (1992). Crystal assembly and phylogenetic evolution in heterococcoliths. Nature, 356: 516-518.

Young, J.R. & Westbroek, P., (1991). Genotypic variation in the coccolithophorid species Emiliania huxleyi. Marine Micropaleontology, 18: 5-23.

This page was produced by Jeremy Young, comments welcome