Nannoplankton plankton 2-63 Ám in diameter. (Alternative spelling nanoplankton, see appendix). Informal grouping including coccolithophorids, Thoracosphaera, chrysophytes, etc., but excluding the bacterial picoplankton. {Lohmann 1909}
Calcareous nannoplankton nannoplankton with calcareous tests {?Stradner 1961}
Nannofossil fossil <63 Ám in diameter, excluding fragments and juveniles of larger fossils.
Calcareous nannofossil nannofossil formed of calcium carbonate.
Coccolithophore noun, calcareous nannoplankton belonging to the division Haptophyta {Lohmann 1902}
Coccolithophorid adjective, e.g. Coccolithophorid algae.
Coccosphere test of coccolithophore (not necessarily spherical). An extracellular cover made up of numerous coccoliths. {Wallich 1860}
Coccolith calcareous structure formed by coccolithophore. {Huxley 1868}
Haptophyte unicellular alga belonging to the division Haptophyta, includes all coccolithophores, and also related non-calcifying forms, e.g. Prymnesium, Phaeocystis, Pavlova, Chrysochromulina (Alternative term Prymnesiophyte, see appendix).
Nannolith calcareous nannofossil lacking the typical features of calcareous dinophytes, heterococcoliths or holococcoliths and so of uncertain affinity, see also Young (1992a), Young et al. (1994, 1999). The division between coccoliths and nannoliths varies between authors and is liable to revision as new data becomes available. N.B. This rather restricted definition of the term has little etymological justification, but has been widely used, e.g. Haq 1978, Perch-Nielsen (1985a, 1985b), Bown (1987), Aubry (1989). (The terms heliolith and ortholith provide an alternative basis for sub-dividing the calcareous nannofossils, see appendix). {?Haq 1978}
Heterococcolith coccolith formed of crystal-units of variable shape and size. Crystal units typically arranged in cycles with radial symmetry. {Braarud et al. 1955a, 1955b}
Heterococcolithophore cell bearing coccosphere of heterococcoliths.
Holococcolith coccolith formed of numerous minute (<0.1 Ám) crystallites all of similar shape and size (N.B. Many of the terms below are not applicable to holococcoliths, and there is a separate section for specific holococcolith terms). {Braarud et al. 1955a, 1955b}
Holococcolithophore cell bearing coccosphere of holococcoliths.
Lith a coccolith or nannolith, a relatively informal term but often useful.
Combination coccosphere coccosphere with both hetero- and holococcoliths. N.B. These are thought to represent a transitional state between heterococcolithophorid and holococcolithophorid phases of the life cycle. (The alternative term combination cell is less precise so is not now recommended). {Thomsen et al. 1991, Cros et al. 2000}
Since the terminology guide was written additional examples have been recorded in Ceratolithus/Neosphaera (Sprengel & Young 2000) and Alisphaera/Polycrater (Cros & Fortu˝o 2002) involving nannoliths and heterococcoliths. These are clearly analogous to the heterococcolith/holococcolith examples and have been termed combination coccospheres, so a broader definition is now needed. "Coccospheres containing coccoliths or nannoliths produced by two different biomineralization modes and likely representing a transition between two life-cycle phases." [JRY 2015]
Xenosphere anomalous coccosphere containing coccoliths normally regarded as forming on quite discrete species (e.g. Emiliania huxleyi and Gephyrocapsa oceanica; Winter et al. 1979). N.B. These are very probably artefacts, the term is suggested specifically to suggest the abnormal nature of these structures. See also Young & Geisen (2002). {Young et al. 1997, from Greek xenos, stranger}

(Coccolithus pelagicus holococcolith phase)

(Gephyrocapsa oceanica)

(Gephyrocapsa oceanica)

(Syracolithus catilliferus)

(Lithraphidites carniolensis)

(Ceratolithus cristatus - CE cristatus type

Combination coccosphere
(Calcidiscus leptoporus with holococcolith formerly assigned to Syracolthus quadriperforatus)

(bearing Emiliania huxleyi and Gephyrocapsa oceanica cocoliths)

Nannofossils and coccolithophores - notes for editors and other pedants

Nannofossil or nanofossil? Nannoplankton or nanoplankton?
What do you mean nannofossil, nanometers are only 10-9m and your things are far bigger than that? Also surely you have got the spelling wrong, it should be nano- not nanno-, shouldn't it? This is a boringly common query. The simple answer is that we have been talking about nannoplankton since Lohmann (1909) coined the term, whilst the use of nano- as a prefix for 10-9 was only introduced in 1947 (at 14th conference of the Union Internationale de Chimie). Both terms are derived from the greek word nanos, meaning dwarf. Nano is closer to the greek spelling but nanno reflects better the pronunciation, so neither is "correct". Almost all specialists in nannofossils and most nannoplankton workers prefer the spelling 'nanno' and the pronunciation with a short 'a'. Also this does provide some indication that we are not dealing with nanometer-scale organisms. Most dictionaries reflect this preference. So we recommend use of nannofossil and nannoplankton, but would not condemn the use of nanofossil or nanoplankton.

Coccolithophore or coccolithophorid?
The terms coccolithophore and coccolithophorid have been used interchangeably by different workers. Jordan et al. (1995) considered them synonyms and argued that coccolithophorid had priority;
Regarding the terminology of the coccolith bearing haptophytes in particular, the informal names 'coccolithophorid' and 'coccolithophore' are both in common use and both are based on the generic name Coccolithophora Lohmann 1902). Lohmann himself used the German form Coccolithophoriden, with the stem Coccolithophorid-, for the group generally and we therefore prefer the Anglicized form 'coccolithophorid' to the more recent 'coccolithophore' (Honjo & Okada, 1974).
This opinion was followed by Young et al. (1996) in the published version of this terminology guide, i.e. we recommended then that coccolithophorid should be used. However, this opinion has not been universally followed and Cros (2001) has noted that the two forms have different etymological significance and so are not strictly synonyms:
coccolitho+phor+id; (PHOR, from Greek -phoros, -phoron, bearing) and (-ID, from Latin -is, -ides; from the Greek -is, ides; is a patronymic suffix which means: 'belonging to' or 'connected with').

coccolitho+phore; (-PHORE , from Modern Latin -phorus, -phorum, from Greek -phoros, -phoron, bearing). The suffix -phore is an english combining form which constitute nouns: 'bearer', 'producer'.

From this she argued that The suffix -id, spoils the real characteristic of the group which is that all of them 'bear coccoliths' and not that they are 'related with the coccolith bearers'. This characteristic of 'bearing coccoliths' is correctly described by the suffix -phore, and for that reason the word coccolithophore (coccolith bearer) is here considered the appropriate name.
Essentially similarly, Linda Medlin (pers. comm.) suggested that coccolithophore should be considered a noun and used in contexts such as "H. carteri is a coccolithophore". Whilst coccolithophorid should be considered an adjective and used in contexts such as "the typical coccolithophorid pigmentation is."
Whilst Jordan et al. (1995) do have historical justification, it is fundamentally true that the terms are now used in the sense of coccolith-bearing algae rather than algae related to Coccolithophora. Hence we recommend here following the opinion of Medlin, but are not too dogmatic on the point.

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