Nannotax3 - ntax_cenozoic - Pleurochrysidaceae Nannotax3 - ntax_cenozoic - Pleurochrysidaceae


Classification: ntax_cenozoic -> Coccolithales -> Pleurochrysidaceae
Sister taxa: Coccolithaceae, Calcidiscaceae ⟩⟨ Hymenomonadaceae, Pleurochrysidaceae

Daughter taxa (time control age-window is: 0-800Ma)Granddaughter taxa
Coccoliths elliptical narrow-rimmed placoliths with complex rim structure, open central area
Chrysotila carterae
Chrysotila dentata
Chrysotila gayraliae
Chrysotila la-hague
Chrysotila placolithoides
Chrysotila roscoffensis
Chrysotila scherffelii
Chrysotila stipitata
Chrysotila sp.


Citation: Pleurochrysidaceae Fresnel & Billard, 1991
taxonomic rank: Family
Taxonomic discussion: At one time species were assigned to either Cricosphaera or Pleurochrysis on the basis of their life-cycles. Following revisions of Jordan et al. (1993) the family is now monogeneric.

Distinguishing features:
Parent taxon (Coccolithales): 2N: Mostly placolith heterococcoliths with V-unit forming the distal shield; R-unit the proximal shield. Non-motile
N: Form holococcoliths formed of single block, or non-calcifying

This taxon: 2N: cells motile, bearing narrow-rimmed placoliths, with obviously interlocking V and R units, open central areas. Neritic. N: non-calcifying.

Farinacci & Howe catalog pages: Pleurochrysidaceae


Coccoliths are formed of two cycles of tightly interlocked anvil-shaped crystal-units. V-unit forms distal shield and tube. R-unit forms proximal shield and small element on inside of tube (Marsh 1999). Central area open. Coccoliths with this structure have been termed cricoliths. Coccospheres large with numerous liths, monomorphic.

Ecology & Biogeography


Biology & life-cycles
These species are neritic and easily isolated and maintained in culture., hence taxonomy is based on cultures. Diploid phase is motile and heterococcolith-bearing, haploid phase is non-calcifying, flagellate or benthic.
Key references: Gayral & Fresnel (1983) - life-cycle; van der Wal et al. (1983) - cytology; Fresnel & Billard (1991) - species overview; Marsh (1999) - coccolith ultrastructure.

Phylogenetic relations
This family was included in the Coccolithales by Young & Bown (1997) since the rim structure appears to be a simplified version of that of the Coccolithaceae. This is supported by the detailed analysis of coccolith structure of Marsh (1999) and molecular genetic data, (Edvardsen et al., 2000; Fujiwara et al., 2001; Sáez et al. 2004)

Search data:
Lith size: 1.5->4µm;
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 ranges of the species in this database
First occurrence (base): within No known fossil record modern (0.00-0.00Ma, base in "Holocene" stage). Data source: Total of ranges of species in this database

Plot of occurrence data:


Edvardsen, B., Eikrem, W., Green, J. C., Andersen, R. A., Moon-Van Der Staay, S. Y. & Medlin, L. K. (2000). Phylogenetic reconstructions of the Haptophyta inferred from 18S ribosomal DNA sequences and available morphological data. Phycologia. 39: 19-35. gs

Fresnel, J. & Billard, C. (1991). Pleurochrysis placolithoides sp. nov. (Prymnesiophiceae), a new marine coccolithophorid with remarks on the status of cricolith-bearing species. British Phycological Journal. 26: 67-80. gs

Fujiwara, S., Tsuzuki, M., Kawachi, M., Minaka, N. & Inouye, I. (2001). Molecular phylogeny of the haptophyta based on the rbcL gene and sequence variation in the spacer region of the RUBISCO operon. Journal of Phycology. 37: 121-129. gs

Gayral, P. & Fresnel, J. (1983b). Description, sexualité et cycle de développment d'une nouvelle coccolithophoracée (Prymnesiophyceae): Pleurochrysis pseudoroscoffensis sp. nov. Protistologica. 19(2): 245-261. gs

Jordan, R. W., Kleijne, A. & Heimdal, B. R. (1993). Proposed changes to the classification system of coccolithophorids. III. INA Newsletter. 15(1): 18-22. gs

Marsh, M. E. (1999). Coccolith crystals of Pleurochrysis carterae: Crystallographic faces, organisation and development. Protoplasma. 207: 54-66. gs

Sáez, A. G., Probert, I., Young, J. R., Edvardsen, B., Wenche, E. & Medlin, L. K. (2004). A review of the phylogeny of the Haptophyta. In, Thierstein, H. R. & Young, J. R. (eds) Coccolithophores - from molecular processes to global impact. Springer, Berlin 251-270. gs

van der Wal, P., de Jong, E. W., Westbroek, P., de Bruijn, W. C. & Mulder-Stapel, A. A. (1983). Ultrastructural polysaccharide localization in calcifying and naked cells of the coccolithophorid Emiliania huxleyi. Protoplasma. 118: 157-168. gs

Young, J. R. & Bown, P. R. (1997). Cenozoic calcareous nannoplankton classification. Journal of Nannoplankton Research. 19(1): 36-47. gs


Pleurochrysidaceae compiled by Jeremy R. Young, Paul R. Bown, Jacqueline A. Lees viewed: 24-5-2024

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