Nannotax3 - ntax_cenozoic - narrow rimmed placoliths Nannotax3 - ntax_cenozoic - narrow rimmed placoliths

narrow rimmed placoliths

Classification: ntax_cenozoic -> Coccolith families inc sed -> narrow rimmed placoliths
Sister taxa: Alisphaeraceae, Papposphaeraceae, Umbellosphaeraceae, narrow rimmed placoliths, Coccolith genera inc sed, U. heterococcoliths

Daughter taxa (time control age-window is: 0-800Ma)Granddaughter taxa
Calyptrosphaera sphaeroidea HET
Coccoliths elliptical narrow-rimmed placoliths with plate formed from numerous small elements in central area

Coccoliths narrow-rimmed placoliths with robust central spine; CFCs with tall, sail-like, spines
Navilithus altivelum
Navilithus sp.

Coccoliths rhombic narrow-rimmed placoliths with four plates in central area
Placorhombus ziveriae
Placorhombus sp. cf. ziveriae
Placorhombus sp.

Coccoliths elliptical narrow-rimmed placoliths with four plates in central area
Tetralithoides quadrilaminata
Tetralithoides symeonidesii
Tetralithoides sp.

Coccoliths elliptical narrow-rimmed placoliths with quadrate tower-like central structure
Turrilithus latericioides
Turrilithus sp.


Citation: narrow rimmed placoliths - informal Young et al., 2003
taxonomic rank: Family
Taxonomic discussion: This grouping is discussed in detail in Young & Andruleit (2006).

Distinguishing features:
Parent taxon (Coccolith families inc sed): 2N: Various heterococcolith groups not obviously related to the well-defined orders
N: mostly unknown

This taxon: Diverse group of coccoliths with narow placolith rims and variable central structures, usually showing four-fold symmetry.

Farinacci & Howe catalog pages: narrow rimmed placoliths [no catalog entry yet]


Rims in these genera appear to reformed of a single cycle of non-imbricate elements with radial sutures. Central area structures are highly variable but disjunct and usually with four-fold symmetry

Coccoliths very small 0.5-2.5 mm) except in Tetralithoides (4-7.5 µm) 

Ecology & Biogeography

Deep photic

Biology & life-cycles
Calyptrosphaera sphaeroidea has both holococcolith and heterococcolith phases and has been cultured (Noël et al. 2004), the other taxa are so far only known from the heterococcolith phase and have not been cultured.

Phylogenetic relations
Calyptrosphaera sphaeroidea falls within the Coccolithales clade in molecular genetic analyses (Fujiwara et al., 2001; Saez et al., 2004, Young et al. 2014 Cryptogamie)

Search data:
Lith size: 0.5->7.5µm;
The morphological data given here can be used on the advanced search page. See also these notes

Geological Range:
Notes: Only Tetralithoides has a documented fossil record, extending back to the Early Miocene (Theodoridis, 1984; Young, 1998).
Last occurrence (top): Extant. Data source: Total of ranges of the species in this database
First occurrence (base): within NP9 zone (55.86-57.21Ma, base in Thanetian stage). Data source: Total of ranges of species in this database

Plot of occurrence data:


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

Noël, M. -H., Kawachi, M. & Inouye, I. (2004). Induced dimorphic life cycle of a coccolithophorid, Calyptrosphaera sphaeroidea. Journal of Phycology. 40(1): 112-129. 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

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

Young, J. R. & Andruleit, H. (2006). Navilithus altivelum: a remarkable new genus and species of deep photic coccolithophores. Journal of Micropalaeontology. 25(2): 141-152. gs

Young, J. R. (1998). Neogene. In, Bown, P. R. (ed.) Calcareous Nannofossil Biostratigraphy. British Micropalaeontological Society Publication Series . 225-265. gs

Young, J. R., Geisen, M., Cros, L., Kleijne, A., Probert, I. & Ostergaard, J. B. (2003). A guide to extant coccolithophore taxonomy. Journal of Nannoplankton Research. S1: 1-132. gs

Young, J. R., Liu, H., Probert, I., Aris-Brosou, S. & de Vargas, C. (2014). Morphospecies versus phylospecies concepts for evaluating phytoplankton diversity: The Case of the Coccolithophores. Cryptogamie Algologie. 35(4): 353-377. gs


narrow rimmed placoliths compiled by Jeremy R. Young, Paul R. Bown, Jacqueline A. Lees viewed: 24-6-2024

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