Original descriptions of taxa. For coccolithophores, and many calcispheres, these are pages from the Farinacci & Howe Catalog of Calcareous Nannofossils. In other cases (e.g. non-calcifying haptophytes) the data is directly compiled on this site. The "Catalogue of Calcareous Nannofossils" was originally compiled by Prof A. Farinacci 1969-1989, since 2000 it has been updated and extended by Richard Howe - see The Farinacci and Howe Catalog - an Introduction.
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Current identification/main database link: Chrysochromulina pyramidosa Thomsen 1977
Compiled data
Original Description
Extra details from original publication
The haptonema of C. pyramidosa measures 5-6 µm, which is about twice the body length and approximately half the length of the flagella (Fig. 1A). The two flagella, which both end in a hairpoint (Fig. 1A), differ slightly in length. The cell proper is saddle-shaped, with the flagella and the haptonema inserted in the apical depression (Fig. 1A).
Two types of scales cover the cell body. The inner layer consists of circular, plate-like scales, approximately 0.7 µm in diameter (Fig. 1B, C). These scales show a loosely woven pattern of radiating ridges (24) and 7-8 approximately equidistant concentric rings. The dorsal and ventral surfaces of these scales are virtually indistinguishable. All the ridges that form the scale are of equal thickness, with the exception of the outermost ring which is conspicuously thicker (Fig. 1B).
The outer layer consists of more elaborate scales, made up of a subtending circular flat base plate, and a superstructure composed of four converging struts (Fig. 2A-C). The plate-like base, which in many respects is similar to the inner scale type described above, is 0.8-0.9 µm in diameter, and is formed by 27- 28 radiating ridges and 8-9 concentric rings. The innermost rings are equidistant, whereas the distance between the outermost two rings is considerably greater (Fig. 2 B, arrows). The outermost ring as well as the four struts that form a pyramidal structure (Figs. 1C, 2 C) are thicker than the remainder of the mesh work.
Fig. 2A, C (arrowheads) shows some additional scale material between the four struts, apparently running from one strut to a point above the centre of the scale and back again to the neighbouring strut. A transverse section of the pyramidal superstructure thus presents itself as two right triangles joined together to form a cross. From Fig. 2 B it appears, however, that this extra material is not always present.
Fig. 2D, E was kindly supplied by Professor I. Manton. They show some very similar scales from a water sample collected off the South African coast (November 13, 1972; 4 miles NW of Hout Bay Neck near Cape Town; 33° 57.6 S, 18° 16.9 E; 33ft. depth, water temperature 12°C). The differences between the Danish and the African material are marginal. The simple plate-like inner scales of the latter are slightly larger (approximately 0.8 µm versus 0.7 µm) and have 9-11 concentric rings versus 7-8; otherwise they appear identical. The pyramidal scales seem to agree completely with those found in the Danish material. The interconnecting material between the four struts found on some of the pyramidal scales from the Danish material is apparently lacking in the equivalent South African scales.
In spite of minor differences the Danish and the South African material seem to represent the same species, suggesting that C. pyramidosa has a worldwide distribution.
Thomsen, H. A. (1977). Chrysochromulina pyramidosa sp. nov. (Prymnesiophyceae) from Danish coastal waters. Botaniska Notiser. 130: 147-153. gsReferences:
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Chrysochromulina pyramidosa: Catalog entry compiled by Jeremy Young. Viewed: 17-2-2025
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