Original descriptions of taxa. For coccolithophores, and many calcispheres, these are pages from the 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 compiled by Prof A. Farinacci 1969-1989 and updated by Richard Howe 2000-2016 - see also this page.
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|Imantonia rotunda Reynolds 1974|
= Dicrateria rotunda
Current identification/main database link: Dicrateria Parke 1949Compiled data
Cells motile, not metabolic. Flagella two, smooth, homodynamic; haptonema not found. Chloroplasts parietal, golden brown, with embedded pyrenoids. Cell body bearing more or less circular scales with coarse radial fibrils on their proximal faces.
Etymology: The name Imantonia,/i> was suggested by Dr M. Parke, in recognition of the very valuable contribution made by Professor Irene Manton, F.R.S., to our knowledge of the flagellates, and of the Haptophyceae in particular.
Extra details from original publication
Discussion: In its internal structure Imantonia agrees with the general concept of a haptophycean cell except for the absence of a haptonema. This is perhaps offset by the presence of the "peculiar" thickenings of the Golgi body which appear to be characteristic of this class. It closely resembles Dicrateria inornata Parke (Parke, 1949), but the chloroplasts are a little better defined and there is a tendency towards an indentation in the region of the flagella bases that is not evident in Dicrateria. Separation of the one from the other would be difficult with the light microscope, especially as they share the habit of the cells rotating while swimming and travelling in a constant direction for relatively long distances with the flagella more or less parallel behind the cell. Under the electron microscope Imantonia is immediately identified by its scales.
This flagellate appears to be differentiated from Isochrysis by the absence of a haptonema and of metaboly, and also the considerably difference in the type of scales. It is suggested that it should be placed in the Isochrysidales as a separate genus.