Murray & Blackman 1898
R. stylifera Lohmann 1902.
After Young et al. 2003. Spines robust, formed of five clockwise-spiral sets of elements with pentameral terminal papilla. Lith bases elliptical/oblong, 3-3.5 μm. Spine-bearing liths with wider rim than non spine-bearing liths.
Southern Ocean, south of Tasmania.
After Young et al. 2003. Forms with club-shaped and narrower parrel-sided spines are often separated as varieties of R. clavigera. However the two types intergrade and both can be found on single coccospheres, so this is evidently an example of degree of calcification variation rather than genotypic variation. Hence, taxonomic names should not be used for the different morphotypes, although it may be useful to informally differentiate them for ecological studies.
HOL?= Sphaerocalyptra quadridentata, see Cros & Fortuno (2002)