Taxonomic Information
Jr. Synonymy:
- Coscinodiscus denarius Schmidt var. Van Huerck, 1909, p. 47, pl. 12, fig. 164.
- Thalassiosira antarcticus? in McCollum, 1975, p. 536, pl. 14, figs. 1, 2.
- Thalassiosira cf. burckliana Gombos, 1977, pl. 5, fig. 4.
- Thalassiosira torokina Brady, 1977, p. 122, 123, figs. 1-5; Brady, 1979, pl. 4, figs. 1-5; Ciesielski, 1983, pl. 7, figs. 3-6. Harwood, 1986a, pl. 15, figs. 11, 13, 14; pl. 19, figs. 10, 11; pl. 25, figs. 1-3; Scherer, 1991, pl. 2, fig. 4; Mahood and Barron, 1996b, p. 296, pl. 6, figs. 1-3, pl. 8, fig. 8.
- Thalassiosira genloffi Ramirez, 1981, pp. 73-82, pl. 26-28, figs. 164-177.
Morphometry:
- Diameter Range: 37 to 45 µm
Species Description:
- Mini Description:
- Original Name Coscinodiscus denarius Schmidt var. Van Huerck, 1909
Modern Description and Remarks by Mahood and Barron (1996, p. 296):
- Expanded description; Valve circular, convex, 37 to 45 µm in diameter (pl. 6, figs. 1a, 1b). The areolae are linear, fasciculate on valve face, 7-8 in 10 µm, external poroid, internal with cribruym (fig. 3b). Valve face separated from mantle by closely abutted marginal strutted processes (pl. 6, figs. 1d, 1e), 10 in 10 µm. Central cluster of 10 to 19 strutted processes each with 3-5 satellite pores, usually 4 (pl. 6, figs. 1c, 3c). Prominent labiate process takes place of a strutted process (pl. 6, figs. 3a); external tube prominent (pl. 6, figs. 1a, 1d, 2.).
- In most aspects T. torokina and T. gerloffi show some striking similarities. The row of marginal strutted process in T. torokina (pl. 6, figs. 1a, 1e, 3a, 3b) and T gerloffi (Ramirez 1981, fig. 176, 172) are linked without an areolae separating the processes. T. torokina from this sample is convex and heavily silicified while T. gerloffi is concave (Ramirez, 1981) and weakly silicified. A comparison of figures 175 and 176 (Ramirez 1981) and plate 6, figures 1a, 1b, and 1e (this paper) show dissimilar areolae mantle patterns (G.A. Fryxell, personal communication, 1994). Further studies will be necessary to determine synonymy if any and the relationship between the two taxa.
|
