Taxonomic Information
Jr. Synonymy:
- Thalassiosira miocenica Schrader, 1974, p. 916, pl. 22, figs. 1- 5, 11-13; Barron, 1985a, p. 445, pl. 5, fig. 6; Barron, 1985b, pl. 11, fig. 11; Gersonde and Burckle, 1990, p. 782, pl. 3, figs. 4-5; Baldauf and Barron, 1991, p. 591, pl. 6, fig. 2.
Morphometry:
- Diameter Range: valves small 16-25 µm in diameter
Species Description:
- Original Name Thalassiosira miocenica Schrader, 1974: Cells solitary, valves small 16-25 µm in diameter. Valves convex (appr. 7 µm in height). One row of spines near the margin. No labiate process could be observed near the margin with normal light microscope methods. Central area flattened with one to three mucous pores (compare fig. 4). Areolae hexagonal forming a complete meshwork over the entire valve, approximately of the same size all over the valve, 7-8 in 10 µm. Areolae arranged in curved rows forming somewhat parallel lines, which are often tangential. Valve margin distinct, approximately 0.5 µm wide; hyaline with one row of hexagonal areolae 8 in 10 µm.
- Differentiation: This species is near to Thalassiosira praeconvexa Burckle, 1972, from which it differs by its tangential rows of areolae and the more convex valves, to T. usatschevii Jouse, 1961, from which it differs by the finer areolation and the smaller margin, to T. convexa var. aspinosa Schrader, 1974, from which it differs in the coarser areolation and the nonradiate rows.
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