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Valvaeodinium koessenium
Valvaeodinium koessenium (Morbey, 1975) Below, 1987
Originally Comparodinium, subsequently (and now) Valvaeodinium.
Taxonomic junior synonym: Comparodinium (subsequently Valvaeodinium) diacrorhaetium, according to Below (1987b, p.66).
Holotype: Morbey, 1975, pl.15, figs.14a–b; text-fig.19a, no.a; Fensome et al., 1995, figs.1–3 — p.1589.
Locus typicus: Salzburg Fazies, Kendelbachgraben, south of Wolfgangsee, Austria
Stratum typicum: Rhaetian-Hettangian
Original diagnosis: Morbey, 1975, p.44: Comparodinium koessenium
Cyst chorate, marginate; spheroidal, ovoidal, cylindroidal in shape. Wall thin, microgranulate, with a superimposed fine microreticulation. Tabulation indeterminate, vaguely defined by intratabular and plate-bounding processes, and when evident sutures. Processes tractal in development, simple heteromorphic, unequal/equal in length, 9--25 % cyst length in length, 15--30 (rarely upto 40) in number per tract. Proximally, processes distinctly hollow, wall often internally ramified. Distally, process terminations seemingly closed. Process cavity/cyst cavity relationship generally indeterminate. Process cavities of internally ramified processes seemingly not in communication with cyst cavity. Process bases angular, sharply curved; stems tapered, conical, slender; terminations finely bifurcate, sometimes trifurcate, quadrifurcate. Cingulum reflected by unornamented equatorial region, ca. 5-15 µm in width; sulcal area, where evident, almost cyst length in extent. Archaeopyle apical.
Dimensions: Cyst length 25 (29) 48 µm (27 specimens measured). Cyst breadth 13 (18) 32 µm. Ratio Cyst length: breadth 2:1-3:4. Process length 3-10 µm, diameter upto 3 µm.
Remark: Due to their preservation, the majority of specimens possess a number of processes with truncate terminations. The fine "hair-like" furcations are somewhat delicate and appear to be easily removed.
Originally Comparodinium, subsequently (and now) Valvaeodinium.
Taxonomic junior synonym: Comparodinium (subsequently Valvaeodinium) diacrorhaetium, according to Below (1987b, p.66).
Holotype: Morbey, 1975, pl.15, figs.14a–b; text-fig.19a, no.a; Fensome et al., 1995, figs.1–3 — p.1589.
Locus typicus: Salzburg Fazies, Kendelbachgraben, south of Wolfgangsee, Austria
Stratum typicum: Rhaetian-Hettangian
Original diagnosis: Morbey, 1975, p.44: Comparodinium koessenium
Cyst chorate, marginate; spheroidal, ovoidal, cylindroidal in shape. Wall thin, microgranulate, with a superimposed fine microreticulation. Tabulation indeterminate, vaguely defined by intratabular and plate-bounding processes, and when evident sutures. Processes tractal in development, simple heteromorphic, unequal/equal in length, 9--25 % cyst length in length, 15--30 (rarely upto 40) in number per tract. Proximally, processes distinctly hollow, wall often internally ramified. Distally, process terminations seemingly closed. Process cavity/cyst cavity relationship generally indeterminate. Process cavities of internally ramified processes seemingly not in communication with cyst cavity. Process bases angular, sharply curved; stems tapered, conical, slender; terminations finely bifurcate, sometimes trifurcate, quadrifurcate. Cingulum reflected by unornamented equatorial region, ca. 5-15 µm in width; sulcal area, where evident, almost cyst length in extent. Archaeopyle apical.
Dimensions: Cyst length 25 (29) 48 µm (27 specimens measured). Cyst breadth 13 (18) 32 µm. Ratio Cyst length: breadth 2:1-3:4. Process length 3-10 µm, diameter upto 3 µm.
Remark: Due to their preservation, the majority of specimens possess a number of processes with truncate terminations. The fine "hair-like" furcations are somewhat delicate and appear to be easily removed.