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Mombasadinium parvelatum
Mombasadinium parvelatum (Jiang Qinghua in Jiang Qinghua et al., 1992, p.85,87, pl.2, fig.10) Riding and Helby, 2001f, p.162. Emendation: Riding and Helby, 2001f, p.162, as Mombasadinium parvelatum.
Originally Indodinium?, subsequently (and now) Mombasadinium.
Taxonomic junior synonym: Omatia jurabiana (name not validly published), according to Riding and Helby (2001f, p.162).
Holotype: Jiang Qinghua et al., 1992, pl.2, fig.10.
Age: Kimmeridgian–Tithonian.
Original description (Jiang Qinghue et al., 1992):
?lndodinium parvelatum Jiang sp. nov. (Plate II, 10)
Diagnosis: Central body elongate, circumcavate, with a tAa archaeopyle. No apical horn is present; the antapex is broadly rounded. Thin smooth periphragm. Thicker endophragm surface, more or less smooth, but granules and thin solid process may be present and may be aligned at times.
Description." The operculum is often missing, but no horn is present on either wall layer. The pericoels are narrow and thin processes may span the gap between, as in Belodinium; these are rare, however, and usually are seen to be more common near the antapex. The cingulum may be marked by thickening of the endophragm or may not be distinguished at all; if it appears, it is about 6 µm wide. The splits at the apical margin indicate six precingular paraplates and sometimes rows of granules suggest a plate boundary. These few indications suggest that the tabulation is of gonyaulacoid type.
Holotype: Slide MP26 (iv), EF reference V60/1; Plate lI, 10.
Dimensions. Length: 52-69 µm, holotype 73 µm: breadth: 33-34 µm, holotype 48 µm. Specimens measured: 10.
Derivation of name." Referring to the narrow pericoels.
Remarks. The general absence of supporting processes excludes the species from Belodinium to which it shows clear morphological similarities. However, allocation to Indodinium is questionable, because of the lack of evidence about the apical structures of the type species of that genus. The species is clearly not proximate, although it resembles in outline Clathroctenocysta asapha (Drugg, 1978) Stover and Helby, 1987, and Fistulacysta simplex Davey, 1988, which are.
Occurrence: All samples from MP25 to MP40. Rare to abundant.
Originally Indodinium?, subsequently (and now) Mombasadinium.
Taxonomic junior synonym: Omatia jurabiana (name not validly published), according to Riding and Helby (2001f, p.162).
Holotype: Jiang Qinghua et al., 1992, pl.2, fig.10.
Age: Kimmeridgian–Tithonian.
Original description (Jiang Qinghue et al., 1992):
?lndodinium parvelatum Jiang sp. nov. (Plate II, 10)
Diagnosis: Central body elongate, circumcavate, with a tAa archaeopyle. No apical horn is present; the antapex is broadly rounded. Thin smooth periphragm. Thicker endophragm surface, more or less smooth, but granules and thin solid process may be present and may be aligned at times.
Description." The operculum is often missing, but no horn is present on either wall layer. The pericoels are narrow and thin processes may span the gap between, as in Belodinium; these are rare, however, and usually are seen to be more common near the antapex. The cingulum may be marked by thickening of the endophragm or may not be distinguished at all; if it appears, it is about 6 µm wide. The splits at the apical margin indicate six precingular paraplates and sometimes rows of granules suggest a plate boundary. These few indications suggest that the tabulation is of gonyaulacoid type.
Holotype: Slide MP26 (iv), EF reference V60/1; Plate lI, 10.
Dimensions. Length: 52-69 µm, holotype 73 µm: breadth: 33-34 µm, holotype 48 µm. Specimens measured: 10.
Derivation of name." Referring to the narrow pericoels.
Remarks. The general absence of supporting processes excludes the species from Belodinium to which it shows clear morphological similarities. However, allocation to Indodinium is questionable, because of the lack of evidence about the apical structures of the type species of that genus. The species is clearly not proximate, although it resembles in outline Clathroctenocysta asapha (Drugg, 1978) Stover and Helby, 1987, and Fistulacysta simplex Davey, 1988, which are.
Occurrence: All samples from MP25 to MP40. Rare to abundant.