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Spinidinium ovale
Spinidinium ovale (Vozzhennikova, 1967, p.99, pl.40, figs.1a–b,2a–b) Lentin and Williams, 1977b, p.147. Holotype: Vozzhennikova, 1967, pl.40, figs.1a–b, lost according to Lentin and Vozzhennikova (1990, p.69), who stated that no potential lectotype is available. Originally Canninginopsis, subsequently Spinidinium?, thirdly (and now) Spinidinium. Questionable assignment: Lentin and Williams (1977b, p.147): however, Sluijs et al. (2009, p.48) retained this species in Spinidinium without question. Age: Paleocene–Eocene.
Original description: Vozzhennikova, 1967, p.99: Canninginopsis ovalis
Theca oval, strongly compressed in a dorsoventral direction, with a small apical and a sharply pointed antapical horn. The latter may be absent. Thecal surface divided into fielas by rows of spinules which may be blunt or sharply ended. Field formula: on the epitheca 4a + 6pr: on the hypotheca 6zb or (?5)zb + (?2sr") + 1a". Apical plates of various shapes and sizes; the first rhomboidal, the second and fourth are small plates lying one to each side of the first, the third, which is trapeziform, lying above the first. The third anterior equatorial plate is recognizable because of its small size and rectangular form; it lies between the transverse furrow and the third apical plate. To the side of it lie the 2nd and 4th large anterior equatorial plates. The 1st and 6th plates are small and border onto the longitutinal furrow, above which lie the 2nd and 4th apical plates, and to the right and left of which lie the 2nd and 5th anterior equatorial plates. Among the posterior equatorial plates the first ant 6th are considerably smaller than the others. Between them and the antapical plates lies a small intercalary plate (2cp") which is difficult to distinguish. The antapical plate is polygonal. The transverse furrow is faintly spiral but not subdividet into plates. The longitudinal furrow is straight ant extends from the rhombic plate to the antapex. The theca is light-colored ant has a smooth surface.
Size: Holotype, length 53µm, width 46µm, width of paracingulum about 6µm.
Affinities:
Lentin and Vozzhennikova, 1990, p.70: Although the details of the paratabulation given in the original description suggest a gonyaulacoid pattern, it is clear from the illustrations of the species, particularly pl. 40, fig. 2a-b (reproduced here), that the paratabulation is peridinioid.
Original description: Vozzhennikova, 1967, p.99: Canninginopsis ovalis
Theca oval, strongly compressed in a dorsoventral direction, with a small apical and a sharply pointed antapical horn. The latter may be absent. Thecal surface divided into fielas by rows of spinules which may be blunt or sharply ended. Field formula: on the epitheca 4a + 6pr: on the hypotheca 6zb or (?5)zb + (?2sr") + 1a". Apical plates of various shapes and sizes; the first rhomboidal, the second and fourth are small plates lying one to each side of the first, the third, which is trapeziform, lying above the first. The third anterior equatorial plate is recognizable because of its small size and rectangular form; it lies between the transverse furrow and the third apical plate. To the side of it lie the 2nd and 4th large anterior equatorial plates. The 1st and 6th plates are small and border onto the longitutinal furrow, above which lie the 2nd and 4th apical plates, and to the right and left of which lie the 2nd and 5th anterior equatorial plates. Among the posterior equatorial plates the first ant 6th are considerably smaller than the others. Between them and the antapical plates lies a small intercalary plate (2cp") which is difficult to distinguish. The antapical plate is polygonal. The transverse furrow is faintly spiral but not subdividet into plates. The longitudinal furrow is straight ant extends from the rhombic plate to the antapex. The theca is light-colored ant has a smooth surface.
Size: Holotype, length 53µm, width 46µm, width of paracingulum about 6µm.
Affinities:
Lentin and Vozzhennikova, 1990, p.70: Although the details of the paratabulation given in the original description suggest a gonyaulacoid pattern, it is clear from the illustrations of the species, particularly pl. 40, fig. 2a-b (reproduced here), that the paratabulation is peridinioid.