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Tianjinella elliptica
From Fensome et al., 2019:
Tianjinella elliptica He Chengquan and Sun Xuekun, 1996, p.385, pl.1, figs.1–9; pl.2, figs.1–6; text-fig.3.
Holotype: He Chengquan and Sun Xuekun, 1996, pl.1, fig.1.
Age: Eocene.
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1978 Dinogymnium cf. decorum - Song et al., pp. 93-94, pl. 6, figs. 3 6, non Dinogymnium cf. decorum (Deflandre) Evitt - Clarke and Verdier, 1967
1992 Dinogymnium granulatum sensu Liu et al., p. 67, pl. 7, fig. 10, non Dinogymnium granulatum - Song et al., 1978
Holotype: Slide G8-55-9; Plate I, 1; Eocene, southern Tianjin, China.
Occurrence: The upper part of the 3rd Member of the Shahejie Formation, Eocene, southern Tianjin and Jinxian County, Liaoning Province, China.
Description: The cyst is small, ellipsoidal or dumbbell-shaped with the equatorial area being constricted. Epicyst and hypocyst are approximately equal-sized and similar in shape. Apical area and antapical area are rounded, occasionally truncate; the apical end may be slightly narrower than the antapical end. The autophragm is thin, about 0.5 µm thick, with a granulate or wrinkled wall surface. The paracingulum is circular, 3.5-6 µm wide and indicated by the equatorial constriction; the parasulcus is not indicated. The paratabulation is expressed by archeopyle and intratabular processes. The processes are low (0.6-2 µm, generally <1 µm), bead-shaped; process tips are wide, open (Plate II, 1) or closed. The development of the processes may show some intra-specific variations. On some specimens (Plate I, 2, 5), for example, the processes are much lower or even reduced. The holotype shows 4 apical processes but no indications of paracingular processes; its precingular and postcingular processes are relatively well developed and the antapical process is normally undeveloped. The process formula is 4", 6", 0c, 5-6"", 0-1"". The archeopyle is apical, Type 4A, with the principal archeopyle suture being zigzag. The operculum is free along its entire margin.
Dimensions: Holotype: length, 29 µm; breadth, 24.5 µm. Range: length, 24-34 µm; breadth, 21-27 µm; 20 specimens were measured.
Comparisons: Tianjinella elliptica He and Sun, sp. nov. differs from Tianjinella ovata (Song et al., 1978) He and Sun, comb. nov. in being ellipsoidal or dumbbell-shaped, whereas the latter has an ovoidal to subspherical shape and lacks an equatorial constriction.
Tianjinella elliptica He Chengquan and Sun Xuekun, 1996, p.385, pl.1, figs.1–9; pl.2, figs.1–6; text-fig.3.
Holotype: He Chengquan and Sun Xuekun, 1996, pl.1, fig.1.
Age: Eocene.
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1978 Dinogymnium cf. decorum - Song et al., pp. 93-94, pl. 6, figs. 3 6, non Dinogymnium cf. decorum (Deflandre) Evitt - Clarke and Verdier, 1967
1992 Dinogymnium granulatum sensu Liu et al., p. 67, pl. 7, fig. 10, non Dinogymnium granulatum - Song et al., 1978
Holotype: Slide G8-55-9; Plate I, 1; Eocene, southern Tianjin, China.
Occurrence: The upper part of the 3rd Member of the Shahejie Formation, Eocene, southern Tianjin and Jinxian County, Liaoning Province, China.
Description: The cyst is small, ellipsoidal or dumbbell-shaped with the equatorial area being constricted. Epicyst and hypocyst are approximately equal-sized and similar in shape. Apical area and antapical area are rounded, occasionally truncate; the apical end may be slightly narrower than the antapical end. The autophragm is thin, about 0.5 µm thick, with a granulate or wrinkled wall surface. The paracingulum is circular, 3.5-6 µm wide and indicated by the equatorial constriction; the parasulcus is not indicated. The paratabulation is expressed by archeopyle and intratabular processes. The processes are low (0.6-2 µm, generally <1 µm), bead-shaped; process tips are wide, open (Plate II, 1) or closed. The development of the processes may show some intra-specific variations. On some specimens (Plate I, 2, 5), for example, the processes are much lower or even reduced. The holotype shows 4 apical processes but no indications of paracingular processes; its precingular and postcingular processes are relatively well developed and the antapical process is normally undeveloped. The process formula is 4", 6", 0c, 5-6"", 0-1"". The archeopyle is apical, Type 4A, with the principal archeopyle suture being zigzag. The operculum is free along its entire margin.
Dimensions: Holotype: length, 29 µm; breadth, 24.5 µm. Range: length, 24-34 µm; breadth, 21-27 µm; 20 specimens were measured.
Comparisons: Tianjinella elliptica He and Sun, sp. nov. differs from Tianjinella ovata (Song et al., 1978) He and Sun, comb. nov. in being ellipsoidal or dumbbell-shaped, whereas the latter has an ovoidal to subspherical shape and lacks an equatorial constriction.