Back
Impagidinium victorianum
From Fensome et al., 2019:
Impagidinium victorianum (Cookson and Eisenack, 1965a, p.123, pl.12, figs.8–9) Stover and Evitt, 1978, p.166. Holotype: Cookson and Eisenack, 1965a, pl.12, figs.8–9; Jan du Chêne et al., 1986a, pl.149, figs.1–4. Originally Leptodinium, subsequently (and now) Impagidinium. Age: Late Eocene.
---------------------------------------------------------------------------------------------------
Locus typicus: Browns Creek Clays, SW. Victoria, Australia
Stratum typicum: Late Eocene
Original description: Cookson and Eisenack, 1965, p.123: Leptodinium victorianum
Shell nearly spherical, clearly tabulated, borders of plates, including those of girdle distinct, thin and transparent. Girdle strongly helicoid, represented by six plates, the lower borders of the two plates adjacent to the longitudinal field usually missing. Longitudinal field partially divided into three plates, the two upper ones always incompletely separated, the third adjacent to plate 1'''' clearly delimited. Archeopyle formed by the detachment of plate 3".
Tabulation: 3', 6", 5''', 1p, 1''''.
Dimensions: Holotype-overall length 100 µm, overall width 100 µm. Range-overall length 80-120 µm, overall width 80-123 µm.
Affinities:
Cookson and Eisenack, 1965, p.124: Leptodinium victorianum
At first sight L. victorianum appears very similar to L. dispertitum. The main distinguishing features are the larger size, spherical form, and the constant absence of the transverse dividing between the upper two plates of the ventral field in L. victorianum. This species differs from L. maculatum from Western Australia in having a smooth surface and in the constant presence of a clearly defined plate adjacent to the antapical plate.
Impagidinium victorianum (Cookson and Eisenack, 1965a, p.123, pl.12, figs.8–9) Stover and Evitt, 1978, p.166. Holotype: Cookson and Eisenack, 1965a, pl.12, figs.8–9; Jan du Chêne et al., 1986a, pl.149, figs.1–4. Originally Leptodinium, subsequently (and now) Impagidinium. Age: Late Eocene.
---------------------------------------------------------------------------------------------------
Locus typicus: Browns Creek Clays, SW. Victoria, Australia
Stratum typicum: Late Eocene
Original description: Cookson and Eisenack, 1965, p.123: Leptodinium victorianum
Shell nearly spherical, clearly tabulated, borders of plates, including those of girdle distinct, thin and transparent. Girdle strongly helicoid, represented by six plates, the lower borders of the two plates adjacent to the longitudinal field usually missing. Longitudinal field partially divided into three plates, the two upper ones always incompletely separated, the third adjacent to plate 1'''' clearly delimited. Archeopyle formed by the detachment of plate 3".
Tabulation: 3', 6", 5''', 1p, 1''''.
Dimensions: Holotype-overall length 100 µm, overall width 100 µm. Range-overall length 80-120 µm, overall width 80-123 µm.
Affinities:
Cookson and Eisenack, 1965, p.124: Leptodinium victorianum
At first sight L. victorianum appears very similar to L. dispertitum. The main distinguishing features are the larger size, spherical form, and the constant absence of the transverse dividing between the upper two plates of the ventral field in L. victorianum. This species differs from L. maculatum from Western Australia in having a smooth surface and in the constant presence of a clearly defined plate adjacent to the antapical plate.