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Apteodinium fallax
From Fensome et al., 2019:
Apteodinium fallax (Morgenroth, 1968, p.535–536, pl.41, figs.4–6) Stover and Evitt, 1978, p.142. Holotype: Morgenroth, 1968 pl.41, figs.4–5. Originally Gonyaulacysta, subsequently (and now) Apteodinium. Age: Danian.
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Original description: [Morgenroth, 1968] (translated from German):
Derivatio nominis: fallax lat.: deceptive, deceitful.
Holotype: The specimen kept in prep. KG25 and shown in Plate 41, Figs. 4, 5.
Paratypoids: KG25, KG30, KG31.
Locus typicus: Kjölby Gaard, Hunstrup NW Thisted (Denmark).
Stratum typicum: Denmark A
Diagnosis: A small species of the genus Gonyaulacysta with an ovoid theca, the surface of which exhibits very strong granulation. The plaiting is very indistinct, but in some specimens it is indicated by stronger granulation of the plait borders (cf. Plate 41, Fig. 6). By comparing approximately 40 specimens, the following plaiting pattern was found: 4', 6", 6'", p, 1"". The arrangement and shape of the plaits corresponds to that of Gonyaulac cladophora DEFLANDRE 1938. The epitheca is characterized by a fibrously structured, step-shaped-cylindrical apical horn. The superimposed, relatively distinct transverse furrow runs in a left-handed spiral. Their two ends are offset ventrally by approximately 1.5 furrow widths. The longitudinal furrow is only indicated. All specimens have a horseshoe-shaped archeopyle instead of 3".
Dimensions:
Theca length: 37 μ (28 μ/39 μ)
Theca width: 33 μ (28 μ/36 μ)
Length of the apical horn: 4 μ (2 μ/5 μ)
(40 measurements)
Number of specimens examined: 56
Comparisons: The new species has the plate arrangement like, for example, Gonyaulac. cladophora DEFLANDRE 1938, Gonyaulac. granulata KLEMENT 1960, Gonyaulac. wetzeli (LEJEUNE-CARPENTIER), and others. However, it differs from all previously known species that exhibit this plate arrangement in its small size and the very strong granulation of the theca, which makes the plate arrangement unclear.
Apteodinium fallax (Morgenroth, 1968, p.535–536, pl.41, figs.4–6) Stover and Evitt, 1978, p.142. Holotype: Morgenroth, 1968 pl.41, figs.4–5. Originally Gonyaulacysta, subsequently (and now) Apteodinium. Age: Danian.
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Original description: [Morgenroth, 1968] (translated from German):
Derivatio nominis: fallax lat.: deceptive, deceitful.
Holotype: The specimen kept in prep. KG25 and shown in Plate 41, Figs. 4, 5.
Paratypoids: KG25, KG30, KG31.
Locus typicus: Kjölby Gaard, Hunstrup NW Thisted (Denmark).
Stratum typicum: Denmark A
Diagnosis: A small species of the genus Gonyaulacysta with an ovoid theca, the surface of which exhibits very strong granulation. The plaiting is very indistinct, but in some specimens it is indicated by stronger granulation of the plait borders (cf. Plate 41, Fig. 6). By comparing approximately 40 specimens, the following plaiting pattern was found: 4', 6", 6'", p, 1"". The arrangement and shape of the plaits corresponds to that of Gonyaulac cladophora DEFLANDRE 1938. The epitheca is characterized by a fibrously structured, step-shaped-cylindrical apical horn. The superimposed, relatively distinct transverse furrow runs in a left-handed spiral. Their two ends are offset ventrally by approximately 1.5 furrow widths. The longitudinal furrow is only indicated. All specimens have a horseshoe-shaped archeopyle instead of 3".
Dimensions:
Theca length: 37 μ (28 μ/39 μ)
Theca width: 33 μ (28 μ/36 μ)
Length of the apical horn: 4 μ (2 μ/5 μ)
(40 measurements)
Number of specimens examined: 56
Comparisons: The new species has the plate arrangement like, for example, Gonyaulac. cladophora DEFLANDRE 1938, Gonyaulac. granulata KLEMENT 1960, Gonyaulac. wetzeli (LEJEUNE-CARPENTIER), and others. However, it differs from all previously known species that exhibit this plate arrangement in its small size and the very strong granulation of the theca, which makes the plate arrangement unclear.