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Vallodinium picardicum
Vallodinium picardicum Iakovleva, 2016, p.19–20, pl.2, figs.1–2,5–6,9; text-fig.4c (part).
Holotype: Iakovleva, 2016, pl.2, fig.9.
Age: earliest Eocene.
Original description (Iakovleva, 2016):
Vallodinium picardicum sp. nov. Plate 2, figures 1, 2, 5, 6, 9; Figure 4c
Holotype. Plate 2, figure 9; slide MPA 62331-3; England Finder reference L18/1.
Paratype. Plate 2, figure 6; slide MPA 62331-4; England Finder reference H8.
Type stratum and locality. Sample LT-56, ~144.8 m depth, Sinceny Member; BRGM Scientific Borehole Le Tillet, Paris Basin, France.
Diagnosis. A circumcavate species of Vallodinium with a subrounded ambitus and sutural processes that can be oblate or bifurcate distally.
Description. A mid-size, subrounded, narrowly circumcavate cyst, with the pericoel being extremely narrow. The apical horn is very short or absent. Lateral horns are either not developed or represent only small outgrowths on the pericyst. Antapical horns are equal and short. Periphragm thin and ornamented with sutural and penitabular crests with processes; processes are oblate or bifurcate at their distal extremities. Endocyst subcircular in outline; endophragm thin and smooth. Archaeopyle is equiepeliform; operculum free or partially attached.
Dimensions. Holotype: pericyst length 82 µm; pericyst width 80 µm; endocyst length 67 µm; endocyst 62 µm. Paratype: pericyst length 82 µm; pericyst width 67 µm; endocyst length 57 µm; endocyst width 48 µm.
Dimensions of measured specimens: pericyst length 69-85 µm (mean value 77 µm); pericyst width 62-83 µm (mean value 74 µm); endocyst length 55-67 µm (mean value 60 µm); endocyst width 48-66 µm (mean value 57 µm). Fifteen specimens measured.
Comparison. Vallodinium picardicum differs from other species of Vallodinium by the absence of lateral horns, slight development of antapical horns, the character of the sutural ornamentation and its smaller size. The general outline and kind of sutural ornamentation of Vallodinium picardicum are similar to those of Stichodinium parisiense, but Vallodinium picardicum clearly differs in having an equiepeliform archaeopyle.
Stratigraphical range. Earliest Eocene.
Derivation of name. From Picardie (Picardy), the historical region of France from which the holotype was recovered.
Holotype: Iakovleva, 2016, pl.2, fig.9.
Age: earliest Eocene.
Original description (Iakovleva, 2016):
Vallodinium picardicum sp. nov. Plate 2, figures 1, 2, 5, 6, 9; Figure 4c
Holotype. Plate 2, figure 9; slide MPA 62331-3; England Finder reference L18/1.
Paratype. Plate 2, figure 6; slide MPA 62331-4; England Finder reference H8.
Type stratum and locality. Sample LT-56, ~144.8 m depth, Sinceny Member; BRGM Scientific Borehole Le Tillet, Paris Basin, France.
Diagnosis. A circumcavate species of Vallodinium with a subrounded ambitus and sutural processes that can be oblate or bifurcate distally.
Description. A mid-size, subrounded, narrowly circumcavate cyst, with the pericoel being extremely narrow. The apical horn is very short or absent. Lateral horns are either not developed or represent only small outgrowths on the pericyst. Antapical horns are equal and short. Periphragm thin and ornamented with sutural and penitabular crests with processes; processes are oblate or bifurcate at their distal extremities. Endocyst subcircular in outline; endophragm thin and smooth. Archaeopyle is equiepeliform; operculum free or partially attached.
Dimensions. Holotype: pericyst length 82 µm; pericyst width 80 µm; endocyst length 67 µm; endocyst 62 µm. Paratype: pericyst length 82 µm; pericyst width 67 µm; endocyst length 57 µm; endocyst width 48 µm.
Dimensions of measured specimens: pericyst length 69-85 µm (mean value 77 µm); pericyst width 62-83 µm (mean value 74 µm); endocyst length 55-67 µm (mean value 60 µm); endocyst width 48-66 µm (mean value 57 µm). Fifteen specimens measured.
Comparison. Vallodinium picardicum differs from other species of Vallodinium by the absence of lateral horns, slight development of antapical horns, the character of the sutural ornamentation and its smaller size. The general outline and kind of sutural ornamentation of Vallodinium picardicum are similar to those of Stichodinium parisiense, but Vallodinium picardicum clearly differs in having an equiepeliform archaeopyle.
Stratigraphical range. Earliest Eocene.
Derivation of name. From Picardie (Picardy), the historical region of France from which the holotype was recovered.