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Svalbardella partimtabulata
Svalbardella partimtabulata Heilmann-Clausen and Van Simaeys, 2005, p.180,182, pl.11, figs.2–5: text-fig.8.
Holotype: Heilmann-Clausen and Van Simaeys, 2005, pl.11, fig.3; text-fig.8.
Age: middle Eocene.
Original description (Heilmann-Clausen and Van Simaeys, 2005):
Svalbardella partimtabulata sp. nov. Plate 11, figs. 2–5, Text-Figure 8
Description. Dinoflagellate cysts of the genus Svalbardella which are spindle-shaped, proximate and cornucavate with a moderately long, blunt apical horn and a twice, or nearly twice, as long and less blunt antapical horn. Faint parasutural lines or low ridges are present on the periphragm. They are best developed on the dorsal side of the antapical horn and partly show the paratabulation of the cyst (Text-Figure 8). The paratabulation is peridinialean. The paracingulum is not clearly marked; in some specimens it may be vaguely indicated by a fine line. The periphragm is very finely reticulate, almost smooth; the endophragm is smooth. The archeopyle is intercalary, Type I/I (2a), the periarcheopyle is larger than the endoarcheopyle.
Derivation of name. From Latin partim meaning partly, and tabula meaning table, referring to the partly expressed paratabulation.
Designation of holotype. Plate 11, fig. 3 and TextFigure 8, Slide 2653 H5, England Finder coordinates N50/ 1-2. MGUH 27789. Kysing-4 borehole, sample 2653, Middle Eocene. Specimen dimensions: Pericyst length 183 µm; pericyst breadth 30 µm; endocyst length 56 µm; length of apical horn 46 µm; length of antapical horn 81 µm.
Designation of paratype. Paratype 1: Plate 11, fig. 4, Slide 2654 K5, England Finder coordinates H32/2. MGUH 27790. Kysing-4 borehole, sample 2654, Middle Eocene. Specimen dimensions: Pericyst length 186 µm; pericyst breadth 36 µm; endocyst length 48 µm; length of apical horn 45 µm; length of antapical horn 93 µm. Paratype 2: Plate 11, fig. 5, Slide 2653 H6, England Finder coordinates H17/4-H18/3. MGUH 27791. Kysing-4 borehole, sample 2653, Middle Eocene. Paratype 3: Plate 11, fig. 2, Slide 2653 H6, England Finder coordinates Q21/1. MGUH 27792. Kysing-4 borehole, sample 2653, Middle Eocene.
Dimensions of measured specimens. Pericyst length 156 (178) 195 µm. Pericyst breadth 24 (32) 36 µm. Endocyst length 42 (53) 62 µm. Length of apical horn 38 (47) 51 µm. Length of antapical horn 74 (81) 93 µm. (12 specimens measured).
Comparison. Svalbardella partimtabulata sp. nov. is closely related to Svalbardella cooksoniae Manum 1960, but differs by its long antapical horn which is less blunt than the much shorter apical horn. The new species also differs by its clearly visible paratabulation on the antapical horn, and by its less distinct reticulation of the periphragm.
Holotype: Heilmann-Clausen and Van Simaeys, 2005, pl.11, fig.3; text-fig.8.
Age: middle Eocene.
Original description (Heilmann-Clausen and Van Simaeys, 2005):
Svalbardella partimtabulata sp. nov. Plate 11, figs. 2–5, Text-Figure 8
Description. Dinoflagellate cysts of the genus Svalbardella which are spindle-shaped, proximate and cornucavate with a moderately long, blunt apical horn and a twice, or nearly twice, as long and less blunt antapical horn. Faint parasutural lines or low ridges are present on the periphragm. They are best developed on the dorsal side of the antapical horn and partly show the paratabulation of the cyst (Text-Figure 8). The paratabulation is peridinialean. The paracingulum is not clearly marked; in some specimens it may be vaguely indicated by a fine line. The periphragm is very finely reticulate, almost smooth; the endophragm is smooth. The archeopyle is intercalary, Type I/I (2a), the periarcheopyle is larger than the endoarcheopyle.
Derivation of name. From Latin partim meaning partly, and tabula meaning table, referring to the partly expressed paratabulation.
Designation of holotype. Plate 11, fig. 3 and TextFigure 8, Slide 2653 H5, England Finder coordinates N50/ 1-2. MGUH 27789. Kysing-4 borehole, sample 2653, Middle Eocene. Specimen dimensions: Pericyst length 183 µm; pericyst breadth 30 µm; endocyst length 56 µm; length of apical horn 46 µm; length of antapical horn 81 µm.
Designation of paratype. Paratype 1: Plate 11, fig. 4, Slide 2654 K5, England Finder coordinates H32/2. MGUH 27790. Kysing-4 borehole, sample 2654, Middle Eocene. Specimen dimensions: Pericyst length 186 µm; pericyst breadth 36 µm; endocyst length 48 µm; length of apical horn 45 µm; length of antapical horn 93 µm. Paratype 2: Plate 11, fig. 5, Slide 2653 H6, England Finder coordinates H17/4-H18/3. MGUH 27791. Kysing-4 borehole, sample 2653, Middle Eocene. Paratype 3: Plate 11, fig. 2, Slide 2653 H6, England Finder coordinates Q21/1. MGUH 27792. Kysing-4 borehole, sample 2653, Middle Eocene.
Dimensions of measured specimens. Pericyst length 156 (178) 195 µm. Pericyst breadth 24 (32) 36 µm. Endocyst length 42 (53) 62 µm. Length of apical horn 38 (47) 51 µm. Length of antapical horn 74 (81) 93 µm. (12 specimens measured).
Comparison. Svalbardella partimtabulata sp. nov. is closely related to Svalbardella cooksoniae Manum 1960, but differs by its long antapical horn which is less blunt than the much shorter apical horn. The new species also differs by its clearly visible paratabulation on the antapical horn, and by its less distinct reticulation of the periphragm.