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Lejeunecysta mariae
From Fensome et al., 2019:
Lejeunecysta mariae (Harland in Harland et al., 1991, p.653, figs.4j–l) Lentin and Williams, 1993, p.383. Holotype: Harland et al., 1991, fig.4j. Originally Protoperidinium subgenus Protoperidinium section Lejeunecysta (section name not validly published; Appendix B), subsequently (and now) Lejeunecysta. Contrary to the opinion of Lentin and Williams (1993, p.383), the name Protoperidinium marieae was validly published in Harland in Harland et al. (1991) since, although Lejeunecysta as a section name was not validly published, the species was assigned to the validly published generic name Protoperidinium. Age: Early Pleistocene.
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Supplemental description: Head, 1993, p.31
Cysts light brown in color, wall thin and composed of two closely appressed layers. Wall surface moderately to faintly granulate under LM: under SEM surface bears granules/gemmae (0.5 µm or less in diameter) which are themselves covered in minute (<0.1 µm) granules that densely cover entire surface. Blunt spines less than 1.0 µm high occur along paracingular margins and may also be present elsewhere. Epicystlonger than hypocyst, conical and with convex sides. Apical horn weakly developed and indicated by a slightly thickened (< 1.5 µm) apical boss. Hypocyst outline rounded trapezoidal in dorsoventral view, with two equally developed antapical horns that are moderately to strongly divergent and bear solid, acuminate tips. Paracingulum fairly pronounced and indicated by transverse folding. Parasulcus is shallow. Archeopyle intercalary hexa 2a isodeltaform with short H3 and H5 sides; operculum free, sometimes adherent on adcingular margin. There are no other indications of paratabulation.
Dimensions.--Length, 27(36.8)47 µm; width, 27(33.4)38 µm; antapical horn tip length (from base of solid thickening), 1.7(4.1)5.7 µm. Twenty-two specimens measured.
Comparison.--This species most closely compares with Lejeunecysta convexa Matsuoka and Bujak, 1988, described from the upper Oligocene to lower Miocene of the Bering Sea. Lejeunecysta convexa differs in its larger average size (length, 46-59 µm, albeit overlapping with L. mariea), smooth wall surface, and an archeopyle stated to be trapezoidal (Matsuoka and Bujak, 1988, p. 57 and text-fig. 11). Lejeunecysta pulchra Biffi and Grignani, 1983, described from the Oligocene of the Niger Delta is also larger (length, 55-80 µm) than L. mariea and has a smooth wall surface.
Lejeunecysta mariae (Harland in Harland et al., 1991, p.653, figs.4j–l) Lentin and Williams, 1993, p.383. Holotype: Harland et al., 1991, fig.4j. Originally Protoperidinium subgenus Protoperidinium section Lejeunecysta (section name not validly published; Appendix B), subsequently (and now) Lejeunecysta. Contrary to the opinion of Lentin and Williams (1993, p.383), the name Protoperidinium marieae was validly published in Harland in Harland et al. (1991) since, although Lejeunecysta as a section name was not validly published, the species was assigned to the validly published generic name Protoperidinium. Age: Early Pleistocene.
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Supplemental description: Head, 1993, p.31
Cysts light brown in color, wall thin and composed of two closely appressed layers. Wall surface moderately to faintly granulate under LM: under SEM surface bears granules/gemmae (0.5 µm or less in diameter) which are themselves covered in minute (<0.1 µm) granules that densely cover entire surface. Blunt spines less than 1.0 µm high occur along paracingular margins and may also be present elsewhere. Epicystlonger than hypocyst, conical and with convex sides. Apical horn weakly developed and indicated by a slightly thickened (< 1.5 µm) apical boss. Hypocyst outline rounded trapezoidal in dorsoventral view, with two equally developed antapical horns that are moderately to strongly divergent and bear solid, acuminate tips. Paracingulum fairly pronounced and indicated by transverse folding. Parasulcus is shallow. Archeopyle intercalary hexa 2a isodeltaform with short H3 and H5 sides; operculum free, sometimes adherent on adcingular margin. There are no other indications of paratabulation.
Dimensions.--Length, 27(36.8)47 µm; width, 27(33.4)38 µm; antapical horn tip length (from base of solid thickening), 1.7(4.1)5.7 µm. Twenty-two specimens measured.
Comparison.--This species most closely compares with Lejeunecysta convexa Matsuoka and Bujak, 1988, described from the upper Oligocene to lower Miocene of the Bering Sea. Lejeunecysta convexa differs in its larger average size (length, 46-59 µm, albeit overlapping with L. mariea), smooth wall surface, and an archeopyle stated to be trapezoidal (Matsuoka and Bujak, 1988, p. 57 and text-fig. 11). Lejeunecysta pulchra Biffi and Grignani, 1983, described from the Oligocene of the Niger Delta is also larger (length, 55-80 µm) than L. mariea and has a smooth wall surface.