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Spinidinium boydii
Spinidinium boydii Morgan, 1975
Now Chichaouadinium. Originally Spinidinium, subsequently (and now) Chichaouadinium.
Holotype: Morgan, 1975, pl.1, fig.3a-d
Locus typicus: Great Australian Basin, Australia
Stratum typicum: Late Aptian-Albian
Original description: Morgan, 1975, p. 159
Cyst is very broadly fusiform in dorsal-ventral view. The apical horn is broadly conical and distally truncate. A single, small broad, pointed antapical horn is present and is offset only slightly from the longitudinal axis. The sides are smoothly convex as there is no prominent cingular furrow. The surface ornament consists of relatively sparse solid granulae to truncate spinulae, (usually about 1-3 µm long and 0.5 µm thick) that are aligned in rows. Tabulation is defined by the alignment of the ornament, mostly peritabular with few intratabular granulae or spinulae. The cingulum and sulcus are always devoid of ornament. Alignment may define reflected plate outlines only weakly, with apparently random granulae or spinulae scattered over most of the periphragm, except for the cingulum and the sulcus. Both endophragm and periphragm are thin, and always separate at the base of the apical and the antapical horns. The archeopyle is intercalary, type Ia (2a only); the operculum is attached antapically.
Affinities:
Morgan, 1975, p. 159: Spinidinium vestitum Brideaux 1971, differs from this species by having an angular pentagonal outline due to the much longer horns, and by bearing ornament consisting of cones and spines. Separation of the wall layers at the horns is absent in S. vestitum.
Spinidinium styloniferum Cookson and Eisenack, 1962 differs from this species by having more strongly developed horns, a deep cingular furrow, thicker wall layers, and much denser, stouter ornament.
Now Chichaouadinium. Originally Spinidinium, subsequently (and now) Chichaouadinium.
Holotype: Morgan, 1975, pl.1, fig.3a-d
Locus typicus: Great Australian Basin, Australia
Stratum typicum: Late Aptian-Albian
Original description: Morgan, 1975, p. 159
Cyst is very broadly fusiform in dorsal-ventral view. The apical horn is broadly conical and distally truncate. A single, small broad, pointed antapical horn is present and is offset only slightly from the longitudinal axis. The sides are smoothly convex as there is no prominent cingular furrow. The surface ornament consists of relatively sparse solid granulae to truncate spinulae, (usually about 1-3 µm long and 0.5 µm thick) that are aligned in rows. Tabulation is defined by the alignment of the ornament, mostly peritabular with few intratabular granulae or spinulae. The cingulum and sulcus are always devoid of ornament. Alignment may define reflected plate outlines only weakly, with apparently random granulae or spinulae scattered over most of the periphragm, except for the cingulum and the sulcus. Both endophragm and periphragm are thin, and always separate at the base of the apical and the antapical horns. The archeopyle is intercalary, type Ia (2a only); the operculum is attached antapically.
Affinities:
Morgan, 1975, p. 159: Spinidinium vestitum Brideaux 1971, differs from this species by having an angular pentagonal outline due to the much longer horns, and by bearing ornament consisting of cones and spines. Separation of the wall layers at the horns is absent in S. vestitum.
Spinidinium styloniferum Cookson and Eisenack, 1962 differs from this species by having more strongly developed horns, a deep cingular furrow, thicker wall layers, and much denser, stouter ornament.