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Hystrichosphaeropsis galeata
Hystrichosphaeropsis galeata (Cookson and Eisenack, 1960) Gocht, 1976
Originally Scriniodinium, subsequently Psaligonyaulax, thirdly (and now) Hystrichosphaeropsis.
Holotype: Cookson and Eisenack, 1960, pl.1, fig.16; Jan du Chêne et al., 1986, pl.48, figs.11-13
Locus typicus: Carnarvon Basin, Western Australia
Stratum typicum: Albian-Cenomanian
Original description: Cookson and Eisenack, 1960, p.3: Scriniodinium galeatum
Shell about two to three times longer than broad, rather variable in outline, divided aproximatelly equally by an ill-defined circular girdle. Central part of shell with convex sides, fully occupied by a roughly sphaerical capsule, the potion of the epitheca above capsule usually straight-sided (rarely convex), gradually narrowing toward the apex, which is terminated by a short, straight horn; the portion of the hypotheca below the capsule has straight, slightly sloping sides (rarely convex) and terminates in a rounded or oblique antapex. The girdle is indicated either by re-entrant angles at the sides, by coarse, linearly arranged granules, or rarely by a few fields. A longitudinal furrow has not been observed.
The shell membrane in the region of the capsule is ornamented to varying degrees by short spines, particularly at the sides, and by sphaerical granules or spinules arranged in lines, usually running parallel to the length of the shell, but sometimes giving the impression of fields. In the regions beyond the capsule the shell membrane is usually unpatterned except at the apical horn, where it bears a few small granules, and at the distal limit of the hypotheca, where it is usually finely serrated. A pylome has only been observed in three of the many examples. It is large, trapezoidal in form, and extends from the upper limit of the capsule almost to the girdle.
Dimensions: Holotype: 90 Ám long, 40 Ám broad, diameter of capsule ca. 38 Ám. Range: 78-110 Ám long, 27-46 Ám broad.
Originally Scriniodinium, subsequently Psaligonyaulax, thirdly (and now) Hystrichosphaeropsis.
Holotype: Cookson and Eisenack, 1960, pl.1, fig.16; Jan du Chêne et al., 1986, pl.48, figs.11-13
Locus typicus: Carnarvon Basin, Western Australia
Stratum typicum: Albian-Cenomanian
Original description: Cookson and Eisenack, 1960, p.3: Scriniodinium galeatum
Shell about two to three times longer than broad, rather variable in outline, divided aproximatelly equally by an ill-defined circular girdle. Central part of shell with convex sides, fully occupied by a roughly sphaerical capsule, the potion of the epitheca above capsule usually straight-sided (rarely convex), gradually narrowing toward the apex, which is terminated by a short, straight horn; the portion of the hypotheca below the capsule has straight, slightly sloping sides (rarely convex) and terminates in a rounded or oblique antapex. The girdle is indicated either by re-entrant angles at the sides, by coarse, linearly arranged granules, or rarely by a few fields. A longitudinal furrow has not been observed.
The shell membrane in the region of the capsule is ornamented to varying degrees by short spines, particularly at the sides, and by sphaerical granules or spinules arranged in lines, usually running parallel to the length of the shell, but sometimes giving the impression of fields. In the regions beyond the capsule the shell membrane is usually unpatterned except at the apical horn, where it bears a few small granules, and at the distal limit of the hypotheca, where it is usually finely serrated. A pylome has only been observed in three of the many examples. It is large, trapezoidal in form, and extends from the upper limit of the capsule almost to the girdle.
Dimensions: Holotype: 90 Ám long, 40 Ám broad, diameter of capsule ca. 38 Ám. Range: 78-110 Ám long, 27-46 Ám broad.