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Glyphanodinium facetum
Glyphanodinium facetum Drugg, 1964
Holotype: Drugg, 1964, fig.1-2
Locus typicus: California, USA
Stratum typicum: Danian
Original diagnosis: Drugg, 1964, p. 238-239
Same as for the genus with the following additional remarks. The girdle is circular. The slightly sunken longitudinal furrow is displaced a little to the left at the point where it crosses the transverse furrow but the portions above and below the girdle are in alignment. The tabulation of the hypotheca is distinct but that of the epitheca is less easily discernible. The archeopyle operculum is very small and difficult to interpret because the flattened test does not commonly assume a vertical orientation. The epitheca is in the form of a dorsoventrally flattened cone. The hypotheca is chisel-shaped with the ventral side flat or slightly concave. The dorsal side exhibits a flat central plate (4""") with the lateral plates (3""", 5""") and the antapical plate (1"""") each angled downward from the plane of the central plate. A cross section through the hypotheca is in the form of an isosceles trapezoid, the longer of the parallel sides being the ventral side. A section through the girdle area has a flattened reniform shape, the concave side being ventral. The test membrane is thin, single-layered, translucent. It can be seen to be faintly punctate when observed under high magnificaffon. The sutures are only slightly raised above the surface of the test on the hypotheca and are flush on the epitheca.
Dimensions: Holotype 28 Ám high, 26 Ám broad. Size range 27-32 Ám high with operculum in place, 22-27 Ám without operculum; 20-25 Ám broad. Thickness front to back ca. 9 Ám. Seventy-five specimens located and examined.
Holotype: Drugg, 1964, fig.1-2
Locus typicus: California, USA
Stratum typicum: Danian
Original diagnosis: Drugg, 1964, p. 238-239
Same as for the genus with the following additional remarks. The girdle is circular. The slightly sunken longitudinal furrow is displaced a little to the left at the point where it crosses the transverse furrow but the portions above and below the girdle are in alignment. The tabulation of the hypotheca is distinct but that of the epitheca is less easily discernible. The archeopyle operculum is very small and difficult to interpret because the flattened test does not commonly assume a vertical orientation. The epitheca is in the form of a dorsoventrally flattened cone. The hypotheca is chisel-shaped with the ventral side flat or slightly concave. The dorsal side exhibits a flat central plate (4""") with the lateral plates (3""", 5""") and the antapical plate (1"""") each angled downward from the plane of the central plate. A cross section through the hypotheca is in the form of an isosceles trapezoid, the longer of the parallel sides being the ventral side. A section through the girdle area has a flattened reniform shape, the concave side being ventral. The test membrane is thin, single-layered, translucent. It can be seen to be faintly punctate when observed under high magnificaffon. The sutures are only slightly raised above the surface of the test on the hypotheca and are flush on the epitheca.
Dimensions: Holotype 28 Ám high, 26 Ám broad. Size range 27-32 Ám high with operculum in place, 22-27 Ám without operculum; 20-25 Ám broad. Thickness front to back ca. 9 Ám. Seventy-five specimens located and examined.