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Deflandrea truncata
Deflandrea truncata Stover, 1974
Holotype: Stover, 1974, pl.5, fig.3a-c
Locus typicus: Flounder-3 well, Australia
Stratum typicum: Early Eocene
Original diagnosis: Stover, 1974, p.176
Periphragm is elliptical to ovoid in dorso-ventral view and has an obtusely rounded apical margin and a truncated, straight to slightly concave antapical margin. Surface 1-1.5 Ám thick; smooth, finely pitted, or granulate (sculpturing evenly distributed). Cingulum is poorly defined by a shallow transverse band about 6 Ám wide located just below midheight. Ventrally, the cingulum is not offset and is interrupted by an ill-defined sulcus. Cingulum and sulcus discernible on about half the specimens. Periphragm may be thickened slightly at the apex and a thickening or a nipple-like projection may occur at each antapical corner.
Outline of the endoblast is circular or nearly so in dorso-ventral view; endophragm is smooth and as thick as or slightly thicker than the periphragm. Endoblast occupies a considerable part of the pericoel.
Intercalary archeopyle trapezoidal and the opening in the endophragm is nearly as large as that in the periphragm but usually appears shorter due to foreshortening. Operculum is free and isolated. Opercula usually consist of adherent pieces from both wall layers. Archeopyle is 34-40 Ám wide and 16-22 Ám long (width consistently about twice the length).
Dimensions: Entire specimens are 86-104 Ám long and 68-86 Ám wide (mean length:width ratio is 1:0.8). The nearly circular endoblast is 65-78 Ám long and 66-79 Ám wide. Usually the length-width dimensions on any specimen will be within 5Ám of each other.
Holotype: Stover, 1974, pl.5, fig.3a-c
Locus typicus: Flounder-3 well, Australia
Stratum typicum: Early Eocene
Original diagnosis: Stover, 1974, p.176
Periphragm is elliptical to ovoid in dorso-ventral view and has an obtusely rounded apical margin and a truncated, straight to slightly concave antapical margin. Surface 1-1.5 Ám thick; smooth, finely pitted, or granulate (sculpturing evenly distributed). Cingulum is poorly defined by a shallow transverse band about 6 Ám wide located just below midheight. Ventrally, the cingulum is not offset and is interrupted by an ill-defined sulcus. Cingulum and sulcus discernible on about half the specimens. Periphragm may be thickened slightly at the apex and a thickening or a nipple-like projection may occur at each antapical corner.
Outline of the endoblast is circular or nearly so in dorso-ventral view; endophragm is smooth and as thick as or slightly thicker than the periphragm. Endoblast occupies a considerable part of the pericoel.
Intercalary archeopyle trapezoidal and the opening in the endophragm is nearly as large as that in the periphragm but usually appears shorter due to foreshortening. Operculum is free and isolated. Opercula usually consist of adherent pieces from both wall layers. Archeopyle is 34-40 Ám wide and 16-22 Ám long (width consistently about twice the length).
Dimensions: Entire specimens are 86-104 Ám long and 68-86 Ám wide (mean length:width ratio is 1:0.8). The nearly circular endoblast is 65-78 Ám long and 66-79 Ám wide. Usually the length-width dimensions on any specimen will be within 5Ám of each other.