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Deflandrea balcattensis
Deflandrea balcattensis Cookson and Eisenack, 1969
Now Subtilisphaera. Originally Deflandrea, subsequently (and now) Subtilisphaera.
Holotype: Cookson and Eisenack, 1969, fig.1B
Age: Albian-Cenomanian
Original description (Cookson & Eisenack, 1969)
Occurrence. Balcatta Bore No. 1, 120-160 feet, 230-270 feet. Balcatta Bore No. 2 at 150 and 200 feet.
Description. Shell smooth, rather flat, roughly oval in outline divided unequally by a relatively broad, deep girdle the hypotheca being shorter than the epitheca. The sides of the epitheca, which are convex, narrow distally towards a short truncate apex. The wall of the hypotheca narrows gradually, one side usually being
longer and somewhat convex, the other shorter and slightly oblique, so that the antapex is situated, more or less, to one side of the midline. An archeopyle has not been evident. A characteristic feature of the ventral surface has been the constant presence, in the mid-line. just below the lower limits of the girdle, of a
short, wavy, longitudinal thickening (Fig. 1 E, F) closely similar to that associated with the flagellum in some living dinofiagellates. The capsule, which is well defined and approximately spherical, does not quite fill the shell laterally. Its wall is smooth, unornamented, and relatively thick.
Dimensions. Holotype-overall length 72 μ, overall width 52 μ, capsule about 38 x 42 μ. Range-overall length about 55-72 μ, overall width about 38-52 μ.
Comment. D. balcattensis is obviously closely related to D. rotundata Eisenack and Cookson 1960, from an Albian deposit in the Oodnadatta Bore, South Australia, at 3221 feet and D. foliacea Eisenack and Cookson 1960 from Upper Cretaceous deposits such as the Upper Gearle Siltstone and the Molecap Greensand in Western Australia. In both, as in D. balcattensis, an archeopyle is apparently not developed, a feature which casts some doubt as to their close affinity with the genus Defiandrea. In neither D. rotundata nor D. foliacea has the small wavy thickening, invariably present on the midventral surface of D. balcattensis, ·been evident. Dimensions. Holotype: diameter of shell about 70 μ, overall diameter about 130 μ, appendages
about 28-30 μlong, 8-10 μwide. Range of appendages about 25-30 μ long.
Comment. C. tubulosum differs from C. striatoconus in both the shape and size of the appendages. In C. striatoconus they are relatively short and conical whereas in C. tubulosum they are relatively long, cylindrical or only slightly conical.
Now Subtilisphaera. Originally Deflandrea, subsequently (and now) Subtilisphaera.
Holotype: Cookson and Eisenack, 1969, fig.1B
Age: Albian-Cenomanian
Original description (Cookson & Eisenack, 1969)
Occurrence. Balcatta Bore No. 1, 120-160 feet, 230-270 feet. Balcatta Bore No. 2 at 150 and 200 feet.
Description. Shell smooth, rather flat, roughly oval in outline divided unequally by a relatively broad, deep girdle the hypotheca being shorter than the epitheca. The sides of the epitheca, which are convex, narrow distally towards a short truncate apex. The wall of the hypotheca narrows gradually, one side usually being
longer and somewhat convex, the other shorter and slightly oblique, so that the antapex is situated, more or less, to one side of the midline. An archeopyle has not been evident. A characteristic feature of the ventral surface has been the constant presence, in the mid-line. just below the lower limits of the girdle, of a
short, wavy, longitudinal thickening (Fig. 1 E, F) closely similar to that associated with the flagellum in some living dinofiagellates. The capsule, which is well defined and approximately spherical, does not quite fill the shell laterally. Its wall is smooth, unornamented, and relatively thick.
Dimensions. Holotype-overall length 72 μ, overall width 52 μ, capsule about 38 x 42 μ. Range-overall length about 55-72 μ, overall width about 38-52 μ.
Comment. D. balcattensis is obviously closely related to D. rotundata Eisenack and Cookson 1960, from an Albian deposit in the Oodnadatta Bore, South Australia, at 3221 feet and D. foliacea Eisenack and Cookson 1960 from Upper Cretaceous deposits such as the Upper Gearle Siltstone and the Molecap Greensand in Western Australia. In both, as in D. balcattensis, an archeopyle is apparently not developed, a feature which casts some doubt as to their close affinity with the genus Defiandrea. In neither D. rotundata nor D. foliacea has the small wavy thickening, invariably present on the midventral surface of D. balcattensis, ·been evident. Dimensions. Holotype: diameter of shell about 70 μ, overall diameter about 130 μ, appendages
about 28-30 μlong, 8-10 μwide. Range of appendages about 25-30 μ long.
Comment. C. tubulosum differs from C. striatoconus in both the shape and size of the appendages. In C. striatoconus they are relatively short and conical whereas in C. tubulosum they are relatively long, cylindrical or only slightly conical.