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Diconodinium pusillum
Diconodinium pusillum Singh, 1971
Tax. jr. synonym of Diconodinium multispinum (Deflandre and Cookson, 1955) Eisenack and Cookson, 1960, according to Morgan, 1977. Below, 1981, retained Diconodinium pusillum as a separate species.
Holotype: Singh, 1971, pl.68, fig.5
Locus typicus: Peace River area, Alberta, Canada
Stratum typicum: Middle-Late Albian
Original description: Singh, 1971, p. 383
Test broadly fusiform with one side more convex than the other; body with one short, blunt, and bifid apical horn, and a single, spine-like, 2 to 4 Ám long antapical horn; antapical horn situated closer to one side, and not median in position; cingulum faint, 2 to 3 Ám wide, and dividing the body unequally into a larger, slightly conical epitract and a smaller, rounded hypotract; sulcus very faint and wide, barely discernible on the ventral surface of some specimens; body wall ornamented by 0.5 Ám long spinules; test thin walled and hyaline.
Size range: Total length of the test (16 specimens) 40(47)54 Ám. Holotype 50 Ám.
Total breadth of the test (16 specimens) 28(36.5)43 Ám. Holotype 36 Ám.
Affinities:
Singh, 1971, p. 384: Diconodinium multispinum (Deflandre and Cookson) Eisenack and Cookson, 1960, resembles Diconodinium pusillum but differs in being larger (overall length 56-100 Ám) and in having equally convex sides. The antapical horn in D. multispinum is in median position and the cingulum divides the body equally. Diconodinium arcticum Manum and Cookson, 1964, can be distinguished from D. pusillum in being larger (overall length 50-73 Ám) and in having a granular ornamentation. The apical horn in D. arcticum is truncate or toothed, and the body wall is double layered.
Tax. jr. synonym of Diconodinium multispinum (Deflandre and Cookson, 1955) Eisenack and Cookson, 1960, according to Morgan, 1977. Below, 1981, retained Diconodinium pusillum as a separate species.
Holotype: Singh, 1971, pl.68, fig.5
Locus typicus: Peace River area, Alberta, Canada
Stratum typicum: Middle-Late Albian
Original description: Singh, 1971, p. 383
Test broadly fusiform with one side more convex than the other; body with one short, blunt, and bifid apical horn, and a single, spine-like, 2 to 4 Ám long antapical horn; antapical horn situated closer to one side, and not median in position; cingulum faint, 2 to 3 Ám wide, and dividing the body unequally into a larger, slightly conical epitract and a smaller, rounded hypotract; sulcus very faint and wide, barely discernible on the ventral surface of some specimens; body wall ornamented by 0.5 Ám long spinules; test thin walled and hyaline.
Size range: Total length of the test (16 specimens) 40(47)54 Ám. Holotype 50 Ám.
Total breadth of the test (16 specimens) 28(36.5)43 Ám. Holotype 36 Ám.
Affinities:
Singh, 1971, p. 384: Diconodinium multispinum (Deflandre and Cookson) Eisenack and Cookson, 1960, resembles Diconodinium pusillum but differs in being larger (overall length 56-100 Ám) and in having equally convex sides. The antapical horn in D. multispinum is in median position and the cingulum divides the body equally. Diconodinium arcticum Manum and Cookson, 1964, can be distinguished from D. pusillum in being larger (overall length 50-73 Ám) and in having a granular ornamentation. The apical horn in D. arcticum is truncate or toothed, and the body wall is double layered.