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Ceratiopsis striata
Ceratiopsis striata, (Drugg, 1967), Lentin and Williams, 1977
Combination illegitimate since the generic name Ceratiopsis is illegitimate.
Now Cerodinium. Originally Deflandrea, subsequently Ceratiopsis (combination illegitimate), thirdly (and now) Cerodinium.
Stover and Evitt, 1978, retained this species in Deflandrea Eisenack, 1938. Lentin and Williams, 1981, retained it in Ceratiopsis.
Holotype: Drugg, 1967, pl.2, fig.13
Locus typicus: Escarpado Canyon, California, USA
Stratum typicum: Early Paleocene
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Original description as Deflandrea striata: [Drugg 1967, p. 18]:
Diagnosis:
Apical horn long, tapered, bluntly pointed. Antapical horns broad, tapered, pointed, connected to each other below the cyst by a web. Large internal cyst always present, circular to ellipsoidal in outline. Cyst wall single layered, unornamented, about 1 µm thick. Test wall thin, ornamented with rows of grana paralleling the long axis of the test. These grana sometimes coalesce to form low ridges. Parallel wrinkles often present, grana, ridges and wrinkles together presenting a markedly striata appearance. Girdle circular, shallow, about 8 µm wide, delineated by two parallel rows of grana (beading) or by low, denticulate walls. The center line of the girdle sometimes marked by a single row of grana, but the girdle is more often ornamented only by close-set vertical wrinkles. Longitudinal furrow broad, usually distinct. Opening in cyst always present, large, somewhat angular but in gross outline semicircular, about 35 µm wide and 22 µm high. It is dorsally located but sometimes extends onto the ventral side of the cyst as though the top were sliced off with a cut inclined dorsally.
The archaeopyle in the test wall is less distinct but coincides with the cyst opening. The opercula of both openings break free first on the lower border.
Dimensions:
Range: 79 to 97 µm broad, 138 to 168 µm long.
Affinities:
This species differs from Deflandrea delineata Cookson and Eisenack 1965 in that it is slightly smaller, lacks tabulation, and is more uniformly striate. In addition the girdle is bordered by beaded or denticulate edges, a feature lacking on D. delineata.
Combination illegitimate since the generic name Ceratiopsis is illegitimate.
Now Cerodinium. Originally Deflandrea, subsequently Ceratiopsis (combination illegitimate), thirdly (and now) Cerodinium.
Stover and Evitt, 1978, retained this species in Deflandrea Eisenack, 1938. Lentin and Williams, 1981, retained it in Ceratiopsis.
Holotype: Drugg, 1967, pl.2, fig.13
Locus typicus: Escarpado Canyon, California, USA
Stratum typicum: Early Paleocene
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Original description as Deflandrea striata: [Drugg 1967, p. 18]:
Diagnosis:
Apical horn long, tapered, bluntly pointed. Antapical horns broad, tapered, pointed, connected to each other below the cyst by a web. Large internal cyst always present, circular to ellipsoidal in outline. Cyst wall single layered, unornamented, about 1 µm thick. Test wall thin, ornamented with rows of grana paralleling the long axis of the test. These grana sometimes coalesce to form low ridges. Parallel wrinkles often present, grana, ridges and wrinkles together presenting a markedly striata appearance. Girdle circular, shallow, about 8 µm wide, delineated by two parallel rows of grana (beading) or by low, denticulate walls. The center line of the girdle sometimes marked by a single row of grana, but the girdle is more often ornamented only by close-set vertical wrinkles. Longitudinal furrow broad, usually distinct. Opening in cyst always present, large, somewhat angular but in gross outline semicircular, about 35 µm wide and 22 µm high. It is dorsally located but sometimes extends onto the ventral side of the cyst as though the top were sliced off with a cut inclined dorsally.
The archaeopyle in the test wall is less distinct but coincides with the cyst opening. The opercula of both openings break free first on the lower border.
Dimensions:
Range: 79 to 97 µm broad, 138 to 168 µm long.
Affinities:
This species differs from Deflandrea delineata Cookson and Eisenack 1965 in that it is slightly smaller, lacks tabulation, and is more uniformly striate. In addition the girdle is bordered by beaded or denticulate edges, a feature lacking on D. delineata.