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Spinidinium macmurdoense
Spinidinium macmurdoense (Wilson, 1967) Lentin and Williams, 1976
Originally Deflandrea, subsequently (and now) Spinidinium.
Holotype: Wilson, 1967, figs.11-13
Locus typicus: Erratics on Black Island, McMurdo Sound, Antarctica
Stratum typicum: Early Tertiary
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G.L. Williams short notes on species, Mesozoic-Cenozoic dinocyst course, Urbino, Italy, May 17-22, 1999
Spinidinium macmurdoense (Wilson, 1967a) Lentin and Williams, 1976. According to Wilson (1967a, p.60-62), Spinidinium macmurdoense has an asymmetric pericyst with a well developed left antapical horn and a pentagonal endocyst. Pericyst tabulate with small penitabular spines (length 5-9 µm). Periarcheopyle is isodeltaform with operculum being posteriorly attached. Spinidinium macmurdoense differs from Spinidinium echinoideum, from S. denticulatum in overall shape and in the nature of the archeopyle, as well as being atabulate, and from S.colemanii in being larger, overall shape, fewer spines, and equal size of epicyst and hypocyst. Length is 61-99 µm.
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Original description: Wilson, 1967, p.60, 62: Deflandrea macmurdoensis
Test bi-layered, dorso-ventrally flattened, angular, bilaterally asymetric. Outer cyst divided into fields by small spines (l=5-9 µm); smooth hyaline inner cyst closely follows outline of outer cyst. Horns formed by polar extensions of outer cyst; apical horn relatively long (l=14-20µm) narrow, blunt-ended and bordered by very small spines; right antapical horn either non-existent or very small. Prominent slightly laevo-rotary transverse girdle delimited by a double row of spines or sometimes, on the dorsal surface, by a spiny ridge. Archaeopyle intercalary, hoof-shaped or subhexagonal, located on dorsal epitheca; operculum always fixedto shell by its posterior margin; remainders of archaeopyle perimeter bordered by a double row of spines, one on operculum, the other on outer cyst, with line of rupture between the two rows. Tabulation uncertain, but that of dorsal epitheca apparently consistent with Gonyaulax.
Dimensions: Holotype: l=99 µm, b=72 µm, inner cyst 72x63 µm. Range: l=61(87)99 µm, b=58(67)80 µm (10 specimens)
Originally Deflandrea, subsequently (and now) Spinidinium.
Holotype: Wilson, 1967, figs.11-13
Locus typicus: Erratics on Black Island, McMurdo Sound, Antarctica
Stratum typicum: Early Tertiary
--------------------------------------------------
G.L. Williams short notes on species, Mesozoic-Cenozoic dinocyst course, Urbino, Italy, May 17-22, 1999
Spinidinium macmurdoense (Wilson, 1967a) Lentin and Williams, 1976. According to Wilson (1967a, p.60-62), Spinidinium macmurdoense has an asymmetric pericyst with a well developed left antapical horn and a pentagonal endocyst. Pericyst tabulate with small penitabular spines (length 5-9 µm). Periarcheopyle is isodeltaform with operculum being posteriorly attached. Spinidinium macmurdoense differs from Spinidinium echinoideum, from S. denticulatum in overall shape and in the nature of the archeopyle, as well as being atabulate, and from S.colemanii in being larger, overall shape, fewer spines, and equal size of epicyst and hypocyst. Length is 61-99 µm.
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Original description: Wilson, 1967, p.60, 62: Deflandrea macmurdoensis
Test bi-layered, dorso-ventrally flattened, angular, bilaterally asymetric. Outer cyst divided into fields by small spines (l=5-9 µm); smooth hyaline inner cyst closely follows outline of outer cyst. Horns formed by polar extensions of outer cyst; apical horn relatively long (l=14-20µm) narrow, blunt-ended and bordered by very small spines; right antapical horn either non-existent or very small. Prominent slightly laevo-rotary transverse girdle delimited by a double row of spines or sometimes, on the dorsal surface, by a spiny ridge. Archaeopyle intercalary, hoof-shaped or subhexagonal, located on dorsal epitheca; operculum always fixedto shell by its posterior margin; remainders of archaeopyle perimeter bordered by a double row of spines, one on operculum, the other on outer cyst, with line of rupture between the two rows. Tabulation uncertain, but that of dorsal epitheca apparently consistent with Gonyaulax.
Dimensions: Holotype: l=99 µm, b=72 µm, inner cyst 72x63 µm. Range: l=61(87)99 µm, b=58(67)80 µm (10 specimens)