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Cometodinium obscurum
Cometodinium obscurum, Deflandre and Courteville, 1939; emend. Monteil, 1991
Holotype: Deflandre and Courteville, 1939, pl.2, fig.1 (lost according to Monteil, 1991)
Lectotype: Monteil, 1991, pl.1, figs.1a-b (designated by Monteil, 1991)
Topotype: Monteil, 1991: Pl. 1, fig. 2a-d.
Locus typicus: Vaux-Andigny, Aisne; Northern France
Stratum typicum: Late Turonian.
Age: Turonian
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Emended description:
Monteil 1991, p. 444:
Diagnosis:
Chorate (skolochorate) cysts with subspherical body.
One-layered acavate cyst; undifferentiated autophragm. Hair-like processes, very thin and very numerous, flexuous, apparently nontabular, nonfibrous, cylindrical, solid, distally closed, similar in size and shap,e Process base undivided, bulbous. Tip evexate.
Archeopyle apical, type (tA), with angular margin, often difficult to discern; operculum attached, sometimes tilted inside the cyst.
Paratabulation rarely expressed; occasionally indicated by archeopyle and/or by paracingulum. Paratabulation probably gonyaulacacean, epicystal formula: ?pr, 4", Oa, 6", as (pl. 1, fig 1a, b).
Paracingulum may be suggested by alignment of two parallel more or less equatorial rows of processes. Parasulcus not indicated
Dimensions:
Holotype Lectotype Topotyperange (8 specimens):
Cyst diameter 96-93 µm 65-70 µm 58 µm 55-70 µm
Central body diameter 45-49 µm 48-50 µm 43 µm 42-50 µm
Length of processes 40 µm up to 20 µm up to 15 µm up to 20 µm
Remarks:
The length of the processes (up to 20 µm) measured on 8 specimens recorded in the type material is half of the one given for the lost holotype (40 µm) by DEFLANDRE & COURTEVILLE (1939). Either the holotype had abnormally long processes, or measurement of this parameter was difficult, the cyst being observed in a flint chip.
Comments: microscopical re-examination of the specimens illustrated as "Cometodinium obscurum" in SRIVASTAVA, 1984, (Barremian of southeast France) suggests their attribution to the genus Cleistosphaeridium DAVEY et al. 1966.
Affinities:
see Cometodinium ? comatum emend. and C. whitei emend.
Holotype: Deflandre and Courteville, 1939, pl.2, fig.1 (lost according to Monteil, 1991)
Lectotype: Monteil, 1991, pl.1, figs.1a-b (designated by Monteil, 1991)
Topotype: Monteil, 1991: Pl. 1, fig. 2a-d.
Locus typicus: Vaux-Andigny, Aisne; Northern France
Stratum typicum: Late Turonian.
Age: Turonian
-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Emended description:
Monteil 1991, p. 444:
Diagnosis:
Chorate (skolochorate) cysts with subspherical body.
One-layered acavate cyst; undifferentiated autophragm. Hair-like processes, very thin and very numerous, flexuous, apparently nontabular, nonfibrous, cylindrical, solid, distally closed, similar in size and shap,e Process base undivided, bulbous. Tip evexate.
Archeopyle apical, type (tA), with angular margin, often difficult to discern; operculum attached, sometimes tilted inside the cyst.
Paratabulation rarely expressed; occasionally indicated by archeopyle and/or by paracingulum. Paratabulation probably gonyaulacacean, epicystal formula: ?pr, 4", Oa, 6", as (pl. 1, fig 1a, b).
Paracingulum may be suggested by alignment of two parallel more or less equatorial rows of processes. Parasulcus not indicated
Dimensions:
Holotype Lectotype Topotyperange (8 specimens):
Cyst diameter 96-93 µm 65-70 µm 58 µm 55-70 µm
Central body diameter 45-49 µm 48-50 µm 43 µm 42-50 µm
Length of processes 40 µm up to 20 µm up to 15 µm up to 20 µm
Remarks:
The length of the processes (up to 20 µm) measured on 8 specimens recorded in the type material is half of the one given for the lost holotype (40 µm) by DEFLANDRE & COURTEVILLE (1939). Either the holotype had abnormally long processes, or measurement of this parameter was difficult, the cyst being observed in a flint chip.
Comments: microscopical re-examination of the specimens illustrated as "Cometodinium obscurum" in SRIVASTAVA, 1984, (Barremian of southeast France) suggests their attribution to the genus Cleistosphaeridium DAVEY et al. 1966.
Affinities:
see Cometodinium ? comatum emend. and C. whitei emend.