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Cometodinium
From Fensome et al., 2019:
Cometodinium, Deflandre and Courteville, 1939, p.98.
Emendation: Monteil, 1991a, p.440.
Type: Deflandre and Courteville, 1939, pl.2, fig.1, as Cometodinium obscurum (which see for lectotype).
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Original description: [Deflandre and Courteville, 1939]: (Translation: Stover and Evitt, 1978, p. 227):
Globular shell provided with a circular equatorial girdle marked by two irregular not very prominent bands. Surface of shell covered entirely with long flexuous hair giving the appearance of a veritable head of hair.
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Emended description:
Monteil, 1991:
Synopsis:
Cysts chorate (skolochorate), subspherical; body with numerous hair-like processes, sometimes grouped into tufts. Processes apparently
nontabular, nonfibrous, cylindrical solid or hollow, distally closed, similar in size and shape Process base undivided or dichotomously divided. Tip evexate. Paratabuation probably gonyaulacacean, epicystal formula :?pr, 4`, Oa, 6", as; archeopyle apical, type (4A); operculum attached.
Diagnosis:
Shape: Chorate (skolochorate) cysts, subspherical body.
Wall relationships: Two to one-layered acavate cyst; periphragm and endophragm appressed, except where processes are formed, or differentiated autophragm.
Wall features: Numerous, thin and flexuous hair-like processes, sometimes grouped into tufts Processes apparently nontabular, nonfibrous, cylindrical, solid or hollow, distally closed, similar in size and shape. Base undivided, and sometimes bulbous, or dichotomously divided. Tip evexate.
Archeopyle: Apical, type (tA), with angular margin; often difficult to discern; single operculum attached, sometimes tilted inside the cyst.
Paratabulation: Rarely expressed, occasionally indicated by archeopyle and/or paracingulum. Probably gonyaulacacean, epicysta formula :?pr, 4`, Oa, 6", as.
Paracingulum: May be suggested by alignment of two parallel, more or less equatorial, rows of processes.
Parasulcus: Not indicated.
Affinities:
Cometodinium differs from Cleistosphaeridium Davey et al, 1966, in having an attached operculum and hair-like processes, with evexate tips, giving to the cyst the appearance of a veritable head of hair, rather than a free operculum and acicular or conical processes with acuminate, bifurcate or branched distal extremities.
Prolixosphaendium Davey et al. (1966), differs from Cometodinium in having an elongate ellipsoidal body and free operculum rather than a subspherical body and attached operculum. Cometodinium differs from Impletosphaeridium Morgenroth (1966), in having an apical archeopyle rather than an unknown or uncertain archeopyle type.
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Poulsen 1996, p. 79:
Remarks:
Monteil (1991) assigned this genus to the Gonuaulacaceae Lindemann 1928 and to the Conyaulacales Taylor 1980. Monteil (1991) showed that the archeopyle of this genus is apical, type tA, with an attached operculum. The specimens studied from Poland also have an apical archeopyle, type (tA)a with an attached operculum.
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Notes:
G.L. Williams short notes on species, Mesozoic-Cenozoic dinocyst course, Urbino, Italy, May 17-22, 1999 - LPP VIEWER CD-ROM 99.5.
Cometodinium Deflandre and Courteville, 1939, emend. Monteil, 1991a. According to Monteil (1991a), this is a chorate (skolochorate) cyst with subspherical body. Sparse, hair-like processes, thin and numerous, flexuous, typically grouped into short tufts. Processes apparently non-tabular, nonfibrous, cylindrical, distally closed, similar in size and shape, distally evexate. Archeopyle apical type (A) with angular margin, often difficult to discern. Operculum attached. Paratabulation probably gonyaulacacean. Enantiomorphy is found in C.habibii.
Cometodinium, Deflandre and Courteville, 1939, p.98.
Emendation: Monteil, 1991a, p.440.
Type: Deflandre and Courteville, 1939, pl.2, fig.1, as Cometodinium obscurum (which see for lectotype).
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Original description: [Deflandre and Courteville, 1939]: (Translation: Stover and Evitt, 1978, p. 227):
Globular shell provided with a circular equatorial girdle marked by two irregular not very prominent bands. Surface of shell covered entirely with long flexuous hair giving the appearance of a veritable head of hair.
-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Emended description:
Monteil, 1991:
Synopsis:
Cysts chorate (skolochorate), subspherical; body with numerous hair-like processes, sometimes grouped into tufts. Processes apparently
nontabular, nonfibrous, cylindrical solid or hollow, distally closed, similar in size and shape Process base undivided or dichotomously divided. Tip evexate. Paratabuation probably gonyaulacacean, epicystal formula :?pr, 4`, Oa, 6", as; archeopyle apical, type (4A); operculum attached.
Diagnosis:
Shape: Chorate (skolochorate) cysts, subspherical body.
Wall relationships: Two to one-layered acavate cyst; periphragm and endophragm appressed, except where processes are formed, or differentiated autophragm.
Wall features: Numerous, thin and flexuous hair-like processes, sometimes grouped into tufts Processes apparently nontabular, nonfibrous, cylindrical, solid or hollow, distally closed, similar in size and shape. Base undivided, and sometimes bulbous, or dichotomously divided. Tip evexate.
Archeopyle: Apical, type (tA), with angular margin; often difficult to discern; single operculum attached, sometimes tilted inside the cyst.
Paratabulation: Rarely expressed, occasionally indicated by archeopyle and/or paracingulum. Probably gonyaulacacean, epicysta formula :?pr, 4`, Oa, 6", as.
Paracingulum: May be suggested by alignment of two parallel, more or less equatorial, rows of processes.
Parasulcus: Not indicated.
Affinities:
Cometodinium differs from Cleistosphaeridium Davey et al, 1966, in having an attached operculum and hair-like processes, with evexate tips, giving to the cyst the appearance of a veritable head of hair, rather than a free operculum and acicular or conical processes with acuminate, bifurcate or branched distal extremities.
Prolixosphaendium Davey et al. (1966), differs from Cometodinium in having an elongate ellipsoidal body and free operculum rather than a subspherical body and attached operculum. Cometodinium differs from Impletosphaeridium Morgenroth (1966), in having an apical archeopyle rather than an unknown or uncertain archeopyle type.
----------------------------------
Poulsen 1996, p. 79:
Remarks:
Monteil (1991) assigned this genus to the Gonuaulacaceae Lindemann 1928 and to the Conyaulacales Taylor 1980. Monteil (1991) showed that the archeopyle of this genus is apical, type tA, with an attached operculum. The specimens studied from Poland also have an apical archeopyle, type (tA)a with an attached operculum.
-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Notes:
G.L. Williams short notes on species, Mesozoic-Cenozoic dinocyst course, Urbino, Italy, May 17-22, 1999 - LPP VIEWER CD-ROM 99.5.
Cometodinium Deflandre and Courteville, 1939, emend. Monteil, 1991a. According to Monteil (1991a), this is a chorate (skolochorate) cyst with subspherical body. Sparse, hair-like processes, thin and numerous, flexuous, typically grouped into short tufts. Processes apparently non-tabular, nonfibrous, cylindrical, distally closed, similar in size and shape, distally evexate. Archeopyle apical type (A) with angular margin, often difficult to discern. Operculum attached. Paratabulation probably gonyaulacacean. Enantiomorphy is found in C.habibii.