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Trichodinium
From Williams et al., 2017:
[Trichodinium, Eisenack and Cookson, 1960, p. 5; Emendation: Clarke and Verdier, 1967, p.18–19.
Type species: Trichodinium pellitum, Eisenack and Cookson, 1960 (pl.2, fig.4)]
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Original description: [Eisenack and Cookson, 1960]:
Description:
Shell spherical to oval with a circular girdle and without indication of a longitudinal furrow and definite tabulation; epitheca with a short horn and a pylome on the dorsal surface. Shell-membrane more or less densely covered with hairs, bristles or spines.
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Emended description:
Clark and Verdier, 1967:
Description:
Shell sphaerical to oval with a circular girdle and without indication of a longitudinal furrow and definite tabulation ; epitheca with a short horn and a pylome on the dorsal surface. Shellmembrane +/- densely covered with hairs, bristles or spines.
Affinities:
The genus Trichodinium differs from the genus Apteodinium in the ornamentation of the shell and from the genus Cometodinium Defl. & Courteville in the development of an apical horn.
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Modified description:
Stover and Evitt 1978, p. 196-197:
Synopsis:
Cyst proximochorate, body subspherical to ellipsoidal with a short apical protrusion; autophragm bears relatively dense covering of generally short hairs, spines, or truncated processes; paratabulation indicated by paracingulum and archeopyle, latter precingular, Type P.
Description:
Shape: Body subspherical to ellipsoidal with a short apical protrusion; a short antapical projection may also be present.
Wall relationships: Autophragm only.
Wall features: No parasutural features. Autophragm bears numerous short hairs, spines, or truncated processes. Spines and processes smooth to faintly fibrous.
Paratabulation: Indicated by archeopyle and paracingulum, occasionally also by parasulcus.
Archeopyle: Precingular, Type P (3`` only); operculum free.
Paracingulum: Indicated by transverse equatorial alignment of processes or spines, which may also be slightly longer than those on other parts of cyst.
Parasulcus: Not indicated, or indicated vaguely by reduction in density of ornamentation.
Size: Intermediate to large.
Affinities:
Trichodinium differs from Xenicodinium in having indications of a paracingulum, a more densely covered autophragm, and an apical protrusion. Because transitional forms between typical examples of Trichodinium and Xenicodinium do occur, assignment of species to one or the other genus may be subjective.
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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.
Trichodinium Eisenack and Cookson, 1960, emend. Clarke and Verdier, 1967. Synopsis from Stover and Evitt (1978, p.196), cysts proximochorate, body subspherical to ellipsoidal with a short apical protrusion; autophragm bears relatively dense covering of generally short hairs, spines, or truncated processes; paratabulation indicated by paracingulum and archeopyle, latter precingular, type P.
[Trichodinium, Eisenack and Cookson, 1960, p. 5; Emendation: Clarke and Verdier, 1967, p.18–19.
Type species: Trichodinium pellitum, Eisenack and Cookson, 1960 (pl.2, fig.4)]
-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Original description: [Eisenack and Cookson, 1960]:
Description:
Shell spherical to oval with a circular girdle and without indication of a longitudinal furrow and definite tabulation; epitheca with a short horn and a pylome on the dorsal surface. Shell-membrane more or less densely covered with hairs, bristles or spines.
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Emended description:
Clark and Verdier, 1967:
Description:
Shell sphaerical to oval with a circular girdle and without indication of a longitudinal furrow and definite tabulation ; epitheca with a short horn and a pylome on the dorsal surface. Shellmembrane +/- densely covered with hairs, bristles or spines.
Affinities:
The genus Trichodinium differs from the genus Apteodinium in the ornamentation of the shell and from the genus Cometodinium Defl. & Courteville in the development of an apical horn.
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Modified description:
Stover and Evitt 1978, p. 196-197:
Synopsis:
Cyst proximochorate, body subspherical to ellipsoidal with a short apical protrusion; autophragm bears relatively dense covering of generally short hairs, spines, or truncated processes; paratabulation indicated by paracingulum and archeopyle, latter precingular, Type P.
Description:
Shape: Body subspherical to ellipsoidal with a short apical protrusion; a short antapical projection may also be present.
Wall relationships: Autophragm only.
Wall features: No parasutural features. Autophragm bears numerous short hairs, spines, or truncated processes. Spines and processes smooth to faintly fibrous.
Paratabulation: Indicated by archeopyle and paracingulum, occasionally also by parasulcus.
Archeopyle: Precingular, Type P (3`` only); operculum free.
Paracingulum: Indicated by transverse equatorial alignment of processes or spines, which may also be slightly longer than those on other parts of cyst.
Parasulcus: Not indicated, or indicated vaguely by reduction in density of ornamentation.
Size: Intermediate to large.
Affinities:
Trichodinium differs from Xenicodinium in having indications of a paracingulum, a more densely covered autophragm, and an apical protrusion. Because transitional forms between typical examples of Trichodinium and Xenicodinium do occur, assignment of species to one or the other genus may be subjective.
-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Notes:
G.L. Williams short notes on species, Mesozoic-Cenozoic dinocyst course, Urbino, Italy, May 17-22, 1999 - LPP VIEWER CD-ROM 99.5.
Trichodinium Eisenack and Cookson, 1960, emend. Clarke and Verdier, 1967. Synopsis from Stover and Evitt (1978, p.196), cysts proximochorate, body subspherical to ellipsoidal with a short apical protrusion; autophragm bears relatively dense covering of generally short hairs, spines, or truncated processes; paratabulation indicated by paracingulum and archeopyle, latter precingular, type P.